# Correlation Between Postoperative Vitreous Hemorrhage and Preoperative Evaluation of Optical Coherence Tomography Angiography in Proliferative Diabetic Retinopathy Surgery

## TL;DR

This study shows that more extensive retinal neovascularization before surgery is linked to postoperative vitreous hemorrhage in diabetic retinopathy patients.

## Contribution

The study introduces OCTA as a potential preoperative evaluation tool for predicting postoperative vitreous hemorrhage in PDR patients.

## Key findings

- Preoperative retinal neovascular area was significantly larger in patients who developed postoperative vitreous hemorrhage.
- Postoperative neovascular area remained significantly larger in the vitreous hemorrhage group compared to the control group.
- The reduction rate of neovascular area after surgery was not significantly different between the two groups.

## Abstract

Purpose: To measure and compare the extent of retinal neovascularization using optical coherence tomography angiography (OCTA) between patients with good postoperative outcomes for proliferative diabetic retinopathy (PDR) requiring surgical treatment and patients with vitreous hemorrhage (VH).

Methods: This retrospective study included patients who were diagnosed with PDR between January 2022 and December 2023 and underwent vitreous surgery. Cases that developed postoperative VH were classified as the VH group, and cases with good postoperative progress were classified as the control group. The extent of retinal neovascularization was measured from preoperative and postoperative images of the two groups taken by OCTA measured with a widefield optical coherence tomography (Canon, Xephilio OCT-A1), and a comparative study was conducted.

Results: The VH group consisted of 8 patients with 11 eyes (4 men and 4 women) with a mean age of 49.7 ± 14.2 years, while the control group consisted of 23 patients with 26 eyes (19 men and 4 women) with a mean age of 56.9 ± 11.8 years. The preoperative retinal neovascular area was 50,233.7 ± 38,581.1 (pixels) in the VH group and 17,155.4 ± 27,950.2 (pixels) in the control group, showing a significant difference (p=0.046). The postoperative retinal neovascular area was 36,315.7 ± 44,311.8 (pixels) in the VH group and 2261.0 ± 9072.2 (pixels) in the control group, showing a significant difference (p=0.046), but there was no significant difference in the reduction rate of the neovascular area before and after surgery (p=0.30).

Conclusions: In PDR developing VH after vitrectomy surgery, the appearance of neovascularization seen on pre- and postoperative OCTA is significantly more extensive than in cases that do not develop postoperative VH, and OCTA may be useful for preoperative evaluation.