Comparative efficacy and safety of micropulse transscleral laser cyclophotocoagulation using different duration protocols in eyes with good visual acuity

Purpose To compare the success rates and safety of micropulse transscleral laser cyclophotocoagulation (MP-TSCPC) for the treatment of refractory glaucoma using the 240-s and 160-s duration protocols in eyes with good visual acuity. Methods A retrospective analysis of patients with refractory glaucoma who underwent MP-TSCPC from December 2017 to September 2019 with baseline best-corrected visual acuity (BCVA) of >= 20/60. Laser treatments for the moderate and short duration protocols were defined as 240 s and 160 s with settings of 2000 mW/Cm2 and a duty cycle of 31.3%. Follow-up examinations were performed regularly until 12 months after the procedure. Results Seventy-six eyes of 76 patients were included with BCVA ranging from 20/60 to 20/20. Forty-four eyes were treated with 240 s and 32 eyes were treated with 160-s duration protocols. There was no significant reduction in mean logMAR BCVA and visual field parameters from baseline at any follow-up point in both groups. Visual acuity remained unchanged or improved in 39 of 44 patients (88.6%) in 240-s group and in 28 of 32 patients (87.5%) in 160-s group. Seven of 44 eyes (15.9%) in 240-s group and 12 of 32 eyes (37.5%) in 160-s group required re-treatment for adequate IOP control. After the re-treatments, both protocols showed similar success rates of 79.5% in 240-s group and 75% in 160-s group at 12 months, respectively (p > 0.05). Conclusions MP-TSCPC can be offered as a primary surgical treatment for the management of refractory glaucoma in patients with good visual acuity. Considering the high re-treatment rates in 160-s group, the 240-s duration protocol appears to be more effective than 160-s protocol for adequate IOP control.