Anterior Segment OCT for Detection of Narrow Angles: A Community-Based Diagnostic Accuracy Study.

PURPOSE: To assess the diagnostic accuracy of anterior segment OCT (AS-OCT) screening for detecting gonioscopically narrow angles. DESIGN: Population-based cross-sectional study. PARTICIPANTS: A stratified random sample of individuals aged ≥ 60 years, selected from a door-to-door census performed in low-lying Nepal. TESTING: Participants underwent AS-OCT, posterior segment OCT, and intraocular pressure (IOP) testing in the community. Those meeting referral criteria in either eye were invited to have a comprehensive eye examination including gonioscopy. Referral criteria included (i) the lowest 2.5% of AS-OCT measurements, (ii) retinal OCT results suggestive of glaucomatous optic neuropathy, diabetic retinopathy, or age-related macular degeneration, and (iii) elevated IOP. MAIN OUTCOME MEASURES: Sensitivity and specificity of 5 semiautomated AS-OCT parameters relative to gonioscopically narrow angles, defined as the absence of visible trabecular meshwork for ≥ 180° on nonindentation gonioscopy. RESULTS: Of 17 656 people aged ≥ 60 years enumerated from 102 communities, 12 633 (71.6%) presented for AS-OCT testing. Referral was recommended for 697 participants based on AS-OCT criteria and 2419 participants based on other criteria, of which 858 had gonioscopy performed by a glaucoma specialist. Each of the 5 AS-OCT parameters offered good diagnostic information for predicting eyes with gonioscopically narrow angles, with areas under the receiver operating characteristic curve ranging from 0.85 to 0.89. The angle opening distance at 750 µm from the scleral spur (AOD750) provided the most diagnostic information, providing an optimal sensitivity of 87% (95% confidence interval [CI], 75%-96%) and specificity of 77% (71%-83%) at a cutpoint of 367 µm, and a sensitivity of 65% (95% CI, 54%-74%) when specificity was constrained to 90% (cutpoint, 283 µm). CONCLUSIONS: On AS-OCT, the AOD750 parameter detected approximately two-thirds of cases of gonioscopically narrow angles when test specificity was set to 90%. Although such a sensitivity may not be sufficient when screening solely for narrow angles, AS-OCT requires little additional effort if posterior segment OCT is already being performed and thus could provide incremental benefit when performing OCT-based screening. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.

Risk factors for corneal abrasions in Nepal: a community-based study.

BACKGROUND: South Asia is experiencing rapid urbanization, which may be changing the risk factor profile for ocular trauma. The objective of this study was to compare risk factors for traumatic corneal abrasions in rural versus urban Nepal, and to assess if any risk factors were associated with a poor outcome. METHODS: In a prospective, cross-sectional, community-based study performed as part of a cluster-randomized trial, community health workers from Nepal were trained to diagnose and treat traumatic corneal abrasions. Participants with an abrasion were invited to complete a risk factor survey. The main exposure variable was the object of eye injury, stratified by rural-urban residence. The main outcome measure was a lack of corneal healing after a three-day course of antimicrobials. RESULTS: Of 3657 participants diagnosed with a corneal abrasion, 2265 completed a survey. Eye trauma occurred most frequently during agricultural activities. The most common object of injury was vegetative matter, accounting for approximately 40% of injuries in rural, peri-urban, and urban communities. Wood injuries were more common in rural communities (24%) compared with urban or peri-urban communities (13%). Eye injury from an animal was more likely to result in a non-healing corneal abrasion after 3 days of treatment compared with other types of trauma (prevalence ratio 2.59, 95%CI 1.16-5.76). CONCLUSIONS: Health promotion activities for prevention of corneal ulcers in Nepal should focus on agricultural trauma in both rural and urban areas. Community members experiencing eye trauma from an animal may benefit from early referral to an eye clinic.

Diagnostic accuracy of smartphone corneal photography for detection of corneal opacities in a resource-limited setting: a community-based study.

