Comparison of exudative age-related macular degeneration subtypes in Japanese and French Patients: multicenter diagnosis with multimodal imaging.

Purpose: To compare and analyze differences and similarities between Japanese and French patients in subtype diagnosis of exudative age-related macular degeneration (AMD) as determined by fundus photography (FP) and fluorescein angiography (FA), and a multimodal imaging involving FP, FA, indocyanine green angiography (ICGA), and optical coherence tomography (OCT).

Design: Retrospective chart review.

Methods: We determined the subtype diagnosis for 99 consecutive Japanese eyes and 94 consecutive French eyes with exudative AMD. The first-step diagnosis was made using FP and FA, while the second-step diagnosis was made using FP, FA/ICGA, and OCT. The diagnoses made by Japanese and French physicians were compared, and when the diagnoses differed, a third institute was consulted to arrive at a final consensus and diagnosis.

Results: The first-step diagnosis showed 20%-30% disagreement against the final diagnosis, but the second-step diagnosis showed only 10% disagreement. Polypoidal choroidal vasculopathy (PCV) was observed more in Japanese patients (48%) than in French (9%), and the rate of PCV with type 1 or 2 choroidal neovascularization (CNV) was extremely low: 3% in Japanese and 0% in French. Type 1 CNV was found significantly more in French cases (53.3% vs 35.1%, P=.018), while the rate of eyes with type 2 CNV only or chorioretinal anastomosis was similar between populations.

Conclusions: Multimodality imaging significantly improved the sub-classification of AMD. There were significant differences between the 2 series in the proportions of type 1 CNV and PCV, while the proportions of type 2 CNV only and chorioretinal anastomosis were similar between groups.