MedWorm: Astigmatism

Heritability of corneal refraction and corneal astigmatism: a population‐based twin study among 66‐ to 79‐year‐old female twins

Acta Ophthalmologica — Wed, 01 Feb 2012 05:00:00 +0100

Conclusions: Most of the variance in CR among older Finnish women could be explained by genetic factors. (Source: Acta Ophthalmologica)

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Prospective contralateral eye study to compare conventional and wavefront‐guided laser in situ keratomileusis

Acta Ophthalmologica — Wed, 01 Feb 2012 05:00:00 +0100

Conclusion: Visual acuity and refractive error outcomes were similar in both treatment group and no patient preference was observed. Customized ablation was associated with a smaller but not statistically significant postoperative increase in HOAs, better preservation of scotopic contrast sensitivity, quicker treatment time and removal of less corneal tissue. (Source: Acta Ophthalmologica)

Optimal refraction with monofocal intraocular lenses: no beneficial effect of astigmatism: author’s reply

Acta Ophthalmologica — Wed, 01 Feb 2012 05:00:00 +0100

(Source: Acta Ophthalmologica)

Surgical outcome of Descemet’s stripping automated endothelial keratoplasty for bullous keratopathy secondary to argon laser iridotomy

Graefe's Archive for Clinical and Experimental Ophthalmology — Fri, 27 Jan 2012 17:54:24 +0100

Conclusions Descemet’s stripping automated endothelial keratoplasty for BK secondary to ALI showed rapid postoperative visual improvement, with similar efficacy and safety to that observed in DSAEK for PBK or FED. Content Type Journal ArticleCategory CorneaPages 1-8DOI 10.1007/s00417-012-1927-6Authors Masatoshi Hirayama, Department of Ophthalmology, Ichikawa General Hospital, Tokyo Dental College, 5-11-13, Sugano, Ichikawa, Chiba 272-8513, JapanTakefumi Yamaguchi, Department of Ophthalmology, Ichikawa General Hospital, Tokyo Dental College, 5-11-13, Sugano, Ichikawa, Chiba 272-8513, JapanYoshiyuki Satake, Department of Ophthalmology, Ichikawa General Hospital, Tokyo Dental College, 5-11-13, Sugano, Ichikawa, Chiba 272-8513, JapanJun Shimazaki, Department of Ophthal...

Excimer laser refractive surgery versus phakic intraocular lenses for the correction of moderate to high myopia.

Cochrane Database of Systematic Reviews — Thu, 26 Jan 2012 08:18:08 +0100

CONCLUSIONS: The results of this review suggest that phakic IOLs are safer than excimer laser surgical correction for moderate to high myopia in the range of -6.0 to -20.0 D and phakic IOLs are preferred by patients. While phakic IOLs might be accepted clinical practice for higher levels of myopia (greater than or equal to 7.0 D of myopic spherical equivalent with or without astigmatism), it may be worth considering phakic IOL treatment over excimer laser correction for more moderate levels of myopia (less than or equal to 7.0 D of myopic spherical equivalent with or without astigmatism). Further RCTs adequately powered for subgroup analysis are necessary to further elucidate the ideal range of myopia for phakic IOLs. PMID: 22258972 [PubMed - in process] (Source: Cochrane Database of S...

Three-Dimensional Super-Resolution Imaging of the Midplane Protein FtsZ in Live Caulobacter crescentus Cells Using Astigmatism.

Chemphyschem — Fri, 20 Jan 2012 05:00:00 +0100

Authors: Biteen JS, Goley ED, Shapiro L, Moerner WE Abstract Single-molecule super-resolution imaging provides a non-invasive method for nanometer-scale imaging and is ideally suited to investigations of quasi-static structures within live cells. Here, we extend the ability to image subcellular features within bacteria cells to three dimensions based on the introduction of a cylindrical lens in the imaging pathway. We investigate the midplane protein FtsZ in Caulobacter crescentus with super-resolution imaging based on fluorescent-protein photoswitching and the natural polymerization/depolymerization dynamics of FtsZ associated with the Z-ring. We quantify these dynamics and determine the FtsZ depolymerization time to be <100 ms. We image the Z-ring in live and fixed C. cresce...

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Effect of Ramadan fasting in tropical summer months on ocular refractive and biometric characteristics

Clinical and Experimental Optometry — Tue, 17 Jan 2012 05:00:00 +0100

Conclusions: Ramadan fasting is associated with statistically significant alterations in anterior chamber depth and axial length that result in both statistically and clinically significant changes in intraocular lens power calculations. Therefore, relying on measurements taken during this month might lead to refractive errors after cataract surgery. (Source: Clinical and Experimental Optometry)

Effect of pupil size on uncorrected visual acuity in astigmatic eyes

British Journal of Ophthalmology — Mon, 16 Jan 2012 05:00:00 +0100

Conclusions Both the amount of astigmatism and the pupil size can affect UCVA in astigmatic eyes. It is suggested that not only the amount of astigmatism but also the pupil size should be taken into consideration for acquiring better visual performance in astigmatic eyes. (Source: British Journal of Ophthalmology)

Controlled clinical trial comparing biaxial microincision with coaxial small incision for cataract surgery.

European Journal of Ophthalmology — Fri, 13 Jan 2012 05:00:00 +0100

Conclusions. Compared to the standard small incision technique, B-MICS showed earlier improvement in BCVA, better overall UCVA, less SIA, and less endothelial cell loss. PMID: 22267455 [PubMed - as supplied by publisher] (Source: European Journal of Ophthalmology)

Dual-objective STORM reveals three-dimensional filament organization in the actin cytoskeleton

Nature Methods — Sun, 08 Jan 2012 05:00:00 +0100

Authors: Ke Xu, Hazen P Babcock & Xiaowei Zhuang By combining astigmatism imaging with a dual-objective scheme, we improved the image resolution of stochastic optical reconstruction microscopy (STORM) and obtained <10-nm lateral resolution and <20-nm axial resolution when imaging biological specimens. Using this approach, we resolved individual actin filaments in cells and revealed three-dimensional ultrastructure of the actin cytoskeleton. We observed two vertically separated layers of actin networks with distinct structural organizations in sheet-like cell protrusions. (Source: Nature Methods)

[Suitability of various topographic corneal parameters for diagnosis of early keratoconus].

Der Ophthalmologe — Sun, 01 Jan 2012 05:00:00 +0100

CONCLUSION: After lowering the critical values the keratometric indices yielded a high discriminative ability for the detection of early KC stages. However, the excellent classification rates for wavefront-based metrics were not achieved. PMID: 22274296 [PubMed - in process] (Source: Der Ophthalmologe)

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Power Vector Analysis of Refractive, Corneal, and Internal Astigmatism in an Elderly Chinese Population: The Shihpai Eye Study [Clinical and Epidemiologic Research]

Investigative Ophthalmology — Wed, 28 Dec 2011 05:00:00 +0100

Conclusions. Astigmatism affects approximately three quarters of the Chinese population aged 65 years and older in Taiwan. With increasing age, the prevalence of astigmatism increases, and refractive and corneal astigmatism shift toward ATR. Continuous corneal changes appear to be responsible for the age trend in refractive astigmatism. The severity of lens opacity plays only a minor role in the change of internal astigmatism. (Source: Investigative Ophthalmology)

Evaluation of intra-lesional corticosteroids in the treatment of peri-ocular haemangioma of infancy: still an alternative besides propranolol

Pediatric Surgery International — Mon, 26 Dec 2011 16:45:55 +0100

Conclusions This study shows that intra-lesional therapy with corticosteroids is very safe in the treatment of peri-ocular HOI. It remains a good and safe alternative besides propranolol or when propranolol therapy is not possible (e.g. asthma, PHACE syndrome, and certain cardiac diseases). Content Type Journal ArticleCategory Original ArticlePages 1-6DOI 10.1007/s00383-011-3037-7Authors Sherief R. Janmohamed, Department of Paediatric Surgery, Erasmus MC-Sophia Children’s Hospital, University Medical Center Rotterdam, Rotterdam, The NetherlandsGerard C. Madern, Department of Paediatric Surgery, Erasmus MC-Sophia Children’s Hospital, University Medical Center Rotterdam, Rotterdam, The NetherlandsKlaske Nieuwenhuis, Department of Paediatrics, Erasmus MC-Sophia Chi...

Med Sci Monit 2012; 18(1):PI1-4 "Results of the AcrySof Toric intraocular lenses implantation"

Medical Science Monitor — Thu, 22 Dec 2011 19:17:00 +0100

Conclusions: We noticed clinically and statistically important vision acuity improvement in the corneal astigmatism patients. The patients’ high satisfaction was conditioned by proper pre-surgery qualification. Astigmatism correction by cataract removal surgery is a safe and effective surgical solution. In the future, we expect the use of toric intraocular lenses will become widespread and significant. (Source: Medical Science Monitor)

Evaluation of corneal hysteresis and corneal resistance factor after corneal cross-linking for keratoconus

Graefe's Archive for Clinical and Experimental Ophthalmology — Wed, 21 Dec 2011 20:06:32 +0100

Conclusions ORA parameters demonstrate significant differences between KC and non-KC eyes. Both CH and CRF present significant correlations with visual acuity and corneal parameters. CXL exerts a non-significant impact on ORA measurements. Content Type Journal ArticleCategory CorneaPages 1-9DOI 10.1007/s00417-011-1897-0Authors Maria Gkika, Eye Institute of Thrace and Department of Ophthalmology, Democritus University of Thrace, Dragana, Alexandroupolis, Greece PC: 68100Georgios Labiris, Eye Institute of Thrace and Department of Ophthalmology, Democritus University of Thrace, Dragana, Alexandroupolis, Greece PC: 68100Athanassios Giarmoukakis, Eye Institute of Thrace and Department of Ophthalmology, Democritus University of Thrace, Dragana, Alexandroupolis, Greece PC: ...

Line focusing for soft x-ray laser-plasma lasing

Applied Optics — Tue, 20 Dec 2011 05:00:00 +0100

A computational study of line-focus generation was done using a self-written ray-tracing code and compared to experimental data. Two line-focusing geometries were compared, i.e., either exploiting the sagittal astigmatism of a tilted spherical mirror or using the spherical aberration of an ... (Source: Applied Optics)

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Central vault after phakic intraocular lens implantation: Correlation with anterior chamber depth, white-to-white distance, spherical equivalent, and patient age

Journal of Cataract and Refractive Surgery — Tue, 13 Dec 2011 17:01:47 +0100

Purpose: To compare the central postoperative vault of a phakic intraocular lens (pIOL) to correct myopia, myopic astigmatism, and hyperopia and identify ocular and lens parameters that might predict the vault amount.Setting: Fernández-Vega Ophthalmological Institute, Oviedo, Spain.Design: Cohort study.Methods: Three months after implantation of Implantable Collamer Lens pIOLs to correct myopia, hyperopia, and myopic astigmatism, central vault was measured using optical coherence tomography. Patients were divided into groups according to the preoperative anterior chamber depth (ACD) to compare the effects of ACD, white-to-white (WTW) distance, and lens diameter on postoperative pIOL vault.Results: Hyperopic pIOLs had statistically significantly lower vault followed by myopic pIOLs and tor...

