National Blindness and Visual Impairment Survey 2015-2019

Introduction

India was the first country in the world to launch the National Program for Control of Blindness in 1976 with the goal of reducing blindness prevalence to 0.3% by the year 2020. In 1999, the WHO launched Vision 2020: The Right to Sight, a joint endeavor with IAPB, to eliminate avoidable blindness by 2020. In 2013, World Health Assembly adopted Universal Eye Health: Global Action Plan 2014-19 with an aim to reduce prevalence of avoidable visual impairment by 25% by 2019 compared to the baseline prevalence at 2010. India has implemented a series of measures in its ongoing National Programme for Control of Blindness and Visual Impairment (NPCB&VI) to combat blindness and visual impairment.

The National Blindness and Visual Impairment Survey 2015-2019 was conducted in order to provide evidence about the present status of blindness and visual impairment in India. The survey was planned by the Ministry of Health and Family Welfare, Government of India. Dr Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS, New Delhi was responsible for planning and executing the field work, monitoring, analysis and report writing of the survey. The survey was done in partnership with various reputed eye health institutes of the country.

The survey was conducted in population aged ≥ 50 years using Rapid Assessment of Avoidable Blindness (RAAB) strategy in 31 districts of 24 States/Union Territories of India from September 2015- June 2018. This house-to-house survey was designed to generate representative data for the sampled districts as well as for India. Both rural and urban areas were included in this survey. An additional survey was performed in 0-49 years age group in Jan-Feb 2019. This survey was conducted in 6 districts selected from six zones (north, south, east, west, central and northeast) of India. The results of both surveys, in 0-49 age group and in ≥ 50 years population, were used to estimate the prevalence of blindness and visual impairment in India across all age groups.

Objectives of the survey

• To determine the prevalence of blindness and visual impairment (including avoidable blindness) in India
• To identify the major causes of blindness and visual impairment (including avoidable blindness) in India
• To estimate the cataract surgical coverage in India in ≥ 50 years population
• To ascertain the visual outcomes after cataract surgery in ≥ 50 years population
• To ascertain barriers for uptake of cataract surgery in ≥ 50 years population

Methods

Blindness (RAAB-6) methodology developed at the International Centre for Eye Health (ICEH), London and recommended by the WHO. The RAAB survey methodology was developed as a rapid and cost-effective survey method for the assessment of avoidable blindness. A total of 31 districts were randomly selected among the districts in India for the survey and a sample size of 3,000 was calculated to represent each district. Hence, total sample size estimated for the 31 districts was thus 93,000. The districts and the clusters within districts were chosen using PPS (probability proportionate to size) sampling. Further, segments were identified within each cluster and one of them was randomly picked up and covered by compact segment sampling technique. The prevalence of blindness and visual impairment were assessed based on presenting visual acuity, followed by ophthalmic examination to rule out the causes of blindness and visual impairment as per the RAAB protocol. Direct age and sex standardization of each district’s survey data to that district’s population age-sex structure was done as per the 2011 census, to estimate district-wise prevalence. Finally, in order to account for variation in population size of various districts, each district was allotted a sampling weight based on the district’s total population aged ≥ 50 years. These weights were applied on the standardized district prevalence to calculate the overall prevalence across 31 districts, which was extrapolated to the entire country.

For 0-49 years population survey, sample size was estimated as 18,000 for the country. One district was chosen from each of the 6 zones of the country to ensure the heterogeneity of the sample population. A total of 3,000 individuals aged 0-49 years were enumerated in each district. In this survey, 30 clusters were selected randomly from each district and 100 individuals were covered in each cluster.

Results of both these surveys were used to estimate the prevalence of blindness, SVI, MVI, EVI, MSVI and VI across all age groups in India. Based on the prevalence of blindness and VI, the total number of blind and visually impaired persons were extrapolated for the country for the year 2017.

National Advisory Committee Members

Dr. Atul Kumar, Professor & Chief, Dr. R.P. Centre, AIIMS, New Delhi
Dr. Promila Gupta, Principal Consultant, MoHFW, GOI
Dr. Praveen Vashist, Professor & Officer-in-charge, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Dr. R.M. Pandey, Professor & HOD, Bio-Statistics Department, AIIMS, New Delhi
Dr. R.S. Dhaliwal, Scientist ‘G’ & Head (NCD), ICMR, New Delhi

National Investigators

Dr. Praveen Vashist, Professor & Officer-in-charge, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Dr. Suraj Singh Senjam, Additional Professor, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Dr. Vivek Gupta, Associate Professor, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Dr. Noopur Gupta, Associate Professor, Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Dr. V. Rajshekhar, Assistant Commissioner, MoHFW, GOI
Dr. B.R Shamanna, Professor, University of Hyderabad, Telangana

DATA ANALYSIS AND REPORT WRITING

Dr. Praveen Vashist, Professor & Officer-in-charge, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Dr. Suraj Singh Senjam, Additional Professor, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Dr. Vivek Gupta, Associate Professor, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Dr. Noopur Gupta, Associate Professor, Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Dr. Meenakshi Wadhwani, Senior Research Officer, Dr. R.P. Centre, AIIMS, New Delhi
Dr. Pallavi Shukla, Senior Research Officer, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Dr. Talvir Sidhu, Research Officer, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Dr. Parul Jain, Research Officer, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Mr. Amit Bharadwaj, Research Officer, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Mr. Sumit Sharma, Program Manager, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Mr. Deepak Kumar, Programmer, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi
Mr. Rajesh Kumar Sharma, Statistician, Community Ophthalmology, Dr. R.P. Centre, AIIMS, New Delhi

State Investigators