MedWorm.com provides a medical RSS filtering service. Over 5000 RSS medical sources are combined and output via different filters. This feed contains the latest headlines from journals and sites in the Ophthalmology category. Fri, 04 Jul 2008 08:57:29 +0100 http://www.medworm.com/rss/comments.php?id= http://journalofvision.org/8/9/1/icon.gif The primate visual system faces a difficult problem whenever it encounters the motion of an object moving over a patch of the retina. Objects typically contain a number of edges at different orientations and so a range of image velocities are generated within the receptive field of a neuron processing the object movement. It is still a mystery as to how these different velocities are combined into one unified and correct velocity. Neurons in area MT (V5) are considered to be the neural substrate for this motion integration process. Some MT neurons (pattern type) respond selectively to the correct global motion of an object, whereas others respond primarily to the individual components making up the pattern (component type). Recent findings from MT pattern cells tested with small patches of motion (N. J. Majaj, M. Carandini, & J. A. Movshon, 2007) have put further constraints on the possible mechanisms underlying MT pattern motion integration. We tested and refined an existing model of MT pattern neurons (J. A. Perrone, 2004) using these same small patch stimuli and found that it can accommodate these new findings. We also discovered that the speed of the test stimuli may have had an impact on the N. J. Majaj et al. (2007) results and that MT direction and speed tuning may be more closely linked than previously thought. (Source: Journal of Vision Articles) <p>&nbsp;</p><p><b><i>MedWorm Sponsored Message:</i></b> Find out how you can <a href="http://www.medworm.com/rss/medicalsponsorship.php" target="_self">get your message across here</a> by sponsoring this MedWorm news feed.</p> Journal of Vision Articles journals http://www.medworm.com/rss/comments.php?id=1574490 Thu, 03 Jul 2008 12:03:00 +0100 1574490 http://www.medicalnewstoday.com/articles/113813.php Bausch & Lomb announced that it has received approval from the Food and Drug Administration (FDA) to market the Crystalens HD™ in the United States. Crystalens accommodating intraocular lens (IOL) was first approved by the FDA in November 2003. The Crystalens HD is the fourth generation of the only FDA approved accommodating lens. The surface of the Crystalens HD has been shaped to enhance the depth of focus with a proprietary optical modification. (Source: Eye Health / Optometry News From Medical News Today) Eye Health / Optometry News From Medical News Today news http://www.medworm.com/rss/comments.php?id=1574157 Thu, 03 Jul 2008 10:00:00 +0100 1574157 http://www.medicinenet.com/guide.asp?s=rss&a=90760&k=Eyesight_General Title: Glaucoma Treatment Can Prevent BlindnessCategory: Health NewsCreated: 7/3/2008 2:00:00 AMLast Editorial Review: 7/3/2008 (Source: MedicineNet Eyesight General) MedicineNet Eyesight General consumer http://www.medworm.com/rss/comments.php?id=1574128 Thu, 03 Jul 2008 07:00:00 +0100 1574128 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00023.htm Page: A5DOI: 10.1097/OPX.0b013e31817fb487Authors: Adams, Tony (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560182 Wed, 02 Jul 2008 08:25:44 +0100 1560182 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00022.htm Page: 609DOI: 10.1097/OPX.0b013e318180df0a (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560181 Wed, 02 Jul 2008 08:25:44 +0100 1560181 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00021.htm Page: 608DOI: 10.1097/OPX.0b013e3181809cf7 (Source: Optometry and Vision Science) <p>&nbsp;</p><p><b><i>MedWorm Sponsored Message:</i></b> Find out how you can <a href="http://www.medworm.com/rss/medicalsponsorship.php" target="_self">get your message across here</a> by sponsoring this MedWorm news feed.</p> Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560180 Wed, 02 Jul 2008 08:25:44 +0100 1560180 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00020.htm Page: E605DOI: 10.1097/OPX.0b013e31817dc8b0Authors: Merabet, Lotfi B. OD, PhD; Wanye, Seth MD (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560179 Wed, 02 Jul 2008 08:25:44 +0100 1560179 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00019.htm Page: E593DOI: 10.1097/OPX.0b013e31817dba0bAuthors: Becken, Wolfgang PhD; Altheimer, Helmut Dipl-Ing; Esser, Gregor Dipl-Ing; Mueller, Werner PhD; Uttenweiler, Dietmar PhD (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560178 Wed, 02 Jul 2008 08:25:44 +0100 1560178 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00018.htm Page: E581DOI: 10.1097/OPX.0b013e31817db9f9Authors: Becken, Wolfgang PhD; Altheimer, Helmut; Esser, Gregor; Mueller, Werner PhD; Uttenweiler, Dietmar PhD (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560177 Wed, 02 Jul 2008 08:25:44 +0100 1560177 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00017.htm Page: 574DOI: 10.1097/OPX.0b013e31817dad7aAuthors: Court, Helen PhD; Greenland, Katy PhD; Margrain, Tom H. PhD (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560176 Wed, 02 Jul 2008 08:25:44 +0100 1560176 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00016.htm Page: 566DOI: 10.1097/OPX.0b013e31817dba1dAuthors: Moehnke, Terry D. OD, MS, FAAO; Sowka, Joseph OD, FAAO; Shallo-Hoffmann, Josephine PhD, FAAO; Hardigan, Patrick PhD; Woods, Albert D. MS, OD, FAAO (Source: Optometry and Vision Science) <p>&nbsp;</p><p><b><i>MedWorm Sponsored Message:</i></b> Find out how you can <a href="http://www.medworm.com/rss/medicalsponsorship.php" target="_self">get your message across here</a> by sponsoring this MedWorm news feed.