Eyes with poor visual acuity may benefit from TTT

MONTREAL — There was no significant difference in a treatment group undergoing transpupillary thermotherapy compared with a sham group for the treatment of age-related macular degeneration, Elias Reichel, MD, said here at the American Society of Retina Specialists meeting. However, patients with baseline visual acuities of 20/100 or worse showed a lower mean visual acuity loss and a greater percentage showed improvement than those randomized to the sham treatments, he said.

A total of 303 patients who had subfoveal occult choroidal neovascularization were included in a multicenter study, he said. Initial visual acuity ranged from 20/50 to 20/400. Patients were randomized to receive transpupillary thermotherapy (TTT) or sham treatment, with about 200 patients given TTT.

“Inclusion criteria was occult neovascularization with some lesions having up to 10% classic disease. The greatest diameter was 3 mm, and this was based upon limitations of the large spots most resistant,” he said.

A secondary endpoint of vision change from baseline “favored TTT with a four-letter difference,” he said. “However, there’s no significant difference overall or at a specific time in this analysis. This is a secondary endpoint. The most important primary endpoint is loss of less than three lines of VA … what we call the avoidance of modern vision loss. Again, the trends favored TTT, but this was not statistically significant and therefore we did not meet the primary endpoint.”

In a subgroup analysis of patients whose initial visual acuity was worse than 20/100, “we did see levels of improvement, and they were statistically significant with no patients in the sham group showing any level of improvement,” Dr. Reichel said. “When we looked at mean visual acuity change over time, there appeared to be a benefit of the mixed model analysis, and this was significant of the time of treatment interaction with a P value of .03.”