Choroidal Thickness Increase after Subliminal Transscleral Cyclophotocoagulation

Background: The purpose of this study is to estimate the success rate of subliminal transscleral cyclophotocoagulation for refractory glaucoma and to determine the correlation between the decrease in intraocular pressure and the variation in choroidal thickness. Methods: A pre−post study was conducted over a period of 3 years, including 81 eyes from 67 patients with different types of drug-refractory glaucoma who underwent subliminal transscleral cyclophotocoagulation. The variables included best-corrected visual acuity, intraocular pressure and choroidal thickness. Results: We observed the following success rates (defined as IOP < 21 mmHg): 80% at 1 month (65 patients), 74% at 3 months (60 patients), 64% at 6 months (52 patients) and 50.6% at 1 year (41 patients). A strong correlation was noted between the decrease in intraocular pressure and the increase in the average choroidal thickness at 1 year (318.42 µm) compared to the average preoperative thickness (291.78 µm). A correlation of increased choroidal thickness at 1-month with the success rate of the procedure was also observed. Conclusions: We observed a statistically significant correlation between the success rate, decrease in intraocular pressure and choroidal thickness. The correlation of increased choroidal thickness at 1-month with the success rate of the procedure could be used clinically as a predictive factor for the final outcome of patients. Further experimental research is warranted to determine whether the increase in choroidal thickness after subliminal transscleral cyclophotocoagulation is indeed evidence of increased uveoscleral drainage.