Objective
To evaluate the effectiveness of low-vision rehabilitation in 2 cohorts derived from the Veterans Affairs Low-Vision Intervention Trial.
Methods
In a prospective study, we observed 44 participants randomly assigned to outpatient low-vision rehabilitation who did not receive additional treatment after the trial ended at 4-month follow-up and 56 participants randomly assigned to the waiting-list control group and thereafter to standard therapy. The outcome measures included visual ability domains (reading, mobility, visual information processing, and visual motor skills) and overall visual ability estimated from difficulty ratings using the 48-item Veterans Affairs Low-Vision Visual Functioning Questionnaire. Mean visual ability scores for the treatment and control groups were compared at baseline, 4 months, and 1 year. A mixed-effects model was used to test treatment effects between groups over time. Differences in visual ability mean scores from baseline to 1 year were compared between the 2 groups. Within-group changes in visual ability were compared from baseline to 1 year, from baseline to 4 months, and from 4 months to 1 year.
Results
At baseline, there were no significant differences in mean visual ability scores between groups. From baseline to 4 months, the treatment effects for all visual ability domains and overall visual ability increased to a maximum in the treatment group (P < .001), whereas the mean scores (except visual motor skills) decreased in the control group (P < .01). From 4 months to 1 year, the differences became smaller. There was a loss of visual ability in reading and visual information processing (but not in visual motor skills, mobility, or overall visual ability) in the treatment group and a gain in all visual ability measures in the control group. Interactions of treatment and follow-up time in the mixed models showed the trend of treatment effects significantly changed over time from baseline to 1 year (P < .001) for all visual ability domains and overall visual ability. Both groups demonstrated improvement in visual ability from baseline to 1 year (P < .001) (except for mobility in the control group). Overall visual ability (but not other visual ability domains) improved more in the treatment group than in the control group (P = .01).
Conclusions
Visual ability improved significantly in both groups from baseline to 1 year. The Low-Vision Intervention Trial treatment effect is robust and well maintained for patients with macular diseases.