A new approach for CW-TSCPC to improve its safety and efficacy in glaucoma treatment

Abstract

Purpose: The goal of our study was to compare the outcomes of transscleral diode cyclophotocoagulation using a new protocol with new settings. In fact, we targeted the ciliary body guided by transillumination, reduced the energy applied at each spot, and enlarged the treatment area posteriorly from the pars plicata to the pars plana.

Patients and methods: Data were collected retrospectively from two groups of glaucoma patients. The first group of patients underwent transscleral diode laser cyclophotocoagulation as usual, with one-row applications of a maximum of 1200mW of energy and a duration of 2000ms. The second group was treated in three rows, using the same settings as the first group. Transillumination was used continuously during all of our procedures, to focus accurately on the location of the ciliary body. Outcome measures included intraocular pressure (IOP) and visual acuity (VA) at baseline and at a minimum of 3 months postoperatively, as well as complications occurring up until last follow-up visit. Patients were considered successfully treated if their intraocular pressure was lowered by at least 25% compared to their baseline or if their intraocular pressure was less than 21mmHg after the procedure, with or without glaucoma medications.

Results: Sixty eyes were treated with the one-row protocol, followed by 508 eyes treated with the three-row protocol. The mean follow-up was 19 (range 3-31) months. Success rates were 62% and 86% for the one-row group and three-row group, respectively. The IOP decrease was 40.5% (a mean reduction from 37.5±8.1mmHg to 22.3±10.2mmHg) in the one-row group and 57.6% in the three-row group (mean reduction from 36.05±10.4mmHg to 15.7±7.3mmHg), which was statistically significant in each group (P=0.0001). Additionally, a significant improvement in efficacy was found in the 3-row compared to the 1-row group (P=0.0001) No significant difference was found in VA before or after the procedure or between the 2 groups. No serious complications were reported.

Conclusions: Diode laser TSCPC is a practical, rapid and well-tolerated procedure. The treatment protocol used, with lower energy levels applied to the eye, guided systematically by transillumination and targeting a wider area, appears to be safer and more effective.

Keywords: Continuous wave transscleral cyclophotocoagulation; Cyclophotocoagulation par diode laser; Cyclophotocoagulation transsclérale à micro-impulsions; Cyclophotocoagulation transsclérale à ondes continues; Glaucoma; Glaucome; Glaucome réfractaire; Laser diode cyclophotocoagulation; Micropulse transscleral cyclophotocoagulation; Refractory glaucoma; Three rows of treatment; Transillumination; Trois rangs de traitement.