Micropulse Cyclophotocoagulation: A Multicenter Study of Efficacy, Safety, and Factors Associated With Increased Risk of Complications.

Abstract

The purpose of this study was to evaluate the efficacy and complications of MPCP in a large series of patients with all stages of glaucoma. Multicenter, retrospective chart review of patients from 3 clinical sites. One hundred sixty-seven eyes of 143 patients. MPCP was performed with 2000 mW energy, 31.3% duty cycle and 2 to 4 180-degree applications of 80 seconds duration each per treatment. The procedure was considered a failure if any of the following occurred: additional IOP lowering intervention, <20% IOP reduction from baseline at the last follow-up (with or without medication), or severe complications. Mean age was 71 years, 53% were female, and 53% were Asian. 60% of eyes had POAG, 63% were pseudophakic, 38% had prior glaucoma surgery, and 51% had Snellen visual acuity (VA) of 20/40 or better. Mean follow-up time was 11.9±7.8 months. Mean IOP was 21.9±8.4 mm Hg before intervention, and 17.4±7.2 mm Hg at last follow-up (P<0.0001). There was no change in mean logMAR VA (P=0.0565) but 15% lost ≥3 Snellen lines of VA. The success rate was 36.5% (61/167 eyes) at last follow-up. The probability of survival by Kaplan-Meier analysis was 82%, 71%, and 57% at 3, 6, and 12 months after the procedure, respectively. The reasons for failure were additional intervention in 47%, inadequate IOP reduction in 14%, and severe complication in 1.8%. In a multivariable Cox proportional hazard model, female sex was associated with a 56% decrease in failure rate compared with males (P<0.0001), while a unit increase in baseline IOP corresponded with a 5.7% increase in failure rate (P<0.0001). If repeat MPCP was allowed then success rate increased to 58%. There were no complications in 73% (122/167) but 11% (18/167) had persistent complications at the last follow-up and half of these 18 eyes had decrease in VA of 1 to 6 Snellen lines. Asian race (odds ratio 13.5, P=0.0131) and phakic status (odds ratio 3.1, P=0.0386) were associated with higher odds of developing mydriasis, which was the most common complication. MPCP lowered IOP in the short-term but nearly half required additional IOP lowering intervention. Potential complications should be discussed in detail especially when the procedure is being considered for those with good VA and early stage disease.