# Significant Correlation Between Retinal Blood Flow and Oxygen Saturation During Intravitreal Aflibercept Treatment for Central Retinal Vein Occlusion

## TL;DR

This study shows that retinal blood flow and oxygen levels improve with aflibercept treatment for a type of eye disease called central retinal vein occlusion.

## Contribution

The study demonstrates a significant correlation between retinal venous oxygen saturation and blood flow after aflibercept treatment for CRVO.

## Key findings

- Visual acuity and retinal thickness improved significantly after aflibercept treatment.
- Venous oxygen saturation increased significantly from one month post-treatment.
- A positive correlation was found between venous oxygen saturation and mean blur rate after treatment.

## Abstract

The purpose of this study was to evaluate the relationship between retinal blood flow and oxygen saturation during intravitreal aflibercept treatment for central retinal vein occlusion (CRVO) using OxymapT1 and laser speckle flowgraphy (LSFG).

Thirty-two untreated patients (32 eyes) with nonischemic CRVO received monthly intravitreal aflibercept injections for 3 months followed by a pro re nata regimen; they were followed up for approximately 1 year. Central retinal thickness, retinal oxygen saturation, and retinal blood flow were measured using optical coherence tomography, OxymapT1, and LSFG, respectively.

Visual acuity (VA) and central retinal thickness (CRT; µm) significantly improved from 1 month onward in both the all-patient and nonischemic groups (VA baseline = 0.51, 0.48, 1 month = 0.30, 0.29, P = 0.049, P = 0.032; and CRT baseline = 615.0, 615.0, 1 month = 278.4, 275.0, P = 0.049, P < 0.001). Using OxymapT1, retinal venous oxygen saturation was reduced at baseline but significantly increased from 1 month after aflibercept injection and remained elevated in both groups (baseline = 34.1%, and 1 month = 41.1%, P = 0.006). Mean blur rate (MBR) remained stable overall, with a significant increase at the final visit in the nonischemic group (baseline = 22.4, and final = 27.4, P = 0.001). A significant positive correlation was found between venous oxygen saturation and MBR from 1 month after treatment onward (1 month = R = 0.538, P = 0.002).

In CRVO, venous oxygen saturation and MBR were significantly correlated.

Measuring and evaluating retinal blood flow and oxygen saturation during treatment of CRVO eyes is recommended.