RESUMO
OBJECTIVE: To evaluate the effect of pan-retinal photocoagulation (PRP) on central macular thickness (CMT) in a sample of Iraqi patients with proliferative diabetic retinopathy (PDR). METHODS: This prospective study was conducted at Ghazi Al-Hariri for Surgical Specialties Hospital, Baghdad, from March 2024 to May 2024. A total of 24 eyes from 18 treatment-naive PDR patients with no previous diabetic macular edema (DME) were enrolled. Each eye received PRP in two sessions, one week apart, using the Nidek GYC 500 laser system. CMT was measured at baseline and four weeks after the second PRP session using the Topcon DRI Triton Plus optical coherence tomography (OCT). Statistical analyses, including paired t-tests and Shapiro-Wilk tests for normality, were performed to evaluate changes in CMT. RESULTS: The mean CMT increased from 258.4 ± 30.7 microns at baseline to 269.9 ± 36.8 microns post PRP, with a mean increase of 11.5 ± 26.3 microns. This increase was statistically significant (p = 0.042). The Shapiro-Wilk test confirmed that the data were approximately normally distributed both before (W = 0.960, p = 0.445) and after (W = 0.931, p = 0.103) PRP treatment. CONCLUSION: PRP significantly increases CMT in PDR patients, although no additional treatment for macular edema was necessary. These findings align with previous studies, suggesting that PRP-induced macular thickening is a common outcome. Further research is recommended to explore long-term effects and potential mitigation strategies.