Rohit C Khanna

The global burden of cataract.

Purpose of review To review the previous years literature related to prevalence of blindness in general, blindness due to cataract, cataract surgical coverage (CSC) and cataract surgical rates (CSRs). Recent findings Cataracts are the major cause of blindness and visual impairment in developing countries and contributes to more than 90% of the total disability adjusted life years. This review shows that coverage continues to be a problem in many countries, especially for the female population, those residing in rural areas and those who are illiterate. Although CSR is an indicator of the availability and acceptability of services, for measuring the impact of the program, we should look at combining CSR with CSC. This strategy would also enable us achieve our goal of eliminating avoidable blindness due to cataracts by the year 2020. Summary Cataracts still continue- to be a major cause of blindness globally and with the rapidly aging population, it is a challenge to tackle. We need to plan a comprehensive strategy addressing issues related to availability, affordability, accessibility and acceptability of eye-care services.

Prevalence and risk factors for refractive errors in the South Indian adult population: The Andhra Pradesh Eye disease study

Aim: To report the prevalence, risk factors and associated population attributable risk percentage (PAR) for refractive errors in the South Indian adult population. Methods: A population-based cross-sectional epidemiologic study was conducted in the Indian state of Andhra Pradesh. A multistage cluster, systematic, stratified random sampling method was used to obtain participants (n = 10293) for this study. Results: The age-gender-area-adjusted prevalence rates in those ≥40 years of age were determined for myopia (spherical equivalent [SE] < −0.5 D) 34.6% (95% confidence interval [CI]: 33.1–36.1), high-myopia (SE < −5.0 D) 4.5% (95% CI: 3.8–5.2), hyperopia (SE > +0.5 D) 18.4% (95% CI: 17.1–19.7), astigmatism (cylinder < −0.5 D) 37.6% (95% CI: 36–39.2), and anisometropia (SE difference between right and left eyes >0.5 D) 13.0% (95% CI: 11.9–14.1). The prevalence of myopia, astigmatism, high-myopia, and anisometropia significantly increased with increasing age (all p < 0.0001). There was no gender difference in prevalence rates in any type of refractive error, though women had a significantly higher rate of hyperopia than men (p < 0.0001). Hyperopia was significantly higher among those with a higher educational level (odds ratio [OR] 2.49; 95% CI: 1.51–3.95) and significantly higher among the hypertensive group (OR 1.24; 95% CI: 1.03–1.49). The severity of lens nuclear opacity was positively associated with myopia and negatively associated with hyperopia. Conclusions: The prevalence of myopia in this adult Indian population is much higher than in similarly aged white populations. These results confirm the previously reported association between myopia, hyperopia, and nuclear opacity.

Prevalence and Risk Factors for Primary Glaucomas in Adult Urban and Rural Populations in the Andhra Pradesh Eye Disease Study

PURPOSE To compare the prevalence of and risk factors for primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) in urban and rural populations in the Andhra Pradesh Eye Disease Study. DESIGN A population-based, cross-sectional study using a stratified, random, cluster, and systematic sampling strategy. PARTICIPANTS Between 1996 and 2000, participants from 94 clusters in 1 urban and 3 rural areas representative of the population were included. METHODS We performed a detailed eye examination, including applanation tonometry, gonioscopy, and dilated fundus evaluation after ruling out risk of angle closure. Humphrey threshold 24-2 visual fields were performed when indicated. MAIN OUTCOME MEASURES Glaucoma was diagnosed and categorized using International Society of Geographical and Epidemiological Ophthalmology criteria. The prevalence and risk factors for POAG and PACG in subjects aged > or = 40 years were compared between the urban and rural cohorts. RESULTS There were 3724 subjects > or = 40 years, with 934 in the urban and 2790 in the rural cohort. The prevalence of POAG was greater in the urban compared with the rural cohort (4% vs 1.6%; P<0.001). Age and intraocular pressure (IOP) were risk factors for POAG in both cohorts. Blindness owing to POAG was 11.1% in the rural and 2.7% in the urban cohort. The prevalence of PACG (1.8% vs 0.7%; P<0.01), primary angle closure (PAC) (0.8% vs 0.2%; P = 0.02) and primary angle closure suspect (PACS; 3.5% vs 1.5%; P<0.01) were significantly different between the urban and rural cohorts. Increasing age was a risk factor in the urban cohort. Intraocular pressure was a risk factor in both the populations. Blindness owing to PACG was equal (20%) in both the populations. Female gender was a risk factor in the rural cohort (P = 0.032). CONCLUSIONS The prevalence of both POAG and PACG was greater in urban than in the rural population. Intraocular pressure was a significant risk factor for both POAG and PACG in both cohorts. Increasing age was a significant risk factor for POAG in both cohorts and for PACG in the urban cohort. Female gender was a risk factor for PACG in the rural cohort. There was more blindness owing to PACG than to POAG. FINANCIAL DISCLOSURE(S) The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Cataract surgery in developing countries.