</p> Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560175 Wed, 02 Jul 2008 08:25:44 +0100 1560175 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00015.htm Page: 559DOI: 10.1097/OPX.0b013e31817dad8bAuthors: Nehmad, Leon OD, MSW, FAAO; Madonna, Richard J. OD, MA, FAAO (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560174 Wed, 02 Jul 2008 08:25:44 +0100 1560174 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00014.htm Page: 547DOI: 10.1097/OPX.0b013e31817dba51Authors: Vaegan, PhD; Rahman, Anmar M. A. FRANZCO; Sanderson, Gordon F. BSc, FBOA (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560173 Wed, 02 Jul 2008 08:25:44 +0100 1560173 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00013.htm Page: 543DOI: 10.1097/OPX.0b013e31817dd06dAuthors: Loughman, James PhD, FAOI; Davison, Peter PhD; Flitcroft, Ian FRCOphth, DPhil (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560172 Wed, 02 Jul 2008 08:25:44 +0100 1560172 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00012.htm Page: 538DOI: 10.1097/OPX.0b013e31817dad6aAuthors: Konstantakopoulou, Evgenia MSc; Reeves, Barnaby C. MA, MSc, DPhil; Fenerty, Cecilia MD, FRCS, FRCOphth; Harper, Robert A. DPhil, DipGlauc, MCOptom (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560171 Wed, 02 Jul 2008 08:25:44 +0100 1560171 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00011.htm Page: 531DOI: 10.1097/OPX.0b013e31817dba2eAuthors: Keay, Lisa PhD; Edwards, Katie BAppSc(Optom); Dart, John MD; Stapleton, Fiona PhD, FAAO (Source: Optometry and Vision Science) <p>&nbsp;</p><p><b><i>MedWorm Sponsored Message:</i></b> Find out how you can <a href="http://www.medworm.com/rss/medicalsponsorship.php" target="_self">get your message across here</a> by sponsoring this MedWorm news feed.</p> Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560170 Wed, 02 Jul 2008 08:25:44 +0100 1560170 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00010.htm Page: 526DOI: 10.1097/OPX.0b013e31817dba7cAuthors: Boost, Maureen DPhil, FIBMS; Cho, Pauline PhD, FAAO; Lai, Sindy BSc(Hons); Sun, Wing-Man BSc(Hons) (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560169 Wed, 02 Jul 2008 08:25:44 +0100 1560169 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00009.htm Page: 520DOI: 10.1097/OPX.0b013e31817c92f3Authors: Santos, Livia MSc; Rodrigues, Diana BSc; Lira, Madalena MSc; Real Oliveira, M Elisabete C. D. PhD; Oliveira, Rosario PhD; Vilar, Eva Yebra-Pimente PhD; Azeredo, Joana PhD (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560168 Wed, 02 Jul 2008 08:25:44 +0100 1560168 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00008.htm Page: E512DOI: 10.1097/OPX.0b013e31817c930bAuthors: Dobson, Velma PhD, FAAO; Harvey, Erin M. PhD; Miller, Joseph M. MD, MPH; Clifford-Donaldson, Candice E. MPH (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560167 Wed, 02 Jul 2008 08:25:44 +0100 1560167 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00007.htm Page: E508DOI: 10.1097/OPX.0b013e31817c92dfAuthors: Pang, Yi PhD, OD, FAAO; Frantz, Kelly A. OD, FAAO (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560166 Wed, 02 Jul 2008 08:25:44 +0100 1560166 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00006.htm Page: 507DOI: 10.1097/OPX.0b013e31817dd3cfAuthors: Jacobsen, Carl H. (Source: Optometry and Vision Science) <p>&nbsp;</p><p><b><i>MedWorm Sponsored Message:</i></b> Find out how you can <a href="http://www.medworm.com/rss/medicalsponsorship.php" target="_self">get your message across here</a> by sponsoring this MedWorm news feed.</p> Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560165 Wed, 02 Jul 2008 08:25:44 +0100 1560165 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00005.htm Page: 505DOI: 10.1097/OPX.0b013e31817dd39bAuthors: Goss, David A. (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560164 Wed, 02 Jul 2008 08:25:44 +0100 1560164 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00004.htm Page: 504DOI: 10.1097/OPX.0b013e318180de89 (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560163 Wed, 02 Jul 2008 08:25:44 +0100 1560163 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00003.htm Page: 500DOI: 10.1097/OPX.0b013e318180de55 (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560162 Wed, 02 Jul 2008 08:25:44 +0100 1560162 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00002.htm Page: 499DOI: 10.1097/OPX.0b013e318180753cAuthors: Adams, Anthony J. (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560161 Wed, 02 Jul 2008 08:25:44 +0100 1560161 http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?tmpl=NoSidebarfile&db=PubMed&cmd=Retrieve&list_uids=18592249&dopt=Abstract <table border="0" width="100%"><tr><td align="left"/><td align="right"><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Display&dopt=PubMed_PubMed&from_uid=18592249">Related Articles</a></td></tr></table> <p><b>[Determination of toric intraocular lenses.]</b></p> <p>Ophthalmologe. 