Elimination of avoidable blindness due to cataract: where do we prioritize and how should we monitor this decade?

BACKGROUND: In the final push toward the elimination of avoidable blindness, cataract occupies a position of eminence for the success of the Right to Sight initiative. AIMS: Review existing situation and assess what monitoring indicators may be useful to chart progress towards attaining the goals of Vision 2020. SETTINGS AND DESIGN: Review of published papers from low and middle income countries since 2000. MATERIALS AND METHODS: Published population-based data on prevalence of cataract blindness/visual impairment were accessed and prevalence of cataract blindness/visual impairment computed, where not reported. Data on prevalence of cataract blindness, cataract surgical coverage at different visual acuity cut offs, surgical outcomes, and prevalence of cataract surgery were analyzed. Scatter plots were used to look at relationships of some variables, with Human Development Index (HDI) rank. Available data on Cataract Surgical Rate (CSR) was plotted against prevalence of cataract surgery reported from surveys. RESULTS: Worse HDI Ranks were associated with higher prevalence of cataract blindness. Most studies showed that a significant proportion of the blind were covered by surgery, while a fifth showed that a significant proportion, were operated before they went blind. A good visual outcome after surgery was positively correlated with higher surgical coverage. CSR was positively correlated with cataract surgical coverage. CONCLUSIONS: Cataract surgical coverage is increasing in most countries at vision <3/60 and visual outcomes after cataract surgery are improving. Establishing population-based surveillance of cataract surgical need and performance is a strong monitoring tool and will help program planners immensely

Birth prevalence of neural tube defects and orofacial clefts in India: a systematic review and meta-analysis.

BACKGROUND: In the last two decades, India has witnessed a substantial decrease in infant mortality attributed to infectious disease and malnutrition. However, the mortality attributed to birth defects remains constant. Studies on the prevalence of birth defects such as neural tube defects and orofacial clefts in India have reported inconsistent results. Therefore, we conducted a systematic review of observational studies to document the birth prevalence of neural tube defects and orofacial clefts. METHODS: A comprehensive literature search for observational studies was conducted in MEDLINE and EMBASE databases using key MeSH terms (neural tube defects OR cleft lip OR cleft palate AND Prevalence AND India). Two reviewers independently reviewed the retrieved studies, and studies satisfying the eligibility were included. The quality of included studies was assessed using selected criteria from STROBE statement. RESULTS: The overall pooled birth prevalence (random effect) of neural tube defects in India is 4.5 per 1000 total births (95% CI 4.2 to 4.9). The overall pooled birth prevalence (random effect) of orofacial clefts is 1.3 per 1000 total births (95% CI 1.1 to 1.5). Subgroup analyses were performed by region, time period, consanguinity, and gender of newborn. CONCLUSION: The overall prevalence of neural tube defects from India is high compared to other regions of the world, while that of orofacial clefts is similar to other countries. The majority of studies included in the review were hospital based. The quality of these studies ranged from low to moderate. Further well-designed, high quality community-based observational studies are needed to accurately estimate the burden of neural tube defects and orofacial clefts in India

Regional variation in diabetic retinopathy and associated factors in Spectrum of Eye Disease in Diabetes (SPEED) study in India-Report 5.

