# Normative Database and Determinants of Retinal and Choroidal Vessel Density in Tibetan Children

## TL;DR

This study finds that retinal blood vessel density in Tibetan children is linked to their body's oxygen levels, suggesting a unique adaptation to high-altitude hypoxia.

## Contribution

The study introduces systemic oxygen saturation as a novel determinant of foveal vascular density in Tibetan children.

## Key findings

- Foveal retinal vessel density is positively correlated with systemic oxygen saturation in Tibetan children.
- Retinal microcirculation reflects adaptation to chronic hypoxia in this population.

## Abstract

What are the main findings?
Foveal retinal vessel density in Tibetan children is positively correlated with systemic oxygen saturation.The retinal microcirculation reflects adaptation to chronic hypoxia.

Foveal retinal vessel density in Tibetan children is positively correlated with systemic oxygen saturation.

The retinal microcirculation reflects adaptation to chronic hypoxia.

What are the implications of the main findings?
This study provides normative OCTA data for this unique pediatric population and identifies systemic oxygen saturation as a novel determinant of foveal vascular density.This study positions retinal vascular metrics as a potential non-invasive biomarker for systemic oxygen homeostasis and high-altitude adaptation.

This study provides normative OCTA data for this unique pediatric population and identifies systemic oxygen saturation as a novel determinant of foveal vascular density.

This study positions retinal vascular metrics as a potential non-invasive biomarker for systemic oxygen homeostasis and high-altitude adaptation.

Background/Objectives: This study investigates the normative data and determinants of retinal and choroidal vessel density (VD) in Tibetan children using optical coherence tomography angiography (OCTA). Methods: This study recruited students from primary schools in Lhasa who underwent OCTA encompassing VD in the superficial capillary plexus (SCP) and the deep capillary plexus (DCP) and choriocapillaris (CC) in the macular region, as well as refractive status, axial length, and systemic examinations. Results: This study included a total of 645 children who met the criteria. The results showed that VD in the fovea was significantly higher in the SCP than in the DCP, while CC had the highest VD in the fovea. Correlation analysis revealed strong correlations in VD among all quadrants of the SCP, DCP, and CC, as well as significant correlations between corresponding regions of the SCP and DCP. VD showed no significant association with age, sex, axial length, or spherical equivalent. Foveal VD in both the SCP and DCP was positively correlated with oxygen saturation. No consistent correlation was found between choroidal or retinal thickness and VD in any layer. Conclusions: The identified link between systemic oxygen saturation and foveal vascular density offers a novel perspective on human adaptation to chronic hypoxia, positioning the retinal microcirculation as a sensitive indicator of systemic oxygen homeostasis.