2008 Jul 2;</p> <p>Authors: Langenbucher A, Viestenz A, Szentm&#xE1;ry N, Behrens-Baumann W, Viestenz A</p> <p>BACKGROUND: In the last decades, toric posterior chamber lenses (TPCLs) for cataract surgery and phakic toric lenses (PTLs) for refractive surgery have become more and more popular for correcting high or excessive corneal astigmatism. The purpose of this article is to present a vergence-based calculation scheme for TPCLs and PTLs. METHODS: In Gaussian optics (in the paraxial space), spherocylindrical optical surfaces can be described in a mathematically equivalent formulation as vergences. There are dual notations: The standard notation is used for transforming vergences through a homogeneous optical medium, and the component notation is applied to add up the power of a refractive surface to the vergence. Both notations can be used interchangeably. For calculating TPCLs, the vergences in front of and behind the predicted pseudophakic lens position are determined and subtracted. For calculating PTLs, the anterior vergence at the predicted lens position is estimated for the preoperative and postoperative states, and the difference between the two yields the desired lens power. WORKING EXAMPLES: In the 1(st) example, the power of a thin TPCL is determined step by step by applying the presented calculation scheme, which was designed to be transferred directly to a simple computer program (e.g., Microsoft Excel). In the 2(nd) example, the postoperative refraction is estimated for a simulation in which a TPCL similar to that in example 1 is implanted in a slightly misaligned orientation. In a 3(rd) example, the power of a PTL is determined step by step using the above-mentioned calculation scheme. CONCLUSIONS: The presented calculation scheme allows determination of"thin" TPCLs or PTLs to achieve spherocylindrical target refraction with a cylinder axis at random or to predict the postoperative refraction for any toric lens implanted in any axis. The concept can be easily generalized to"thick" toric intraocular lenses if the geometric data and refraction index of the material are known.</p> <p>PMID: 18592249 [PubMed - as supplied by publisher]</p> (Source: Der Ophthalmologe) <p>&nbsp;</p><p><b><i>MedWorm Sponsored Message:</i></b> Find out how you can <a href="http://www.medworm.com/rss/medicalsponsorship.php" target="_self">get your message across here</a> by sponsoring this MedWorm news feed.</p> Der Ophthalmologe journals http://www.medworm.com/rss/comments.php?id=1564675 Wed, 02 Jul 2008 04:00:00 +0100 1564675 http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?tmpl=NoSidebarfile&db=PubMed&cmd=Retrieve&list_uids=18592250&dopt=Abstract <table border="0" width="100%"><tr><td align="left"/><td align="right"><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Display&dopt=PubMed_PubMed&from_uid=18592250">Related Articles</a></td></tr></table> <p><b>[Optic disc drusen.]</b></p> <p>Ophthalmologe. 2008 Jul 2;</p> <p>Authors: Schargus M, Gramer E</p> <p>Optic disc drusen (ODD) are an initially symptom-free, usually bilateral, progressive type of optic neuropathy with genetic disposition. We observed visual field loss (VFL) in 64% (49 of 77) of our patients. Vascular complications such as AION are common. Initially, papilledema is often diagnosed and the diagnosis of ODD is confirmed by means of ultrasound examination. We found an average time interval of 7 years between groups of patients with preperimetric stage and onset of VFL. We also observed more advanced stages of VFL, faster progression of visual field loss and greater visibility of ODD with increasing age. VFL frequently results in loss of driving ability according to driving permission regulations. The aim of our therapy concept is to reduce intraocular pressure (IOP). In a pilot study we found that patients who underwent IOP-lowering therapy showed significantly less progression of VFL than patients who did not undergo this therapy. The present article summarizes current knowledge on epidemiology, pathogenesis, clinical presentation, diagnostics and therapy of optic disc drusen.</p> <p>PMID: 18592250 [PubMed - as supplied by publisher]</p> (Source: Der Ophthalmologe) Der Ophthalmologe journals http://www.medworm.com/rss/comments.php?id=1564674 Wed, 02 Jul 2008 04:00:00 +0100 1564674 http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?tmpl=NoSidebarfile&db=PubMed&cmd=Retrieve&list_uids=18592251&dopt=Abstract <table border="0" width="100%"><tr><td align="left"/><td align="right"><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Display&dopt=PubMed_PubMed&from_uid=18592251">Related Articles</a></td></tr></table> <p><b>[Experiences with a centralised national service for autologous serum eyedrops in England.]</b></p> <p>Ophthalmologe. 2008 Jul 2;</p> <p>Authors: Maclennan S, Hartwig D, Geerling G</p> <p>The majority of patients with dry eye syndromes respond to conventional treatment aimed at optimising the ocular surface environment. There are some, however, who do not respond adequately to conventional lubricants. The first description of the use of autologous serum as a nutrient tears substitute was published more than 20 years ago. In 1997, NHS Blood and Transplant (NHSBT) developed a reliable and reproducible method for the production of eyedrops derived from autologous serum according to GMP Guidelines. The current cost of a batch of eyedrops (i. e. the product from one donation episode) is approximately 1300 GBP - this covers costs of collection, processing, testing and distribution. One "batch" of eyedrops will last for approximately 5 months if a bottle a day is used. A 6 month shelf life is put on the product and patients keep them in their domestic freezer.