High-frequency deep sclerotomy as adjunctive therapy in open angle glaucoma patients

Abstract

Introduction: Glaucoma is a chronic, progressive disease of the optic nerve that can cause vision loss and blindness. High-frequency deep sclerotomy (HFDS) is a novel ab interno procedure used to lower intraocular pressure (IOP). This study aims at examining hypotensive effects of HFDS in patients with medically uncontrolled primary open-angle glaucoma (POAG). Methods: 23 patients (23 eyes) participated in this study. They were all affected by primary open-angle glaucoma and used maximum prescribed medical therapy. It is important to note that the target intraocular pressure (IOP) was not detected in any study participant. The target intraocular pressure is the highest IOP value at which no new damages of the optic nerve occur. The procedure was performed with a custom-made, high-frequency dissection probe by applying bipolar current of 500 kHz. Six pockets (1mm deep, 0.3mm high, and 6mm wide) were made ab interno in nasal sclera (through trabecular meshwork and Schlemm's canal). Tobramycin/dexamethasone and pilocarpine eye drops were administered postoperatively for a month. Results: The mean value of the base intraocular pressure had been 25.6mmHg before the procedure. Significant complications were not recorded either during the surgery or in a post-operative follow-up period. The average IOP for our patients reduced by 8.6mmHG (33.6%) after a year. The mean value of the instilled anti-glaucoma eye drops had been 2.78 (SD=0.45) before the HFDS and 0.61 (SD=1.04) at the end of the research. The target IOP was not achieved in five cases (21.7% of our sample). Discussion/Conclusion: This study presents the data on our first surgical experience with high-frequency deep sclerotomy that was conducted on 23 patients who had medically-uncontrolled, primary, open-angle glaucoma. The results indicate that HFDS is safe and efficient in reducing IOP.