Factors Influencing the Choice of Low-vision Devices for Visual Rehabilitation in Stargardt Disease

Background: Stargardt disease is the most common cause of juvenile macular degeneration leading to early central visual loss. Dispensing of correct low-vision devices based on the residual visual function and specific visual requirements of a patient can result in a positive outcome. It is important to know the factors involved in the selection of these devices. This study was undertaken to assess these factors.

Methods: Patients with Stargardt disease referred to a low-vision clinic underwent evaluation of visual status, disease stage, visual requirements and lifestyle. They were evaluated for suitability for successful use of various low-vision devices. Their education level and occupation were noted. They were counselled regarding the proper use of the devices and lifestyle modifications. For patients with extensive use of computers, modifications related to contrast, font size and audio software were explained.

Results: Among the 97 patients in the study (age range 7-66 years, mean 23.7 ± 13.1), there were 49 (50.5 per cent) students, 36 (37.1 per cent) employed, eight (8.2 per cent) unemployed, and four (4.2 per cent) homemakers. Except for seven patients (7.2 per cent), all were literate, with education ranging from primary school to college graduation. The presenting visual acuity for distance was 0.10-1.47 (0.79 ± 0.28), and for near was N4-N40 (N9.95 ± 6.65). This acuity showed positive correlation with age (p < 0.0001, R = 0.16) and with magnification required (p < 0.0001, R = 0.26). Patients above 40 years preferred higher adds and half-eye glasses, whereas younger patients preferred dome magnifiers. The occupation also influenced the choice. Disease stage was seen to affect the choice with advanced stages requiring higher magnifiers (p = 0.03, R = 0.11). Duration of disease and the magnification of low-vision devices showed a positive correlation (p = 0.03, R = 0.049).

Conclusions: Age, presenting visual acuity, disease stage, duration, education and occupation influenced the choice of low-vision devices in patients with Stargardt disease. However, they appear to be interdependent and a larger, controlled study is required to provide information on the individual effect.