</p> <p>PMID: 18592251 [PubMed - as supplied by publisher]</p> (Source: Der Ophthalmologe) Der Ophthalmologe journals http://www.medworm.com/rss/comments.php?id=1564673 Wed, 02 Jul 2008 04:00:00 +0100 1564673 http://media.libsyn.com/media/mtrope/ASFH2008-07-01.mp3 Guest: John P. Berdahl, M.D.Duke University Eye CenterDurham, North Carolina (Source: As Seen From Here) As Seen From Here podcasts http://www.medworm.com/rss/comments.php?id=1559045 Wed, 02 Jul 2008 00:00:00 +0100 1559045 http://www.optvissci.com/pt/re/ovs/abstract.00006324-200807000-00001.htm DOI: 10.1097/OPX.0b013e31817f3cf0 (Source: Optometry and Vision Science) Optometry and Vision Science journals http://www.medworm.com/rss/comments.php?id=1560160 Tue, 01 Jul 2008 23:42:24 +0100 1560160 http://www.medicalnewstoday.com/articles/113418.php This month the General Optical Council (GOC) celebrates its 50th birthday. On 7 July 2008 it will be 50 years to the day since the beginning of statutory regulation for optometrists and dispensing opticians, as created by the Opticians Act. To mark the golden anniversary, Council members past and present, along with optical bodies, charities, and other partner organisations, will gather in London on 2 July to commemorate the Council's achievements. (Source: Eye Health / Optometry News From Medical News Today) <p>&nbsp;</p><p><b><i>MedWorm Sponsored Message:</i></b> Find out how you can <a href="http://www.medworm.com/rss/medicalsponsorship.php" target="_self">get your message across here</a> by sponsoring this MedWorm news feed.</p> Eye Health / Optometry News From Medical News Today news http://www.medworm.com/rss/comments.php?id=1558436 Tue, 01 Jul 2008 10:00:00 +0100 1558436 http://www.medicinenet.com/guide.asp?s=rss&a=90696&k=Eyesight_General Title: Health Tip: Wear Eye ProtectionCategory: Health NewsCreated: 7/1/2008 2:00:00 AMLast Editorial Review: 7/1/2008 (Source: MedicineNet Eyesight General) MedicineNet Eyesight General consumer http://www.medworm.com/rss/comments.php?id=1558395 Tue, 01 Jul 2008 07:00:00 +0100 1558395 http://journalofvision.org/8/8/13/icon.gif Numerous studies indicate that perceiving global object motion results from the integration of local component motions across space and time. Less attention has been paid to the issue of motion selection, necessary to avoid spurious associations of component motions belonging to different objects and to solve the so-called “superposition catastrophe problem” (F. Rosenblatt, 1961). We address this issue using outlines of geometrical shapes moving behind apertures that concealed their vertices such that recovering their global motion requires the selection and integration of some, but not all, component motions. Depending on which local motions are selected for motion integration, these stimuli yield the perception of either expansion/contraction, of global translation, or of segments moving independently. We show that the selection process depends on local and global stimulus parameters, including the local direction of figure's line-endings or the spatial configuration of component motions. In contrast, motion selection depends less on the width—i.e., spatial frequency content—or polarity of the edges. Finally, synchronous temporal modulation of component motions in the gamma range has little effect on motion selection. These results indicate that selecting component motions for motion integration is primarily determined by form constraints. As a consequence, current models assuming that mutually consistent component motions are bounded in a velocity space-lacking spatial organization should be revised to account for the present data. Alternately, interactions between visual areas selectively processing form and motion could be introduced in order to account for the perceptual binding of moving objects. (Source: Journal of Vision Articles) Journal of Vision Articles journals http://www.medworm.com/rss/comments.php?id=1555808 Tue, 01 Jul 2008 00:04:00 +0100 1555808 http://www.medscape.com/viewarticle/575586?src=rss Increased use of improvised blast devices is causing more blast/eye orbital injuries worldwide. What are the vital strategies to reduce this increasing burden? Expert Review of Ophthalmology (Source: Medscape Ophthalmology Headlines) Medscape Ophthalmology Headlines info http://www.medworm.com/rss/comments.php?id=1556564 Mon, 30 Jun 2008 21:19:52 +0100 1556564 http://journalofvision.org/8/7/16/icon.gif The motion correspondence problem, one of the classical examples of perceptual organization, addresses the question of how elements are grouped across space and time. Here, we investigate motion correspondences using a new feature attribution technique. We present, for example, a grating of four lines followed by a spatially shifted grating of three lines. Observers perceive a contracting grating. To study individual line-to-line correspondences, (1) we add, as a “perceptual marker,” a small Vernier offset to one line of the first grating and (2) determine to which line of the second grating this offset is attributed. This procedure allows us inferring motion correspondences because this kind of feature attribution follows perceptual