Abstract
Purpose :
Retinopathy of prematurity (ROP) is a leading cause of preventable childhood blindness in high- and middle-income countries. Appropriate screening and timely treatment are critical and can reduce the risk of blindness due to ROP. Plus disease is a certain degree of vascular dilation and tortuosity that is usually present in treatment indicated (type 1) ROP. This study uses the semiautomated software ROPtool to quantitatively compare posterior pole vascular changes after bevacizumab versus laser treatment.
Methods :
This retrospective study used prospectively-collected narrow-field retinal images from preterm infants screened and treated for ROP. We included retinal images acquired in the session just prior to and in all sessions post-treatment. Using quadrant-level methodology where ≤3 images/session were included, we used ROPtool to trace and analyze ≤2 vessels/quadrant, following the same vessels over time (Figure 1). For each imaging session, these ROPtool indices were calculated: tortuosity index (TI), dilation index (DI), and combination dilation/tortuosity indices: sum of adjusted indices (SAI) and tortuosity-weighted plus (TWP). We used Wilcoxon signed-rank test to compare each average ROPtool index before and after treatment, and Wilcoxon rank sum test to compare the rates of percent change of each index between bevacizumab versus laser.
Results :
Of 15 eyes with type 1 ROP, 6 were treated with bevacizumab and 9 with laser. We included a median of 5 imaging sessions/eye. Compared to pre-treatment values, all ROPtool indices significantly decreased 1 week after bevacizumab (p=0.03) and 1 month after laser (p=0.05). Those treated with bevacizumab versus laser had higher rates of percent change in TI (p=0.01), SAI (p=0.02), and TWP (p=0.01) 1 week after and in SAI (p=0.03) and TWP(p=0.01) 1 month after treatment (Figure 2).
Conclusions :
Regression of vessel dilation and tortuosity in type 1 ROP occurs earlier after bevacizumab versus laser. The quantification of retinal vascular characteristics post-treatment helps guide clinical expectations after bevacizumab versus laser.
This is a 2021 ARVO Annual Meeting abstract.