Lenticular meridional astigmatism secondary to iris mesectodermal leiomyoma

Journal of Cataract and Refractive Surgery — Tue, 13 Dec 2011 17:01:47 +0100

A 61-year-old African American man presented with decreased vision of 2 months duration. Examination revealed a significant lenticular astigmatism and sectoral cataract as a result of an amelanotic iris lesion. Slitlamp optical coherence tomography (OCT) revealed angle crowding. An excisional biopsy was performed along with phacoemulsification in the right eye, with intraocular lens implantation for meridional lenticular astigmatism. Histopathology and histoimmunochemistry confirmed a diagnosis of uveal mesectodermal leiomyoma. Lenticular astigmatism may be a subtle sign of an anterior segment tumor. Anterior segment slitlamp OCT is an effective tool in diagnosing as well as monitoring small interval changes in these types of tumors.Financial Disclosure: No author has a financial or propri...

Refractive Surgical Problem: January consultation #1

Journal of Cataract and Refractive Surgery — Tue, 13 Dec 2011 17:01:47 +0100

A 51-year-old man who had previous penetrating corneal transplantation (penetrating keratoplasty [PKP]) for keratoconus in the right eye presented to his primary ophthalmologist 2 years later with a visually significant cataract. Because of high and relatively symmetric astigmatism, the patient had phacoemulsification with implantation of an Acrysof IQ toric intraocular lens (IOL) (SN60T7, Alcon Laboratories, Inc.) to correct post-PKP astigmatism. (Source: Journal of Cataract and Refractive Surgery)

January consultation #4

Journal of Cataract and Refractive Surgery — Tue, 13 Dec 2011 17:01:47 +0100

Treatment of post-PKP corneal astigmatism has always been a challenge to ophthalmic surgeons. The introduction of refractive procedures, such as laser in situ keratomileusis (LASIK), femtosecond-assisted arcuate keratotomies, and toric IOL implantation, has offered effective approaches to manage this problem. (Source: Journal of Cataract and Refractive Surgery)

January consultation #5

Journal of Cataract and Refractive Surgery — Tue, 13 Dec 2011 17:01:47 +0100

The key issue in this case is astigmatic management. The implantation of the high-power toric IOL makes the eye have an inherent 3.00 diopters (D) of cylinder at the corneal plane. There are 3 possible approaches to rehabilitate the patient's vision. The first is a traditional PKP. The combination of the astigmatism from the repeat corneal transplantation and from the toric IOL will lead to challenging postoperative astigmatic correction. The curvature of the corneal plane would have to be adjusted to offset the astigmatism induced by the toric IOL. This is achievable as long as the axis of the toric IOL is known. (Source: Journal of Cataract and Refractive Surgery)

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January consultation #7

Journal of Cataract and Refractive Surgery — Tue, 13 Dec 2011 17:01:47 +0100

The overall picture suggests that the visual loss is caused by graft edema secondary to endothelial failure. Although the irregular astigmatism on topography is a concern, the patient achieved 20/25 CDVA after cataract surgery. Thus, the astigmatism is probably the result of epithelial irregularity secondary to edema. In-office epithelial debridement followed by topography of the deepithelialized cornea could differentiate epithelial irregularity from true corneal irregularity. Because the patient was satisfied after cataract surgery (before graft failure), he could have DSAEK. I make my main incision in the steep meridian and expect an approximate 1.00 D hyperopic shift postoperatively. (Source: Journal of Cataract and Refractive Surgery)

January consultation #9

Journal of Cataract and Refractive Surgery — Tue, 13 Dec 2011 17:01:47 +0100

With the toric IOL in place, a PKP regraft would lead to induced astigmatism even if the transplant were perfectly spherical. If the regraft were not spherical, it would lead to complex astigmatism in combination with the IOL. Therefore, placement of an endothelial keratoplasty under the failed PKP is a better choice if the patient had acceptable visual and refractive results before PKP failure, which this patient did. This case is a great example of why toric IOLs should be implanted after PKP only when the PKP failure can be treated with endothelial keratoplasty. (Source: Journal of Cataract and Refractive Surgery)

Retinopathy of Prematurity Linked to AstigmatismRetinopathy of Prematurity Linked to Astigmatism

Medscape Today Headlines — Mon, 12 Dec 2011 21:26:55 +0100

About half of all infants born with retinopathy of prematurity will develop astigmatism, a new study suggests. Medscape Medical News (Source: Medscape Today Headlines)

Screening for amblyopia risk factors in pre-verbal children using the Plusoptix photoscreener: a cross-sectional population-based study

British Journal of Ophthalmology — Mon, 12 Dec 2011 05:00:00 +0100

Conclusion The Plusoptix is a useful objective screening instrument, but still has low specificity for detecting amblyopia risk factors in the paediatric population. (Source: British Journal of Ophthalmology)

Femtosecond laser-assisted lock-and-key shaped penetrating keratoplasty

British Journal of Ophthalmology — Mon, 12 Dec 2011 05:00:00 +0100

In this study, we developed a novel ‘lock-and-key’ configuration for PK by using the femtosecond laser (IntraLase FS Laser, Abbott Medical Optics, US) and compared its mechanical stability against traditional and mushroom-shaped PK... (Source: British Journal of Ophthalmology)

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The effects of induced oblique astigmatism on symptoms and reading performance while viewing a computer screen

Ophthalmic and Physiological Optics — Sat, 10 Dec 2011 05:00:00 +0100

Conclusions: The presence of induced astigmatism produced a significant increase in post‐task symptoms but did not affect reading rate or the number of reading errors. The correction of small astigmatic refractive errors may be important in optimizing patient comfort during computer operation. (Source: Ophthalmic and Physiological Optics)

Design of Dyson imaging spectrometers based on the Rowland circle concept

Applied Optics — Fri, 02 Dec 2011 05:00:00 +0100

We aim to show that Dyson imaging spectrometers can be easily designed by applying the concept of the Rowland circle to refracting surfaces. This allows us to conceive an analytical procedure that is based on the removal of astigmatism at two wavelengths. Following this procedure, ... (Source: Applied Optics)

Genome-Wide Meta-Analysis of Five Asian Cohorts Identifies PDGFRA as a Susceptibility Locus for Corneal Astigmatism

PLoS Genetics — Thu, 01 Dec 2011 05:00:00 +0100

by Qiao Fan, Xin Zhou, Chiea-Chuen Khor, Ching-Yu Cheng, Liang-Kee Goh, Xueling Sim, Wan-Ting Tay, Yi-Ju Li, Rick Twee-Hee Ong, Chen Suo, Belinda Cornes, Mohammad Kamran Ikram, Kee-Seng Chia, Mark Seielstad, Jianjun Liu, Eranga Vithana, Terri L. Young, E.-Shyong Tai, Tien-Yin Wong, Tin Aung, Yik-Ying Teo, Seang-Mei Saw Corneal astigmatism refers to refractive abnormalities and irregularities in the curvature of the cornea, and this interferes with light being accurately focused at a single point in the eye. This ametropic condition is highly prevalent, influences visual acuity, and is a highly heritable trait. There is currently a paucity of research in the genetic etiology of corneal astigmatism. Here we report the results from five genome-wide association studies of corneal astigmat...

Refractive profile in oculocutaneous albinism and its correlation with final visual outcome.

The British Journal of Ophthalmology — Thu, 01 Dec 2011 05:00:00 +0100

ConclusionsThe poorest visual acuity was found in those with OCA1A, which was associated with the highest rate of high hypermetropia (statistically significant different from other subgroups). Astigmatism was the most common visually significant refractive error across all subtypes of albinism. These results may help to clarify the prevalence of refractive errors in albino patients and aid the prediction of visual outcome in this heterogeneous population. PMID: 22133989 [PubMed - as supplied by publisher] (Source: The British Journal of Ophthalmology)

Outcomes of deep anterior lamellar keratoplasty following successful and failed 'big bubble'

The British Journal of Ophthalmology — Thu, 01 Dec 2011 05:00:00 +0100

ConclusionsIn DALK, manual lamellar dissection is a reasonable alternative when BB separation of the DM is not achieved. PMID: 22133987 [PubMed - as supplied by publisher] (Source: The British Journal of Ophthalmology)

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Association between Ocular Dominance and Spherical/Astigmatic Anisometropia, Age, and Sex: Analysis of 10,264 Myopic Individuals [Clinical and Epidemiologic Research]

Investigative Ophthalmology — Fri, 25 Nov 2011 05:00:00 +0100

Conclusions. In contrast to previous reports, this study, including myopic refractive surgery candidates, revealed that the nondominant eye was more myopic for SE anisometropia >2.5 and more astigmatic for cylindrical anisometropia >0.5 D. (Source: Investigative Ophthalmology)

Simulation of toric intraocular lens results: Manual keratometry versus dual-zone automated keratometry from an integrated biometer

Journal of Cataract and Refractive Surgery — Tue, 22 Nov 2011 16:29:28 +0100

Conclusions: Simulated outcomes suggest that overall results for a group of patients whose toric IOL surgery planning is performed with the dual-zone automated keratometry data from the biometer will be equivalent to those when manual keratometry is used. The reduced site-to-site variability with the biometer suggests an operational advantage.Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. (Source: Journal of Cataract and Refractive Surgery)

December consultation #4

Journal of Cataract and Refractive Surgery — Tue, 22 Nov 2011 16:29:28 +0100

Complete iris loss due to trauma causes severe aesthetic limitations and visual impairment due to photophobia, aberration disorders, glare effects, and loss of depth of focus. There are 2 possible approaches to this patient. One would be to use a scleral-fixated iris-diaphragm IOL (Ophtec). Different diaphragm configurations and different colors are available, with the models having comparable C-loop haptics. The drawback of these IOLs is that they are poly(methyl methacrylate) and require a large corneal incision for implantation, thus risking intraoperative complications and high postoperative astigmatism. (Source: Journal of Cataract and Refractive Surgery)

December consultation #5

Journal of Cataract and Refractive Surgery — Tue, 22 Nov 2011 16:29:28 +0100

The injury to this patient's eye has produced irregular astigmatism, corectopia with iris disinsertion, and aphakia without significant residual capsule support. The significant steepening of the central cornea and what appears to be superficial corneal haze suggest heaped up epithelium or subepithelial scarring. Goals of rehabilitation include (1) reduction, regularization, and/or elimination of corneal astigmatism; (2) IOL implantation in the absence of capsule support; and (3) restoration of the pupil by iris reconstruction, implantation of an iris prosthesis, or both. (Source: Journal of Cataract and Refractive Surgery)

