Aim of the work: This study aimed to assess the effect of Panretinal photocoagulation (PRP) on the peripapillary Retinal Nerve Fiber (RNFL) thickness in diabetic patients using Optical Coherence Tomography Angiography. Methods: A prospective study was conducted on 100 eyes of 62 patients who had severe non-proliferative (SNPDR) or proliferative diabetic retinopathy (PDR) and underwent PRP treatment. The study population underwent 4.5×4.5 MM scans centered on the optic nerve head using Optical Coherence Tomography Angiography (OCTA) (RTVue XR Avanti Optovue, Fremont, CA) for measuring the peripapillary RNFL thickness before and after PRP by 2 months and 6 months. Results: Mean age of the study population was 49.85± 8.26 years (25-64 years). There was a significant increase in thickness of the nasal, temporal, superior and inferior peripapillary RNFL from baseline to 2 months post-PRP (all P value <0.05) and then decreased significantly from 2 months to 6 months (all P value <0.05). However, the thickness decreased significantly to amount less than baseline after 6 months for superior and inferior quadrants (P value <0.05) and decreased insignificantly for nasal and temporal quadrants (P value > 0.05). Conclusions: Peripapillary RNFL thickness at 6 months has decreased post-PRP, suggesting that PRP had neuronal insult.