Abstract: Objective To evaluate the efficacy and safety of two trans-scleral diode laser cyclophotocoagulation (TDLCP) protocols based on “pop” for refractory glaucoma. Design Retrospective comparative case series. Participants Sixty-two eyes in 62 patients with refractory glaucoma. Methods Thirty patients (30 eyes) were treated with pop-titrated TDLCP, and 32 patients (32 eyes) were treated with fixed-energy TDLCP. The laser power was adjusted depending on the occurrence of an audible “pop” in pop-titrated group. The laser power was constant in fixed-energy group. The patients were followed up 3 months. Main Outcome Measures Total mean laser energy, pop numbers, intraocular pressure (IOP), visual acuity, anti-glaucoma medications, and complications. Results In pop-titrated group, mean IOP decreased from 46.1±10.7 mmHg before surgery to 15.8±6.9 mmHg 3 months after surgery. In fixed-energy group, mean IOP decreased from 44.9±12.3 mmHg before surgery to 16.7±8.2 mmHg on 3 months after surgery. 80% patients in pop-titrated group whose IOP reduced to less than 21 mmHg without medications was significantly higher than 65.6% patients in fixed-energy group (χ2=5.643, P=0.018). The IOP reduction was moderate correlated with the number of pops both pop-titrated group( r=0.517，P=0.001) and fixed-energy group( r=0.572，P=0.001). In pop-titrated group, BCVA decreased in 1 eye after TDLCP. In fixed-energy group, BCVA decreased in 2 eyes, and prolonged hypotonia occurred in 1 eye after TDLCP. Conclusion The pop-titrated TDLCP is more effective than the pop-fixed TDLCP for the treatment of refractory glaucoma. （Ophthalmol CHN, 2020,29: 147-151）

Key words: trans-scleral cyclophotocoagulation, refractory glaucoma