Micropulse Cyclophotocoagulation Outcomes in Primary Open Angle Glaucoma

Abstract

Background: Micropulse cyclophotocoagulation (MPCPC) uses a pulsed application of laser energy to produce a more mild and predictable lowering of intraocular pressure (IOP) compared to traditional CPC with fewer adverse events. It is unclear if particular types of glaucoma are better suited for treatment with MPCPC. Primary open angle glaucoma (POAG) is a leading cause of visual disability in the world and is the most common form of glaucoma in the United States.  A retrospective, observational clinical study was done in order to determine the efficacy and safety of MPCPC specifically for patients with POAG in an urban patient population at a tertiary referral academic medical center. Methods: Patients with primary open angle glaucoma who underwent an MPCPC procedure and had never undergone previous cyclodestructive procedures were considered.  Patients were followed for 6 consecutive months.  IOP, number of topical glaucoma medications, and best corrected visual acuity (BCVA) were recorded prior to the laser procedure, and at follow-up intervals of 1, 3, and 6 months after the procedure. Procedural success was defined as a 20% reduction in IOP, with IOP between 6-21, and no need for subsequent glaucoma filtering surgery. A Wilxocon signed rank test was used to determine statistical significance. Results: A total of 39 eyes in patients aged 28-82 with POAG that underwent MPCPC were included in the study. Mean baseline IOP was 22.9 mmHg, mean baseline number of drops was 3.1, and mean baseline BCVA in LogMAR notation was 1.0.  The MPCPC procedure produced a statistically significant decrease in IOP of 42.1% (p<0.001), 31.0% (p<0.001), and 34.0% (p<0.001) at 1, 3, and 6 months respectively. The number of required topical glaucoma drops was not significantly reduced at any of the three follow-up time points, but there was a modest trend towards requiring fewer drops. Patients met the criteria for procedural success at a rate of 74.4%.   Conclusions: Our results are consistent with the hypothesis that the MPCPC is safe and effective in lowering IOP in patients with POAG.  Further research is needed to determine if MPCPC is equally safe and effective in other forms of glaucoma.