Peripapillary nerve fiber layer thickness changes after macular photocoagulation for clinically significant diabetic macular edema

Purpose: To evaluate the effect of macular photocoagulation (MPC) on peripapillary nerve fiber layer (PNFL) thickness measurement in patients with clinically significant diabetic macular edema (CSME). Methods: This study was a prospective interventional case series. Patients with CSME underwent MPC. Optical coherence tomography (OCT) was used to measure the PNFL and central macular thicknesses before and 3 months after MPC. Results: Thirty-three eyes of 25 patients with a mean age of 59.4 +/- 7.2 years were included. There was no statistically significant difference between pre- and post-MPC mean best corrected visual acuity (0.35 +/- 0.29 and 0.40 +/- 0.23 LogMAR, respectively, P = 0.2). Mean baseline and 3 months central macular subfield thickness was 305.9 +/- 90.7 and 317.5 +/- 112.4 microns, respectively (P = 0.1). Peripapillary nerve fiber layer thickness was 105.7 +/- 10.0 before and 106.1 +/- 9.9 three months after MPC (P = 0.7). No significant differences were found between pre and post MPC measurements in temporal, nasal, inferior and superior nerve fiber layer thickness in each quadrant around optic nerve head (P > 0.05). Conclusions: Macular photocoagulation has no statistically significant effect on PNFL thickness measurements in patients with CSME.