Ophthalmology

OBJECTIVE: To assess the impact of laser peripheral iridotomy (LPI) on forward-scatter of light and subjective visual symptoms and to identify LPI parameters influencing these phenomena. DESIGN: Cohort study derived from a randomized trial, using an external control group. PARTICIPANTS: Chinese subjects initially aged 50 or older and 70 years or younger with bilateral narrow angles undergoing LPI in 1 eye selected at random, and age- and gender-matched controls. METHODS: Eighteen months after laser, LPI-treated subjects underwent digital iris photography and photogrammetry to characterize the size and location of the LPI, Lens Opacity Classification System III cataract grading, and measurement of retinal straylight (C-Quant; OCULUS, Wetzlar, Germany) in the treated and untreated eyes and completed a visual symptoms questionnaire. Controls answered the questionnaire and underwent straylight measurement and (in a random one-sixth sample) cataract grading. MAIN OUTCOME MEASURES: Retina...

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Introduction-Vertebral artery is Sonographically evaluated in terms of its Diameter, blood flow volume and other characteristics in cases of vertebrobasilar insufficiency. Anatomical variants in its origin and course are therefore important for a proper evaluation. Aim And Methodology-This study aimed to study Sonoanatomy of Vertebral artery and its variations on Color Doppler Ultrasonography in Normal Healthy Individuals aged over 35 Years enrolled as Controls and subjects of the same age group with a Clinical Diagnosis of Cervical Spondylitis who were called Cases. This Observational Comparative study included 120 individuals ( 60 cases and 60 controls) , selected by Convenience sampling at a the Radiology Department of a Medical College in Central India. Observations- Majority of individuals in both groups were in the age group 41-50 years, with the mean age 43 years. Anatomic origin of the vertebral artery from subclavian artery could sonographically be visualised more commonly ...

Title: The Burden of Glaucoma on Canadian Patients: Gaps in Understanding the Disease and its Treatments
Authors: Chad Andrews and Jennifer Pereira
Category: Global and Public Health Ophthalmology
Conference: Canadian Opthalmological Society Annual Conference (June 2020)

Purpose: Affecting over 400,000 Canadians, glaucoma is a disease of the optic nerve and one of the leading causes of blindness in North America. This study seeks to better understand the daily struggles of living with glaucoma, and to offer the resulting analysis as a framework for guiding decisions related to new treatments in Canada. Any considered treatment should significantly reduce at least one of the following burdens: physical, psychological, and socioeconomic. One of the best ways to measure these burdens and to scrutinize our own understanding of a disease is to survey patients and provide them with a platform to describe their experiences. 

Study design: Mixed-methods, cross-sectional survey study.

Methods: Designed to collect data on the physical, psychological, financial, and other burdens associated with glaucoma, an online, IRB-approved survey was posted to Fighting Blindness Canada’s website on July 20, 2018, where it gathered responses over the course of several months. Data was analyzed for themes, patterns, and keywords. 

Results: 244 Canadian respondents self-confirmed living with glaucoma. Most patients indicated having glaucoma in “both eyes” (76%), while a minority indicated having the disease in “one eye” (18%), and the remainder selected “other.” Patients rated the “severity of vision loss resulting from your glaucoma” on a scale from 1 to 10: most indicated 1 for “no vision loss” (24%), followed by ratings of 2 (17%), 3 (14%), 4 (12%), and 8 (7%). The average of these ratings is 3.88. Patients were also asked about how serious they consider their disease to be, how often they think about it, what kinds of barriers they face, what kind of activities they find difficult, what types of treatments they take, and which treatments they are aware of. Open-ended responses were collected in each section as well, providing qualitative perspectives that heightened and, in some cases, provided context for the quantitative survey results.

Conclusions: A review of both qualitative and quantitative data showed that, especially in the context of an overall paucity of literature on the subject, there are significant gaps in our collective understanding of glaucoma: (1) gaps in our general understanding of the burdens associated with the disease; (2) gaps in the patient’s understanding of the treatment landscape; and (3) gaps in how patients understand the specific details of their own disease and diagnosis. A discussion of these gaps is the primary focus of this presentation.

