Blindness Dr. Gopalrao Jogdand, M.D. Ph.D. Professor & Head, Department of Community Medicine
Visual acuity less than 3/60 by Snellen’s chart.
Economic blindness: Such level of visual acuity, where an individual is not able to earn the livelihood.
Categories of visual impairment Light Perception. 1/60 No light perception. Blindness 1. 6/60 2. 3/60 3. 1/60 1. 6/18 2.6/60 3. 3/60 Low vision Minimum equal to or better than Maximum or less than Level of visual impairment
Magnitude of the problem
Global: It is estimated that 180 million people are visually impaired of them 45 million people are blind.
India: The prevalence of blindness is 77% and 68 lakh people are blind as per W.H.O. statistics.
Major causes of blindness
Global: cataract 19 million people are affected globally.
Glaucoma: 6.4 million.
Trachoma: 5.7 million.
Childhood blindness: More than 1.5 million.
Onchocerciasis: 0.29 million.
Other causes: 10 million.
Causes of blindness in India
Refractive errors: 19.7%.
Posterior segment Pathology: 4.7%.
Corneal opacity: 0.9%
Other causes: 6.2%
Age: 30% of the blind loose their eyesight before the age of 20 years and many in this category loose eye sight before the age of 5 years.
Many loose their eye sight at 20-40 years of age due to various reasons.
62.6% people loose their eye sight due to Cataract.
Nutritional blindness: Vitamin a deficiency leads to childhood blindness, major manifestation of low vitamin A intake from dietary sources.
Occupation: Occupational injuries are the most common cause of blindness in working population.
Social class: Twice more common in poor population as compared to the rich.
Changing concepts in ophthalmic care
Primary eye care: Inclusion of eye care in primary health care delivery system and delivered through it, objective is to improve the quality and coverage of eye care.
Epidemiologic approach: Used as a tool to find out the prevalence/incidence of diseases causing blindness. Finding out risk factors for the same and determine the action needed.
Team approach: As the availability of ophthalmic surgeon is scarce, govt. has inducted ophthalmic assistants, multipurpose workers, village health guides and the services of voluntary health agencies for providing eye care to rural/tribal population.
Commissioning of the National Program: Increasing recognition of application of primary health care approach to blindness control has resulted in development of a comprehensive blindness control program at the national level. The goal of this program was to reduce blindness to 0.3% by the year 2000 A.D.
Components of the National blindness control program
Initial assessment: First step is to find out the magnitude, geographic distribution and causes of blindness in the country. Objective is to set up the priorities and development of suitable interventions.
Methods of intervention
Primary eye care: Wide range of eye conditions can be treated at grass root level by locally trained health workers
Secondary eye care: Involves the management of diseases like cataract, glaucoma, trichiasis, entropion etc at the secondary level i.e. PHC and District hospitals.
Tertiary eye care: Delivered through medical colleges and super specialty hospitals they provide sophisticated eye care like retinal detachment surgery, corneal grafting and other sophisticated forms of eye care.
Trachoma control: National Trachoma Control Program which started in 1963 is now merged with National program for control of blindness in 1976.
School eye health services: Screening of school children for preventable ocular morbidities, e.g. refractive errors, vit. A deficiency, squint, trachoma etc.
Occupational eye services: Provisions are made to provide eye care to the workers on campus through the industrial medical officer and a occupational nurse. Minor injuries and ailments are treated on campus, for serious injuries referral is given.
Control of Nutritional blindness
Vitamin A prophylaxis: Under this program 200000 I.U. of vitamin A is given to the children in the age group 1-6 years at the interval of 6 months. The children are kept under surveillance for five years to monitor the signs of Vitamin A deficiency i.e. Xeropthalmia.
Long term policy
Creating awareness in the population regarding the importance of consumption of foods rich in vitamin A, maintenance of good personal hygiene, control of poor environmental sanitation, supply of adequate and safe water. These are long term interventions to bring out the improvement in eye care.
Evaluation of the program
Like any other health program evaluation of the National blindness control program should be an integral part, to know the impact of the program. To know to which extent ophthalmic diseases and blindness is controlled, assess the manner and degree to which program activities are carried out and determine the changes that may have been produced.
Role of National and International Agencies
The National Association for the blind (NAB) is working in this field since 1952 it is providing welfare services to the blinds.
The Royal Society for the blind is active in the country since 1950.
International Agency for the prevention of blindness is a W.H.O. initiative for preventing blindness globally.
Danish International Development Agency (DANIDA) It is providing support to the National Blindness control Program in the form of training of personnel, direct technical co-operation and funding for the program. It is the initiative of DANIDA that doctors in this country are trained in community ophthalmology.
The right to sight is a global initiative started by W.H.O. on 18 th February 1999.
The objective of vision 2020 is to assist member countries in developing a sustainable system which will enable them to eliminate avoidable/preventable blindness by the year 2020.