Micropulse Transscleral Diode Laser Cyclophotocoagulation in Refractory Glaucoma: Short-Term Efficacy, Safety, and Impact of Surgical History on Outcomes

PURPOSE:To assess the short-term efficacy and safety of micropulse transscleral diode laser cyclophotocoagulation (MP-TSCPC) in the management of refractory glaucoma and to compare outcomes based on prior glaucoma surgeries. DESIGN:Retrospective analysis. PARTICIPANTS:Patients with refractory glaucoma who underwent MP-TSCPC at a single institution by 1 of 4 surgeons. METHODS:Chart review of cases of MP-TSCPC using the Iridex Cyclo G6 (Mountain View, CA) laser with standard parameters and laser duration at the discretion of each treating physician. MAIN OUTCOME MEASURES:Probability of postoperative success was estimated by the Kaplan-Meier method. Success parameters included intraocular pressure (IOP) 6 to 21 mmHg with or without topical antihypertensive therapy, 20% or more IOP reduction from baseline for any 2 consecutive visits after 3 postoperative months, and no subsequent glaucoma surgery. RESULTS:One hundred sixteen eyes of 116 patients (mean age, 65.8±16.9 years) were included. Baseline IOP was 22.2±7.9 mmHg, and mean postoperative follow-up time was 6.3±3.4 months (range, 3-12 months.) Postoperative IOP at the final follow up was 15.3±6.6 mmHg (P < 0.01), corresponding to a reduction of approximately 6.9 mmHg (31.1%). Most eyes (66.4%) underwent at least 6 months of follow-up. Short-term probability of success was 93.1% at 3 months and 74.3% at 6 months. Eyes that had undergone prior traditional glaucoma surgery (trabeculectomy, tube shunt, excessive pressure-regulating shunt system miniature glaucoma shunt [Alcon, Fort Worth, TX], or a combination thereof) demonstrated a higher probability of success (67.6%) compared with eyes that had not (41.4%; P = 0.014). The most common complications were decline in best-corrected visual acuity (7.8%) and hypotony (1.7%). CONCLUSIONS:Micropulse transscleral diode laser cyclophotocoagulation has a significant short-term ocular hypotensive effect and favorable safety profile in eyes with refractory glaucoma. The probability of successful outcome was greater in eyes that had undergone prior traditional glaucoma surgery.