Disclosure of Relationships: Dr. Andrews reports grants received by Fighting Blindness Canada from AGTC, Allergan, Bayer, BMO, CIBC, Glaukos, I-MED Pharma, L'Occitane en Provence, MEDEC, MeiraGTx, Novartis, RBC Foundation, Shire, Spark Therapeutics, and Specialty Pharma Solutions.

Binocular stereopsis, or stereo vision, is the ability to derive information about how far away objects are, based solely on the relative positions of the object in the two eyes. It depends on both sensory and motor abilities. In this review, I briefly outline some of the neuronal mechanisms supporting stereo vision, and discuss how these are disrupted in strabismus. I explain, in some detail, current methods of assessing stereo vision and their pros and cons. Finally, I review the evidence supporting the clinical importance of such measurements.

The surgical management of macular holes has been a subject of controversy in recent years. Various techniques such as vitrectomy, membrane peeling, and gas tamponade with or without transforming growth factor-beta 2, and recently the use of autologous platelets have produced closure rates from 58% to 96%, depending on the stage of the hole. The authors present preliminary results in a study of 19 consecutive patients with stage 3 or stage 4 macular hole who underwent vitrectomy followed by placement of an absorbable partially cross-linked gelatin plug in the macular hole. The vitreous cavity was filled with a nonexpanding gas or air alone; the patient was instructed to maintain prone positioning for 2-3 days. Anatomic attachment of the edges of the macular hole was achieved in 19 out of 19 patients with a minimum follow-up period of 6 months (average 11.5 months). A cross-linked gelatin plug can effectively reattach the edges of macular holes of stages 3 and 4. Its use is recommend...

To examine the optical quality of healthy presbyopic eyes before and after implantation of the pseudoaccommodating AcrySof ReSTOR Natural intraocular lens (IOL) (Alcon Laboratories) by measuring visual acuity and wavefront aberrations.University of Valencia, Fernández-Vega Ophthalmological Institute, Valencia, Spain.Monocular refraction and photopic distance (6 m) and near (0.33 m) visual acuities were determined before and after clear lens extraction with bilateral AcrySof ReSTOR Natural IOL implantation in 30 hyperopic eyes (+0.50 to +4.00 diopters [D]) of presbyopic patients with low astigmatism (≤1.00 D). Postsurgical binocular visual acuity was measured over a range of effective distances. Wavefront aberrations were measured before and after surgery. Aberrations for 2 pupil diameters (3.0 mm and 5.0 mm) were decomposed using Zernike polynomials; total, defocus, astigmatism spherical, and coma aberration terms were studied separately. Postimplantation results were compared with preoperative values.Safety and efficacy indices for distance vision were 1.01 and 0.96, respectively. At near, they improved to 1.07 and 1.06, respectively. Vision at intermediate distances was noticeably poorer. Total, defocus, and spherical aberrations changed after IOL implantation with both pupil diameters (P<.01). Total and defocus aberrations were significantly reduced postoperatively. Spherical aberration coefficients changed to negative and less positive values for a 3.0 mm and a 5.0 mm pupil, respectively.Implantation of the pseudoaccommodating IOL in healthy eyes yielded uncorrected levels of high-contrast, distance, and near acuities comparable to preoperative best corrected values. Higher-order aberration levels appeared to be similar to the preoperative values.

Keratometry is currently achieved by projecting a circular mire onto the patient&#39;s cornea and analyzing the size and shape of its reflected image. The projection mires are decisive for the precision of the measurement. We have previously developed a keratometric module for slit lamps, and the development of four projection mires are presented. Mire 1 is composed of optical fibers and electrical cables; Mire 2, 48 LEDs; Mire 3, optical fibers and no electrical cables; and Mire 4, mechanical parts--cable free. Mires 2-4 provide accurate keratometry measurements at slit lamps. Mire 4 is the most adequate for the clinical environment.