December consultation #8

Journal of Cataract and Refractive Surgery — Tue, 22 Nov 2011 16:29:28 +0100

This patient has 3 main problems for visual rehabilitation: (1) aphakia, (2) aniridia, and (3) corneal cicatricial opacification reaching the optical axis with massive irregular (cicatricial) astigmatism. The situation is complicated by secondary glaucoma. (Source: Journal of Cataract and Refractive Surgery)

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Reply

Journal of Cataract and Refractive Surgery — Tue, 22 Nov 2011 16:29:28 +0100

We appreciate Dr. Naeser’s interest in our work. As he stated, in our study we evaluated the outcomes with a specific type of toric IOL using the Alpins vector method for evaluating astigmatic outcomes. We followed this procedure for analyzing the changes occurring in astigmatism step by step. We are surprised by the concern expressed in the letter because the data requested were included and analyzed in detail in the article. A more careful reading of the article would probably answer the questions. (Source: Journal of Cataract and Refractive Surgery)

Long-term Change in Corneal Astigmatism after Sutureless Cataract Surgery

American Journal of Ophthalmology — Tue, 22 Nov 2011 16:29:14 +0100

We read with great interest the article by Hayashi and associates on age-related changes in corneal astigmatism in pseudophakic and phakic patients. Changes in corneal astigmatism with age have been well documented in the literature. Corneal astigmatism changes from with-the-rule astigmatism to against-the-rule astigmatism with age. An interesting aspect is the effect of cataract surgery on this natural shift in astigmatism. The literature in this regard is sparse. The authors herein provide valuable information about the age-related changes in pseudophakic patients in their comparative analysis of long-term change in astigmatism in pseudophakic and phakic patients. It is interesting to note that the change in astigmatism in psuedophakic patients follows the same trend as that in phakic pa...

Reply

American Journal of Ophthalmology — Tue, 22 Nov 2011 16:29:14 +0100

We are grateful for the comments from Pahuja and associates on our article regarding long-term changes in corneal astigmatism with aging after sutureless cataract surgery. Although their comments seem to be theoretically appropriate, some important facts have been overlooked. (Source: American Journal of Ophthalmology)

STAAR toric IOL receives CE mark

Modern Medicine — Tue, 22 Nov 2011 12:04:35 +0100

STAAR Surgical Co. has received CE mark approval for a single-piece toric IOL (nanoFLEX Toric Collamer Single Piece IOL). The IOL, which is designed for patients who have cataracts and astigmatism, was approved for correction of 1.0 D to 4.0 D of cylinder in 0.5-D steps. (Source: Modern Medicine)

Nonlinear Optical Macroscopic Assessment of 3-D Corneal Collagen Organization and Axial Biomechanics [Cornea]

Investigative Ophthalmology — Fri, 11 Nov 2011 05:00:00 +0100

Conclusions. The axial gradient in lamellar intertwining appears to be associated with an axial gradient in the effective elastic modulus of the cornea, suggesting that collagen fiber intertwining and formation of bow spring–like structures provide structural support similar to cross-beams in bridges and large-scale structures. Future studies are necessary to determine the role of radial and axial structural–mechanical heterogeneity in controlling corneal shape and in the development of keratoconus, astigmatism, and other refractive errors. (Source: Investigative Ophthalmology)

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Derivation of the propagation equations for higher order aberrations of local wavefronts

Journal of the Optical Society of America A — Thu, 10 Nov 2011 05:00:00 +0100

From the literature the analytical calculation of local power and astigmatism of a wavefront after refraction and propagation is well known; it is, e.g., performed by the Coddington equation for refraction and the classical vertex correction formula for propagation. Recently the authors succeeded ... (Source: Journal of the Optical Society of America A)

Rotational stability of a toric intraocular lens: Influence of axial length and alignment in the capsular bag

Journal of Cataract and Refractive Surgery — Mon, 07 Nov 2011 05:00:00 +0100

This study enrolled eyes that had AcrySof toric IOL implantation. The AL was measured using optical coherence biometry or immersion A-scan biometry. Corneal astigmatism was determined by manual keratometry and topography. The IOL alignment was vertical, horizontal, or oblique. Rotational stability was measured using the purpose-designed software, and the mean absolute difference was determined. The effect of AL and IOL alignment on rotational stability was determined 6 months postoperatively.Results: The study evaluated 168 eyes (168 patients). The mean AL was 23.86 mm ± 1.63 (SD), (range 19.50 to 29.03 mm). The median IOL rotation was 0.3 degree from baseline to 1 week, 1.0 degree from 1 week to 1 month, 0.2 degree from 1 to 3 months, and 0.1 degree from 3 to 6 months. The maximum rotati...

Development of Educational Materials to Improve Rates of Early Eye Care for Hispanic Children

Journal of Immigrant and Minority Health — Thu, 03 Nov 2011 16:56:23 +0100

Abstract The purpose of this study was to develop targeted materials to encourage Hispanic parents to seek eye care for their children. Hispanic children present with high rates of eye problems such as astigmatism, strabismus, and amblyopia. Related vision impairment can be prevented with timely detection and treatment. After failing a vision screening, a child must obtain professional eye care to take care of the suspected problem. We involved Hispanic community members and health care experts in Alabama to develop educational materials to encourage Hispanic parents to seek eye care for their children. There were six stages in the development of the educational materials: (a) focus groups with Hispanic parents, (b) development of preliminary materials (c) panel with Hispa...

Novel Tissue Adhesive Shows Promise in Cataract SurgeryNovel Tissue Adhesive Shows Promise in Cataract Surgery

Medscape Today Headlines — Tue, 01 Nov 2011 23:07:10 +0100

A new tissue adhesive shows promise in reducing astigmatism after clear corneal cataract surgery. However, with the benefit comes the risk for endophthalmitis. Medscape Medical News (Source: Medscape Today Headlines)

Prevalence of the refractive errors by age and gender: the Mashhad eye study of Iran

Clinical and Experimental Ophthalmology — Tue, 01 Nov 2011 04:00:00 +0100

Conclusions: In children and the elderly, hyperopia is the most prevalent refractive error. After hyperopia, astigmatism is also of importance in older ages. Age is the most important demographic factor associated with different types of refractive errors. (Source: Clinical and Experimental Ophthalmology)

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Visual outcome of Soflens Daily Disposable and Soflens Daily Disposable for Astigmatism in subjects with low astigmatism

Clinical and Experimental Optometry — Tue, 01 Nov 2011 04:00:00 +0100

Conclusions: The results of the present study show that both subjective and objective vision in myopic subjects with low astigmatism improves significantly when corrected with toric lenses compared with spherical lenses. (Source: Clinical and Experimental Optometry)

Corneal parameters of six‐ to 12‐year‐old Chinese children

Clinical and Experimental Optometry — Tue, 01 Nov 2011 04:00:00 +0100

Conclusions: All corneas were prolate elliptical in shape along the flat meridian and the peripheral flattening rate was found to be greater along the flat meridian. A greater flattening rate was observed in the corneas of Chinese children when compared to that of Caucasian children. The Q between male and female subjects was not significantly different. Male subjects tended to have larger HVID and flatter corneas than female subjects. (Source: Clinical and Experimental Optometry)

Optical ray tracing–guided laser in situ keratomileusis for moderate to high myopic astigmatism

Journal of Cataract and Refractive Surgery — Fri, 28 Oct 2011 04:00:00 +0100

Conclusions: The new optical ray-tracing algorithm for individualized LASIK ablation profiles to treat moderate to high myopic astigmatism was efficacious, safe, and predictable. The UDVA in eyes with high myopic astigmatism was better than in those treated with wavefront-guided LASIK.Financial Disclosure: Drs. Schumacher and Mrochen are paid scientific consultants to and Drs. Seiler and Cummings and Mr. Maus are members of the medical advisory board of Wavelight, Erlangen, Germany. (Source: Journal of Cataract and Refractive Surgery)

Prevalence of refractive errors among school children in Northeastern Iran

Ophthalmic and Physiological Optics — Thu, 27 Oct 2011 04:01:12 +0100

Conclusions: The prevalence of myopia in schoolchildren in Northeastern Iran is considerably lower than that of East Asian populations, but similar to many other populations, including South Africa, Chile and other countries of the Middle East. Whilst comparisons with other studies show that the prevalence of hyperopia and astigmatism in Northeastern Iran is higher than that of some countries, it is lower compared with others. (Source: Ophthalmic and Physiological Optics)

Indications and outcomes for revision of gold weight implants in upper eyelid loading.

The British Journal of Ophthalmology — Thu, 27 Oct 2011 04:00:00 +0100

ConclusionHigh pretarsal placement was successful in treating lagophthalmos, with a complication rate of 1 in 6 requiring a revision procedure, the majority within 12 months. Main indications were unsatisfactory cosmesis from prominence of implant and poor eyelid contour. PMID: 22034542 [PubMed - as supplied by publisher] (Source: The British Journal of Ophthalmology)

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Off-plane anastigmatic imaging in Offner spectrometers

Journal of the Optical Society of America A — Wed, 26 Oct 2011 05:00:00 +0100

In this paper, the imaging performance of an Offner concentric imaging spectrometer is analyzed when the spectrometer entrance slit is disposed arbitrarily on the plane that is parallel to the grating grooves and contains the common center of curvature. Astigmatism-corrected designs are obtained ... (Source: Journal of the Optical Society of America A)

Toric soft contact lens fit in a postoperative LASIK keratoectasia patient with high and irregular astigmatism

Optometry - Journal of the American Optometric Association — Mon, 24 Oct 2011 04:00:00 +0100

Conclusion: This case report confirms that toric soft contact lenses are a good first choice in fitting patients with high and irregular astigmatism from postoperative LASIK corneal ectasia. It also confirms that excellent vision and comfort with toric soft contact lenses is possible in these patients. (Source: Optometry - Journal of the American Optometric Association)

Limbal relaxing incisions during phacoemulsification: 6-month results

Journal of Cataract and Refractive Surgery — Sun, 23 Oct 2011 05:15:52 +0100

Limbal relaxing incisions (LRIs) are one of the more commonly performed adjunctive procedures with phacoemulsification to correct preexisting astigmatism, primarily because of the cost effectiveness and the predictable surgical profile. We conducted a prospective interventional study to evaluate the effect and stability of LRIs in reducing preexisting astigmatism at the time of phacoemulsification. (Source: Journal of Cataract and Refractive Surgery)

November consultation #2

Journal of Cataract and Refractive Surgery — Sun, 23 Oct 2011 05:15:52 +0100

This is an interesting case of bilateral ectasia after LASIK in a patient with apparently normal preoperative corneal topographies. The most likely causes for the ectasia are undiagnosed keratoconus and excessive keratectomy depth. It is possible that this patient had very early keratoconus in which the cone was small enough for epithelial thickness changes to compensate fully such that the front-surface topography appeared normal, as previously described. The corneal topography back surface shows a slightly elevated and eccentric apex, which may indicate the presence of a subsurface cone masked by epithelium. The keratometric map shows skew astigmatism in both eyes, which might also indicate keratoconus. (Source: Journal of Cataract and Refractive Surgery)

The power of a bubble: Descemet's stripping endothelial keratoplasty (DSEK) and rebubbling

British Journal of Ophthalmology — Fri, 21 Oct 2011 04:00:00 +0100

The history of lamellar keratoplasty (LK) surgery spans several decades, and its advantages have long been known. However, new strategies and technology have promoted a resurgence of LK in visual rehabilitation. One specific type of LK is endothelial transplantation, in all its variations. This is a form of corneal transplantation in which a donor posterior corneal button, including corneal endothelium, Descemet's membrane with, or more recently without, posterior corneal stroma (DSEK or Descemet's membrane endothelial keratoplasty, DMEK respectively) is used for selective replacement of the diseased corneal endothelium.1–5 Endothelial keratoplasty has numerous advantages over penetrating keratoplasty for indications related to endothelial dysfunction. These include faster visual imp...