grouping in dynamic displays (H. Öğmen, T. U. Otto, & M. H. Herzog, 2006). Our results show that feature attribution between outer lines of the grating is more consistent than between inner lines. We interpret our results according to the principle of the “primacy of bounding contours,” which states that bounding contours of an object provide a framework for element correspondences that is more important than the internal structure of that object. (Source: Journal of Vision Articles) Journal of Vision Articles journals http://www.medworm.com/rss/comments.php?id=1556088 Mon, 30 Jun 2008 04:00:00 +0100 1556088 http://journalofvision.org/8/7/15/icon.gif Processing of global contours requires integration of local visual information. To study the involvement of different cortical areas and the temporal characteristics of their activity in such integration, we recorded neuromagnetic responses to arrays of Gabor patches in which a proportion of the patches was oriented either tangentially or radially with respect to a global circular contour; arrays with random patch orientations served as control stimuli. The first responses at 60–80 ms around the calcarine sulcus were similar to all stimuli. Starting from 130 ms, responses to the tangential contours differed significantly from responses to control stimuli, and the difference reached its maximum at 275 ms. The most pronounced differences emerged around the parieto-occipital sulcus, precuneus, cuneus, and superior and middle occipital gyri. This pattern of cortical activity was similar irrespective of whether the local elements were radial or tangential to the circle; however, the differences were smaller for the radial contours and tended to start 20–30 ms later. Correspondingly, discrimination reaction times were shortest for the contours consisting of tangential elements. These results demonstrate two spatially and temporally distinct stages of visual cortical processing, the first one limited to local features and the second one integrating information at a more global level. (Source: Journal of Vision Articles) <p>&nbsp;</p><p><b><i>MedWorm Sponsored Message:</i></b> Find out how you can <a href="http://www.medworm.com/rss/medicalsponsorship.php" target="_self">get your message across here</a> by sponsoring this MedWorm news feed.</p> Journal of Vision Articles journals http://www.medworm.com/rss/comments.php?id=1556087 Mon, 30 Jun 2008 04:00:00 +0100 1556087 http://journalofvision.org/8/8/11/icon.gif Information in the cortex is thought to be represented by the joint activity of neurons. Here we describe how fundamental questions about neural representation can be cast in terms of the topological structure of population activity. A new method, based on the concept of persistent homology, is introduced and applied to the study of population activity in primary visual cortex (V1). We found that the topological structure of activity patterns when the cortex is spontaneously active is similar to those evoked by natural image stimulation and consistent with the topology of a two sphere. We discuss how this structure could emerge from the functional organization of orientation and spatial frequency maps and their mutual relationship. Our findings extend prior results on the relationship between spontaneous and evoked activity in V1 and illustrates how computational topology can help tackle elementary questions about the representation of information in the nervous system. (Source: Journal of Vision Articles) Journal of Vision Articles journals http://www.medworm.com/rss/comments.php?id=1555810 Mon, 30 Jun 2008 04:00:00 +0100 1555810 http://journalofvision.org/8/8/12/icon.jpg Vernier alignment thresholds are strongly compromised when the vernier is embedded in an array of equal-length flanking lines. Here, we show that these contextual interactions can be diminished by giving the flanks the opposite contrast polarity, e.g., white flanks surrounding a black vernier. Similar results are obtained for red verniers and equiluminant green flanks and when vernier and flanks have different binocular disparity. Using special flank configurations, we can eliminate location uncertainty as an important factor for this kind of contextual interactions. We interpret these results as evidence that perceptual grouping of the vernier and the flanks plays an important role in the vernier threshold elevation caused by contextual flanks. (Source: Journal of Vision Articles) Journal of Vision Articles journals http://www.medworm.com/rss/comments.php?id=1555809 Mon, 30 Jun 2008 04:00:00 +0100 1555809 http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?tmpl=NoSidebarfile&db=PubMed&cmd=Retrieve&list_uids=18587585&dopt=Abstract <table border="0" width="100%"><tr><td align="left"/><td align="right"><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Display&dopt=PubMed_PubMed&from_uid=18587585">Related Articles</a></td></tr></table> <p><b>[Legal regulations to produce serum eye drops : When is it necessary, and how can it be obtained?]</b></p> <p>Ophthalmologe. 