Response of Diabetic Macular Edema to Anti-VEGF Medications Correlates with Improvement in Macular Vessel Architecture Measured with OCT Angiography.

Purpose: Improvements in best-corrected visual acuity (BCVA) and central subfield thickness (CST) have been well documented after intravitreal injection of anti-VEGF medications in diabetic macular edema (DME); however, their effect on the vasculature of the macula in diabetic retinopathy (DR) remains poorly understood. Our aim was to explore the effect of intravitreal injection of anti-VEGF on parameters of retinal vascular microstructure in DR with OCT angiography (OCTA). Design: Retrospective study of adult patients with DME that were treated with anti-VEGF intravitreal injections at the University of Illinois at Chicago between 2017 and 2022. Participants: Forty-one eyes from 30 patients with nonproliferative or proliferative DR with a mean age of 58.83 ± 11.71 years, mean number of intravitreal injections of 2.8 ± 1.4, and mean follow-up of 6.5 ± 1.7 months. Methods: ImageJ was employed to measure parameters of retinal vascular microstructure in OCTA images, which included perfusion density, vessel-length density (VLD), vessel diameter, and foveal avascular zone (FAZ) characteristics (area, perimeter, and circularity). Student Main Outcome Measures: A primary analysis was performed comparing the mean of each parameter of all patients as a single group at the beginning and end of the study period. A subgroup analysis was then performed after stratifying patients based on visual improvement, change in CST, prior injection history, and number of injections. Results: Eyes demonstrated statistical improvement in BCVA logarithm of the minimum angle of resolution score and CST after anti-VEGF treatment. Primary analysis showed a reduction in the vessel diameter of the superficial and deep retinal vasculature, as well as an increase in the circularity of the FAZ within the superficial retinal vasculature after anti-VEGF treatment. Subgroup analysis revealed that eyes with improvement in BCVA exhibited reduced vessel diameter in the superficial retinal vasculature and that eyes with the largest decrease in CST displayed increased perfusion density and VLD in the deep retinal vasculature. Conclusions: Intravitreal injection of anti-VEGF agents to treat DME improved parameters of retinal vascular microstructure on OCTA over a period of 3 to 9 months, and this effect was most pronounced in eyes that experienced improvement in BCVA and CST. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.