Purpose of review To review the previous years literature related to cataract surgery in developing countries and to provide fast, up-to-date information to the scientific world. Recent findings Cataract is the leading cause of blindness, especially in developing countries. The prevalence of cataract increases with the aging population. Although cataract surgery is the most cost-effective intervention, its delivery in developing countries has many issues and challenges. A paradigm shift has occurred in the surgical techniques used for delivering cataract services and the outcomes have been positive in some countries compared to the scenario a decade ago. However, in some parts of Africa, it still continues to be a challenge. Apart from this, the issues related to ongoing supply of consumables and human resources continue to be a challenge in these countries. Summary Although manual small incision cataract surgery is the most cost-effective intervention, there are other issues related to the delivery of services in developing countries. We need to plan a comprehensive strategy to deliver the services in developing countries if we want to achieve our goal of VISION 2020.

Angle Closure in the Andhra Pradesh Eye Disease Study

OBJECTIVE To estimate the prevalence and associated risk factors for primary angle-closure glaucoma (PACG), primary angle closure (PAC), and primary angle-closure suspects (PACS) in the Indian state of Andhra Pradesh. DESIGN A population-based, cross-sectional study using a stratified, random, cluster, and systematic sampling strategy. PARTICIPANTS Between 1996 and 2000, participants aged > or =40 years from 94 clusters in 1 urban and 3 rural areas were included. METHODS Trained professionals performed a detailed eye examination, including visual acuity, refraction, slit-lamp biomicroscopy, applanation tonometry, gonioscopy, and dilated fundus evaluation after ruling out risk of angle closure. Humphrey threshold 24-2 visual fields (VFs) were performed when indicated by disc criteria or if intraocular pressure (IOP) was > or =22 mmHg. MAIN OUTCOME MEASURES Angle closure was diagnosed and categorized using International Society of Geographical and Epidemiological Ophthalmology criteria. RESULTS Primary angle-closure glaucoma was present in 35 of 3724 subjects aged > or =40 years, an age- and gender-adjusted prevalence of 0.94% (95% confidence interval [CI], 0.63-1.24). Primary angle closure was present in 12 subjects (0.3%; 95% CI, 0.1-0.5), and PACS was present in 71 subjects (2%; 95% CI, 1.5-2.3). The prevalence of angle-closure disease (ACD=PACG+PAC) was 1.26% (95% CI, 0.90-1.62). Forty-one of 47 subjects (87.2%) with ACD were unaware of their disease. The prevalence of PACG increased from 0.56% (0.17-0.94) in the fourth decade to 2.5% (0.87-4.12) in the seventh decade. Seven (20%) of the 35 subjects with PACG were blind (visual acuity <3/60). Intraocular pressure increase (odds ratio [OR] 1.16; 95% CI, 1.11-1.22; P<0.001), diabetes mellitus (OR 3.18l; 95% CI, 1.34-7.58; P=0.001), and female gender (OR 2.07; 95% CI, 1.09-3.93; P=0.025) were significantly associated with angle-closure disease. No significant association was found with systemic hypertension (P=0.24) and hyperopia (P=0.05). CONCLUSIONS The prevalence of PACG in this population was 0.94%. Increasing age, increasing IOP, diabetes mellitus, and female gender were significantly associated with angle-closure disease. Blindness due to PACG was 20%.

