Remodeling of macular vortex veins in pachychoroid neovasculopathy

Superior and inferior macular vortex veins are divided by a horizontal watershed passing through the macula. We evaluated macular vortex vein remodeling in eyes with pachychoroid neovasculopathy (PNV). Thirty eyes of 30 patients with treatment-naïve PNV and 30 normal eyes of 30 age-, gender-, and refraction-matched subjects were studied. We assessed the features of macular vortex veins employing en face optical coherence tomography (OCT) and determined central choroidal thickness (CCT) using B-mode OCT. Of the 30 normal eyes, a horizontal watershed was identified in 24 eyes (80%), while venous anastomosis between the superior and inferior vortex veins was observed in 6 eyes (20%). Mean CCT was 233 μm. Of the 30 eyes with PNV, vortex veins were dilated in all 30 eyes with PNV. In 27 of the 30 PNV eyes (90%), the horizontal watershed had disappeared, and collateral veins had instead developed via anastomosis between the superior and inferior vortex veins, making this finding significantly more frequent than in normal eyes (P < 0.001). Mean CCT was 357 μm, significantly thicker than that of normal eyes (P < 0.001). Remodeling of choroidal drainage routes by venous anastomosis between superior and inferior vortex veins was common in eyes with PNV. This observation suggests longstanding congestion of the choroidal veins.