High intensity focused ultrasound cyclodestruction versus cyclodiode treatment of refractory glaucoma: A retrospective comparative study

Abstract

To compare the efficacy of two cyclodestructive treatments for refractory glaucoma: High Intensity Focused Ultrasound (HIFU) cyclocoagulation and transscleral diode laser cyclophotocoagulation (cyclodiode). A retrospective comparative single centre study including all patients who underwent cyclodestruction for refractory glaucoma by either HIFU cyclocoagulation or cyclodiode. "Refractory glaucoma" was defined as an uncontrolled high IOP despite medical treatment and at least one filtering surgery. Uncontrolled high IOP was defined as an IOP≥16mmHg. The diagnosis of glaucoma was confirmed by automated visual field (VF) testing and peripapillary RNFL scans using a time-domain ocular coherence tomography device. Treatment success was defined as: postoperative IOP between 5mmHg and 21mmHg and IOP reduction greater than or equal to 20% as compared to preoperative values. Among the 99 eyes of 86 patients included in this study, 29 eyes were treated by cyclodiode and 70 eyes by HIFU. Median follow-up was 3 months (IQR 3-6) for the cyclodiode group and 6 months (IQR 3-8) for the HIFU group. Average preoperative intraocular pressure (IOP) was 34.3±11.1mmHg (cyclodiode group) and 23±6.8mmHg (HIFU group). The treatment success rate at last follow-up was 52% [34-70] for the cyclodiode group and 25% [15-35] for the HIFU group (P value=0.01). Kaplan-Meier survival analysis showed that the mean estimated time to failure was 5.9 months (4.4-7.5) for the cyclodiode group and 3.7 months (2.8-4.7) for the HIFU group (log-Rank test, P=0.02). A 2-line visual acuity loss was observed for 31% of the patients treated by cyclodiode and 17% for those treated by HIFU. In the cyclodiode group 4 cases of hypotony were reported vs. none in the HIFU group. The success rate was significantly higher for cyclodiode treatment as compared to HIFU cyclodestruction when treating refractory glaucoma. However, significantly fewer complications were observed with HIFU cyclocoagulation as compared to cyclodiode.