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

Purpose: To assess the effect of anti-VEGF intravitreal injection (IVI) on vascularity and size of retinal angiomas using quantitative analysis of color fundus images. Methods: Color 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. Results: Seventeen 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 (P = 0.001), and the red index decreased from 1.14 to 0.85 (P < 0.001) post-IVI. In the VHL group, white intensity increased from 1.41 to 1.58 (P = 0.013), and the red index decreased from 1.04 to 0.84 (P < 0.001). In the VPT group, white intensity increased from 1.17 to 1.36 (P = 0.031) and red index decreased from 1.39 to 0.87 (P = 0.156) after IVI. Lesion-disc area ratio decreased significantly in both groups. Conclusion: Anti-VEGF induces whitening and reduces the red component of angiomas, diminishing vascularity and facilitating subsequent invasive treatments.