SIGNIFICANT REDUCTION OF BOTH PERIPAPILLARY AND SUBFOVEAL CHOROIDAL THICKNESS AFTER PANRETINAL PHOTOCOAGULATION IN PATIENTS WITH TYPE 2 DIABETES.

PURPOSE: To evaluate changes in peripapillary choroidal thickness (PCT) and subfoveal choroidal thickness (SFCT) after panretinal photocoagulation (PRP) for diabetic retinopathy. METHODS: This retrospective interventional study included 59 treatment-naive eyes of 33 patients who underwent PRP and completed ≥12 months of follow-up. Peripapillary choroidal thickness and SFCT were measured at baseline and 1, 3, 6, and 12 months post-PRP. Differences between baseline and 12 months (ΔSFCT and ΔPCT) and percentage changes (ΔSFCT or ΔPCT/baseline × 100%) were determined. RESULTS: Mean SFCT was 287.7 ± 76.7 µm (139.0-469.0 µm) at baseline and 225.8 ± 62.0 µm (102.5-379.5 µm) 12 months post-PRP (P < 0.001). Mean PCT was 161.2 ± 16.5 µm (75.3-308.1 µm) at baseline and 128.4 ± 41.8 µm (73.0-212.9 µm) 12 months post-PRP (P < 0.001). ΔSFCT was -61.3 ± 28.7 µm (-139.5 to -17.0 µm), and %SFCT was 21.2 ± 7.2% (6.8% to 36.1%). ΔPCT was -36.4 ± 23.2 µm (-149.1 to 5.4 µm), and %PCT was 22.4 ± 12.0% (2.5% to 62.6%). Diabetic retinopathy severity was the only factor significantly correlated with %SFCT (ß = 0.500, P = 0.004) and %PCT (ß = 0.152, P = 0.024). CONCLUSION: Both PCT and SFCT reduced significantly after PRP. Diabetic retinopathy severity was significantly correlated with post-PRP changes of peripapillary and SFCT.