Abstract
Purpose: :
To characterize long-term retinal morphology following full-fluence photodynamic therapy (PDT) for neovascular age-related macular degeneration (AMD).
Methods: :
A retrospective review was conducted of consecutive patients meeting criteria seen between January and April 2011 by a single physician (GAW) after IRB approval. Retinal thickness and morphology measurements were gathered from spectral domain optical coherence tomography (OCT) and autofluorescence (AF) images performed on the Spectralis (Heidelberg, Germany). The area of hypoautofluorescence was traced and calculated by a masked reader (MDN).
Results: :
A total of 22 eyes from 11 patients were included in the analysis. In this cohort, 15 eyes were treated with PDT and the remaining 7 untreated eyes served as control. Baseline vision was 20/109(20/20- CF) in the PDT-treated eyes and 20/55 (20/20-20/150) in the untreated eyes. At the time of Spectralis imaging, the average final vision of PDT-treated eyes was 20/332. In 17 eyes with AF available, mean area of hypoautofluorescence was 14.26mm2 in the PDT-treated eyes versus 7.59mm2 in the untreated eyes. In the 15 PDT-treated eyes, mean central average thickness was 327.33um and mean central minimum thickness was 208.13um. In the 7 control eyes, mean central average thickness was 249.29um and mean central minimum thickness was 185.29um. Final retinal anatomy after PDT could be characterized into two subgroups: 1) atrophic and 2) cystic. In the 11 atrophic PDT-treated eyes, mean central average thickness was 250.64um and mean central minimum thickness was 135.09um. In the 4 cystic PDT-treated eyes, mean central average thickness was 538.25um and mean central minimum thickness was 409um.
Conclusions: :
Although our initial hypothesis was that retinal thinning is a long-term adverse effect of PDT, our results showed two distinct subgroups: 1) atrophic and 2) cystic. In the atrophic subgroup, there is evidence of focal thinning that is likely due to PDT. In the cystic group, average thickness is actually greater than untreated eyes. The area of hypoautofluorescence is larger in the PDT-treated eyes than contralateral eyes. In the absence of prospective randomized data, our study supports the theoretical concern of long-term retinal scarring after PDT.
Keywords: age-related macular degeneration • photodynamic therapy