Abstract
Purpose :
To report the choroidal characteristics of vortex vein (VV) drainage system in healthy individuals via ultra-widefield optical coherence tomography angiography (UWF-OCTA).
Methods :
A cross-sectional study included 207 healthy eyes of 207 participants in Zhongshan Ophthalmic Center (ZOC) from June 2022 to June 2023. The inclusion criteria were: (1) age (20-80 years); (2) axis length (AL) (21-26.5 mm); (3) spherical equivalent (SE) (–6.00 D ∼3.00 D); (4) BCVA ≤ 0.10 logMAR; (5) intraocular pressure (IOP) (10∼21 mm Hg); and (6) OCTA image quality score (0–10) ≥ 7. The exclusion criteria were: (1) history of ocular diseases; (2) systemic diseases affecting the choroidal circulation; (3) pregnancy and lactating; (4) long-term use of corticosteroids or vasoactive medications. All the participants underwent comprehensive ophthalmic examination, including UWF-OCTA (> 200 degrees). Mean choroidal thickness (ChT) and choroidal vascularity index (CVI) in each vortex vein quadrant (9 × 9 mm OCTA scan mode; superotemporal (ST), superonasal(SN), inferonasal (IN), and inferotemporal (IT) quadrants, respectively) were measured (Fig 1A). In addition, the VV drainage system was categorized as normal, hyperperfusion and hypoperfusion subtypes based on the ChT&CVI scheme. ChT (< 150 µm low; 150-250 µm normal; >250 µm high) and CVI (<25% low; 25-35% normal; >35% high).
Results :
A total of 207 healthy eyes from 207 participants (90 men and 107 women; mean age, 45.42 ± 16.92 years) were included, and the mean AL was 24.04 ± 1.13 mm. The ChT declined significantly after 50 years old (Fig 2A). However, CVI declined steadily from 20 to 80 years old (Fig 2B). Among the four VV drainage quadrants, the mean ChT (Figs 1B, 1D) and CVI (Figs 1C,1E) decreased in (ST-SN-IT-IN) order, and the ST quadrant had the thickest choroidal layer and the highest CVI. Compared with women, men had higher CVI in all VV quadrants (all P < 0.05). The proportion of females and the age of participants markedly decreased with increasing grades of the VV perfusion subtype (Fig 3).
Conclusions :
In healthy eyes, the most common preferential VV drainage route is the ST drainage system. Age- and sex-related differences are found in the choroidal VV drainage system of healthy eyes. The characteristics of choroidal VV drainage systems in healthy people may help to understand the pathological changes in diseases.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.