Demographic characteristics of the vision-disabled elderly.

PURPOSE: To profile certain demographic features of the low-vision population in Ontario, Canada. METHODS: Sixty-six optometrists or optometry centers, 8 ophthalmologists, and 23 Canadian National Institute for the Blind rehabilitation worker teams were recruited to the study. They were required to report on their low-vision examinations during a 3-year period. RESULTS: Reports from 4744 low-vision examinations were received. Of the patients examined, 71% were over age 65 (subsequently called seniors or elderly), and 55% were over age 75. Ninety percent of all the patients lived in households and 10% lived in institutions. Seniors made up 71% of the patients living in households and 88% of the patients living in institutions. Most of the seniors were women (65%), and 57% had functional limitations in addition to low vision, most commonly limitations in mobility, hearing, or agility. Age-related maculopathy was the primary diagnosis in 75% of seniors, and the most common secondary diagnosis was cataract (46%). The main objective for most elderly low-vision patients was to gain improvement in personal reading (75%). CONCLUSIONS: The vast majority of low-vision patients were elderly, the largest number being 75 to 84 years old. When older senior low-vision patients (> or = 85 years) were compared with younger seniors (65 to 74 years), the older seniors were more likely to be women, more likely to have additional functional limitations, more likely to live in an institution, and more likely to have age-related maculopathy and cataract. Whether some elderly low-vision patients may be helped by cataract surgery needs to be determined.

Unexpectedly large enhancement of a severely constricted field with reversed Galilean telescopes.

A 25-year-old female presented with severely constricted visual fields secondary to stroke associated with mitral valve prolapse. Repeatably measured central fields of less than 4 degrees diameter showed an unexpected enlargement up to 20 to 40 degrees diameter, when fitted with reversed full field 1.3x and 1.7x Galilean telescopes. Although initial tests indicated no psychogenic component, fields of approximately 20 degrees diameter were eventually obtained through an imitation telescope made with 2 plano lenses. This technique may be useful in determining whether there is a psychogenic component to inexplicable field results in other patients.

A confrontation test of visual fields in the low-vision patient.

We report a simple method for measuring the extent of the visual field in patients from whom this measurement is difficult. One Maddox rod is used before the eye under test. Through the Maddox rod lens, this eye sees a white streak produced by a penlight. While fixating this white streak another penlight is brought into the field of view from the periphery. The patient is required to report only whether he sees one or two light streaks. The results correlate well with field measurements made on the tangent screen in patients with simulated field losses.