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A randomised, prospective study to investigate the efficacy of riboflavin/ultraviolet A (370 nm) corneal collagen cross-linkage to halt the progression of keratoconus

British Journal of Ophthalmology — Fri, 21 Oct 2011 04:00:00 +0100

Conclusions Corneal collagen cross-linkage appears to be an effective and safe modality to halt the progression of keratoconus. Improvements in visual and topographic parameters are seen in some eyes. (Source: British Journal of Ophthalmology)

Toric soft contact lens fit in a postoperative LASIK keratoectasia patient with high and irregular astigmatism.

Optometry — Fri, 21 Oct 2011 04:00:00 +0100

CONCLUSION: This case report confirms that toric soft contact lenses are a good first choice in fitting patients with high and irregular astigmatism from postoperative LASIK corneal ectasia. It also confirms that excellent vision and comfort with toric soft contact lenses is possible in these patients. PMID: 22019833 [PubMed - as supplied by publisher] (Source: Optometry)

Vectorial astigmatic changes after corneal collagen crosslinking in keratoconic corneas previously treated with intracorneal ring segments: a preliminary study.

European Journal of Ophthalmology — Thu, 20 Oct 2011 04:00:00 +0100

Conclusions. Crosslinking is able to induce a corneal astigmatic change, but it is variable, not predictable, and insufficient to provide an effective astigmatic correction. PMID: 22020986 [PubMed - as supplied by publisher] (Source: European Journal of Ophthalmology)

Relationship between minimum corneal thickness and refractive state, keratometry, age, sex, and left or right eye in refractive surgery candidates

Journal of Cataract and Refractive Surgery — Thu, 20 Oct 2011 04:00:00 +0100

Purpose: To evaluate the relationship between the thinnest point in corneal thickness and the refractive state, keratometry, age, sex, and the ocular side.Setting: Eye clinics in Germany and Austria and the Department of Ophthalmology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.Design: Cross-sectional study.Methods: Medical records of refractive surgery candidates from 2006 to 2010 were reviewed. Univariate variance analysis, covariance analysis, Bravis-Pearson correlations, Spearman rank correlations, and t tests were performed to analyze the relationship between the thinnest point in corneal thickness and the biometric parameters.Results: The study evaluated 4600 eyes. The mean thinnest point in corneal thickness was 549 μm ± 33 (SD). Refractive state, mean keratome...

Low-cost adaptive astigmatism compensator for improvement of eye fundus camera

Optics Letters — Wed, 19 Oct 2011 05:00:00 +0100

In this work we show a conceptually simple and cheap means by which to improve retinal image quality in fundus cameras. We will explain how to build a low-cost variable astigmatism-correcting device with a pair of identical commercial ophthalmic lenses. We have developed and tested a low order ... (Source: Optics Letters)

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A phenotypic study of congenital stationary night blindness (CSNB) associated with mutations in the GRM6 gene

Acta Ophthalmologica — Wed, 19 Oct 2011 04:00:00 +0100

Conclusions: The phenotype associated with GRM6 mutation is variable in terms of presentation, refractive error, visual acuity and macular function. ERGs are electronegative and suggest ON‐pathway dysfunction. (Source: Acta Ophthalmologica)

Spectrum of visual impairment among urban female school students of Surat

Indian Journal of Ophthalmology — Wed, 19 Oct 2011 04:00:00 +0100

Conclusion : This study highlighted the load of eye morbidities of adolescent Indian urban girls. (Source: Indian Journal of Ophthalmology)

Outcomes of an Elementary School-Based Vision Screening Program in North Carolina.

The Journal of School Nursing — Tue, 04 Oct 2011 04:00:00 +0100

Authors: Kemper AR, Helfrich A, Talbot J, Patel N Abstract School nurses can play a key role in the detection of significant refractive error. The purpose of this study was to assess the impact of a statewide school nurse vision screening program by evaluating the outcomes of screening among first, third, and fifth graders in 10 schools in North Carolina during the 2009-2010 school year. Of the 2,726 children who were screened, 7.7% (n = 209) were abnormal, of which 89% (n = 186) were placed into a comprehensive database for follow-up. No documentation of any follow-up was available for 35% (n = 65) of these children. Of the 106 with complete eye examination data available, 54.7% (n = 58) had myopia, 22.6% (n = 24) had hyperopia, 11.3% (n = 12) had astigmatism, 1.9% (n = 2) had ani...

Amblyopia Prevalence and Risk Factors in Australian Preschool Children

Ophthalmology — Mon, 03 Oct 2011 04:00:00 +0100

Purpose: To determine the prevalence of and factors associated with amblyopia in a sample of Australian preschool children. Design: Population-based, cross-sectional study. Participants: The Sydney Paediatric Eye Disease Study examined 2461 (73.8% participation) children aged between 6 and 72 months from 2007 to 2009. Methods: Visual acuity (VA) was assessed in children aged ≥30 months using the Electronic Visual Acuity system, and a subset using the logarithm of the minimum angle of resolution chart. Amblyopia was categorized into unilateral and bilateral subtypes: Unilateral amblyopia was defined as a 2-line difference in reduced VA between the 2 eyes, in addition to strabismus, anisometropia, and/or visual axis obstruction; bilateral amblyopia was defined as bilateral reduced V...

Atropine for the Treatment of Childhood Myopia: Safety and Efficacy of 0.5%, 0.1%, and 0.01% Doses (Atropine for the Treatment of Myopia 2)

Ophthalmology — Mon, 03 Oct 2011 04:00:00 +0100

Conclusions: Atropine 0.01% has minimal side effects compared with atropine at 0.1% and 0.5%, and retains comparable efficacy in controlling myopia progression. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. (Source: Ophthalmology)

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Case Report: The correction of a high magnitude of astigmatism with laser-assisted in situ keratomileusis.

Optometry — Sat, 01 Oct 2011 04:00:00 +0100

CONCLUSION: This case focuses on the utilization of a wavefront-optimized LASIK treatment profile to eliminate a high magnitude of astigmatic refractive error without inducing higher-order aberrations. Wavefront-guided treatments are not required in most cases but should be considered if the magnitude of preoperative root-mean-square higher-order aberrations is greater than 0.35 μm. Wavefront-optimized aspheric corneal ablations attempt to avoid reducing the prolate eccentricity of the average cornea, and optimized treatments have shown improved visual outcomes compared with conventional LASIK treatments. A thorough knowledge of refractive surgery is important for any treating eye care practitioner to provide patients with the full range of options to correct all types of refractive error...

Factors Influencing the Changes in Coma-like Aberrations after Myopic Laser in Situ Keratomileusis.

Current Eye Research — Sat, 01 Oct 2011 04:00:00 +0100

Conclusions: High myopic eyes requiring larger amounts of laser correction and eyes undergoing conventional LASIK tend to induce more coma-like aberration after surgery. Wavefront-guided LASIK may be a better surgical approach for preventing the induction of coma-like aberrations, especially in eyes with high myopia. PMID: 21950695 [PubMed - in process] (Source: Current Eye Research)

Outcomes of deep anterior lamellar keratoplasty versus intralase enabled penetrating keratoplasty in keratoconus.

Canadian Journal of Ophthalmology — Sat, 01 Oct 2011 04:00:00 +0100

CONCLUSIONS: BSCVA and complication rates are similar after DALK and IEK, but each technique has its advantage. IEK offered shorter time to suture removal whereas DALK offered lower postoperative astigmatism and HOA rates. PMID: 21995982 [PubMed - in process] (Source: Canadian Journal of Ophthalmology)

Retinopathy of prematurity tied to more astigmatism

Modern Medicine — Fri, 30 Sep 2011 04:00:00 +0100

NEW YORK (Reuters Health) - High-risk prethreshold retinopathy of prematurity (ROP) is tied to heightened chances of the subsequent development of astigmatism, researchers report online August 26 in Ophthalmology. (Source: Modern Medicine)

Case Report: The correction of a high magnitude of astigmatism with laser-assisted in situ keratomileusis

Optometry - Journal of the American Optometric Association — Thu, 29 Sep 2011 17:02:10 +0100

Conclusion: This case focuses on the utilization of a wavefront-optimized LASIK treatment profile to eliminate a high magnitude of astigmatic refractive error without inducing higher-order aberrations. Wavefront-guided treatments are not required in most cases but should be considered if the magnitude of preoperative root-mean-square higher-order aberrations is greater than 0.35 μm. Wavefront-optimized aspheric corneal ablations attempt to avoid reducing the prolate eccentricity of the average cornea, and optimized treatments have shown improved visual outcomes compared with conventional LASIK treatments. A thorough knowledge of refractive surgery is important for any treating eye care practitioner to provide patients with the full range of options to correct all types of refractive error...

