Treating advanced glaucoma often requires numerous therapeutic modalities in order to achieve the desired intraocular pressure (IOP) reduction. The purpose of this study was to evaluate the IOP lowering efficacy of both cyclocryotherapy (CCT) and transscleral diode laser cyclophotocoagulation (TS-DCPC) in the management of refractory primary open-angle glaucoma. This prospective, randomized, controlled clinical trial included 40 patients (40 eyes) with refractory glaucoma treated at the Eye Department, Clinical Center of Vojvodina, Novi Sad, Serbia, between January 2016 and June 2019. Twenty patients underwent CCT (group 1), while another twenty patients were treated with TS-DCPC (group 2). Each patient underwent complete eye examination on the treatment day, as well as follow-up eye examinations 7 days and 1, 6 and 12 months after the intervention, when IOP and number of anti-glaucoma drugs used were recorded. The median baseline IOP was 36.50 mm Hg (IQR, 28.75-42.00) in group 1 and 27.00 mm Hg (IQR, 22.00-35.00) in group 2. Follow-up measurements of IOP in group 1 showed the following results: 16.50 mm Hg (IQR, 7.75-20.00) (60% decrease from the baseline value), 12.00 mm Hg (IQR, 9.25-18.00) (67% decrease from the baseline value), 9.00 mm Hg (IQR, 2.00-13.75) (73% decrease from the baseline value), and 9.50 (IQR, 2.50-12.00) (75% decrease from the baseline value) after 7 days, 1, 6 and 12 months, respectively. Follow-up measurements of IOP in group 2 showed the following results: 16.00 mm Hg (IQR, 10.00-17.00) (48% decrease from the baseline value), 14.00 mm Hg (IQR, 10.00-16.00) (56% decrease from the baseline value), 14.00 mm Hg (IQR, 12.25-16.50) (43% decrease from the baseline value) and 14.00 mm Hg (IQR, 11.25-15.75) (53% decrease from the baseline value) after 7 days, 1, 6 and 12 months, respectively. The mean number of antiglaucoma drugs used decreased from 4 to 0.65±0.81 and 2.25±1.07 in groups 1 and 2, respectively. In conclusion, study results confirmed the CCT and TS-DCPC to have a rapid and statistically significant ocular hypotensive effect in eyes with refractory glaucoma at one-year follow-up.
Keywords: Cyclocryotherapy; Diode laser cyclophotocoagulation; Intraocular pressure; Refractory glaucoma.