Effectiveness of unilateral selective laser trabeculoplasty for primary open angle glaucoma

Abstract

To study the effectiveness of unilateral selective laser trabeculoplasty (SLT) on the both eyes of patients with primary open-angle glaucoma (POAG). This was a self-controlled clinical study. Thirty-two patients of 32 eyes with OAG who used same anti-glaucoma medications for both eyes were included aat the Department of Ophthalmology Peking University third Hospital from February 2010 to April 2014. SLT was performed for the poorly controlled eye for each patient. Patients were examined before operation and 1 hour, 1 week, 1 month, 3 months and 6 months after operation. The intraocular pressure was examined after 1 hour of SLT. The rest time points were examined by visual acuity, intraocular pressure (IOP), slit lamp microscope, fundus ophthalmoscope and visual field. The paired t test (Bonferroni) was used to compare the IOP at each time point after SLT with the baseline IOP before SLT. Single factor analysis of variance was used to compare the percentage of IOP drop. Linear correlation analysis was used to analyze the amplitude of the decrease of IOP between treated eyes and untreated eyes at 6-month post-operatively and analyze the IOP between preoperative eyes and 6-month post-operative eyes. The magnitude of the decrease of IOP in patients with glaucoma medication and 6 months after surgery was analyzed. We also analyzed the types of antiglaucoma medications and IOP reductions range for 6 month after SLT. The preoperative mean IOP was (18.9±2.5) mmHg (1 mmHg=0.133 kPa) in the treated eye of patients with OAG. Mean IOP reduction for 1 week, 1, 3, and 6 months after SLT were (1.7±2.9) mmHg, (2.5±2.5) mmHg, (3.5±2.8) mmHg, (3.4±2.5) mmHg and the percentage of IOP reduction were (8±16) %, (13±13) % (18±14) %, (18±12) % respectively (compared with the baseline, P< 0.05) . With the success criteria of IOP reduction ≥3.0 mmHg or ≥20%, the success rate of SLT in the treated eye after 1 week, 1, 3, 6 months was 38%, 52%, 50% and 60% respectively. For the untreated fellow eyes, the preoperative mean IOP was (17.3±2.4) mmHg. Mean IOP reduction for 1 week, 1month, 3 month, and 6 month after SLT were (1.1±2.0) mmHg, (1.0±2.7) mmHg, (2.6±2.2) mmHg and (2.5±2.2) mmHg respectively (compared with the baseline, P<0.05) . There was a positive correlation between preoperative IOP and IOP reduction either in the treated or in the untreated eyes at 6-month post-SLT (R=0.63, P<0.01; R=0.60, P<0.01) . There was a positive correlation in IOP reduction between treated eyes and untreated eyes at 6-month post-operative (R=0.66, P<0.01). All patients didn't need further treatment such as another laser treatment or surgery. Anti-glaucoma medications were remained unchanged after SLT. In poorly anti-glaucoma medication controlled Chinese POAG eyes with mean IOP about 18.0 mmHg, unilateral STL can reduce the IOP about 18% at 6-month post-operative for the treated eyes. There was also a continuous IOP reduction effects for the fellow eyes.(Chin J Ophthalmol, 2016, 52: 410-415).