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Prevalence and Associations of Anisometropia with Spherical Ametropia, Cylindrical Power, Age, and Sex in Refractive Surgery Candidates [Clinical and Epidemiologic Research]

Investigative Ophthalmology — Thu, 29 Sep 2011 04:00:00 +0100

Conclusions. This large-scale retrospective analysis confirmed an independent association between anisometropia and both spherical ametropia and age in refractive surgery candidates. Notably, an inverse relationship between these parameters in hyperopes was observed. Cylindrical power and female sex were independently associated with anisometropia in myopes. (Source: Investigative Ophthalmology)

Cross-sectional Sample of Peripheral Refraction in Four Meridians in Myopes and Emmetropes [Visual Psychophysics and Physiological Optics]

Investigative Ophthalmology — Thu, 29 Sep 2011 04:00:00 +0100

Conclusions. These results suggest that the myopic eye tends toward an ellipsoid shape, rather than the globular shape of an emmetropic eye. (Source: Investigative Ophthalmology)

Visual outcomes and patient satisfaction after cataract surgery with toric multifocal intraocular lens implantation

Journal of Cataract and Refractive Surgery — Fri, 23 Sep 2011 04:00:00 +0100

Conclusions: Toric IOL implantation in patients with cataract and corneal astigmatism provided good distance and near visual outcomes and acceptable intermediate visual outcomes, allowing patients with considerable amounts of corneal astigmatism to achieve spectacle independence at distance and near.Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes. (Source: Journal of Cataract and Refractive Surgery)

October consultation #7

Journal of Cataract and Refractive Surgery — Thu, 22 Sep 2011 16:57:02 +0100

Following is how I would manage this case: Maintain a 2-chambered eye. Use a scleral-sutured modified Cionni CTR or a standard CTR with an Ahmed segment and a single-piece acrylic IOL. Prevent anisometropia by choosing the IOL power with the knowledge that the sutured bag will often sit more forward in the eye than the predicted effective lens position. Amblyopia is often actually subluxated lens–induced irregular astigmatism. Good visual acuity is frequently achieved. (Source: Journal of Cataract and Refractive Surgery)

Influence of contact lens wear on the results of ultraviolet A/riboflavin cross-linking for progressive keratoconus

British Journal of Ophthalmology — Wed, 21 Sep 2011 04:00:00 +0100

Conclusion CL can be a confounding factor in interpreting the results of CXL: lens wear itself leads to improved topographic parameters. (Source: British Journal of Ophthalmology)

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Rigid iris-fixated phakic lens implantation for high myopia: novel trapezoidal corneal versus scleral incisions.

European Journal of Ophthalmology — Fri, 16 Sep 2011 04:00:00 +0100

Conclusions. The TCI and STI techniques are comparable in terms of safety and induction of astigmatism for the rigid iris-fixated PIOL implantation. However, the TCI is easy to perform and provides a faster visual recovery and lower postoperative corneal astigmatism compared with the STI. PMID: 21928256 [PubMed - as supplied by publisher] (Source: European Journal of Ophthalmology)

Cone location and correction of keratoconus with rigid gas-permeable contact lenses

Contact Lens and Anterior Eye — Thu, 15 Sep 2011 04:00:00 +0100

Abstract: Purpose: To evaluate the influence of cone location and corneal cylinder on RGP corrected visual acuities and residual astigmatism in patients with keratoconus.Methods: In this prospective study, 156 eyes from 134 patients were enrolled. Complete ophthalmologic examination including manifest refraction, Best spectacle visual acuity (BSCVA), slit-lamp biomicroscopy was performed and corneal topography analysis was done. According to the cone location on the topographic map, the patients were divided into central and paracentral cone groups. Trial RGP lenses were selected based on the flat Sim K readings and a ‘three-point touch’ fitting approach was used. Over contact lens refraction was performed, residual astigmatism (RA) was measured and best-corrected RGP visual acuities (...

Combining refractive and topographic data in corneal refractive surgery for astigmatism

Acta Ophthalmologica — Tue, 13 Sep 2011 04:00:00 +0100

Conclusions: The advantage of the optimization method described in this article is a consistent reduction in corneal astigmatism towards sphericity. No new corneal astigmatism is carved on the cornea, and probably less tissue is ablated. The optimization method may also be used to combine refractive and topographic data for higher order aberrations with sinusoidal components. However, compared to the traditional purely refractive driven treatment, more refractive astigmatism will remain in the eye in most cases. A controlled clinical trial is necessary for comparing these two treatment modalities. (Source: Acta Ophthalmologica)

Repeatability and Reproducibility of Biometry and Keratometry Measurements Using a Noncontact Optical Low-Coherence Reflectometer and Keratometer

American Journal of Ophthalmology — Mon, 12 Sep 2011 04:00:00 +0100

Conclusions: The precision of the measurements obtained by the new optical reflectometer and keratometer is extremely high. (Source: American Journal of Ophthalmology)

Effects of primary spherical aberration, coma, astigmatism, and field curvature on the focusing of ultrashort pulses: Gaussian illumination and experiment

Journal of the Optical Society of America A — Fri, 09 Sep 2011 05:00:00 +0100

We analyze the spatiotemporal intensity of Gaussian temporal envelope pulses with initial durations of 200?fs and a carrier wavelength of 810?nm at the paraxial focal plane of an achromatic doublet lens for a well-collimated incoming pulse beam by using the Seidel aberration theory for thin lenses ... (Source: Journal of the Optical Society of America A)

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Wavefield imaging via iterative retrieval based on phase modulation diversity

Optics Express — Thu, 08 Sep 2011 05:00:00 +0100

We present a fast and robust non-interferomentric wavefield retrieval approach suitable for imaging of both amplitude and phase distributions of scalar coherent beams. It is based on the diversity of the intensity measurements obtained under controlled astigmatism and it can be easily implemented ... (Source: Optics Express)

Effects of primary spherical aberration, coma, astigmatism and field curvature on the focusing of ultrashort pulses: homogenous illumination

Journal of the Optical Society of America A — Tue, 06 Sep 2011 05:00:00 +0100

We analyze the spatiotemporal intensity of pulses with durations of 20 fs and shorter and a carrier wavelength of 810 nm at the paraxial focal plane of an achromatic doublet lens. The incident pulse is well-collimated, and we use the Seidel aberration theory ... (Source: Journal of the Optical Society of America A)

Effects of primary spherical aberration, coma, astigmatism and field curvature on the focusing of ultrashort pulses: homogenous illumination

Journal of the Optical Society of America A — Sun, 04 Sep 2011 04:15:01 +0100

We analyze the spatiotemporal intensity of pulses with durations of 20?fs and shorter and a carrier wavelength of 810?nm at the paraxial focal plane of an achromatic doublet lens. The incident pulse is well-collimated, and we use the Seidel aberration theory for thin lenses to evaluate the phase ... (Source: Journal of the Optical Society of America A)

Long-Term Changes of the Anterior Corneal Topography after Photorefractive Keratectomy for Myopia and Myopic Astigmatism [Cornea]

Investigative Ophthalmology — Thu, 01 Sep 2011 04:00:00 +0100

Conclusions. The anterior corneal topography continues to change configuration even long term after PRK. Changes are confined outside the functional optical zone of the cornea. PRK for the correction of myopia was shown not to influence the mechanical stability of the corneal tissue at 8 years after surgery. (Source: Investigative Ophthalmology)

Astigmatism Progression in the Early Treatment for Retinopathy of Prematurity Study to 6 Years of Age

Ophthalmology — Mon, 29 Aug 2011 04:00:00 +0100

Conclusions: By 6 years of age, astigmatism of 1.00 D or more developed in more than 50% of eyes with high-risk prethreshold ROP, and nearly 25% of such eyes had high astigmatism (≥2.00 D). Presence of astigmatism was not influenced by timing of treatment, zone of acute-phase ROP, or presence of plus disease. However, there was a trend toward higher prevalence of astigmatism and high astigmatism in eyes with ROP residua. Most astigmatism was with-the-rule (75°–105°). More eyes with type 2 than type 1 ROP had astigmatism by 6 years. These findings reinforce the need for follow-up eye examinations through early grade school years in infants with high-risk prethreshold ROP.Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in thi...

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Descemet's Membrane Endothelial Keratoplasty: Prospective Study of 1-Year Visual Outcomes, Graft Survival, and Endothelial Cell Loss

Ophthalmology — Mon, 29 Aug 2011 04:00:00 +0100

Conclusions: Descemet's membrane endothelial keratoplasty had better visual acuity results in the first year after surgery than typically reported for other endothelial keratoplasty techniques, such as Descemet's stripping automated endothelial keratoplasty, while having less refractive changes and similar endothelial cell counts but a higher rebubbling rate.Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. (Source: Ophthalmology)

Laser-Assisted In Situ Keratomileusis in High Levels of Myopia With the Amaris Excimer Laser Using Optimized Aspherical Profiles

American Journal of Ophthalmology — Thu, 25 Aug 2011 04:00:00 +0100

Conclusions: LASIK for high myopia using optimized aspherical profiles and the Amaris excimer laser is a safe, effective, and predictable procedure. (Source: American Journal of Ophthalmology)

The Effect of Iris-Fixated Foldable Phakic Intraocular Lenses on Retinal Straylight

American Journal of Ophthalmology — Thu, 25 Aug 2011 04:00:00 +0100

Conclusions: Retinal straylight was reduced significantly after Artiflex pIOL implantation. Besides age, axial length was the only predictor of preoperative and postoperative straylight values. The increased tissue length light has to pass from cornea to retina, might explain the increase in straylight values in longer eyes. (Source: American Journal of Ophthalmology)

Role of angle kappa in patient dissatisfaction with refractive-design multifocal intraocular lenses

Journal of Cataract and Refractive Surgery — Wed, 24 Aug 2011 19:44:26 +0100

We would like to congratulate de Vries et al. for their retrospective study, which looked at multiple factors in patient dissatisfaction. The authors primarily evaluated 2 diffractive intraocular lens (IOL) models and noticed that residual ametropia and astigmatism, posterior capsule opacification, and large pupil were the 3 most significant etiologies in patient dissatisfaction. (Source: Journal of Cataract and Refractive Surgery)

Differences in corneal astigmatism between partial coherence interferometry biometry and automated keratometry and relation to topographic pattern

Journal of Cataract and Refractive Surgery — Wed, 24 Aug 2011 19:44:22 +0100

Conclusion: The difference in corneal astigmatism between the PCI biometer and automated keratometer may depend on the corneal topography pattern.Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. (Source: Journal of Cataract and Refractive Surgery)

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Effect of scanning patterns on the results of femtosecond laser lenticule extraction refractive surgery

Journal of Cataract and Refractive Surgery — Wed, 24 Aug 2011 19:44:20 +0100

Purpose: To report the clinical results of refractive lenticule extraction using a femtosecond laser and describe the effect of scanning patterns on the results.Setting: Private laser center, Vadodara, India.Design: Prospective clinical study.Methods: The Visumax femtosecond laser system was used to perform lenticule extraction to treat refractive errors using 2 scanning trajectories. The laser was used to cut a refractive lenticule intrastromally to correct myopia or myopic astigmatism. The lenticule was then physically extracted from the stroma. In scanning pattern A, the laser scanned from the center out and the periphery in while the 2 surfaces of the lenticule were cut. In scan pattern B, the laser scanned from the periphery in and the center out. Outcome measures were corrected and u...

Surgical and refractive outcomes of cataract surgery with toric intraocular lens implantation at a resident-teaching institution

Journal of Cataract and Refractive Surgery — Wed, 24 Aug 2011 19:44:19 +0100

Purpose: To evaluate the refractive and surgical outcomes of cataract surgery with toric intraocular lens (IOL) implantation performed at a teaching institution.Setting: Miami Veterans Affairs Medical Center, Miami, Florida, USA.Design: Retrospective case series.Methods: All data were obtained by a retrospective chart review and entered into a standard computerized database for analysis. Main outcome measures included refractive and surgical outcomes after Acrysof toric IOL placement, including the deviation from the expected spherical and cylindrical correction and the incidence of ocular complications.Results: The study comprised 94 eyes (80 patients). The mean deviation from the anticipated spherical correction (94 eyes) was +0.06 diopter (D) ± 0.8 (range −2.6 D to +3.6 D), with 80% ...

