Indian Journal of Ophthalmology

: 2000  |  Volume : 48  |  Issue : 3  |  Page : 201--7

A retrospective study of low-vision cases in an Indian tertiary eye-care hospital

SA Khan 
 Deshpande Centre for Sight Enhancement, L.V. Prasad Eye Institute, L.V. Prasad Marg, Banjara Hills, Hyderabad-500 034, India

Correspondence Address:
S A Khan
Deshpande Centre for Sight Enhancement, L.V. Prasad Eye Institute, L.V. Prasad Marg, Banjara Hills, Hyderabad-500 034


Purpose:To obtain data on the characteristics of low-vision patients seen at a tertiary eye care hospital in India. Methods:Records of 410 patients were retrospectively reviewed at the Centre for Sight Enhancement, L.V.Prasad Eye Institute, Hyderabad, India. Patients underwent a comprehensive clinical low-vision examination. Data obtained included age, gender, consangunity, visual acuity, visual fields, ocular conditions causing low vision and types of low-vision devices and methods prescribed. Results:Two hundred and ninety seven (72%) of 450 patients were male. One-fifth were in the 11-20 years age group (21%). Visual acuity in the better eye was <6/18 - 6/60 in almost half these patients (49.3%). One hundred and twenty two patients (29.9%) referred with a visual acuity of ≥ 6/18, either had difficulty in reading normal print or had restricted visual fields. The main causes for low vision were: retinitis pigmentosa (19%), diabetic retinopathy (13%), Macular diseases (17.7%), and degenerative myopia (9%). Visual rehabilitation was achieved using accurate correction of ametropia (174 patients), approach magnification (74 patients) and telescopes (45 patients) for recognising faces, watching television and board work. Spectacle magnifiers (187 patients), hand/stand magnifiers (9 patients), closed-circuit television (3 patients), overhead illumination lamp (143 patients) and reading stand (24 patients) were prescribed for reading tasks. Light control devices (146 patients) were used for glare control, and cane (128 patients) and flashlight (50 patients) for mobility. Patients were trained in activities to improve their daily living skills, (54 patients); counselled in environmental modification (144 patients) and ancillary care (63 patients) for educational and vocational needs. Conclusion:Data obtained from this study elucidates the characteristics of low-vision patients. This information is likely to help in the development of appropriate low vision services.

How to cite this article:
Khan S A. A retrospective study of low-vision cases in an Indian tertiary eye-care hospital.Indian J Ophthalmol 2000;48:201-7

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Khan S A. A retrospective study of low-vision cases in an Indian tertiary eye-care hospital. Indian J Ophthalmol [serial online] 2000 [cited 2020 Sep 26 ];48:201-7
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The most recent (1997) projected estimate for world blindness points to some 45 million blind, and an additional 135 million visually disabled (those with low vision). About 90% of the world's blind live in the developing world.[1] It is estimated that there are 9-12 million blind in India, which amounts to about one-fourth of all the blind people worldwide.[2,3] A survey in 1986 by the World Health Organisation (WHO) and National Programme on Prevention and Control of Blindness (NPPCB) in India showed that 10% of the 9.61, that is 0.96 million persons, have incurable blindness and would require rehabilitation services. It has been observed that almost 90% of the so-called blind population do not have total loss of visual function, but retain a degree of useable residual vision.[4] Given this situation, there is a great need for comprehensive low-vision rehabilitation services in India and other developing countries.

Although there has been an increase in awareness of low-vision rehabilitation among eye-care professionals in India, concrete steps have not been taken to develop low-vision services. Eye-care professionals in the field have called for improvement of vision rehabilitation services in India for many years.[5,6] To plan appropriate and effective low-vision services, we need reliable and up-to-date information on low-vision patients in India. Such information is not readily available. To obtain this information, a retrospective study of patient records was done in a tertiary eye hospital in India.