Integrated model of primary and secondary eye care for underserved rural areas: The L V Prasad Eye Institute experience

Blindness is a major global public health problem and recent estimates from World Health Organization (WHO) showed that in India there were 62 million visually impaired, of whom 8 million are blind. The Andhra Pradesh Eye Disease Study (APEDS) provided a comprehensive estimate for prevalence and causes of blindness for the state of Andhra Pradesh (AP). It also highlighted that uptake of services was also an issue, predominantly among lower socio-economic groups, women, and rural populations. On the basis of this analysis, L V Prasad Eye Institute (LVPEI) developed a pyramidal model of eye care delivery. This article describes the LVPEI eye care delivery model. The article discusses infrastructure development, human resource development, and service delivery (including prevention and promotion) in the context of primary and secondary care service delivery in rural areas. The article also alludes to opportunities for research at these levels of service delivery and the amenability of the evidence generated at these levels of the LVPEI eye health pyramid for advocacy and policy planning. In addition, management issues related to the sustainability of service delivery in rural areas are discussed. The article highlights the key factors required for the success of the LVPEI rural service delivery model and discusses challenges that need to be overcome to replicate the model. The article concludes by noting the potential to convert these challenges into opportunities by integrating certain aspects of the existing healthcare system into the model. Examples include screening of diabetes and diabetic retinopathy in order to promote higher community participation. The results of such integration can serve as evidence for advocacy and policy.

Visual outcomes of bilateral congenital and developmental cataracts in young children in south India and causes of poor outcome

Context: Bilateral pediatric cataracts are important cause of visual impairment in children. Aim: To study the outcome of bilateral pediatric cataract surgery in young children. Setting and Design: Retrospective case series in a tertiary center. Materials and Methods: Records of pediatric cataracts operated between January 2001 and December 2003, with a minimum follow-up of 3 months, were reviewed retrospectively. Statistical Methods: Independent sample t-test, Fishers exact test, and logistic regression using SPSS (Statistical Package for Social Science, Chicago, USA) version 12. Results: 215/257 (83.7%) patients had a minimum follow-up of 3 months. The mean age of presentation to the hospital was 53 months (range: 0-168 months). Congenital cataract was present in 107 patients (58.2%) and developmental cataract in 77 patients (41.8%). The mean age at surgery was 55.2 months (range: 1-168 months). Out of 430 eyes, 269 (62.6%) had an intraocular lens implanted. The mean duration of follow-up was 13.1 months (range: 3-38 months). Pre-operatively, 102 patients (47.3%) had visual acuity <6/60, in the better eye, compared to 37 patients (17.2%) post-operatively (P < 0.001). Eighty-five patients (39.5%) had visual acuity >6/18. The most common early post-operative complication was fibrinous uveitis in 57 eyes (13.3%) and the most common delayed post-operative complication was posterior capsular opacification in 118 eyes (27.4%). The most important prognostic factor for poor outcome was congenital cataract (odds ratio [OR]: 26.3; 95% confidence interval [CI], 4.4-158.5) and total cataract (OR: 4.8; 95% CI, 1.3-17).

Cataract, Visual Impairment and Long-Term Mortality in a Rural Cohort in India: The Andhra Pradesh Eye Disease Study

Background A large-scale prevalence survey of blindness and visual impairment (The Andhra Pradesh Eye Diseases Study [APEDS1]) was conducted between 1996-2000 on 10,293 individuals of all ages in three rural and one urban clusters in Andhra Pradesh, Southern India. More than a decade later (June 2009-March 2010), APEDS1 participants in rural clusters were traced (termed APEDS2) to determine ocular risk factors for mortality in this longitudinal cohort. Methods and Findings Mortality hazard ratio (HR) analysis was performed for those aged >30 years at APEDS1, using Cox proportional hazard regression models to identify associations between ocular exposures and risk of mortality. Blindness and visual impairment (VI) were defined using Indian definitions. 799/4,188 (19.1%) participants had died and 308 (7.3%) had migrated. Mortality was higher in males than females (p<0.001). In multivariable analysis, after adjusting for age, gender, diabetes, hypertension, body mass index, smoking and education status the mortality HR was 1.9 (95% CI: 1.5-2.5) for blindness; 1.4 (95% CI: 1.2-1.7) for VI; 1.8 (95% CI: 1.4-2.3) for pure nuclear cataract, 1.5 (95% CI: 1.1-2.1) for pure cortical cataract; 1.96 (95% CI: 1.6-2.4) for mixed cataract, 2.0 (95% CI: 1.4-2.9) for history of cataract surgery, and 1.58 (95% CI: 1.3-1.9) for any cataract. When all these factors were included in the model, the HRs were attenuated, being 1.5 (95% CI: 1.1-2.0) for blindness and 1.2 (95% CI: 0.9-1.5) for VI. For lens type, the HRs were as follows: pure nuclear cataract, 1.6 (95% CI: 1.3-2.1); pure cortical cataract, 1.5 (95% CI: 1.1-2.1); mixed cataract, 1.8 (95% CI: 1.4-2.2), and history of previous cataract surgery, 1.8 (95% CI: 1.3-2.6). Conclusions All types of cataract, history of cataract surgery and VI had an increased risk of mortality that further suggests that these could be potential markers of ageing.