Residual astigmatism produced by toric intraocular lens rotation

Journal of Cataract and Refractive Surgery — Wed, 24 Aug 2011 04:00:00 +0100

Conclusions: The 2 methods gave equivalent results. When the IOL cylinder had a value different from that of the corneal astigmatism, a better choice would be a lower, rather than higher, cylinder value to reduce residual astigmatism. In general, toric IOL rotations less than 10 degrees changed the eye’s refraction less than 0.50 diopter. Thus, small axis rotations are not an obstacle for satisfactory astigmatism correction with toric IOLs.Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. (Source: Journal of Cataract and Refractive Surgery)

Astigmatism and optical coherence tomography measurements

Graefe's Archive for Clinical and Experimental Ophthalmology — Mon, 22 Aug 2011 15:58:57 +0100

Conclusion Although the amount of change was not substantial, RNFL thickness measured by Cirrus HD OCT was affected by astigmatism changes induced by contact lenses. It may be warranted to consider the effect of astigmatism on RNFL thickness measured by OCT in eyes with higher degrees of astigmatism. Content Type Journal ArticleCategory GlaucomaPages 1-8DOI 10.1007/s00417-011-1788-4Authors Young Hoon Hwang, Department of Ophthalmology, Armed Forces Capital Hospital, Seongnam, KoreaSang Mok Lee, Department of Ophthalmology, Armed Forces Capital Hospital, Seongnam, KoreaYong Yeon Kim, Department of Ophthalmology, Korea University College of Medicine, Seoul, KoreaJong Yeon Lee, Department of Ophthalmology, Gachon University Gil Hospital, Incheon, KoreaChungkwon Yoo, De...

Comparison of patient outcomes after implantation of Visian toric implantable collamer lens and iris-fixated toric phakic intraocular lens

Eye — Fri, 19 Aug 2011 07:00:00 +0100

Authors: S Y Lee, H J Kwon, H S Ahn, K Y Seo, E K Kim & T-I Kim (Source: Eye)

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Visual outcome and contrast sensitivity after photorefractive keratectomy in low to moderate myopia: Wavefront-optimized versus conventional methods

Journal of Cataract and Refractive Surgery — Fri, 19 Aug 2011 04:00:00 +0100

Conclusions: Visual acuity and refractive error outcomes were similar in both treatment groups. After 3 months, mesopic and photopic contrast sensitivity were significantly decreased in both groups; the reduction in the 2 groups was almost comparable.Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. (Source: Journal of Cataract and Refractive Surgery)

Risk Factors for Hyperopia and Myopia in Preschool Children: The Multi-Ethnic Pediatric Eye Disease and Baltimore Pediatric Eye Disease Studies

Ophthalmology — Fri, 19 Aug 2011 04:00:00 +0100

Conclusions: Children in specific racial or ethnic groups and age groups are at higher risk of having myopia and hyperopia. Cessation of maternal smoking during pregnancy may reduce the risk of hyperopia in these children. Given that both myopia and hyperopia are risk factors for the development of amblyopia and strabismus, these risk factors should be considered when developing guidelines for screening and intervention in preschool children.Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. (Source: Ophthalmology)

Risk Factors for Astigmatism in Preschool Children: The Multi-Ethnic Pediatric Eye Disease and Baltimore Pediatric Eye Disease Studies

Ophthalmology — Fri, 19 Aug 2011 04:00:00 +0100

Objective: To evaluate risk factors for astigmatism in a population-based sample of preschool children.Design: Population-based cross-sectional study.Participants: Population-based samples of 9970 children ages 6 to 72 months from Los Angeles County, California, and Baltimore, Maryland.Methods: A cross-sectional study of children participating in the Multiethnic Pediatric Eye Disease Study and the Baltimore Eye Disease Study was completed. Data were obtained by clinical examination or by in-person interview. Odds ratios and 95% confidence intervals (CI) were calculated to evaluate potential associations between clinical, behavioral, or demographic factors and astigmatism.Main Outcome Measures: Odds ratios (ORs) for various risk factors associated with astigmatism.Results: Participants with...

Risk Factors Associated with Childhood Strabismus: The Multi-Ethnic Pediatric Eye Disease and Baltimore Pediatric Eye Disease Studies

Ophthalmology — Fri, 19 Aug 2011 04:00:00 +0100

Objective: To investigate risk factors associated with esotropia or exotropia in infants and young children.Design: Population-based cross-sectional prevalence study.Participants: Population-based samples of 9970 children 6 to 72 months of age from California and Maryland.Methods: Participants were preschool African-American, Hispanic, and non-Hispanic white children participating in the Multi-Ethnic Pediatric Eye Disease Study and the Baltimore Eye Disease Study. Data were obtained by parental interview and ocular examination. Odd ratios and 95% confidence intervals were calculated to evaluate the association of demographic, behavioral, and clinical risk factors with esotropia and exotropia.Main Outcome Measures: Odds ratios (ORs) for various risk factors associated with esotropia or exot...

The use of propranolol in the treatment of periocular infantile haemangiomas: a review

British Journal of Ophthalmology — Thu, 18 Aug 2011 23:00:00 +0100

Infantile haemangiomas (IH) are benign vascular tumours characterised by their very rapid growth. Although usually innocuous, periocular IH can cause serious visual loss through induction of strabismic, deprivational or anisometropic astigmatism. Common treatment modalities for these IH include intralesional and systemic oral steroids; however, both treatments are associated with potentially severe side effects. A report was published recently demonstrating the impressive effect of propranolol in the treatment of IH. This exciting finding has provoked a paradigm shift in the management of this condition. So far little has been reported in the specific ophthalmologic literature, although case reports are emerging. This review gives an overview of the recent findings and includes the authors...

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Visual Acuity After Laser In Situ Keratomileusis to Correct High Astigmatism in Adults with Meridional Amblyopia

American Journal of Ophthalmology — Thu, 18 Aug 2011 04:00:00 +0100

Conclusions: In eyes with high myopic astigmatism and suboptimal preoperative BSCVA, laser in situ keratomileusis may result in a significant improvement in BSCVA. (Source: American Journal of Ophthalmology)

Survival of Mushroom Keratoplasty Performed in Corneas With Postinfectious Vascularized Scars

American Journal of Ophthalmology — Thu, 18 Aug 2011 04:00:00 +0100

Conclusions: Similarly to penetrating keratoplasty, microkeratome-assisted mushroom keratoplasty restores vision in eyes with postinfectious, full-thickness, central corneal scars. For these vascularized corneas at high risk for immunologic rejection, mushroom keratoplasty combines the visual and refractive advantages of large penetrating keratoplasty grafts with the high survival rate of small penetrating keratoplasty grafts. (Source: American Journal of Ophthalmology)

Prevalence of corneal astigmatism in patients having routine cataract surgery at a teaching hospital in the United Kingdom

Journal of Cataract and Refractive Surgery — Tue, 16 Aug 2011 04:00:00 +0100

Conclusions: Of patients attending for routine cataract surgery at a single center, 497 (40.41%) had more than 1.00 D of astigmatism. The results can help hospitals analyze the demand for and cost of using toric IOLs in patients with corneal astigmatism.Financial Disclosure: Neither author has a financial or proprietary interest in any material or method mentioned. (Source: Journal of Cataract and Refractive Surgery)

Transepithelial photorefractive keratectomy: Clinical results

Journal of Cataract and Refractive Surgery — Tue, 16 Aug 2011 04:00:00 +0100

Purpose: To assess the effectiveness, safety, and comfort of transepithelial photorefractive keratectomy (PRK) using the Amaris laser platform.Setting: Ophthalmic Consultants of Beirut, Jal-El-Dib, Metn, Lebanon.Design: Comparative case series.Methods: Myopic eyes with or without astigmatism were treated by transepithelial PRK (study group) and compared with variable-adjusted eyes treated by conventional PRK (control group) during which the epithelium was removed with alcohol. Postoperative pain, epithelial healing time, uncorrected distance visual acuity (UDVA), manifest refraction, and haze were analyzed.Results: The mean subjective postoperative pain score (out of 10, indicating worst pain) at 48 hours was 2.0 in the study group (50 eyes) and 4.5 in the control group (50 eyes) (P=.02). ...

Prevalence of uncorrected refractive errors among schoolchildren In northeast of Iran

Acta Ophthalmologica — Sat, 13 Aug 2011 09:31:14 +0100

Conclusion The results of this study indicated that the prevalence of UCREs in schoolchildren of Iran northeast were similar to the most places of the world . Vision screening and correction refractive errors can prevented from visual impairment in schoolchildren. (Source: Acta Ophthalmologica)

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Treatment and visual outcome in orbital and palpebral hemangiomas of infancy

Acta Ophthalmologica — Sat, 13 Aug 2011 09:30:47 +0100

Conclusion In our study 10 patients treated for visual impairment and available for long‐term follow‐up showed an excellent functional outcome with no residual amblyopia.In most cases,early intervention to address hemangioma‐related visual disturbances can lead to a good functional outcome. Intervention typically involves medical debulking of the hemangioma(using oral steroids)combined with the treatment of early amblyopia through selective patching and/or optical correction with refractive lenses. (Source: Acta Ophthalmologica)

A retrospective comparison of enhancement rate between low myopic astigmatism and high myopic astigmatism in patients treated with Femtosecond LASIK

Acta Ophthalmologica — Sat, 13 Aug 2011 09:30:27 +0100

Conclusion In patients with primary myopic astigmatism treated with FSBK, we found an statistically significant higher rate of enhancements in eyes with high myopic astigmatism ( 26.9 % ) than in eyes with low myopic astigmatism ( 6.48 % ). (Source: Acta Ophthalmologica)

Corneal biomechanical properties in myopic LASIK

Acta Ophthalmologica — Sat, 13 Aug 2011 09:30:20 +0100

Conclusion LASIK surgery decreases the corneal hysteresis and corneal resistance factor. The percentage decline of corneal hysteresis and corneal resistance factor after LASIK surgery was no different between the three groups based on the preoperative hysteresis. Although there is a correlation between variations of the CH and CRF, with microns of ablation and the refractive error corrected. (Source: Acta Ophthalmologica)

Characteristics of the anterior eye segment in patients affected by ehlers‐danlos‐syndrome

Acta Ophthalmologica — Sat, 13 Aug 2011 09:24:10 +0100

Conclusion Most of the clinical features described in association with EDS like thin and translucent sclera, keratoconus, lens luxation, retinal detachment or angoid streaks have not been observed in this study. Thinner cornea and perhaps more frequent anterior vitreal detachment were the only consistent pathological findings associated with the classical type of EDS which could be demonstrated in this study. (Source: Acta Ophthalmologica)

Accommodative IOL' s and Pseudo Accommodation

Acta Ophthalmologica — Sat, 13 Aug 2011 09:22:15 +0100

Conclusion Accommodative IOLs represent the future in the battle for the correction of presbyopia and restoration of near vision. (Source: Acta Ophthalmologica)

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Limitations of 'hard' Keratoprosthesis in Clinical Practice ‐ can 'soft' KPs lead the way out?

