Vanishing pachy-choroid in pachychoroid neovasculopathy under long-term anti-vascular endothelial growth factor therapy

BACKGROUND: To investigate the diagnostic value of choroidal thickness in the definition of pachychoroid neovasculopathy (PNV), especially in eyes treated with anti-vascular endothelial growth factor (VEGF) therapy. METHODS: Twenty-two consecutive eyes of 11 patients with uni- or bilateral PNV were analyzed. Anti-VEGF treatment was correlated with changes in choroidal thickness on enhanced depth imaging optical coherence tomography. RESULTS: There were 14 eyes with PNV and 8 non-neovascular partner eyes. Mean age was 64.2 ± 4.0 (range: 60–72), total follow-up was 1.8 ± 0.4 (1–2) years. In PNV eyes, choroidal thickness at baseline was 400 ± 58 (269–485) μm. After two years and 13 anti-VEGF injections on average, a mean reduction of − 39 ± 10 (− 26 to − 56) % to final 241 ± 52 (162–327) μm was observed (p < 0.0001). Meanwhile, choroidal thickness in the partner eyes remained stable (p > 0.13 for all comparisons). A significant correlation of choroidal thinning and anti-VEGF injection rate was observed at year one (r = − 0.79; R(2) = 0.63; p = 0.00073) and two (r = − 0.69; R(2) = 0.48; p = 0.019). While 85.7% of PNV eyes exceeded a pachychoroid threshold of ≥350 μm at baseline, this figure dropped to 21.4% at year one and 0% at year two. CONCLUSION: In PNV, choroidal thickness significantly decreases with anti-VEGF therapy, resembling a “vanishing pachy-choroid”, and thus does not represent a valid long-term diagnostic criterium, especially when differentiating PNV from nAMD.