Changes in Foveal Thickness and Macular Function after Transpupillary Thermotherapy for Age-Related Macular Degeneration

Abstract

Purpose: To evaluate the effect of transpupillary thermotherapy (TTT) on foveal thickness and macular function in eyes with choroidal neovascularization (CNV) associated with age-related macular degeneration. Methods: Sixteen eyes with occult CNV and 6 eyes with classic CNV were treated with TTT. Optical coherence tomography and focal macular electroretinograms (FMERGs) elicited by a 15-degree stimulus were performed before, 3 months after TTT in 22 eyes and 6 months after TTT in 18 eyes. Results: Before TTT, the fovea in 20 of the 22 eyes with CNV was significantly thicker than that of normal subjects. The foveal thickness was reduced after TTT in 11 of 14 eyes with occult CNV and remained unchanged in 2 eyes. One eye with occult CNV before TTT developed a classic CNV with significant macular edema and increased foveal thickness 3 months after TTT. The amplitudes of the FMERGs were reduced in all eyes before TTT. In eyes with occult CNV, the mean b-wave amplitude increased significantly after TTT (p = 0.0260 at 3 months, p = 0.0142 at 6 months). When the change of foveal thickness was less than 20% after TTT, all eyes with occult CNV had a 30% or more increase in the b-wave amplitude. In eyes with classic CNV, the mean amplitude of the a- and b-waves did not change significantly after TTT. Conclusions: TTT improves macular function in eyes with occult CNV associated with age-related macular degeneration more when the change of foveal thickness is slight.