Observation on the efficacy of reducing IOP by selective laser trabeculoplasty in different region

Objective To observe the efficacy of 180 degree selective laser trabeculoplasty (SLT) in the different trabecular meshwork (TM) area for the treatment of primary open-angle glaucoma (POAG) or ocular hypertension (OHT). Methods This was a prospective randomized clinical trial study. The data of 107 eyes of 89 patients with unilateral or bilateral POAG and OHT were collected. All patients were randomly divided into group A, B, C, and D. Group A was treated with 180 degree SLT in the lower TM, group B in the upper TM, group C in the nasal TM, and group D in the temporal TM. The IOP was measured before and 1 week, 1, 3, 6 and 12 months after SLT. The shots and energy of SLT at different time points were recorded. SLT success was defined as IOP reduction≥20% from baseline without any IOP-lowering medication. Results The average baseline IOP was (23.8±4.0) mmHg , range 22-30 mmHg(1 mmHg=0.133 kPa). At the end of the follow-up, 12 months after SLT treatment, the mean reduction of IOP in group A, B, C and D were (7.1±2.5)mmHg, (6.5±3.3)mmHg, (7.0±3.9)mmHg and (6.4±2.6)mmHg, and the success rates were 46.4%, 44.4%, 42.3% and 42.3%, respectively. The difference were not statistically significant in the IOP reduction and success rate of SLT treatment among the four groups. Three eyes in group A, 2 eyes in group B and 2 eyes in group C happened transient elevation of IOP within 1 hour after SLT treatment. No other complication occurred. Conclusion IOP reduction can be effectively achieved by 180 degree SLT in the different TM area of the patients with POAG or OHT, and the success rate of SLT seems not to be affected by different area of TM. Key words: Laser trabeculoplasty, selective; Glaucoma, open-angle; Ocular hypertension; Efficacy