Introduction: Low vision or Subnormal vision is a term used to describe varying degree of vision loss that cannot be corrected by medication, surgeries or conventional glasses. Vision loss may be due to: • Decreased visual acuity • Visual field defect • Decreased contrast sensitivity • Loss of colour perception A low vision patient is one who has impairment of visual functions even after treatment and /or standard refractive correction and has a visual acuity of less than 6/18 (20/60) to light perception or a visual field of less than 10 degree from the point of fixation, India was the first country in the world to launch the National Programme for Control Blindness in 1976 with the goal of reducing the prevalence of blindness. Of the total estimated 45 million blind persons (best corrected visual acuity <3/60) in the world, 7 million are estimated to be in India. Due to the large population base and increased life-expectancy, the number of blind particularly due to age-related disorders like cataract is expected to increase. Thus, this study is being undertaken with an aim to know the prevalence of various causes of subnormal vision to rural and urban population and manage them at a proper time. Materials and Methods: This study was carried out on patients of rural and urban areas of Meerut district. For the comparison of various causes of subnormal vision, people were studied in the camps and OPD of upgraded department of ophthalmology, LLRM, Medical college, Meerut, during the study period of June 2009 –July2010. The patients of subnormal vision for this study were divided into 2 groups.1st group was of urban areas resident of Meerut City. 2nd Group was of Rural areas residents of peripheral village of Meerut District. Patients from Subnormal vision were screened for Refractive Errors, Cataract, Retinal Diseases, Amblyopia, Corneal Diseases, Optic Atrophy, Glaucoma, Others ocular diseases like Endophthalmitis, Higher visual pathway lesions, posterior capsule opacity after cataract surgery, and indeterminate causes of visual impairment. Visual acuity examination of each patient was taken by snellen’s chart. Results: The present study was carried out in the Upgraded department of ophthalmology. S.V.B.P. Hospital, L.L.R.M. medical college Meerut from June 2009 to July 2010.The study included 800 patient suffering from subnormal vision from the OPD of Eye department and Rural Camps. There were more patients from rural areas (63.5%) in comparison from urban areas (36.5%) attending the medical OPD and camps. out of 800 patients 417 (52.13%) were male while 383 (47.87%) were females. that patient presented with their complain were maximum no. from age group 16-49 years in rural and urban patient (51.9% and 62.28% respectively)\ that in rural areas males (55.73%) were suffering from subnormal vision more than female (44.29%). In urban areas females (54.2%) with subnormal vision are more than males (45.8%) this difference was found statistically significant .This may be because of lack of awareness in rural areas and ignorance of female in rural areas. Maximum no. was of patients of refractive error 366 (45.8%) and cataract 319(39.9%) other common diseases which were causing subnormal vision were retinal disorder, amblyopia, corneal disorders and others. The category of others include Endophthalmitis, Higher visual pathway lesion, posterior capsule opacity following cataract surgery and indeterminate cause of visual impairment. That refractive errors were more common in rural patient (48.03%) as compared to urban patients group (41.75%). Cataract was more common in Urban patients group (40.75%) as compared to Rural patient group (39.37%) but the difference was not statistically significant. Retinal disease, optic atrophy and glaucoma were more common in urban patients group as compared to rural patients group. The percentage of Retinal disease, optic atrophy, glaucoma were in urban patients 4.45% and 2.39% respectively. Amblyopia (3.3%) and corneal disease (2.36%) were greater in rural patients as compared to urban patients. Glucoma prevalence was similar in both the groups. The category others was more common in urban patients (5.47%) as compared to Rural patients (1.96%) Discussion: 800 people of subnormal vision (Vision less than 6/18) selected from rural and urban patients. The present study showed overall percentage of refractive error as 45.8% and cataract 39.9%, Retinal diseases 3.4%, Amblyopia 2.7% corneal disease 2.3%, optic atrophy 1.8%, Glaucoma 1% and others 3.2.%. Considering the Rural and Urban patients refractive error, ambloypia, and corneal disease were more in rural patients (48.03%, 3.34%, 2.36%). Because children and females remain neglected for their problems and also take glasses as a social taboo. Cataract, retinal disorder, optic atrophy, Glaucoma and Others were more common in urban patients (40.75%, 4.45%, 2.39%, 1.36% respectively) In urban area people have easy access to hospital and they keep on coming for regular checkups. Most of the studies found that refractive error was the most common cause of subnormal vision followed by Cataract similar to ours. Conclusion: Uncorrected refractivr errors and cataracts are the main cause of low vision in both urban and rural populations. An increase in ophthalmic care and public education is needed to minimize the irreversible blindness in rural as well as urban parts of society.