Purpose: To evaluate the diagnostic accuracy of smartphone corneal photography in detecting corneal opacities in a community-based setting. Methods: A case-control, diagnostic accuracy study was nested in a cluster-randomized trial of a corneal ulcer prevention intervention in Nepal. Smartphone corneal photography was performed annually on community members self-reporting a potential risk factor for a corneal infection. Corneal photographs were graded for the presence or absence of an opacity. All cases with an opacity on smartphone photography and an equal number of controls were invited for a comprehensive eye examination with a slit lamp biomicroscope at an eye hospital. A mobile team visited participants unable to come to the hospital, conducting a limited examination with a penlight. Results: Of 1332 study participants (666 cases and 666 controls), 1097 had a penlight examination (535 cases and 562 controls) and 191 had a slit lamp examination (120 cases and 71 controls). When penlight examination was considered the reference standard, smartphone diagnosis of a corneal opacity had a positive predictive value (PPV) of 47% (95% confidence interval 43-52%) and negative predictive value (NPV) of 95% (93-97%). When slit lamp examination was considered the reference standard, the overall PPV and NPV were 71% (62-78%) and 80% (70-88%), respectively. The NPV was greater for detection of opacities > 1mm, estimated at 95% (90-98%). Conclusions: Corneal photography performed in a resource-limited community-based setting using a smartphone coupled to an external attachment had acceptable diagnostic accuracy for detection of corneal opacities large enough to be clinically meaningful.

Relationship Between Intraocular Pressure and Age: A Population-Based Study in Nepal.

PRCIS: Intraocular pressure (IOP) decreased with age in a population-based study in Nepal, from a mean of 14.1 mm Hg among those 60-64 years old to 13.0 mm Hg among those 80 years old or older. PURPOSE: Few studies have assessed the distribution of IOP from the Indian subcontinent, despite its large population and high burden of glaucoma. The objective of this study was to assess the distribution of IOP measurements from adults living in a lowland region of Nepal. METHODS: In a population-based cross-sectional study, all individuals aged 60 years and older from an area of lowland Nepal were invited for an IOP assessment with a rebound tonometer. RESULTS: Of 160 communities (28,672 people aged ≥60 y) enrolled, 79 (13,808 people aged ≥60 y) were randomly selected for IOP testing. Of those eligible, 10,017 (72.5%) individuals underwent tonometry. Mean IOP decreased monotonically over 5-year age groups, from 14.1 mm Hg (SD: 3.6) among those aged 60-64 years to 13.0 mm Hg (SD: 4.2) among those 80 years or older. The 97.5th percentile IOP measurement was 21.0 mm Hg for all age groups. In adjusted analyses, younger age, self-reported diabetes, and higher population density were each associated with higher IOP, and self-reported cataract surgery was associated with lower IOP. CONCLUSIONS: Mean IOP was lower among older individuals in Nepal, consistent with many studies from East Asia and in contrast to many studies from western populations. These results suggest that ethnic background might be a consideration when diagnosing ocular hypertension.

Risk factors for corneal ulcers: a population-based matched case-control study in Nepal.

BACKGROUND/AIMS: We aimed to examine risk factors for corneal ulcer in a rural and peri-urban setting in Nepal. METHODS: This population-based matched case-control study was nested in a cluster randomised trial in 24 village development committees in Nepal. Incidence density sampling was used to match incident corneal opacity cases to controls, matching on time of opacity, age, sex and location. Cases and controls were invited to participate in a survey of risk factors for corneal ulcer. Risk factors were evaluated using conditional logistic regression to account for matching. RESULTS: Of the 540 participants with incident opacities identified in the trial, 433 were willing to participate in this substudy and matched to a control. Compared with controls, cases had lower odds of having any education vs no education (adjusted OR, aOR 0.60, 95% CI 0.39 to 0.94), working in non-manual labour occupations vs manual labour occupations (aOR 0.64, 95% CI 0.42 to 0.95) and preferring medical shops for ocular trauma versus eye care system centres (aOR 0.58, 95% CI 0.37 to 0.92). Cases had higher odds of protective goggle use versus no protection (aOR 3.8, 95% CI 1.3 to 11.0) and having an ocular injury vs none (aOR 7.7, 95% CI 4.3 to 13.6) compared with controls. CONCLUSION: We found ocular injury, manual labour and lower education to be strongly associated with the development of corneal ulcer. Given the persistent burden of corneal blindness in this area, prevention efforts could target efforts to increase access to care in areas where these factors are common.

Central retinal artery occlusion in optic disk melanocytoma.

Optic disk melanocytoma (ODM) is a rare benign tumor of the optic disk. We report a rare occurrence of profound visual loss due to central retinal artery occlusion associated with ODM in a 78-year-old female with no significant medical history. The clinical findings were supplemented by ancillary investigations.

Posterior Scleritis Simulating Choroidal Melanoma: A Case Report.

