Abstract
Purpose :
Micropulse transscleral cyclophotocoagulation (MP-TSCPC) is a relatively new procedure that aims to lower intraocular pressure (IOP) by thermally heating the ciliary body without total tissue destruction. By emitting pulsatile waves of energy in duty cycles, the tissue has time to cool off. In theory, this allows for a favorable side effect profile while maintaining pressure-lowering goals comparable to a traditional diode. Several studies have elucidated the safety and efficacy of this laser, but there is little data on clinical outcomes in phakic and pseudophakic eyes. The role of a crystalline lens is well known as a potential barrier for aqueous humor outflow. This study retrospectively analyzes the efficacy of MP-TSCPC as a primary procedure in lowering IOP in phakic and pseudophakic patients over a one year time period. Primary outcomes include IOP, mean number of IOP drugs and success rate.
Methods :
A retrospective chart review was performed on a total of 98 patients at John H. Stroger Cook County hospital in Chicago, Illinois from 2015 to 2019 with primary open angle glaucoma (POAG). Mean IOP and the number of IOP medications were recorded through 12 months. Kaplan-Meier survival analysis was conducted with success defined as IOP between 6 and 21 mmHg or a reduction in IOP ≥20% from baseline without additional glaucoma surgery. Log-rank tests compared survival probabilities between phakic and pseudophakic patients. Paired t-tests were used to study changes in IOP and number of IOP medications. Univariate odds ratios with 95% confidence intervals were calculated to measure binary success/failure outcomes.
Results :
Pseudophakic POAG patients were more likely than phakic POAG patients to succeed through 12 months following MP-TSCPC. The cumulative survival after 12 months was 13.2% in phakic and 38.3% in pseudophakic POAG patients (p=0.04) (Graph 1). The odds ratio for phakic compared with pseudophakic patients in failure rate was 2.5 (p=0.04). Preoperative IOP levels did not significantly differ between the two groups. At 6 months, however, the mean IOP was higher in phakic eyes.
Conclusions :
MP-TSCPC is a procedure that can lower IOP in both phakic and pseudophakic patients with POAG. While several time points indicate equivocal IOP reduction, long-term survival may suggest pseudophakic eyes having a particularly favorable prognosis.
This is a 2020 ARVO Annual Meeting abstract.