Safety and efficacy of high-intensity focused ultrasound in severe or refractory glaucoma

Purpose: The aim of this study was to evaluate the efficacy and safety of ultrasonic cyclocoagulation in severe or refractory glaucoma, and to analyze the procedure-related inflammation. Patients and Methods: In this retrospective study, 15 eyes of 13 patients suffering from severe or refractory glaucoma with uncontrolled intraocular pressure of > 21 mmHg underwent 8-s ultrasonic cyclocoagulation. A complete ophthalmic evaluation, quality of life assessment using Glau-Qol-17, endothelial cell count, and flare measurement were performed. Primary outcome was qualified surgical success (defined as intraocular pressure reduction from baseline > 20% and intraocular pressure >5 mmHg without hypotensive medication adjunction). Secondary outcomes were flare, endothelial cell loss, and quality of life. Results: Qualified success was achieved in 67% of eyes at 6 months (mean intraocular pressure reduction = 42% in these eyes). During the first month after the procedure, the mean flare reached its maximum value when the intraocular pressure was minimal; the flare slowly decreased until normalization at month 3 when the maximal intraocular pressure was noted. At month 3, there was moderate but significant endothelial cell loss (11%), and no significant alteration in quality of life was demonstrated. Conclusion: The efficacy of ultrasonic cyclocoagulation in the present study is comparable to that reported in the literature. The kinetics of intraocular pressure and flare suggest that postoperative inflammation could be partly responsible for the early intraocular pressure decrease. The moderate endothelial cell loss, which could be caused by localized heating, and the preservation of quality of life confirm the safety of ultrasonic cyclocoagulation.