Nodular posterior scleritis (NPS) is rare; however, it is critical to differentiate it from similar intraocular pathologies to prevent inappropriate and potentially irreversible treatment. Multimodal imaging is beneficial in the diagnosis of NPS. This report describes the diagnosis and management of a case of NPS with corticosteroid therapy that led to complete resolution.

Outcomes of the Perplexed Surgical Management of Retinal Detachment in Eyes with Coloboma.

PURPOSE: To determine the anatomical and visual outcomes of retinal detachment in eyes with chorioretinal coloboma managed by pars plana vitrectomy, endolaser photocoagulation and silicone oil (SO) tamponade. METHODS: Retrospective review of 29 eyes of 29 patients with retinal detachment associated with chorioretinal coloboma. All the cases were managed by vitrectomy procedures concluding with SO tamponade. Encircling band was placed based on pre-operative evaluation and/or surgeon's discretion. Endolaser photocoagulation was applied around the peripheral retina, all around the peripheral breaks and around the colobomatous area. The outcome measures were evaluated with regard to functional and anatomical success. RESULTS: The average age at the time of surgery was 21.76 ± 9.58 years (range, 10-50 years). The mean follow-up duration was 12.28 ± 4.8 months (range, 6-24 months). Primary attached retina was obtained in 21 / 29 (72.4%) eyes after single surgery. Re-detachment in 8 / 29 (27.6%) eyes which required revision surgery was the most frequent postoperative complication followed by raised intraocular pressure in 4 / 29 (13.8%) with SO in situ. Out of 29 eyes, 23 were followed up after the removal of SO. The mean duration of SO removal was 7.91 ± 3.9 months (range, 4-18 months). Implantation of encircling band, lens removal and cryotherapy provided no added advantage. At the final examination, improvement in vision was observed in 21 (72.4%) eyes and the anatomical attachment of the retina was attained in 27 (93.1%) eyes. CONCLUSIONS: Complete pars plana vitrectomy, endolaser photocoagulation along with SO tamponade is effective for retinal detachment associated with chorioretinal coloboma. This technique improves the anatomical outcome and helps in regaining significant visual acuity.

Evolution of Lightning Maculopathy: Presentation of Two Clinical Cases and Brief Review of the Literature.

Lightning is a naturally occurring atmospheric phenomenon. Though uncommon, it is a potentially devastating and underreported natural calamity. Lightning accounts for the second leading cause of weather-related death in most parts of the world. Among the survivors of lightning injury, more than half of the victims may suffer from some form of ophthalmic injury. The lightning-associated ocular injury varies from a range of anterior segment to posterior segment pathologies. We report on two clinical cases of ocular injuries among the survivors of lightning injury. Anatomical involvement is seen at different levels with presentation as uveitis, pupillary abnormality, maculopathy, and later development of lenticular opacification. Optical coherence tomography (OCT), a noninvasive diagnostic tool, is particularly useful in the evaluation of lighting maculopathy as well as to monitor its progression through the course of time. Visual prognosis depends upon the structures of the eyes affected in the injury. The presence of irreversible retinal damage as well as optic nerve damage often result in poor visual outcome in the absence of significant anterior segment pathology. This report highlights the evolution of maculopathy through the course of time and signifies the importance of long-term follow-up postlightning injury.

Confrontation with a live subretinal parasite.

BACKGROUND: Parasitic infestation of the eyes are a major cause of ocular diseases across the globe. Filarial and filarial-like nematodes top the list of the nematodes that affect the eye. CASE: A rare case of live sub retinal worm is reported in a 25 years old apparently healthy young male. The case presented with unilateral loss of vision and floaters in the affected eye. Upon examination a live subfoveal worm was identified with continuous wriggling movements and diffuse retinal edema. The worm was removed surgically and sent for parasitological examination. OBSERVATION: The worm was identified microscopically as Loa Loa. However detailed histopathological examination could not be incorporated. The patient's vision improved to 6/12 (0.30 Log MAR) from the initial presentation of 3/60 (1.30 Log MAR) after three months follow-up. CONCLUSION: The rare sub retinal live worm presents a challenge in management. The management depends upon the location and viability of the parasite. Surgical management is aimed at worm removal and vision preservation.

Outcomes of Silicone Oil Removal in Complex Retinal Detachment.

