DIFFERENCE BETWEEN PACHYCHOROID AND NONPACHYCHOROID POLYPOIDAL CHOROIDAL VASCULOPATHY AND THEIR RESPONSE TO ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY

Purpose: Recent investigations have found a biphasic pattern of choroidal thickness within polypoidal choroidal vasculopathy (PCV) patients. This study aims to investigate the relationship between choroidal thickness and the clinical features of PCV eyes. Method: We investigated the correlation between various clinical features including subfoveal choroidal thickness (SFCT) and the response to 3-monthly anti-vascular endothelial growth factor (VEGF) treatments in 62 consecutive, treatment-naive PCV patients (66 eyes). After finding out SFCT as the only factor that was correlated with anti-VEGF treatment, we then set up to determine a best cutoff line for SFCT that could be used as a parameter to differentiate PCV patients into pachychoroid and nonpachychoroid groups using the Youden index for best combined specificity and sensitivity. We then compared the demographic features, clinical characteristics, and the response to anti-VEGF between both groups, to determine whether there is a difference between these two groups. Results: Subfoveal choroidal thickness was the only significant factor for the treatment effect. The SFCT of 267.5 mu m is the best cutoff line. The pachychoroid group showed significant younger ages (64.1 +/- 9.6 vs. 72.0 +/- 8.2,P= 0.004), fewer age-related macular degeneration-like features (50.0 vs. 81.3%,P= 0.027), more central serous chorioretinopathy-like features (typical retinal pigment epithelial mottling [61.1 vs. 16.7%,P= 0.0014] and choroidal vascular hyperpermeability [88.9 vs. 37.5%,P= 0.0002]), and less response to 3-monthly anti-VEGF treatments (27.8 vs. 83.3%,P< 0.0001) as compared to the nonpachychoroid group. Conclusion: Polypoidal choroidal vasculopathy patients could be subclassified into pachychoroid and nonpachychoroid groups. The pachychoroid subtype of PCV has significantly younger ages, fewer age-related macular degeneration-like features, more central serous chorioretinopathy-like features, and less response to anti-VEGF treatment.