Causes of low vision and major low-vision devices prescribed in the low-vision clinic of Nepal Eye Hospital, Nepal

Abstract

Visual impairment is a major public health problem. Identifying the main causes of low vision and the major low-vision devices prescribed will help to develop and implement the low-vision rehabilitation service. We find out the causes of low vision and the low-vision devices prescribed in the low-vision clinic of Nepal Eye Hospital. A retrospective cross-sectional review of all patients attending the low-vision clinic from 1 May 2009 to 31 April 2011. Patients having visual acuity less than 3/60 in the better eye with best refractive correction were excluded. Of the 137 patients, the mean age was 32.53 ± 22.90 years; 71.5% were male and 67.88% were under 40. The major causes of low vision were nystagmus (30.70%), high refractive error (22.62%), cataract (15.30%), retinitis pigmentosa (15.30%) and age-related macular degeneration (13.10%); 78.10% patents were wearing glasses while telescopes were prescribed for 29.20% patients. Nystagmus, high refractive error and cataract are the main causes of low vision in Nepal. The majority of the low-vision patients seen in this clinic are of working age. Telescopes are the major low-vision device prescribed. We review approach the cause of low-vision problem in low-vision clinic Nepal Eye Hospital, Nepal.

Keywords: Cataract; low vision; nystagmus; telescope; vision impairment.

Figure 1.

Best-corrected visual acuity of the participants. Overall, 78.10% patients had at least some amount of refractive error; 61 patients were myopic with mean age 34.85 years (sd: ±23.73). Their mean refractive error was −3.89D (sd: ±4.80D) with a range from −0.25D to −19.50D in the better eye. They had mean visual acuity of 0.92logMAR (sd: ±0.23). There were 46 hyperopic patients with mean refractive error +4.82D (sd: ±4.63D) in the better eye, with visual acuity of 0.91logMAR (sd: ±0.21).

Figure 2.

Causes of low vision. In the group of nystagmus patients, the mean age was 16.02 ± 7.08 years ranging from 4 to 29. Subjects with high refractive error (≥±5.00D) were older: mean age was 21.32 ± 14.38 years ranging from 5 to 77 in the group having high refractive error. There were 13 people with high myopia (9 male and 4 female) with mean myopia −11.54 ± 5.34D ranging from −5.25 to −19.50 in the better eye. Similarly, there were 18 people with high hypermetropia (15 male and 3 female) with mean hyperopia +9.85 ± 3.13D ranging from +5.00 to +16.00.