Acta Ophthalmologica — Sat, 13 Aug 2011 09:22:06 +0100

AbstractTwo winners have emerged among dozens of keratoprostheses (KPros) which have come and gone. The Osteo‐odonto‐keratoprosthesis is the device of choice for end stage inflammatory ocular surface disease associated with a dry eye, such as Stevens Johnson syndrome and ocular cicatricial pemphigoid. The Boston Type 1 keratoprosthesis is successful for wet blinking eyes and can be considered as an alternative to high risk keratoplasty in highly vascularised corneae or in multiple previous graft failure. The main advantage of these "hard" KPros is optical clarity. Whilst the field of view may be somewhat limited, there is no astigmatism and the optical surface is usually bare and clear. Hard KPros depend mostly on bio‐inertness as opposed to biointegration. Soft KPros have the theore...

Refractive and therapeutic applications of femtosecond laser corneal surgery

Acta Ophthalmologica — Sat, 13 Aug 2011 09:19:41 +0100

Conclusion Femtosecond laser technology may offer further promising approaches towards all‐FSL refractive surgery, and dissection procedures in the field of corneal transplantation (Source: Acta Ophthalmologica)

Microincision versus small-incision coaxial cataract surgery using different power modes for hard nuclear cataract

Journal of Cataract and Refractive Surgery — Fri, 12 Aug 2011 04:00:00 +0100

Purpose: To compare the efficacy of microincision and small-incision coaxial phacoemulsification in treating hard cataracts using different ultrasound power modes.Setting: Department of Ophthalmology, Seoul St. Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul, Korea.Design: Randomized clinical trial.Methods: Eyes with hard cataract were randomized to have an initial incision of 1.80 mm, 2.20 mm, or 2.75 mm. The eyes in each group were equally randomized to treatment with burst, pulse, or continuous mode. Ultrasound time (UST), mean cumulative dissipated energy (CDE), corrected distance visual acuity (CDVA), surgically induced corneal astigmatism, incisional and central corneal thickness (CCT), and endothelial cell counts were evaluated.Results: The study enrolled ...

Toric Intraocular Lens Outcome Using the Manufacturer's Prediction of Corneal Plane Equivalent Intraocular Lens Cylinder Power [Clinical Sciences]

Archives of Opthalmology — Sun, 07 Aug 2011 23:00:00 +0100

Conclusions Toric IOLs are a safe, predictable method of astigmatic correction. However, some remaining astigmatism is commonly present owing to the necessary nonzero astigmatic targets imposed by the steps between IOL cylinder powers, variability of axis, and power effects of surgical incisions as well as by underestimation of the corneal plane cylinder power of the IOLs by the manufacturer. (Source: Archives of Opthalmology)

Hereditary hyperferritinemia-cataract syndrome in two large multigenerational American families

Journal of AAPOS — Mon, 01 Aug 2011 04:00:00 +0100

Conclusions: Most clinical and genetic findings from these families are consistent with previous reports of HHCS. Astigmatism, previously not associated with HHCS, was present in the majority. Ferritin levels and age of cataract surgery varied among subjects with both FTL gene mutations, suggesting that phenotypic variability is modulated by other genetic or environmental factors. (Source: Journal of AAPOS)

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Accuracy and validity of IK4 handheld video keratometer measurements in children

Journal of AAPOS — Mon, 01 Aug 2011 04:00:00 +0100

In this study, accuracy of IK4 measurements with the use of standard toric surfaces was within 0.25 D. Validity measurements obtained in 860 children aged 3-7 years demonstrated slightly greater astigmatism measurements in the IK4 than in the Retinomax K+. Measurement success was 98% when the IK4 was used. The IK4 may prove to be clinically useful for screening children as young as 3 years of age at high risk for corneal astigmatism. (Source: Journal of AAPOS)

Comparison of the Ocular Response Analyzer and the Goldmann Applanation Tonometer for Measuring Intraocular Pressure after Deep Anterior Lamellar Keratoplasty [Cornea]

Investigative Ophthalmology — Thu, 28 Jul 2011 23:00:00 +0100

Conclusions. IOP readings by the ORA were significantly greater than those by the GAT, and CH and CRF play a more important role in post-DALK IOP readings by both GAT and ORA than other graft characteristics including curvature and central thickness. (Source: Investigative Ophthalmology)

Dynamic Changes in Ocular Zernike Aberrations and Tear Menisci Measured with a Wavefront Sensor and an Anterior Segment OCT [Cornea]

Investigative Ophthalmology — Thu, 28 Jul 2011 23:00:00 +0100

Conclusions. Systematic changes in some Zernike aberrations after blinking are associated with the changes in tear menisci and TFBUT. There was a substantial individual variation in dynamic changes of Zernike aberrations, suggesting the necessity to explore individual differences in tear quality and tear performance. Dynamic wavefront measurement combined with anterior segment optical coherence tomography could provide a useful tool to understand spatial and temporal processes of the tear film in clinical practice. (Source: Investigative Ophthalmology)

Influence of contact lens wear on the results of ultraviolet A/riboflavin cross-linking for progressive keratoconus.

The British Journal of Ophthalmology — Tue, 26 Jul 2011 23:00:00 +0100

Conclusion CL can be a confounding factor in interpreting the results of CXL: lens wear itself leads to improved topographic parameters. PMID: 21795286 [PubMed - as supplied by publisher] (Source: The British Journal of Ophthalmology)

August consultation #4

Journal of Cataract and Refractive Surgery — Sat, 23 Jul 2011 20:24:52 +0100

This patient has low IOP (usual with massive scleral ectasia) and high astigmatism. Astigmatism cannot be approached with a toric IOL because further scleral or progressive thinning can change the cylinder axis and the power. The cataract is hard, and fluidics must be used with caution due to the extreme weakened condition of the sclera. (Source: Journal of Cataract and Refractive Surgery)

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Phacoemulsification with corneal astigmatism correction with the use of a toric intraocular lens in a case of megalocornea

Journal of Cataract and Refractive Surgery — Sat, 23 Jul 2011 20:24:51 +0100

We report the case of a 49-year-old patient with megalocornea and coexisting corneal astigmatism. The corneal diameter in the right eye was 15.0 mm and in the left eye, 14.9 mm. In both eyes, a nuclear sclerotic cataract developed, with the tendency toward cortical mass swelling in the right eye. The aim of surgical treatment was to remove the cataract with simultaneous correction of corneal astigmatism by implanting an Acrysof toric intraocular lens (IOL). Intraocular lens stabilization was obtained by suturing it to an capsular tension ring (CTR) in the anterior chamber. The IOL–CTR complex was rotated into the lens capsule and aligned with the steep meridian of corneal astigmatism. The surgical technique provides a stable refractive and functional effect in patients with megalocornea ...

Cataract surgery with toric intraocular lens implantation in patients with high corneal astigmatism

Journal of Cataract and Refractive Surgery — Sat, 23 Jul 2011 20:24:45 +0100

Conclusion: Implantation of the toric IOL during cataract surgery was effective and safe in correcting high amounts of corneal astigmatism.Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. (Source: Journal of Cataract and Refractive Surgery)

Long-term corneal wavefront aberration variations after photorefractive keratectomy for myopia and myopic astigmatism

Journal of Cataract and Refractive Surgery — Thu, 21 Jul 2011 23:00:00 +0100

Purpose: To analyze the higher-order corneal wavefront aberration during an 8-year follow-up after photorefractive keratectomy (PRK).Setting: IRCCS Fondazione G.B. Bietti, Rome, Italy.Design: Case series.Methods: Patients having PRK using the Technolas 217C excimer laser platform were divided into 3 groups according to the preoperative refraction as follows: low myopia, high myopia, and astigmatism. The preoperative and 1-, 4-, 6-, and 8-year postoperative root mean square (RMS) values of coma, spherical aberration, and total higher-order aberrations (HOAs) were calculated with 3.5 mm and 6.0 mm simulated pupils. The mean preoperative and postoperative higher-order corneal wavefront aberration maps, point-spread functions, and radial modulation transfer functions (MTFs) were represented t...

Development and distribution of refractive error in children with Down's syndrome

British Journal of Ophthalmology — Sun, 17 Jul 2011 23:00:00 +0100

Conclusion The results provide further evidence of the failure in the emmetropisation process in children with DS. Change in spherical refractive error is minimal throughout childhood and early adulthood. The children show a specific development of oblique astigmatism that may be suggestive of a mechanical induction through eyelids. (Source: British Journal of Ophthalmology)

Combined 23-gauge microincisonal vitrectomy surgery and phacoemulsification with AcrySof toric intraocular lens implantation: a comparative study

Eye — Fri, 15 Jul 2011 07:00:00 +0100

Authors: D H Park, J P Shin & S Y Kim (Source: Eye)

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Corneal topographic changes after transconjunctival 23-gauge sutureless vitrectomy

International Ophthalmology — Wed, 13 Jul 2011 06:18:05 +0100

Abstract To evaluate the topographic changes of cornea after pars plana vitrectomy (PPV) with the 23-gauge- (23-G) transconjunctival sutureless vitrectomy (TSV) system within the first postoperative month. In this prospective study, corneal topographic changes were evaluated in 24 eyes of 24 patients who underwent PPV with the 23-G TSV system. All eyes underwent computer-assisted videokeratography using NAVIS (Nidek Advanced Vision Information System) software preoperatively and at the first day, first week, and first month postoperatively. The topographic parameters that were analyzed statistically were the average corneal power (ACP), corneal surface cylinder (CSC), surface asymmetry index (SAI), and surface regularity index (SRI). Mean induced astigmatism was estimated ...

Astigmatism is common

Modern Medicine — Tue, 12 Jul 2011 23:00:00 +0100

Nearly one-half of patients who require vision correction are significantly astigmatic in at least one eye, according to a study sponsored by Johnson & Johnson Vision Care and published in Eye & Contact Lens. (Source: Modern Medicine)

Oral Propranolol for Treatment of Periocular Infantile Hemangiomas [Clinical Sciences]

Archives of Opthalmology — Sun, 10 Jul 2011 23:00:00 +0100

Conclusions Oral propranolol for treatment of infantile hemangiomas was effective in all patients, with 33% reduction in astigmatism and 39% reduction in surface area. Vision equalized in all but 1 child, who receives ongoing amblyopia therapy. Our results suggest that early treatment with propranolol is remarkably effective in treating and preventing loss of visual acuity associated with periocular infantile hemangiomas. (Source: Archives of Opthalmology)

[Visual development and amblyopia prophylaxis in pediatric glaucoma.]

