Comparative Effectiveness and Tolerance of Subliminal Subthreshold Transscleral Cyclophotocoagulation With a Duty Factor of 25% Versus 31.3% for Advanced Glaucoma.

PRéCIS:: Subliminal subthreshold transscleral cyclophotocoagulation (SS-TSCPC) with duty cycles 25% and 31.3% seems to be an effective approach to reduce intraocular pressure (IOP) in glaucoma that is refractory to medical management. The objective of this study was to compare the effectiveness and the tolerance of SS-TSCPC with a duty cycle of 25% versus 31.3% with Supra 810 nm Subliminal Quantel Medical laser stimulation for advanced glaucoma. This was a retrospective, single-center, comparative case series of patients treated by SS-TSCPC between January 2017 and July 2017. The diagnostic and inclusion criteria were patients with advanced and refractory glaucoma, defined as IOP >21 mm Hg on maximal tolerated medical therapy with or without previous glaucoma surgical procedures, a minimum follow-up of 12 months, and patients who refused or were poor candidates for additional filtering surgery or implantation of glaucoma drainage devices. The primary endpoint was surgical success defined as an IOP of 6 to 21 mm Hg or a reduction of IOP by 20% from baseline without an increase in glaucoma medication from baseline. The secondary endpoints were the mean IOP and best visual corrected acuity best-corrected visual acuity at 12 months after surgery, retreatment outcomes, glaucoma medications, and complications such as inflammation, uveitis, cataract, mydriasis, and phthisis. Forty eyes of 32 patients were included: 20 eyes were subjected to SS-TSCPC with 31.3% duty cycle and 20 eyes with a 25% duty cycle. The surgical success of the TSCPC 12 months after the first procedure was better in the 31.3% duty cycle group (83.5%) than in the 25% duty cycle group (65%). The most common complications were inflammation (50%, 1 mo after surgery) and IOP spikes (increase in IOP of >25% from baseline within 1 mo of laser) in both groups. Inflammation was higher in the 31.3% duty cycle group. SS-TSCPC at 31.3% and 25% duty cycle seems to be an effective approach to reduce IOP in glaucoma that is refractory to medical management. SS-TSCPC at 31.3% duty cycle is more effective than the 25% duty cycle SS-TSCPC. However, the 31.3% duty cycle SS-TSCPC induces more inflammation than the 25% duty cycle SS-TSCPC. Each procedure should be considered on a case by case basis.