Prismatic correction in patients affected by age-related macular degeneration

Objective: To evaluate by means of a controlled clinical trial the effectiveness and the tolerance of prismatic correction in improving visual function in patients affected by advanced bilateral age-related macular degeneration. Setting: Department of Ophthalmology, Eye Clinic, University of Trieste. Subjects and interventions: Each patient underwent an ophthalmologic examination, complete with distance visual acuity measurement using the Standard Early Treatment Diabetic Retinopathy Study chart. Patients were then randomly assigned to the treatment or control group. The treatment group received spectacles lenses with a prismatic correction of low power (5-7 prismatic dioptres) in the better eye. Main measures: Visual acuity was measured at baseline and 1, 90, 180 and 360 days after prescription in both groups. Results: The treatment group consisted of 14 patients, while the control group was of 14 patients. The prismatic correction was well tolerated in 85.7% of cases. Visual acuity in the treatment group improved mostly at three-month follow-up, with a slight further improvement at the six- and 12-month follow-ups, showing a statistically significant difference in comparison with the control group. No visual acuity improvement was registered in the control group. Conclusion: Monolateral prismatic correction may be considered a viable means to improve visual function in patients affected by bilateral age-related macular degeneration at an advanced stage.