Optical coherence tomography use for estimation of the efficacy of anti VEGF therapy in diabetic retinopathy and diabetic macular edema.

Abstract

Objectives: To observe the role of optical coherence tomography in patients receiving anti-vascular endothelial growth factors for the treatment of diabetic retinopathy. Study Design: Observational descriptive study. Setting: The study was conducted at Department of Ophthalmology, Shahida Islam Teaching Hospital, Lodhran. Period: January 2018 to December 2018. Material & Methods: 177 eyes of 156 patients with diabetic retinopathy were analyzed with optical coherence tomography to quantify and explore changes in macula and inner retinal structures and to see different patterns of DME pre and post intra-vitreal anti-VEGF injections. All eyes had baseline OCT, received anti-VEGF intra-vitreal injection Avastin (Bevacizumab) 1.25mg/0.05ml. Follow up OCT imagining was done 6 weeks after last injection. Results: The patients had mean age of 58.36 ± 3.67 years with the mean diabetes duration of 9.30 ± 2.76 years. Before intra-vitreal injection, two different patterns of DME were recognized and analyzed i.e. diffuse thickening of macula (n=117, 66.10%) and cystoids macular edema (n=60, 33.90%). Base line OCT showed mean ± SD central foveal thickness 416 ± 54µm (n=177). On post intra-vitreal injection OCT, mean ± SD macular thickness was 212 ± 35 µm (n=177). Conclusion: OCT is latest non-invasive imaging modality that currently helps in quantifying and understanding the anatomy of DME and inner retinal damage due to diabetes mellitus. Although vascular leakage in DME is assessed qualitatively with Fluorescein angiography, actual macular thickness calculated with OCT is very helpful in yielding efficacy of treatment. This tool should always be used in monitoring the effect of therapies in future studies.