One of the main causes of adult-onset blindness globally is diabetic macular edema (DME). The intravitreal anti-VEGF injection has recently been used as the initial course of treatment.

To assess the association between genetic profile and intravitreal injection response, a prospective trial was carried out among patients with defined ophthalmological status who had intravitreal injections from a single physician to treat non-proliferative diabetic retinopathy (NPDR) with DME. The inclusion criteria were treatment-naïve patients aged 18 years or older, presence of type 2 diabetes mellitus, treatment with oral anti-hyperglycemic agents or insulin, and presence of center-involved DME with central subfield thickness (CST) measuring over 300 μm. All participants underwent standard ophthalmologic examination, including best- corrected visual acuity, slit lamp biomicroscopy, optical coherence tomography and wide-field fluorescein angiography. The scanning protocol consisted of fast macular thickness maps and a 3D OCT 12.0 × 9.0 mm scan. Treatment response was defined as CST < 300 μm after intravitreal injection. The Illumina OmniExpressExome-8 BeadChip was used to conduct genome-wide genotyping analysis, according to the Infinium HD protocol.

Genome-wide association analysis results revealed that the genes DIRC3 on chromosome 2, SLCO3A1 on chromosome 15, and RAB2A on chromosome 8 were associated with treatment response to the intravitreal anti-VEGF injection. SLC35F1, TMEM132D, KIAA0368, HPCAL1, IGF2BP3, SPN2S, COL23A1, and CREB5 were also related to treatment response.

The identified genetic biomarkers may help choose the best therapeutic approach and shed light on the variables influencing a patient's reaction to the intravitreal anti-VEGF injection, claims this study recently published in ‘Scientific Reports’.