2008 Jun 29;</p> <p>Authors: Geerling G, Grus F, Seitz B, Hartwig D, Schirra F</p> <p>According to European Union and German legislation, the production of medicines such as eye drops from autologous serum requires a license from an appropriate authority. However, an exemption is granted to medical doctors who produce and apply medications under their immediate responsibility.If doctors do not actually produce such medications themselves, they must select appropriate personnel to do so. These individuals have to be sufficiently qualified and reliable and must be carefully instructed on the standard quality and manufacturing procedures, although the doctors are responsible for controlling the production and quality of the final product. The treating physicians are also responsible for the appropriate application of the produced medications.To dispense medication to patients without an appropriate license is considered a criminal offense. We describe how two German hospitals have established the production of serum eye drops in full compliance with legal regulations.</p> <p>PMID: 18587585 [PubMed - as supplied by publisher]</p> (Source: Der Ophthalmologe) Der Ophthalmologe journals http://www.medworm.com/rss/comments.php?id=1561640 Sun, 29 Jun 2008 04:00:00 +0100 1561640 http://www.medicalnewstoday.com/articles/113183.php ACUVUE® OASYS™ Brand Contact Lenses for ASTIGMATISM, became the fourth contact lens in the ACUVUE® family of products to receive the AOA Seal of Acceptance for Ultraviolet Absorbing Contact Lenses from the American Optometric Association's Commission on Ophthalmic Standards. The announcement was made in Seattle at Optometry's Meeting™, the annual meeting of the American Optometric Association (AOA). (Source: Eye Health / Optometry News From Medical News Today) Eye Health / Optometry News From Medical News Today news http://www.medworm.com/rss/comments.php?id=1548771 Sat, 28 Jun 2008 09:00:00 +0100 1548771 http://www.springerlink.com/content/l1268027734923u7/ Abstract&nbsp;&nbsp; Purpose To determine the relationship between central corneal thickness (CCT) and myopia among Saudi adults. Methods In a prospective study, the CCT of 982 myopic eyes and 158 emmetropic eyes as a control group was measured using ultrasound pachymetry at the Eye Consultants Center, Riyadh, Saudi Arabia. Result The mean myopic spherical equivalent (SE) was −3.7 ± 2.12 D, range −0.25 to −15.0 D.The mean CCT of the myopic group was 543.8 ± 35.40 μm, while for the emmetropic group it was 545.7 ± 27.6 μm. The difference in mean CCT between the two groups was statistically insignificant (P&nbsp;=&nbsp;0.5). There was no correlation between CCT and the degree of myopic spherical equivalent (r&nbsp;=&nbsp;−0.014, P&nbsp;=&nbsp;0.939). Conclusion This clinical study showed that there was no difference in CCT between emmetropic and myopic eyes. CCT did not correlate with the degree of myopia. It seems that the central cornea is not significantly involved in the process of myopic progression. Content Type Journal ArticleCategory Original PaperDOI 10.1007/s10792-008-9249-8Authors Hani S. Al-Mezaine, King Saud University Department of Ophthalmology, College of Medicine PO BOX 230387 Riyadh 11321 Kingdom of Saudi ArabiaSaleh Al-Obeidan, King Saud University Department of Ophthalmology, College of Medicine PO BOX 230387 Riyadh 11321 Kingdom of Saudi ArabiaDustan Kangave, King Saud University Diabetes Research Center, College of Medicine Riyadh Saudi ArabiaAbdulkareem Sadaawy, The Eye Consultants Center Riyadh Saudi ArabiaTaher A. Wehaib, The Eye Consultants Center Riyadh Saudi ArabiaSaleh A. Al-Amro, King Saud University Department of Ophthalmology, College of Medicine PO BOX 230387 Riyadh 11321 Kingdom of Saudi Arabia Journal International OphthalmologyOnline ISSN 1573-2630Print ISSN 0165-5701 (Source: International Ophthalmology) <p>&nbsp;</p><p><b><i>MedWorm Sponsored Message:</i></b> Find out how you can <a href="http://www.medworm.com/rss/medicalsponsorship.php" target="_self">get your message across here</a> by sponsoring this MedWorm news feed.</p> International Ophthalmology journals http://www.medworm.com/rss/comments.php?id=1559919 Sat, 28 Jun 2008 08:05:26 +0100 1559919 http://www.springerlink.com/content/603011l7572032nt/ Abstract Purpose&nbsp;&nbsp;To assess the efficacy and safety of a heavy silicone oil (Densiron 68®), a mixture of perfluorohexyloctane (F6H8) with silicone oil as temporary internal tamponade in selected retinal detachments treated with large inferior retinectomy. Methods&nbsp;&nbsp;Complicated retinal detachments with severe posterior and anterior proliferative vitreoretinopathy (PVR) were included in this study. In all cases, a large inferior retinectomy involving the inferior quadrants was performed. Densiron 68® was injected at the end of surgery after perfluorocarbon injection. A minimum follow-up of 6 months was required in order to be included in this retrospective study. Results&nbsp;&nbsp;Twenty-seven patients were operated on with a mean follow-up of 57.5&nbsp;weeks. Twenty-three patients presented a posterior PVR &gt; CP6 and 26 patients an anterior PVR &gt; CA5. Heavy silicone oil was removed in 19 patients after a mean follow-up of 14&nbsp;weeks. At the 4-week follow-up visit, only one retinectomy was reopened by a recurrent inferior retinal detachment with PVR CP3. Finally, anatomical success was achieved in 25 of the 27 patients (92.5%) after Densiron 68® removal at the last follow-up. The main adverse effect was inflammatory reaction with fibrin accumulation in the anterior chamber (40.7%). Conclusion&nbsp;&nbsp;Densiron 68® appeared to be an efficient endotamponade agent in selected retinal detachments treated with large inferior retinectomy. It