Visual function following transpupillary thermotherapy with adjusted laser parameters for the treatment of exudative age-related macular degeneration: a pilot study

Purpose: To evaluate the efficacy of transpupillary thermotherapy (TTT) using adjusted laser parameters for the treatment of choroidal neovascularization (CNV) secondary to age-related macular degeneration. Methods: TTT was performed on patients with CNV using a diode laser (810 nm) for 60 s in a subthreshold manner. Power settings were varied between 460 and 1200 mW, depending on lesion size, presence of pigment epithelial detachment and the amount of fundal pigmentation and subretinal fluid. LogMAR visual acuity, contrast sensitivity (Pelli-Robson) and metamorphopsia (Amsler chart) were assessed prior to and 6 months following treatment. Subjects also self-administered the National Eye Institute 25-Item Visual Function Questionnaire. Results: Thirty occult/minimally classic and eight predominantly classic membranes were treated with TTT. At 6 months, absence or significant reduction of fluorescein leakage was observed in 20 (53%) patients. Stabilization of vision (loss of less than 15 letters) was observed in 25/30 (83%) eyes with occult/minimally classic CNV and 5/8 (63%) eyes with predominantly classic CNV. Improvement of contrast sensitivity was noted in 15 (35%) eyes, in 10 (26%) eyes it remained unchanged and in 13 (34%) eyes it deteriorated. There was no statistically significant effect of TTT on the National Eye Institute 25-Item Visual Function Questionnaire composite or subscale scores. Conclusions: TTT using adjusted parameters depending on fundal characteristics appears to be effective in stabilizing subjective and objective visual ability in a considerable number of patients with subfoveal CNV due to age-related macular degeneration. Larger-scale studies are required to confirm the benefit of this technique as opposed to the natural history of occult CNV.