Abstract
Abstract: :
Purpose: To present visual acuity findings from the TTT4CNV clinical trial that compared transpupillary thermotherapy (TTT) to sham for subfoveal occult CNV caused by ARMD. Methods: Patients who had subfoveal occult CNV with maximum diameter of 3 mm and visual acuity of 20/50 to 20/400 were included in this multicenter study. The design included 2:1 randomization (TTT:sham), allocation concealment, and double masking. Patients were examined at 1,3,6,12,18 and 24 months. Re–treatment was permitted only at 3 months. Results: An intent–to–treat evaluation of the primary visual outcome data in 303 enrolled patients showed that TTT, as applied in this trial, did not result in a significantly beneficial effect relative to sham. Based on findings from the TAP and SST trials that eyes with poorer levels of visual acuity responded better to treatment, the subgroup with baseline VA 20/100 or less (n=124) was evaluated. At months 12, 18 and 24, the mean loss of VA was less in the TTT–treated group by 5 to 9 letters. Improvement in VA (by 2 or more lines) was significantly greater (P=0.03) in TTT–treated eyes at 12 months (19% vs. 0%) and at 18 months (17% vs. 0%). Longitudinal analysis of mean VA showed a significant time by treatment interaction (P=0.02) supportive of the reduced loss in TTT–treated eyes. The best results occurred in TTT–treated eyes that were not re–treated. Conclusions: While the overall comparison of TTT to sham did not show a benefit to TTT treatment, subgroup analysis of eyes with poorer baseline VA (20/100 or less) indicated a statistically significant treatment benefit, specifically less mean VA loss and a greater percentage showing improvement.
Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled • laser