avoids fluid accumulation under the inferior retina and seems to limit the rate of inferior retinectomy reopening. Content Type Journal ArticleCategory Retinal DisordersDOI 10.1007/s00417-008-0876-6Authors Sylvain Auriol, Hopital Rangueil Department of Ophthalmology TSA 50032 31059 Toulouse Cedex 9 FranceVéronique Pagot-Mathis, Hopital Rangueil Department of Ophthalmology TSA 50032 31059 Toulouse Cedex 9 FranceLaurence Mahieu, Hopital Rangueil Department of Ophthalmology TSA 50032 31059 Toulouse Cedex 9 FranceClaudia Lemoine, Hopital Rangueil Department of Ophthalmology TSA 50032 31059 Toulouse Cedex 9 FranceAndré Mathis, Hopital Rangueil Department of Ophthalmology TSA 50032 31059 Toulouse Cedex 9 France Journal Graefe's Archive for Clinical and Experimental OphthalmologyOnline ISSN 1435-702XPrint ISSN 0721-832X (Source: Graefe's Archive for Clinical and Experimental Ophthalmology) Graefe's Archive for Clinical and Experimental Ophthalmology journals http://www.medworm.com/rss/comments.php?id=1559851 Sat, 28 Jun 2008 07:59:06 +0100 1559851 http://www.springerlink.com/content/mq26642r27270186/ Abstract Purpose&nbsp;&nbsp;Primary objective was to investigate clinical characteristics of nonarteritic anterior ischemic optic neuropathy (NA-AION) in three families; secondarily, to test these families for a previously detected mitochondrial mutation in a pedigree with familial NA-AION. Methods&nbsp;&nbsp;Study comprised three families where more than one member developed NA-AION. All patients with NA-AION had a detailed ophthalmic, medical and family history, and comprehensive ophthalmic evaluation at initial visit and on follow-up. One patient from family 1, one from family 2, 41 non-familial NA-AION patients, 97 control subjects and 1,488 patients with suspected Leber hereditary optic neuropathy (LHON) were tested for the presence of mitochondrial mutation (G4132A) in a previously reported genetic study of family 3. Results&nbsp;&nbsp;Familial NA-AION was found in seven individuals of family 1, four of family 2 and six of family 3. Symptoms, signs and clinical findings of familial NA-AION were similar to classical NA-AION, with two exceptions: familial NA-AION had an earlier onset (47.3 + 8.6&nbsp;years versus 60.1 + 13.6&nbsp;years) and a higher frequency of bilateral disease. The G4132A mitochondrial variant was not detected outside family 3. None of the three major mutations associated with LHON (G3460A, G11778A, T14484C) was found among Familial NA-AION patients. Conclusions&nbsp;&nbsp;The only difference in clinical features between familial NA-AION and classical NA-AION is that the former has an earlier onset and a higher frequency of bilateral disease. The G4132A mutation is not commonly associated with familial NA-AION, and was not detected in patients with non-familial NA-AION. The role of hereditary factors in familial NA-AION remains largely unknown. Content Type Journal ArticleCategory Neuro-ophthalmologyDOI 10.1007/s00417-008-0853-0Authors Sohan Singh Hayreh, University of Iowa Hospitals & Clinics Department of Ophthalmology and Visual Sciences 200 Hawkins Drive Iowa City IA 52242–1091 USAJohn H. Fingert, University of Iowa Hospitals & Clinics Department of Ophthalmology and Visual Sciences 200 Hawkins Drive Iowa City IA 52242–1091 USAEdwin Stone, University of Iowa Hospitals & Clinics Department of Ophthalmology and Visual Sciences 200 Hawkins Drive Iowa City IA 52242–1091 USADaniel M. Jacobson, Marshfield Clinic Departments of Neurology and Ophthalmology Marshfield WI USA Journal Graefe's Archive for Clinical and Experimental OphthalmologyOnline ISSN 1435-702XPrint ISSN 0721-832X (Source: Graefe's Archive for Clinical and Experimental Ophthalmology) Graefe's Archive for Clinical and Experimental Ophthalmology journals http://www.medworm.com/rss/comments.php?id=1559852 Sat, 28 Jun 2008 07:59:05 +0100 1559852 http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?tmpl=NoSidebarfile&db=PubMed&cmd=Retrieve&list_uids=18590924&dopt=Abstract <table border="0" width="100%"><tr><td align="left"/><td align="right"><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Display&dopt=PubMed_PubMed&from_uid=18590924">Related Articles</a></td></tr></table> <p><b>Rod a-wave analysis using high intensity flashes adds information on rod system function in 25% of clinical ERG recordings.</b></p> <p>Vision Res. 2008 Jun 28;</p> <p>Authors: Nilsson J, Wright T, Westall CA</p> <p>PURPOSE: To investigate whether rod a-wave analysis using high intensity flashes adds information above that obtained with standard ERG. METHODS: A total of 2396 eyes were recorded. Patient age was 2.4 months-84.6 years. RESULTS: A-wave analysis of high intensity flashes provided additional information on rod system function in 25% of eyes recorded, most importantly in subjects with midretinal disease and artificially reduced rod responses. High intensity flashes also provided measurable responses for longitudinal monitoring in rod dystrophies with non-recordable rod ERGs. CONCLUSIONS: Clinical ERG testing would benefit greatly from adding high intensity flashes to its standard testing conditions.