 Materials and Methods

This study was done at the L.V. Prasad Eye Institute (LVPEI) which is a private, not-for-profit, well equipped tertiary referral eye hospital offering low-vision care to the partially sighted at its Centre for Sight Enhancement {CSE}, to both paying and non-paying patients.

Information was obtained from the records of 410 patients who had attended the Centre for Low Vision from 1 September 1997 to 31 August 1998. During this study period 30, 641 patients were seen at LVPEI, and 971 (3.1%) were referred for low vision care. Of these, examined in various services 410 were seen by the author [Table:1]. Among the 30, 641 patients seen at LVPEI, 26, 366 were adults and 701 (2.6%) were referred to CSE; there were 4, 275 children and 270 (6.3%) were referred to CSE [Figure:1]. Females constituted 41% of LVPEI patients; those referred to CSE were 29% [Table:1]. Patients underwent a comprehensive clinical low vision examination[7] [Table:2]. Data obtained from patient records included age, gender, consanguinity, visual acuity, visual fields, ocular conditions causing low vision, and types of low-vision devices and methods prescribed. All data were coded to maintain patient confidentiality. Visual acuity could not be recorded in three children who were very young. Visual field studies in 160 patients could not be done either due to poor fixation, very low vision, or the reason was not specified. The main cause of low vision in the better eye was recorded.

 Definition of low vision

"A person with low vision is one who has impairment of visual function even after treatment and/ or refractive correction, and has a visual acuity in the better eye <6/18 to light perception (LP), or a visual field of <10 from the point of fixation, but who uses or is potentially able to use vision for the planning or execution of a task".[8]


A total of 410 patients was studied; one-fifth (21%) were in the 11 - 20 years age group. The distribution showed a maximum peaked curve with almost half the patients in the 0-30 years age group (46%) and 18% in the above 60 years age group. Males comprised 72% (297) and females, 28% (113) [Table:3]. Parental consanguinity was present in almost one-third of these patients (27%). Visual acuity in the better eye was <6/18 to 6/60 in almost half of these patients (49.3%). Significant visual loss with visual acuity of <6/60 to LP was present in 84 patients (20.8%). One hundred and twenty two patients (29.9%) referred with visual acuity of ≥ 6/18 either had difficulty in reading normal print or restricted visual fields [Figure:2]. Field studies were performed in 250 patients, of whom 12 had less than 10 of central field, 148 had contracted fields, and 90 had central [Table:4].

The four major causes of low vision were retinitis pigmentosa (19%); macular diseases including heredomacular and age-related macular degeneration (17.7%); diabetic retinopathy (13%); and degenerative myopia (9%). The details are shown in [Figure:3].

Standard prescription spectacles were provided to 174 patients [Figure:4]. Hand-held distance telescopes were prescribed for board work for 45 students who had best corrected visual acuity ranging from 2/60 to 6/30 in the better eye. All these students were able to achieve visual acuity of ≥ 6/18 whereas almost 85% had a vision of ≥ 6/12 with the prescribed telescopes. The spectacle magnifiers for reading and writing tasks were prescribed to 187 patients who presented with a reading acuity of N48 to N12. Nearly half these patients (49.2%) improved to N6 and 39% to N8, and the rest to N10. Fourteen patients with reading acuity from N24 to N12 were prescribed bifocals. All achieved a reading acuity of ≥ N8, and 64.3% had N6 vision. Nine patients who had reading acuity ranging from N36 to N12 were given hand/stand magnifiers; these patients achieved N12 or better vision. Among these 55.6% achieved visual acuity of N6, one improved to N12 and three improved to N10 or N8. Three patients with reading acuity of N42 were provided with closed-circuit television (CCTV), and showed improvement to N6 reading acuity. [Table:5] [Table:6]. The three most common non-optical devices prescribed were reading lamps (143) for near tasks, light control devices (absorptive lenses and wide brimmed hat (146) for glare control and mobility canes (128).