INTRODUCTION: Pars plana vitrectomy in combination with intraocular tamponade with silicone oil is a standard technique in the treatment of complex retinal detachment. Although the use of silicone oil has improved the results of retinal detachment surgery, its removal is recommended due to the ocular complications related to its long term use. However, retinal redetachment can occur after silicone oil removal. OBJECTIVE: To evaluate the anatomical and visual outcome after silicone oil removal (SOR) in eyes with complicated retinal detachment. MATERIAL AND METHODS: We retrospectively analyzed 64 eyes of 64 consecutive patients of silicone oil removal over a period of 12 months. All eyes had undergone standard 3 ports pars plana vitrectomy with silicone oil placement for complicated retinal detachment. Cases that completed at least 1 month follow up duration after SOR were included in the study. Anatomical success after SOR was achieved in 56 of 64 eyes (87.5%). Seven of 8 redetachments (87.5%) were seen in eyes with silicone oil tamponade duration of less than 6 months. Visual acuity improved or was stabilized in 49 of 64 eyes (76.6%). Using paired T-test, it was found that there was no significant difference in pre and post SOR visual acuity. Postoperative ocular hypertension, corneal decompensation, band shaped keratopathy and hypotony was observed in 9.4%, 4.7%, 6.4% and 21.9% respectively. CONCLUSION: Although there was no significant improvement in visual acuity, redetachment and complication rates were comparable to other studies. The duration of endotamponade was not significantly associated with the redetachment rate. Key words: Silicone oil removal, Redetachment, Visual outcome, Keratopathy, ocular hypertension.

Factors Affecting the Outcome of Scleral Buckling Surgery for Primary Rhegmatogenous Retinal Detachment.

INTRODUCTION: Scleral buckle surgery retains a special place in treatment of retinal detachment despite development of new and advanced vitreoretinal surgical techniques. The outcome of any retinal detachment surgery depends on correct selection of patient, type and nature of detachment, and the expertise. This study aims to evaluate various other parameters that determine the outcome of scleral buckle surgery. METHOD: Records of 55 patients with primary rhegmatogenous retinal detachment treated with scleral buckling over a duration of 18 months that had a minimum of 3-month follow-up were retrospectively reviewed. Preoperative and postoperative characteristics were recorded. Parameters that were evaluated to determine the outcome were best-corrected visual acuity (BCVA), anatomical success, and complications. RESULTS: A total of 51 eyes of 50 patients that met the inclusion criteria were included. Mean age was 41 ± 19.9 years (range: 9 to 83). Primary anatomical success was achieved in 80.4%. Parameters significantly associated with the anatomical outcome of surgery were status of lens, preoperative visual acuity, and extent of retinal detachment. There was a significant improvement of visual acuity postoperatively. CONCLUSION: Scleral buckle surgery is a highly effective surgery in uncomplicated retinal detachment cases, and single surgery success rates are better in cases with good preoperative visual acuity, partial detachment, and clear crystalline lens.

Prevalence of blindness and cataract surgical coverage in Narayani Zone, Nepal: a rapid assessment of avoidable blindness (RAAB) study.

BACKGROUND: The 1981 Nepal Blindness Survey first identified the Narayani Zone as one of the regions with the highest prevalence of blindness in the country. Subseuqently, a 2006 survey of the Rautahat District of the Narayani Zone found it to have the country's highest blindness prevalence. This study examines the impact on blind avoidable and treatable eye conditions in this region after significant increase in eye care services in the past decade. METHODS: The rapid assessment of avoidable blindness (RAAB) methodology was used with mobile data collection using the mRAAB smartphone app. Data analysis was done using the standard RAAB software. Based on the 2011 census, 100 clusters of 50 participants aged 50 years or older were randomly sampled proportional to population size. RESULTS: Of the 5000 participants surveyed, 4771 (95.4%) were examined. The age-adjusted and sex-adjusted prevalence of bilateral blindness, severe visual impairment (SVI) and moderate visual impairment (MVI) were 1.2% (95% CI 0.9% to 1.5%), 2.5% (95% CI 2.0% to -3.0%) and 13.2% (95% CI 11.8% to 14.5%), respectively. Cataract remains the primary cause of blindness and SVI despite cataract surgery coverage (CSC) of 91.5% for VA<3/60. Women still account for two-thirds of blindness. CONCLUSION: The prevalence of blindness in people over the age of 50 years has decreased from 6.9% in 2006 to 1.2%, a level in keeping with the national average; however, significant gender inequity persists. CSC has improved but continues to favour men.