Der Ophthalmologe — Sat, 02 Jul 2011 23:00:00 +0100

Authors: Steffen H In children with congenital glaucoma the functional long-term result is often disappointing even if the intraocular pressure is well controlled. The reason for this discrepancy is attributed to amblyogenic factors responsible for interfering with normal visual development. These amblyogenic factors are corneal edema, irregular astigmatism and non-corrected ametropia as monocular causes. Binocular causes are anisometropia-induced suppression and strabismus. Full ametropic correction and a very early prophylaxis and treatment of amblyopia with a close follow-up are mandatory to reduce amblyogenic visual impairment in children with congenital glaucoma. PMID: 21725660 [PubMed - as supplied by publisher] (Source: Der Ophthalmologe)

Prevalence and risk factors for refractive errors and ocular biometry parameters in an elderly Asian population: the Singapore Longitudinal Aging Study (SLAS)

Eye — Fri, 01 Jul 2011 07:00:00 +0100

Authors: C S H Tan, Y H Chan, T Y Wong, G Gazzard, M Niti, T-P Ng & S M Saw (Source: Eye)

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Optical and biometric characteristics of anisomyopia in human adults

Ophthalmic and Physiological Optics — Thu, 30 Jun 2011 23:00:00 +0100

Conclusions: An optical cause for anisomyopia related to increased higher order aberrations is not supported by our data. Corneal shape changes and increased astigmatism in more myopic eyes may be a by‐product of the increased anterior chamber growth in these eyes; likewise, the increased positive spherical aberration in more myopic eyes may be a product of myopic eye growth. (Source: Ophthalmic and Physiological Optics)

The Effect of Corneal Anterior Surface Eccentricity on Astigmatism After Cataract Surgery.

Wed, 29 Jun 2011 23:00:00 +0100

CONCLUSION:Postoperative astigmatism was affected by various factors in cataract surgery. The greatest postoperative astigmatism is expected in corneas with high anterior eccentricity, high preoperative corneal astigmatism, and superior location of the main incision. PMID: 21707017 [PubMed - as supplied by publisher] (Source: Ophthalmic Surgery, Lasers and Imaging : the Official Journal of the International Society for Imaging in the Eye)

High prevalence of astigmatism in the forty to sixty‐four year old population of Shahroud, Iran

Clinical and Experimental Ophthalmology — Wed, 29 Jun 2011 23:00:00 +0100

Conclusions: In comparison with those studies conducted in Iran and other countries, the prevalence of astigmatism was higher in this study. Astigmatism was higher in men and age had an important role in astigmatism and its axis. The prevalence of against‐the‐rule and oblique astigmatism increased with age. (Source: Clinical and Experimental Ophthalmology)

High prevalence of astigmatism in the 40‐ to 64‐year‐old population of Shahroud, Iran

Clinical and Experimental Ophthalmology — Wed, 29 Jun 2011 23:00:00 +0100

Comparing the astigmatic outcome after paediatric cataract surgery with different incisions.

The British Journal of Ophthalmology — Mon, 27 Jun 2011 23:00:00 +0100

Conclusions Postoperative astigmatism after paediatric cataract surgery by clear corneal incision was lower compared with scleral incision. However, the difference was small and clinically insignificant. PMID: 21712360 [PubMed - as supplied by publisher] (Source: The British Journal of Ophthalmology)

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Results of higher power toric intraocular lens implantation

Journal of Cataract and Refractive Surgery — Wed, 22 Jun 2011 23:00:00 +0100

Conclusions: Coaxial microincision phacoemulsification with toric IOL safely and predictably reduced high corneal astigmatism and improved surgical outcomes. Thorough planning and precise execution are necessary.Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. (Source: Journal of Cataract and Refractive Surgery)

Reply

Journal of Cataract and Refractive Surgery — Wed, 22 Jun 2011 21:44:15 +0100

We broadly agree with Ramírez-Miranda et al. that combining ICRS with pIOLs is a safe and effective technique for keratoconus treatment. However, our preference is to avoid implanting toric pIOLs in these cases as this introduces another confounding factor if keratoconus advances and astigmatism changes. As we have reported, implanting a toric ICL is a good option if the keratoconus is stable. We prefer to correct astigmatism in keratoconic eyes using ICRS and in a second step, implanting a spherical pIOL with corneal incisions to correct any residual astigmatism. (Source: Journal of Cataract and Refractive Surgery)

July consultation #4

Journal of Cataract and Refractive Surgery — Wed, 22 Jun 2011 21:44:13 +0100

This patient has cataract in the left eye and a history of LASIK for very high myopia, with the irregular astigmatism and very oblate cornea typical after a LASIK procedure. No significant asymmetric astigmatism is seen on the Placido-based scans. Ectasia is in the differential diagnosis for late changes after LASIK and may be picked up better by elevation topography. In this patient, however, the vision change is clearly from the progressive cataract and cataract surgery is indicated for the falling visual function. (Source: Journal of Cataract and Refractive Surgery)

Clinical characterization of corneal ectasia after myopic laser in situ keratomileusis based on anterior corneal aberrations and internal astigmatism

Journal of Cataract and Refractive Surgery — Wed, 22 Jun 2011 21:44:08 +0100

Purpose: To evaluate and characterize the clinical features of corneal ectasia after myopic laser in situ keratomileusis (LASIK) considering internal astigmatism and corneal aberrations and their correlation with other clinical data.Setting: Vissum-Instituto de Oftalmológico de Alicante, Alicante, Spain.Design: Retrospective comparative case series.Methods: In this multicenter study, eyes were divided into 2 groups. The study group comprised eyes that had corneal ectasia after myopic LASIK. The control group comprised eyes that had successful LASIK to correct high myopia. The clinical outcomes were analyzed and compared. Internal astigmatism was calculated using vectorial analysis.Results: The study enrolled 91 eyes (48 study group; 40 control group) of 81 patients (age 18 to 67 years). U...

Vector analysis of astigmatic changes after cataract surgery with implantation of a new toric multifocal intraocular lens

Journal of Cataract and Refractive Surgery — Wed, 22 Jun 2011 21:44:04 +0100

Purpose: To analyze the astigmatic changes after cataract surgery with the implantation of a new toric multifocal intraocular lens (IOL) using the Alpins vector method.Setting: Vissum-Instituto de Oftalmológico de Alicante, Alicante, Spain.Design: Prospective case series.Methods: After cataract surgery with implantation of an AT Lisa 909M toric multifocal IOL, the visual, refractive, corneal topographic, internal astigmatism, defocus curves, and contrast sensitivity outcomes were evaluated over 6 months. Refractive astigmatic changes (target astigmatism [TIA]; surgically induced astigmatism [SIA]; difference vector; magnitude of error; flattening effect; torque) were analyzed using the Alpins vectorial method.Results: The study enrolled 23 eyes (12 patients). Postoperatively, there was a ...

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Prevalence of Corneal Astigmatism in Tohono O'odham Native American Children 6 Months to 8 Years of Age [Clinical and Epidemiologic Research]

Investigative Ophthalmology — Mon, 20 Jun 2011 23:00:00 +0100

Conclusions. The prevalence and mean amount of corneal astigmatism were higher than reported in non–Native American populations. Mean astigmatism increased from 1.43 D in 1-year-olds to nearly 2.00 D by school age. (Source: Investigative Ophthalmology)

Quality of Vision After Femtosecond Laser-Assisted Descemet Stripping Endothelial Keratoplasty and Penetrating Keratoplasty: A Randomized, Multicenter Clinical Trial

American Journal of Ophthalmology — Fri, 17 Jun 2011 04:00:00 +0100

Conclusions: Improvement of straylight and contrast sensitivity was significantly correlated with an improvement of BSCVA. Straylight and contrast sensitivity were improved significantly after FS DSEK and were comparable with those after PK, although BSCVA was slightly better in the PK group. (Source: American Journal of Ophthalmology)

Authors' response

British Journal of Ophthalmology — Wed, 15 Jun 2011 23:00:00 +0100

We thank the editors and Dr Gerald McGwin Jr for their interest and comments with regard to the statistical methodology used in our paper.1 Upon further statistical consultations, we concur that the study would indeed be best considered as a retrospective cohort study, as opposed to a case–control study. Our original intent was to perform frequency matching in comparing deep anterior lamellar keratoplasty (DALK) with penetrating keratoplasty (PK) groups, but this was only partially achievable, as previously stated in our paper, and as a result age, race and diagnosis were demographically profiled rather than identically matched. To re-evaluate the fundamental accuracy of our results, we therefore proceeded to perform ANCOVA analysis of refractive results and logistic regression of vi...

Scanning slit topography: Diagnostic boon in presumed unilateral Terrien's marginal degeneration

Contact Lens and Anterior Eye — Mon, 13 Jun 2011 04:00:00 +0100

Conclusion: Though the diagnosis of TMD is mainly clinical, scanning slit topography findings in TMD have not been described earlier and are useful in establishing the diagnosis of bilateral asymmetric TMD. (Source: Contact Lens and Anterior Eye)

Comparison of the effects of cylindrical correction with and without iris recognition technology in wavefront LASIK

Clinical and Experimental Ophthalmology — Sun, 12 Jun 2011 23:00:00 +0100

Conclusions: Wavefront LASIK for the treatment of astigmatism using IR technology was effective and accurate for the treatment of myopic astigmatism. (Source: Clinical and Experimental Ophthalmology)

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Comparison of the effects of cylindrical correction with and without iris recognition technology in wavefront laser‐assisted in situ keratomileusis

Clinical and Experimental Ophthalmology — Sun, 12 Jun 2011 23:00:00 +0100

Conclusions: Wavefront laser‐assisted in situ keratomileusis for the treatment of astigmatism using IR technology was effective and accurate for the treatment of myopic astigmatism. (Source: Clinical and Experimental Ophthalmology)

Boston ocular surface prosthesis: An Indian experience

Indian Journal of Ophthalmology — Fri, 10 Jun 2011 23:00:00 +0100

Conclusion: BOSP improves VA in patients who have irregular astigmatism as in ectasias and RGP failures and improves vision and symptoms in patients with SJS. (Source: Indian Journal of Ophthalmology)

Generalized beam quality factor of aberrated truncated Gaussian laser beams

Journal of the Optical Society of America A — Wed, 08 Jun 2011 23:45:37 +0100

We outline a theory for the calculation of the beam quality factor of an aberrated laser beam. We provide closed-form equations that show that the beam quality factor of an aberrated Gaussian beam depends on all primary aberrations except tilt, defocus, and x-astigmatism. The model is verified ... (Source: Journal of the Optical Society of America A)

Mean focal length of an aberrated lens

Journal of the Optical Society of America A — Wed, 08 Jun 2011 23:45:36 +0100

We outline an approach for the calculation of the mean focal length of an aberrated lens and provide closed-form solutions that show that the focal length of the lens is dependent on the presence of defocus, x-astigmatism, and spherical aberration. The results are applicable to Gaussian beams in ... (Source: Journal of the Optical Society of America A)