Characteristics of vortex vein in healthy eyes and fundus diseases imaged by ultra-widefield OCTA.

PURPOSE

To investigate the characteristics of the vortex vein (VV) in healthy adults and patients with different fundus diseases using montaged ultra-widefield swept-source optical coherence tomography angiography (UWF SS-OCTA) images.

METHODS

En face UWF SS-OCTA mosaic choroidal images in five fixation directions and macular scan were acquired in healthy adults, patients with normal choroidal thickness (retinal vein occlusion, diabetic retinopathy), patients with thick choroidal thickness (central serous chorioretinopathy and polypoidal choroidal vasculopathy), and patients with thin choroidal thickness (retinitis pigmentosa, and high myopia). The frequency, morphology, anastomoses, asymmetry and vascularity index (CVI) of VVs were assessed.

RESULTS

The totality of VVs and macular CVI presented a gradual decline in the elderly (all P < 0.05). Anastomoses and asymmetric VVs appeared in normal eyes. The quantitation and morphology of VV in retinal vein occlusion, diabetic retinopathy, retinitis pigmentosa, and high myopia were not significantly different from those of controls. Macular CVI was reduced in retinitis pigmentosa and high myopia. There was an increased proportion of type I VV and a decrease in type IV VV in central serous chorioretinopathy and polypoidal choroidal vasculopathy groups (both P < 0.05). CVI in central serous chorioretinopathy was elevated, while it remained unchanged in polypoidal choroidal vasculopathy. The anastomoses and asymmetry in both groups were higher than those of controls (all P < 0.05).

CONCLUSIONS

The distribution patterns of VVs exhibited similarity among healthy adults, patients with fundus diseases and normal choroidal thickness or thin choroidal thickness, with frequent observations of anastomoses and asymmetry. Notedly, pachychoroid diseases demonstrated a higher prevalence of high-resistance VVs (type IV), anastomoses, and asymmetry, which might drive pathogenesis of pachychoroid diseases.