Evaluation of the traveling vision examiner program in the submacular surgery trials pilot study

PURPOSE: To describe methods and results and to assess the value of a Traveling Vision Examiner (TVE) Program designed to provide masked vision measurements by expert vision examiners who were independent of, and traveled to, local clinical centers. METHODS: The Submacular Surgery Trials (SST) Pilot Study was conducted to refine the design and methods for a set of multicenter, randomized clinical trials to evaluate submacular surgery in patients with subfoveal choroidal neovascularization (CNV) due to age-related macular degeneration (AMD) or ocular histoplasmosis (OHS), or idiopathic CNV in which the primary study outcome would be change in 2-year best-corrected vision from baseline. As part of the SST Pilot Study, the feasibility and value of a TVE Program was assessed. The goal of the program was to obtain unbiased vision measurements, according to a standard protocol, of best-corrected visual acuity, reading speed, and contrast threshold, of each patient at 2 and 4 years after enrollment. RESULTS: Eighty-three visits by TVEs were made to 16 centers participating in the SST Pilot Study; 239 patients had at least one masked vision examination. Comparison of pairs of vision measurements of the traveling vision examiners and local vision examiners for 71 patients made on the same day showed good agreement overall (intraclass correlation coefficient > or = 0.81). CONCLUSIONS: The proposed TVE Program was judged to be a feasible and useful method of providing standardized, unbiased, masked vision measurements. This approach was incorporated into the larger clinical trials conducted by the SST Research Group.