PURPOSE: To study the zonal variations in diabetic retinopathy (DR) and associated factors in people with known type 2 diabetes mellitus (T2DM) attending large eye care facilities in different regions of India. METHODS: In this cross-sectional eye-care facility-based study, India was divided into five zones; large eye care facilities with a good referral base and offering an entire range of care for patients with DR were invited. First-time T2DM attendees aged ≥18 years were recruited. All subjects received a comprehensive systemic and ophthalmic examination. DR and systemic diseases were classified as per the international/national standards. Findings were compared between the zones and with the national average. RESULTS: Fourteen eye-care facilities (15% public) from five zones participated. In the cohort of 11,173 people, there were more males (59%); the average age was above 45 years, and in 57%, DM had been diagnosed more than 5 years earlier. Compared with the overall study population, the proportion of people with any DR, sight-threatening DR, and blind were higher in the east zone (42.5%, 95% confidence interval [CI]: 40.2-44.8; 24.3%, 95% CI 22.3-26.3, and 11.5%, respectively); diabetic macular edema was more frequent in the south zone (12.2%, 95% CI 11.2-13.2); people with moderate-to-severe visual impairment were more in the west zone (32.1%) and higher proportion of people in the south-central zone had systemic hypertension (56.8%, 95% CI 54.8-58.9). CONCLUSION: The zonal variation in DR and related vision loss could be related to variable health-seeking behavior, availability, and confidence in the available services

Glaucoma-associated long-term mortality in a rural cohort from India: the Andhra Pradesh Eye Disease Study.

AIM: To evaluate glaucoma-associated mortality in a rural cohort in India. METHODS: The study cohort comprised individuals aged 40 years and above who took part in the Andhra Pradesh Eye Disease Study (APEDS1) during 1996-2000. All participants underwent detailed comprehensive eye examination. Glaucoma was defined using International Society of Geographic and Epidemiologic Ophthalmology criteria. This cohort was followed up after a decade (June 2009 to January 2010; APEDS2). Mortality HR analysis for ocular risk factors was performed using Cox proportional hazards regression after adjusting for sociodemographic, lifestyle and clinical variables. RESULTS: In APEDS1, 2790 individuals aged more than or equal to 40 years were examined. 47.4% were male. Forty-five participants had primary open angle glaucoma (POAG) and 66 had primary angle closure disease (PACD). Ten years later, 1879 (67.3%) were available, 739 (26.5%) had died and 172 (6.2%) had migrated; whereas 22 of the 45 (48.8%) with POAG and 22 of the 66 (33.3%) with PACD had died. In univariate analysis, a higher mortality was associated with POAG (HR 1.9; 95% CI 1.23 to 2.94), pseudoexfoliation (HR 2.79; 95% CI 2.0 to 3.89), myopia (HR 1.78; 95% CI 1.54 to 2.06) and unit increase in cup:disc ratio (HR 4.49; 95% CI 2.64 to 7.64). In multivariable analysis, only cup:disc ratio remained independently associated with mortality (HR 2.5; 95% CI 1.3 to 5.1). The association remained significant when other ocular parameters were included in the model (HR 2.1; 95% CI 1.03 to 4.2). CONCLUSIONS: This is the first longitudinal study to assess the association of glaucoma and mortality in a rural longitudinal cohort in India. Increased cup:disc ratio could be a potential marker for ageing and would need further validation

A Mixed-Method Study to Determine the Benefits of Periconceptional Folic Acid Supplementation and Effects of Folic Acid Deficiency in Mothers on Birth Outcomes.

BACKGROUND: Evidence from high income countries shows mothers who are supplemented with folic acid in their periconceptional period and early pregnancy have significantly reduced adverse outcomes like birth defects. However, in India there is a paucity of data on association of birth defects and folic acid supplementation. We identified a few important questions to be answered using separate scientific methods and then planned to triangulate the information. OBJECTIVE: In this paper, we describe the protocol of our study that aims to determine the association of folic acid and pregnancy outcomes like neural tube defects (NTDs) and orofacial clefts (OFCs). We decided to fill the gaps in knowledge from India to determine public health consequences of folic acid deficiency and factors influencing dietary and periconceptional consumption of folic acid. METHODS: The proposed study will be carried out in five stages and will examine the questions related to folic acid deficiency across selected locations in South and North India. The study will be carried out over a period of 4 years through the hierarchical evidence-based approach. At first a systematic review was conducted to pool the current birth prevalence of NTDs and orofacial clefts OFCs in India. To investigate the population prevalence, we plan to use the key informant method to determine prevalence of NTDs and OFCs. To determine the normal serum estimates of folic acid, iron, and vitamin B12 among Indian women (15-35 years), we will conduct a population-based, cross-sectional study. We will further strengthen the evidence of association between OFCs and folic acid by conducting a hospital-based, case-control study across three locations of India. Lastly, using qualitative methods we will understand community and health workers perspective on factors that decide the intake of folic acid supplements. RESULTS: This study will provide evidence on the community prevalence of birth defects and prevalence folic acid and vitamin B12 deficiency in the community. The case-control study will help understand the association of folic acid deficiency with OFCs. CONCLUSIONS: The results from this study are intended to strengthen the evidence base in childhood disability for planning and policy initiatives