Though it was not possible to measure the improvement objectively, non-optical aids enhanced subjectively the use of vision in these patients with or without the optical devices. These patients were also trained to use these devices, to improve daily living skills (54), given counselling on environmental modification (144) and ancillary care (63) for educational and vocational needs [Figure:5]. It may be noted that a single patient may have been prescribed more than one type of optical device or provided with more than one service.


The data showed a 3% prevalence of low vision among LVPEI patients. One of every 38 (2.6%) adults and one of every 15 (6.3%) children who visited LVPEI for ophthalmology services was referred for low vision care. Relatively fewer females were referred (29%); this needs to be investigated and referrals should be encouraged. However, among children both girls and boys nearly equally represented. This, we believe, could be due to increased awareness among parents. With almost half the patients falling into the 0-30 years age group, it is clear that the socioeconomic burden due to low vision is considerable. In our study, unlike most centres in the developed countries,[9] the elderly group (>60 years) represents a relatively small number (18%). This could be either due to the low life expectancy (62 years) of the Indian population[10] and / or lack of access to low-vision services.

Retinal causes formed the major reason for referral to low-vision care; these include retinitis pigmentosa, macular degeneration, diabetic retinopathy and myopic degeneration. Hereditary eye disease (retinitis pigmentosa, heredomacular disease, achomatopsia, congenital eye anamolies and congenital cataract) was the other main cause of low vision. It is thought that consanguineous marriages, which are common in southern India, may contribute to these causes of low vision. Parental consanguinity was present in almost one-third of these patients, which showed that genetic counselling and educational programs regarding the risk of intermarriages are required in order to reduce the unwanted propagation of genetic ocular diseases in this part of the world.

For most of the visually impaired, there is no prospect of curative treatment of the underlying pathology. It becomes incumbent upon the research community and the clinical and rehabilitation profession, to strive to enable people with low vision to perform tasks that are important at the work place or for daily living. This may mean supplementing visual abilities using low vision devices, and training. The data from this retrospective study showed that a significant number of low-vision patients needed careful refraction followed by standard prescription spectacles which are widely available at low cost. Appropriate magnification was achieved in majority of these patients with basic spectacles with spherical glass lenses and lenticular spherical lenses in power ranging from 12 to 24 diopters. These are available in India, retailing at Rs. 300 - 800 The hand-held and stand magnifier were prescribed to nine patients; they are of relatively low cost (Rs.100-250), but have poor optical quality and are not available in higher magnification. There is a great need in India for research, development and manufacture of good quality, low-vision optical devices with aspheric lenses. Some of these patients required optimal optical devices which included appropriate refractive correction and advice on illumination and light sensitivity. A simple, functioning, adjustable wooden reading stand was developed locally at a cost of Rs.450. This illustrated the point that low-vision care need not be difficult and expensive.

Some of the challenges and possible solutions in the delivery of low vision services in India are outlined below:

To incorporate into Primary Health Care and Primary Eye Care Programs, effective measures for the early identification and referral of those who may benefit from low- vision rehabilitation services. This can include vision screening of specified groups, assessment by eye or health practitioners and rehabilitation personnel. Knowledge of the need for and the range of services available for people with low vision can promote family or self identification.

To spread community awareness and public education.

To create awareness among health-care professionals through pre - and in-service levels of medical education to sensitise the medical community to the s.cope of low vision and to train them in making appropriate referrals to low-vision rehabilitation services.

To develop concerted efforts to eliminate any legal or other barriers that deny people with low vision access to educational and vocational sservices within their communities.

To adopt community-based rehabilitation to provide instruction to the low-vision person in his/her own environment.

To develop and harmonise standards for optical devices including the manufacture of aspherical lenses.

To develop curricula to train various cadres of personnel involved in low-vision care.

To evaluate low-vision care in different settings to strengthen the case for development of appropriate services.

To develop effective quantitative and qualitative evaluation mechanisms that measure consumer satisfaction and the cost, cost effectiveness, and define clear outcome measures.


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