# Delayed anti–vascular endothelial growth factor therapy in patients with type 2 diabetes mellitus and branch retinal vein occlusion–associated macular edema negatively affects visual outcomes

## TL;DR

Delaying anti-VEGF treatment in diabetic patients with retinal vein occlusion worsens their vision recovery after six months.

## Contribution

This study shows that delayed anti-VEGF therapy negatively impacts visual outcomes in T2DM patients with BRVO-ME.

## Key findings

- Early treatment (within 7 days) led to the greatest visual improvement at six months.
- Delayed treatment (>14 days) was an independent factor reducing visual acuity improvement.
- A 14-day cutoff predicted insufficient visual recovery with high sensitivity.

## Abstract

To investigate the effect of delayed treatment on six-month visual outcomes in patients with type 2 diabetes mellitus (T2DM) complicated by branch retinal vein occlusion-associated macular edema (BRVO-ME).

This single-center retrospective cohort study included 148 patients diagnosed with BRVO-ME and receiving their first intravitreal ranibizumab injection between January 2024 and May 2025. Patients were stratified according to the interval from diagnosis to initial anti-vascular endothelial growth factor (VEGF) injection into early treatment (≤7 days, n = 67), intermediate treatment (8–14 days, n = 52), and delayed treatment (>14 days, n = 29) groups. Baseline demographic, systemic, and ophthalmic parameters were collected. Best-corrected visual acuity (BCVA) and central macular thickness (CMT) (μm) were recorded at 1, 3, and 6 months post-injection. Multivariable linear regression was used to identify independent factors affecting six-month BCVA improvement.

All groups exhibited BCVA improvement and CMT reduction at six months, with the early treatment group showing the greatest improvement. Multivariable regression identified delayed treatment as the only independent factor associated with six-month BCVA improvement (β = −0.008, 95% CI: −0.014 to −0.002, P = 0.010). ROC analysis showed an AUC of 0.823 (95% CI: 0.751–0.884, P < 0.001) for delayed treatment predicting insufficient six-month visual improvement, with a sensitivity of 89.4% and specificity of 61.4% using a 14-day cutoff.

Initiation of anti-VEGF therapy within seven days of diagnosis is associated with greater six-month visual improvement in patients with BRVO-ME and T2DM. Delayed treatment may contribute to suboptimal visual recovery.