Surgical and visual outcomes for posterior polar cataract

Aims: The aims of this study were to report the surgical and visual outcomes of posterior polar cataract and to assess the risk factors for posterior capsule rupture. Method: Medical records of 81 eyes of 59 patients were reviewed. The surgical procedure used, intraoperative complications and postoperative visual outcome were recorded. Results: Of the 81 eyes, 61 eyes (75%) underwent phacoemulsification. Seventeen eyes had extra-capsular cataract extraction, and manual small incision cataract surgery was performed on three eyes. Posterior capsule rupture occurred in 25 (31%) eyes: it was more common in young patients (<40 years) and in the extra-capsular cataract extraction group. Two eyes had nucleus drop during phacoemulsification. The postoperative visual acuity was ⩾20/30 in 76 eyes. Conclusion: Posterior capsule rupture occurred more frequently in extra-capsular cataract extraction compared with phacoemulsification and in patients below 40 years of age. Phacoemulsification, done carefully, leads to good visual outcome.

Management and Outcome of Retinoblastoma with Vitreous Seeds

PURPOSE To report the treatment response of retinoblastoma with vitreous seeds to high-dose chemotherapy coupled with periocular carboplatin. DESIGN Retrospective, interventional case series. PARTICIPANTS Consecutive patients with retinoblastoma with vitreous seeds managed over 10 years at a comprehensive ocular oncology center and followed up for at least 12 months after the completion of treatment were included in this study. Institutional review board approval was obtained. INTERVENTION High-dose chemotherapy with a combination of vincristine, etoposide, and carboplatin in patients with focal vitreous seeds and additional concurrent periocular carboplatin in patients with diffuse vitreous seeds. MAIN OUTCOME MEASURES Tumor regression, vitreous seed regression, and eye salvage. RESULTS After excluding the better eye of bilateral cases, 101 eyes of 101 patients were part of the final analysis. All the patients belonged to Reese-Ellsworth group VB, but on the International Classification of Retinoblastoma (ICRB), 21 were group C, 40 were group D, and 40 were group E. The mean basal diameter of the largest tumor was 11.8 ± 4.7 mm. Mean tumor thickness was 7.5 ± 4.0 mm. Vitreous seeds were focal in 21 eyes and diffuse in 80 eyes. Chemotherapy cycles ranged from 6 to 12 (median, 6). Seventy-three eyes with diffuse vitreous seeds received a 15-mg posterior sub-Tenon carboplatin injection (range, 1-13 mg; median, 6 mg). Follow-up duration ranged from 13.4 to 129.2 months (median, 48 months). External beam radiotherapy (EBRT) was necessary in 33 eyes with residual tumor, vitreous seeds, or both. In all, 20 eyes (95%) with ICRB group C retinoblastoma, 34 eyes (85%) with group D retinoblastoma, and 23 eyes (57.5%) with group E retinoblastoma were salvaged. Of 77 eyes that were salvaged, 74 (96%) had visual acuity of 20/200 or better. Twenty-four of 33 chemotherapy failures (73%) regressed with EBRT. None of the patients demonstrated second malignant neoplasm or systemic metastasis. Factors predicting tumor regression and eye salvage were bilateral retinoblastoma and absence of subretinal fluid. Factors predicting vitreous seed regression were absence of subretinal fluid and subretinal seeds. CONCLUSIONS Intensive management with primary high-dose chemotherapy and concurrent periocular carboplatin, and EBRT selectively in chemotherapy failures, provides gratifying outcome in retinoblastoma with vitreous seeds.