Endophthalmitis, an ophthalmic condition characterized by an inflammation of the intraocular cavity, can have substantial implications for vision. However, little is known about the cost of treatment. The objective of this study was to estimate the direct medical cost of treatment for endophthalmitis in the United States. Retrospective data analysis using the 1997 through 2001 Medicare Beneficiary Encrypted Files. Beneficiaries who underwent cataract surgery were identified; baseline and clinical characteristics at the time of diagnosis were determined. Analyses stratified patients based on development of endophthalmitis in the year after surgery. Claims and reimbursements for cases (patients undergoing cataract extraction in whom endophthalmitis developed) and controls (patients who did not experience endophthalmitis) were determined and rates of resource use and costs were calculated from the perspective of Medicare. Annual Medicare payments and claims. A total of 417 beneficiaries with endophthalmitis occurring after cataract surgery were found; 139 558 had cataract surgery without subsequent endophthalmitis. Three fifths of beneficiaries were female and 89% were white. Ophthalmic claims and reimbursements were more than 1.45 times greater for cases than controls ($12 578 in higher claims and $3464 in higher reimbursements; P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001). These findings demonstrate a substantial cost associated with endophthalmitis. With recent studies suggesting that prophylaxis is effective in preventing endophthalmitis, there is potential that inexpensive prophylaxis could result in cost and resource savings to Medicare.

Ocular accommodation is not just a mechanism for altering curvature of the crystalline lens of the eye, it also enables aqueous humor outflow through the trabecular meshwork, influencing intraocular pressure (IOP). Long term stress on the ciliary muscle from sustained near focusing may initiate myopic eye growth in children and primary open angle glaucoma in presbyopic adults. Multi-factorial studies of ocular accommodation that include measures of IOP, ciliary muscle morphology, anterior chamber depth and assessment of nutritional intake and metabolic markers may elucidate etiology and novel strategies for management of both myopia and chronic glaucoma. Anatomy of the ciliary fibers from anterior insertion in the fluid drainage pathway to their posterior consanguinity with the vascular choroid, alters ocular parameters such as micro-fluctuations of accommodation and pulsatile ocular blood flow that are driven by cardiac contractions conveyed by carotid arteries. Stretching of the c...

Trochleas obtained from fresh surgical specimens, autopsy material, and cadavers were studied by means of dissection, light microscopy, and electron microscopy (scanning and transmission). A bursa-like structure that has not previously been described lines the ...

Posterior chamber intraocular lens (PC-IOL) subluxation is uncommon but represents one of the most serious complications following phacoemulsification. Late spontaneous IOL-capsular bag complex dislocation is defined as occurring three months or later following cataract surgery. Unlike early IOL dislocation, late spontaneous IOL dislocation is due to a progressive zonular dehiscence and contraction of the capsular bag many years what seemed to be uneventful surgery. In recent years, late in-the-bag IOL subluxation or dislocation has been reported with increasing frequency, having a cumulative risk of IOL dislocation following cataract extraction of 0.1% after 10 years and 1.7% after 25 years. A predisposition to zonular insufficiency and capsular contraction is identified in 90% of reviewed cases. Multiple conditions likely play a role in contributing to this zonular weakness and capsular contraction. Pseudoexfoliation is the most common risk factor, accounting for more than 50% of ...

Irresponsible failure of health authorities regarding need for protective goggles?- -Introduction References to COVID-19 infection via the eyes Comparison with research dismissal of HIV infection via mosquitoes Masks without Goggles or Masks with Goggles? Indication of range of full-face pandemic masks Convergence on face-covering norms in Muslim-majority countries?

Key Messages:

• The burden of diabetic macular edema is significant, but treatment adherence is poor.

• Low disease education may be a contributing factor, and further research is needed to understand how and when to provide information tailored to specific patients.