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

Folate, vitamin B12, ferritin and haemoglobin levels among women of childbearing age from a rural district in South India

BackgroundLow folate and vitamin B12 levels have negative effect on pregnancy outcomes but there is paucity of data on their levels among Indian women. Ferritin and haemoglobin are associated with maternal mortality and low birth-weight. Our aim was to estimate the prevalence of deficiency of serum folate and vitamin B12, and low levels of serum ferritin and blood haemoglobin among women of childbearing age from a rural population of South India.MethodsWe conducted a community-based cross-sectional study among 15-35 year women in a rural district. We used multistage stratified random sampling. Trained staff interviewed women to collect socio-demographic information and draw blood samples. We analysed samples for serum folate, vitamin B12, ferritin and blood haemoglobin levels and computed means and medians. We computed the proportion of deficiency based on cut-offs recommended by WHO. We examined the association of levels with age, parity and current pregnancy or breastfeeding by multi-variable regression using Stata 13.0.ResultsWe recruited 979 women. One-fifth (185, 19%) were pregnant and one-fifth (196, 20%)were breastfeeding. Median serum folate levels were 2.5 ng/ml (IQR, 1.2-4.8), median vitamin B12 levels were 228.0 pg/ml (IQR, 121 - 390), median ferritin levels were 13.0 μg/l (IQR, 6.0 - 20.0) and median blood haemoglobin levels were 12.1 mg/dl (IQR, 10.7 – 13.6). Low levels of serum folate, vitamin B12, ferritin and haemoglobin were found in 57% (95% CI, 54-60%), 44% (95% CI, 41-48%), 46% (95% CI, 43-49%) and 28% (95% CI, 25-31%) respectively. Women with folic acid deficiency had two times higher prevalence of having vitamin B12 deficiency. In adjusted regression analysis folate levels were lower in older and breastfeeding women, but not associated with parity and were higher among pregnant women. Similar associations were not found with Vitamin B12 deficiency. Ferritin levels were higher in older women; but not associated with parity, pregnancy or breastfeeding. Haemoglobin levels were lower in pregnant and breastfeeding women.ConclusionOur findings suggest that folic acid, vitamin B12 and iron deficiency are important public health problems in India. We observed that half of the women of childbearing age were deficient in these nutrients. Folic acid and vitamin B12 deficiencies co-exist and should be supplemented together

Differential cataract blindness by sex in India: Evidence from two large national surveys.

AIMS: Women suffer disproportionately more from cataract blindness compared to males in low- and middle-income countries. Two large population-based surveys have been undertaken in India at an interval of 7 years and data from these surveys provided an opportunity to assess the trends in gender differentials in cataract blindness. MATERIALS AND METHODS: Data were extracted from the surveys to discern sex differences in cataract blindness. Multivariate analysis was performed to adjust for confounders and their impact on gender differences in cataract blindness. Blindness was defined as presenting vision <20/400 in the better eye, and a cataract blind person was defined as a blind person where the principal cause of loss of vision was cataract. RESULTS: Prevalence of cataract blindness was higher in females compared to males in both surveys. The odds of cataract blindness for females did not change over time as observed in the surveys (1999-2001 and 2006-2007). Adjusted odds ratio from logistic regression analysis revealed that females continued to be at a higher risk of cataract blindness. CONCLUSIONS: Sex differences continued in India in relation to cataract blindness despite the gains made by the national program

Spectrum of Eye Disease in Diabetes (SPEED) in India: A prospective facility-based study. Report # 4. Glaucoma in people with type 2 diabetes mellitus.

