Vascular Regression in Eyes Treated with Bevacizumab Compared with Eyes Treated with Laser for Type-1 Retinopathy of Prematurity

Abstract

Purpose: Most studies assessing treatment outcomes for eyes treated with bevacizumab and laser are based on subjective measures. This study seeks to determine the difference in vascular regression between eyes treated with bevacizumab and eyes treated with laser objectively by measuring vessel width and tortuosity at one to three weeks after treatment.

Methods: Images from 36 eyes (18 infants) with type-1 ROP obtained before and at up to three time points after treatment with either bevacizumab or laser were analyzed. The tortuosity and width of the vessels were measured in arbitrary units (AU) and pixels respectively using computer assisted image analysis of the retina (CAIAR). Statistical comparisons of width and tortuosity were made pre-treatment vs. post- treatment, and also between bevacizumab vs. laser treated eyes pre-treatment and post treatment.

Results: At up to three weeks post treatment, regression in vessel width was significantly more prominent in bevacizumab treated eyes compared with laser treated eyes for all follow-up after treatment (-0.15 vs. 0.05 pixels, p=0.02). There was no significant difference in tortuosity between eyes treated with bevacizumab and eyes treated with laser at one to three weeks after treatment.

Conclusions: One to three weeks after treatment with bevacizumab, vessel width regression is greater than in eyes treated with laser. Vasodilatation appears to decrease more rapidly in bevacizumab-treated eyes than in laser-treated eyes. However, the effects of anti-VEGF treatment on developmental vasculogenesis must be considered.

Keywords: 706 retinopathy of prematurity • 578 laser • 748 vascular endothelial growth factor