Quantitative analysis of the anti-VEGF effect for retinal capillary hemangiomas and vasoproliferative tumors

PurposeTo assess the effect of anti-VEGF intravitreal injection (IVI) on vascularity and size of retinal angiomas using quantitative analysis of color fundus images.MethodsColor fundus images of retinal angiomas underwent RGB analysis with ImageJ software. White intensity (mean RGB values) and red ratio (red value/sum of green and blue values) were calibrated to obtain the white intensity and red indices, respectively. The lesion-disc area ratio was assessed for size changes.ResultsSeventeen image sets of 10 angiomatous lesions were analyzed: 6 retinal hemangiomas from 4 eyes (4 patients) with Von Hippel-Lindau disease (VHL) and 4 retinal vasoproliferative tumors (VPT) from 4 eyes (4 patients). Overall, the white intensity index increased from 1.34 to 1.5 (<i>P</i> = 0.001), and the red index decreased from 1.14 to 0.85 (<i>P</i> < 0.001) post-IVI. In the VHL group, white intensity increased from 1.41 to 1.58 (<i>P</i> = 0.013), and the red index decreased from 1.04 to 0.84 (<i>P</i> < 0.001). In the VPT group, white intensity increased from 1.17 to 1.36 (<i>P</i> = 0.031) and red index decreased from 1.39 to 0.87 (<i>P</i> = 0.156) after IVI. Lesion-disc area ratio decreased significantly in both groups.ConclusionAnti-VEGF induces whitening and reduces the red component of angiomas, diminishing vascularity and facilitating subsequent invasive treatments.