Purpose: To estimate the proportion of people with type 2 diabetes mellitus (T2DM) and glaucoma in a facility-based cross-sectional observational study in India. Methods: All people received a comprehensive eye examination. Glaucoma-specific examinations included applanation tonometry, optic disc and cup evaluation, and stereo biomicroscopy in all people; gonioscopy and visual field testing in glaucoma suspects. The International Society of Geographic and Epidemiologic Ophthalmology guidelines were used to diagnose and classify glaucoma. Results: The study recruited 11,182 people (average age: 58.2 ± 10.6; range 39-96 years). Glaucoma was diagnosed in 4.9% (n = 547) people. About 76.8% (n = 420) of those with glaucoma had bilateral disease, and 98.7% (n = 540) were >40 years. Among people with bilateral disease, 94.5% (n = 397) had primary glaucoma - open angle in 59.3% (n = 228) and angle closure in 40.2% (n = 169). Diabetes duration was ?10 years in 71.5% (n = 300) people. On linear regression, the following were associated with glaucoma: advancing age [compared with 60 years age group (OR: 2.05, 95% CI: 1.57-2.67; P < 0.001), and diabetic neuropathy (OR: 2.62, 95% CI: 1.35-5.10, P < 0.003). Glycemic control did not have significant association (P = 0.425). Conclusion: Presence of glaucoma in people with T2DM in this cohort was similar to the general population prevalence studies in India. Glaucoma was invariably bilateral. A comprehensive eye examination in people age 40 years and older with diabetes and/or glaucoma is beneficial

Spectrum of eye disorders in diabetes (SPEED) in India. Report # 2. Diabetic retinopathy and risk factors for sight threatening diabetic retinopathy in people with type 2 diabetes in India.

Purpose: To assess the proportion of people with type 2 diabetes mellitus (T2DM) with diabetic retinopathy (DR) and sight-threatening DR (STDR) and associated risk factors in select eye-care facilities across India. Methods: In this observational study, data of people with T2DM presenting for the first time at the retina clinic of eye-care facilities across India was recorded. Data collected in 2016 over 6 months included information on systemic, clinical, and ocular parameters. International Clinical Diabetic Retinopathy (ICDR) classification scale was used to grade DR. STDR was defined as presence of severe nonproliferative (NPDR), proliferative diabetic retinopathy (PDR), and/or diabetic macular edema (DME). Results: The analysis included 11,182 people with T2DM from 14 eye-care facilities (mean age 58.2 ± 10.6 years; mean duration of diabetes 9.1 ± 7.6 years; 59.2% male). The age-standardized proportion of DR was 32.3% (95%Confidence Interval, CI: 31.4-33.2) and STDR was 19.1% (95%CI: 18.4-19.8). DME was diagnosed in 9.1% (95%CI: 8.5-9.6) and 10.7% (95%CI: 10.1-11.3) people had PDR. Statistically significant factors associated with increased risk of DR (by multivariate logistic regression analysis) were: male gender (Odds ratio[OR] 1.57, 95%CI: 1.16-2.15); poor glycemic control-glycated hemoglobin (HbA1c >10%)(OR 2.39, 95% CI: 1.1-5.22); requirement of insulin (OR 2.55, 95%CI: 1.8-3.6);history of hypertension (OR 1.42, 95%CI: 1.06-1.88) and duration of diabetes >15 years (OR 5.25, 95%CI: 3.01-9.15). Conclusion: Diabetic retinopathy was prevalent in 1/3rd and sight-threatening DR in 1/5th of people with T2DM presenting at eye-care facilities in this pan-India facility-based study. The duration of diabetes was the strongest predictor for retinopathy