Randomized clinical trial for pop titrated versus the slow coagulation cyclophotocoagulation in treating dark irises neovascular glaucoma

To compare the efficacy and safety of transscleral cyclophotocoagulation (TSCPC) using the pop-titrated (PT-TSCPC) versus the slow-coagulation (SC-TSCPC) energy delivery technique in the treatment of neovascular glaucoma (NVG) patients with dark irises. Randomized clinical trial. Ninety-seven Asian NVG patients. Forty-eight and 49 eyes were randomized to receive PT-TSCPC (1,500-2,500 mW for 2 s) and SC-TSCPC (1,250 mW for 4 s), respectively. Patients were followed up for five years. The success rate, the response rate, the retreatment rate, the cyclodiode efficacy index, the numerical pain rating scale (NPRS), visual acuity (VA), and complications. The preoperative parameters were comparable between both groups. The SC technique required 99.7 ± 35 joules, whereas the PT technique needed 78.3 ± 18.2 joules, P < 0.001). The PT method caused more eye pain during treatment than the SC method (NPRS; 6 vs. 1.8, P < 0.001). The mean intraocular pressure (IOP) at the last visit was 18.8 ± 5.3 mm Hg in the PT-TSCPC group (P < 0.001; 45% reduction from the baseline level) and 15.5 ± 6.7 mm Hg in the SC-TSCPC group (P < 0.001; 56% reduction), P = 0.02). The success rates were 60.4% in the PT-TSCPC group and 71.4% in the SC-TSCPC group (P = 0.14). The response rates were 85.4% and 79.6% for the PT- and SC-TSCPC groups, respectively (P = 0.46). The cumulative probability of success at 5-year follow-up was 48.6% and 69.3% in the PT- and SC-TSCPC groups, respectively (P = 0.03). The SC-TSCPC group required > 1 laser session than the pop-titrated technique (22.4% vs. 6.3%, P = 0.002). VA was worsening in 54.2% of PT-treated eyes and 51% of SC-treated eyes (P = 0.13). Worsening of intraocular inflammation (HR 2.63; 95%CI,1.11-6.26; P = 0.028), PT technique (HR 2.17; 95% CI,1.01-4.71; P = 0.048), male gender (HR 2.13; 95% CI,1.01-4.55; P = 0.048), were the risk factors for TSCPC failure in NVG. The slow-coagulation TSCPC may achieve more efficacious IOP reduction and has better safety profiles than the pop-titrated technique for treating NVG patients with dark irises. Nevertheless, it requires more laser sessions and energy than the power titrating protocol.Trial registration Clinicaltrials.gov Identifier NCT01774227 (23/01/2013).