For diabetic retinopathy—specifically diabetic macular edema (DME)—anti-VEGF resistance has been mainly defined based on OCT images either utilizing the percent decrease in macular thickness compared to pre-treatment (<25%) [14,15] or a threshold based on the macular thickness after a series of anti-VEGF injections (ranging from ≥225–300 μm) [15,16,17,18]. This evidence concerns the gene VEGFA and diabetic macular edema.