Abstract
Purpose:
To evaluate the differences in progression to wet age-related macular degeneration (AMD) in the Asian population.
Methods:
The medical records of 897 AMD patients were reviewed, which included fundus photographs (FP), fluorescein angiography(FAG) and indocyanine green angiography(ICG). We calculated the AREDS score with initial FPs. Asymmetric AMD (asyAMD) was defined as cases which had wet AMD in only one eye and no sign of wet AMD in the fellow eye (f/e). In asyAMD, we evaluated the findings on the f/e before the occurrence of wet AMD. Also, based on the initial AREDS score (2 to 4), the progression rate to wet AMD of the f/e was approximated in asyAMD.
Results:
A total of 665 AMD patients were included in the analysis (mean follow up : 57.51±44.89 months). Patients were classified into either dry or wet AMD (bilateral or asymmetric) group based on initial FPs. The asyAMD group was split into polypoidal choroidal vasculopathy (PCV) and typical AMD cases. 47 patients of asyAMD progressed to bilateral AMD at the end of the follow up period. Before the occurrence of wet AMD in the f/e, the prevalence of RPE change was higher in the PCV than typical AMD (52.3 vs 19.2%) (P=0.029), and that of large drusen was higher in the typical AMD than PCV (14.3 vs 61.5%) (P=0.001). Average AREDS score was lower in the PCV than typical AMD (2.35±0.49 vs 2.61±0.64) (P<0.001). In the f/e with AREDS score 2 (which never had large drusen or RPE change), 3.3% of typical AMD group and 0% of PCV group progressed to wet AMD after 5 years (P=0.091). In the f/e with AREDS score 3 (which had large drusen or RPE change, or both eye had intermediate drusen), 19.8% of the typical AMD group and 12.9% of the PCV group progressed to wet AMD (P=0.138). In the PCV group, only one subject had AREDS score 4 (both eyes had large drusen) and maintained a dry status at the end of the follow up.
Conclusions:
Before the progression to wet AMD in the f/e of PCV group, RPE change was more predominant than large drusen. The 5-year progression rate to wet AMD based on the AREDS score was different (AREDS 2: 0%, 3: 12.9%) especially in the PCV group compared to that of the Caucasian population (AREDS 2: 12%, 3: 25%). Considering the high proportion of PCV and its correlation with RPE change in the Asian population, RPE change should be scored highly when predicting a progression to wet AMD.