Low vision and methods of rehabilitation: a comparison between the past and present

The aims of this study were to determine the clinical effectiveness of optical and video low vision aids (LVA) and analyze the characteristics of the visually impaired at the low vision clinic of Chang Gung Memorial Hospital.

The use of LVA to improve distance and near visual functions was evaluated in 203 new patients from 1998 through 2001 at our clinic. The age, gender, visual status, and primary condition causing low vision of the patients were also compared with data obtained from two different study periods, from 1984 through 1987 and 1991 through 1994.

After careful refraction, spectacles only were able to meet both distance and near visual requirements in 21 patients (10.3%), and among them, 3 patients with hemianopsia were further prescribed Fresnel prisms. Of the 121 patients with distance visual requirements, 84 (69.4%) benefited from using telescopes; however, only one additional patient benefited from the addition of a head-mounted device. Of the 136 patients who could not read the newsprint, 118 (86.8%) succeeded in reading newsprint using optical magnifiers, and up to 125 (91.9%) with using the addition of a closed circuit television. Compared with the previous data, the average age of our patients has steadily increased, and the main cause of ocular pathology has changed accordingly.

Video magnifiers provided suitable rehabilitation for some patients who failed to see clearly using optical magnifiers. However, most of our low vision patients, who have changed during the last decades, can accomplish their desired visual tasks using traditional LVA.