Benefits of SubCyclo Laser Therapy Guided by High-frequency Ultrasound Biomicroscopy in Patients With Refractory Glaucoma

摘要

Purpose: The purpose of this study was to evaluate the efficacy and safety of subliminal cyclophotocoagulation using a 25% duty cycle diode laser (Supra 810, SubCyclo, Quantel Medical). Methods: This was a pilot study of patients who underwent a SubCyclo photocoagulation procedure with a 25% duty cycle, between April 2016 and April 2017 at the Glaucoma Institute of Saint Joseph Hospital of Paris. All patients presented with an evolving moderate to severe glaucoma that were resistant to previous surgical treatments or with a contraindication for filtration surgery. Laser settings were programmed as follows: power 2000 mW, "on" time 0.63 ms, "off" time 1.9 ms, and 25% duty cycle per 100 seconds to each eye. Results: A total of 44 eyes of 34 patients were treated with subliminal cyclophotocoagulation, with a mean follow-up time of 12 months. Surgical success was defined as IOP ranging 6 to 21 mm Hg or a 20% IOP reduction at the last 12 months follow-up visit. The mean age of patients was 63.83 +/- 16.2 years. The mean preoperative IOP was 32.8 +/- 11.8 mm Hg which then decreased postoperatively to 24.02 +/- 7.03 mm Hg after 1 day, 18.34 +/- 8.31 mm Hg after 1 week, 18.26 +/- 8.53 mm Hg after 1 month, 20.5 +/- 8.53 mm Hg after 3 months, 18.9 +/- 9.2 mm Hg after 6 months and 18.8 +/- 9.3 mm Hg after 12 months. Our preliminary study using Subcyclo transscleral cyclophotocoagulation with a 25% duty cycle showed a 37% IOP reduction from the baseline after 3 months with a single laser session and a 45% reduction at the last 12 months follow-up, after more than one laser session. The mean number of ocular antihypertensive medications used was 3.4 +/- 1.7 before treatment which decreased to 3.0 +/- 1.6 after treatment. No significant complications or anatomic modifications were found after subliminal cyclophotocoagulation. Conclusions: Subliminal cyclophotocoagulation with a 25% duty cycle is a safe and effective procedure for reducing IOP in cases of refractory glaucoma and seems to be safer than conventional transscleral cyclophotocoagulation.