Study of the effect of panretinal photocoagulation on macular vasculature in treatment naïve proliferative diabetic retinopathy patients using optical coherence tomography angiography

Abstract

To evaluate the effect of panretinal photocoagulation (PRP) on macular perfusion in treatment-naïve eyes with proliferative diabetic retinopathy (PDR) using Optical coherence tomography angiography. This prospective study included 16 treatment-naïve eyes with PDR treated with PRP. All patients underwent comprehensive ophthalmic examination and Optical coherence tomography angiography imaging at baseline and 3 months post-treatment. Macular vessel density (VD) in the superficial and deep capillary plexuses and foveal avascular zone area was quantitatively analyzed. PRP was delivered in two sessions using a green laser. Best-corrected visual acuity did not change significantly after PRP (0.54±0.27 vs. 0.49±0.22 logMAR; P =0.437), while central sub field thickness increased significantly (246.9±29.4 µm vs. 264.6±50.2 µm, P =0.037). Superficial capillary plexus VD increased significantly in the whole image ( P =0.046), fovea ( P =0.001), and perifovea ( P =0.010), whereas deep capillary plexus (DCP) VD, and foveal avscular zone area were unchanged. PRP enhances macular perfusion in the superficial capillary plexus but not in the DCP, and it does not affect final visual acuity. The limited responsiveness of the DCP highlights the importance of early detection and timely intervention.