Abstract
Purpose :
While several retrospective studies have shown IOP reduction with micropulse transscleral cyclophotocoagulation (MCPC), we investigated long term efficacy in patients undergoing the procedure for the first time and followed for at least 1-2 years. End points included intraocular pressure (IOP) reduction, medication reduction and complications.
Methods :
We reviewed charts from a glaucoma practice in New York City where CPC was performed for at least 3 years on 71 eyes with glaucoma. Data on demographics, IOP, drop use, oral carbonic anhydrase inhibitor (CAI) use, and complications was collected. Average age of patients was 74 years (range 43-93) with 46 female patients and 25 male patients. Average corneal thickness was 541 (range 398-654). Treatment settings was 100 seconds of power based on visual acuities; 2500mw for vision of light perception or worse, 2400mw for hand motion or count finger vision, 2250mw for vision of 20/80-20/400, and 2000mw for vision of 20/20-20/70. Independent T test analysis was conducted with IBM SPSS Version 23.
Results :
Average IOP prior to treatment was 25.6±8.7 and average number of IOP reducing medications was 3.1±1.1. At 1 year, average IOP was 14.2 (a reduction of 11.5 (p<0.001) or 45% reduction of IOP) and average medications was 2.4 (Reduction of 0.63 (p=0.001) or 20%). 77.5% of patients obtained at least 20% IOP reduction and 66.2% obtained at least 30% reduction. 42.3% of patients reduced medications by at least one medication. 11/15 patients (73%) were able to stop oral CAI use. When 2500mw of energy was used, mean baseline IOP was 38.3 and ending IOP was 16.3, a 21.9-point reduction (57%), when 2400mw of energy was used, baseline IOP was 23.2 and ending 11.3 (11.9-point reduction or 51.3%), when 2250mw of energy was used, baseline IOP was 26 and ending 12.7 (13.3-point reduction or 51.1%), and when 2000mw of energy was used, baseline IOP was 21.6 and ending 15.6 (6.5-point reduction or 30%). A statistically significant medication reduction was found in the group receiving 2000mw from 3.0 to 2.5 meds, a reduction of 0.5 or 17%. Per office protocol, OCT was obtained every 6 months and no patients developed cystoid macular edema or phthisis from the laser procedure.
Conclusions :
In this study, we found both long term pressure reduction from CPC as well as a dose response relationship between the amount of pressure lowering and the magnitude of energy used.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.