</p> <p>PMID: 18590924 [PubMed - as supplied by publisher]</p> (Source: Vision Research) Vision Research journals http://www.medworm.com/rss/comments.php?id=1563924 Sat, 28 Jun 2008 04:00:00 +0100 1563924 http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?tmpl=NoSidebarfile&db=PubMed&cmd=Retrieve&list_uids=18590925&dopt=Abstract <table border="0" width="100%"><tr><td align="left"/><td align="right"><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Display&dopt=PubMed_PubMed&from_uid=18590925">Related Articles</a></td></tr></table> <p><b>Evolution of vertebrate visual pigments.</b></p> <p>Vision Res. 2008 Jun 28;</p> <p>Authors: Bowmaker JK</p> <p>The visual pigments of vertebrates evolved about 500 million years ago, before the major evolutionary step of the development of jaws. Four spectrally distinct classes of cone opsin evolved through gene duplication, followed by the rod opsin class that arose from the duplication of the middle-wave-sensitive cone opsin. All four cone classes are present in many extant teleost fish, reptiles and birds, but one or more classes have been lost in primitive fish, amphibians and mammals. Gene duplication within the cone classes, especially in teleosts, has resulted in multiple opsins being available, both temporally and spatially, during development.</p> <p>PMID: 18590925 [PubMed - as supplied by publisher]</p> (Source: Vision Research) Vision Research journals http://www.medworm.com/rss/comments.php?id=1563923 Sat, 28 Jun 2008 04:00:00 +0100 1563923 http://www.medscape.com/viewarticle/575573?src=rss In vivo confocal microscopy (IVCM) reveals characteristic corneal and conjunctival anatomy in vivo at the cellular level. Learn more about the broad array of clinical applications for IVCM. Expert Review of Ophthalmology (Source: Medscape Ophthalmology Headlines) <p>&nbsp;</p><p><b><i>MedWorm Sponsored Message:</i></b> Find out how you can <a href="http://www.medworm.com/rss/medicalsponsorship.php" target="_self">get your message across here</a> by sponsoring this MedWorm news feed.</p> Medscape Ophthalmology Headlines info http://www.medworm.com/rss/comments.php?id=1552044 Fri, 27 Jun 2008 18:47:26 +0100 1552044 http://www.medicalnewstoday.com/articles/112954.php Lux Biosciences announced the completion of enrollment for the landmark LUMINATE (Luveniq Uveitis Multicenter Investigation of a New Approach to TrEatment) pivotal clinical trial program, which is investigating the use of LUVENIQ™ (voclosporin; previously designated LX211) as a corticosteroid-sparing agent for the treatment of patients with non-infectious uveitis. (Source: Eye Health / Optometry News From Medical News Today) Eye Health / Optometry News From Medical News Today news http://www.medworm.com/rss/comments.php?id=1548773 Fri, 27 Jun 2008 09:00:00 +0100 1548773 http://www.medicalnewstoday.com/articles/112960.php Alimera Sciences, Inc., a privately held biopharmaceutical company that specializes in the research, development and commercialization of prescription ophthalmic pharmaceuticals, reported the interim month three safety and efficacy results from the first human pharmacokinetic (PK) study of Medidur(TM) FA, which Alimera Sciences intends to market under the tradename Iluvien(TM), if approved by the U.S. Food and Drug Administration. (Source: Eye Health / Optometry News From Medical News Today) Eye Health / Optometry News From Medical News Today news http://www.medworm.com/rss/comments.php?id=1548772 Fri, 27 Jun 2008 09:00:00 +0100 1548772 http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?tmpl=NoSidebarfile&db=PubMed&cmd=Retrieve&list_uids=18590754&dopt=Abstract <table border="0" width="100%"><tr><td align="left"/><td align="right"><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Display&dopt=PubMed_PubMed&from_uid=18590754">Related Articles</a></td></tr></table> <p><b>How spatial and feature-based attention affect the gain and tuning of population responses.</b></p> <p>Vision Res. 2008 Jun 27;</p> <p>Authors: Ling S, Liu T, Carrasco M</p> <p>How does attention optimize our visual system for the task at hand? Two mechanisms have been proposed for how attention improves signal processing: gain and tuning. To distinguish between these two mechanisms we use the equivalent-noise paradigm, which measures performance as a function of external noise. In the present study we explored how spatial and feature-based attention affect performance by assessing their threshold-vs-noise (TvN) curves with regard to the signature behavioral effects of gain and tuning. Furthermore, we link our psychophysical results to neurophysiology by implementing a simple, biologically plausible model to show that attention affects the gain and tuning of population responses differentially, depending on the type of attention being deployed: Whereas spatial attention operates by boosting the gain of the population response, feature-based attention operates by both boosting the gain and sharpening the tuning of the population response.</p> <p>PMID: 18590754 [PubMed - as supplied by publisher]</p> (Source: Vision Research) Vision Research journals http://www.medworm.com/rss/comments.php?id=1563925 Fri, 27 Jun 2008 04:00:00 +0100 1563925 http://dx.doi.org/10.1038/eye.2008.187 Effect of room temperature and cooled intraocular irrigating solution on the cornea and anterior segment inflammation after phacoemulsification: a randomized clinical trial Eye advance online publication, June 27, 2008. doi:10.1038/eye.2008.187 Authors: M R Praveen, A R Vasavada, R Shah & V A Vasavada (Source: Eye) Eye journals http://www.medworm.com/rss/comments.php?id=1548744 Fri, 27 Jun 2008 04:00:00 +0100 1548744