Intermediate Term Safety and Efficacy of Transscleral Cyclophotocoagulation After Tube Shunt Failure

Purpose: To determine the efficacy and safety of diode transscleral cyclophotocoagulation (TSCPC) after tube shunt failure. Patients and Methods: The patient population consisted of 32 eyes of 31 patients with uncontrolled glaucoma. Each eye had a previously implanted aqueous tube shunt and was currently on maximally tolerated medication. Each eye also underwent TSCPC treatment using the Iridex (Mountain View, CA) diode laser with a maximum of 360 degrees of treatment. All 31 charts were reviewed for data pertaining to demographics, treatment, ocular history, and follow-up clinical examinations. Safety was evaluated by complication data. Efficacy was evaluated in terms of TSCPC treatment parameters (number of laser applications, laser power, application duration, and degrees of ciliary body treated), intraocular pressure, number of hypotensive medications, and any further treatment required. Results: With a mean (SD) follow-up of 17.1 (16.3) (median = 11.7) months from the last treatment, the mean intraocular pressure decreased from 28.6 (10.2) mm Hg to 16.8 (7.5) mm Hg (35% reduction) at 3 months (n = 30, P < 0.0001) and to 14.7 (7.9) mm Hg (43% reduction) at 1 year (n = 13, P< 0.0001). Complications included hypotony (n = 4), hyphema (n = 2), failed corneal transplant (n = 1), and loss of light perception (n = 5). Conclusions: TSCPC has a significant ocular hypotensive effect on glaucoma refractory to both tube shunt and medical therapy. The safety of this intervention remains unclear in this high risk patient population and warrants further study.