VEGF-A gene polymorphisms and responses to intravitreal ranibizumab treatment in patients with diabetic macular edema

Abstract

Purpose: To investigate the association between VEGF gene polymorphisms and the responses to treatment with intravitreal ranibizumab (IVR) in patients with diabetic macular edema (DME).

Methods: This prospective study, conducted at the Kutahya Dumlupinar University Faculty of Medicine, included 95 patients with DME that were treated with IVR and 32 patients without DME despite proliferative diabetic retinopathy (PDR). The participants were divided into three groups: DME with non-proliferative diabetic retinopathy, DME with PDR, and PDR without DME; patients with DME who were treated with IVR were further divided into two groups based on their response to the treatment. Each patient was genotyped for five single nucleotide variations (SNVs) in VEGF-A: rs2010963, rs2146323, rs10434, rs833069, and rs6921438.

Result: There was a statistically significant difference in allelic distribution of VEGF-A rs833069 polymorphism in relation to the severity of diabetic retinopathy (DRP) (p = 0.031). The allelic distribution of VEGF-A rs2146323 polymorphism tended to be associated with the severity of DRP (p = 0.069). There were no statistically significant differences in the allelic distribution of the studied five SNVs in DME patients regarding the patients' responses to IVR therapy.

Conclusions: There is no association between the studied VEGF-A SNVs and the responses to IVR therapy in DME. However, the VEGF-A rs833069 gene polymorphism has a clear association with the severity of diabetic retinopathy.

Keywords: Diabetic macular edema; Diabetic retinopathy; Ranibizumab; VEGF gene polymorphisms.