Optical Coherence Tomography Biomarkers in Diabetic Macular Edema and Their Role in Predicting Visual Outcome After Ranibizumab or Triamcinolone Injection

Background Diabetic macular edema (DME) is the most common cause of defective vision in patients with diabetic retinopathy. With intravitreal injection being a treatment option, different forms of anti-vascular endothelial growth factor (anti-VEGF) and steroid injections are available. In order to choose the effective intravitreal injection based on the retinal changes in optical coherence tomography (OCT) biomarkers, analysis is crucial. Aim This study aimed to investigate the changes in OCT biomarkers after intravitreal injection of anti-VEGF (ranibizumab) or steroid (triamcinolone) in DME and to correlate them with visual outcome. Methods This prospective observational study included patients diagnosed with diabetic retinopathy with clinically significant macular edema (CSME). Best corrected visual acuity (BCVA) and OCT biomarkers were measured at baseline and after one month of intravitreal injection. Results A total of 58 eyes were included. There was a significant change in OCT parameters, central macular thickness (CMT), subretinal fluid (SRF) height, intraretinal cyst height, and hyperreflective foci (HRF), one month after a single intravitreal injection (p<0.05). There was a significant change in BCVA after one injection (p=0.046). Also, a significant correlation was noted between BCVA and CMT (r=-0.455; p<0.001), SRF height (r=-0.438; p=0.001), and intraretinal cyst height (r=-0.540; p<0.001). Conclusion OCT biomarkers can be used to monitor therapeutic response and to predict visual outcome after intravitreal injection in DME. The presence of more HRF at baseline might be considered for steroid injection.