Inversion of Asymmetric Vortex Vein Dilatation in Pachychoroid Spectrum Diseases

Abstract

PurposeIntervortex venous anastomosis is widely recognized as compensating for vortex vein congestion in pachychoroid spectrum diseases. However, determining the blood flow direction within the compensated drainage route is often challenging. Herein, we investigated the morphological patterns of vortex veins in eyes showing retrograde pulsatile vortex venous flow. DesignRetrospective observational case series. Subjects689 consecutive eyes with treatment-naïve central serous chorioretinopathy, pachychoroid neovasculopathy, or polypoidal choroidal vasculopathy. MethodsWe reviewed the clinical records of patients with these pachychoroid spectrum diseases. Multimodal images including indocyanine green angiography (ICGA) and en face optical coherence tomography were analyzed. Main Outcome MeasuresIntervortex venous anastomosis between superotemporal and inferotemporal vortex veins and the dominant site of dilated temporal vortex veins were determined in the eyes with retrograde pulsatile vortex venous flow in the temporal vortex veins. Results22 eyes with retrograde pulsatile vortex venous flow in the temporal vortex veins were identified utilizing early-phase ICGA videos. In 9 eyes, retrograde pulsatile flow was detected in the superotemporal vortex veins which were connected to the inferotemporal vortex veins via intervortex venous anastomoses. Among these cases, contralateral inferotemporal vortex vein dilatation was dominant in 7 eyes (77.8%), while superotemporal and inferotemporal vortex veins were symmetrically dilated in the other 2 eyes (22.2%). On the other hand, in 13 eyes, the retrograde pulsatile flow was detected in the inferotemporal vortex veins which were linked to the superotemporal vortex veins via intervortex venous anastomoses. In these eyes, contralateral superotemporal vortex vein dilatation was dominant in 10 eyes (76.9%). Superotemporal and inferotemporal vortex veins were symmetrically dilated in 2 eyes (15.4%), while mainly inferotemporal vortex veins were dilated in 1 eye (7.7%). ConclusionsIn pachychoroid spectrum diseases, there are cases wherein congested venous blood might drain into the contralateral vortex veins via intervortex anastomoses. Overloaded contralateral vortex veins may, as a consequence, become more dilated than the primary congested vortex veins. Inversion of asymmetric vortex vein dilatation might thereby develop in pachychoroid spectrum diseases.