Pattern of intraocular pressure reduction following laser trabeculoplasty in open-angle glaucoma patients: comparison between selective and nonselective treatment

Abstract

Eglailson Dantas Almeida Júnior1, Luciano Moreira Pinto1,2, Rodrigo Antonio Brant Fernandes1,2, Tiago Santos Prata1,31Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil; 2Cerpo Oftalmologia, São Paulo, Brazil; 3Hospital Medicina dos Olhos, São Paulo, BrazilObjective: To compare the pattern of intraocular pressure (IOP) reduction following selective laser trabeculoplasty (SLT) versus argon laser trabeculoplasty (ALT) in open-angle glaucoma (OAG) patients, and to investigate the ability of initial IOP reduction to predict mid-term success.Methods: A prospective, nonrandomized, interventional case series was carried out. Consecutive uncontrolled OAG glaucoma patients underwent SLT or ALT; the same preoperative medical regimen was maintained during follow-up. Data collected included age, type of OAG, pre- and postoperative IOP, number of glaucoma medications, and surgical complications. Post-treatment assessments were scheduled at day 1 and 7 and months 1, 3, and 6.Results: A total of 45 patients (45 eyes) were enrolled [SLT group (n = 25); ALT group (n = 20)]. Groups were similar for age, baseline IOP, and number of glaucoma medications (P ≥ 0.12). We found no significant differences in mean IOP reduction between SLT (5.1 ± 2.5 mmHg; 26.6%) and ALT (4.4 ± 2.8 mmHg; 22.8%) groups at month 6 (P = 0.38). Success rates (IOP ≤ 16 mmHg and IOP reduction ≥25%) at last follow-up visit were similar for SLT (72%) and ALT (65%) groups (P = 0.36). Comparing the pattern of IOP reduction (% of IOP reduction at each visit) between groups, we found a greater effect following SLT compared with ALT at day 7 (23.7% ± 13.7% vs 8.1% ± 9.5%; P < 0.001). No significant differences were observed at other time points (P ≥ 0.32). Additionally, the percentage of IOP reduction at day 7 and at month 6 were significantly correlated in the SLT group (R2 = 0.36; P < 0.01), but not in the ALT group (P = 0.89). Early postoperative success predicted late success in most SLT cases (82%). No serious complications were observed.Conclusion: Although mid-term results suggest SLT and ALT as effective and equivalent alternatives, a greater initial IOP reduction was observed following SLT. In addition, the initial IOP reduction was a good predictor of mid-term success in patients undergoing SLT, but not ALT.Keywords: open-angle glaucoma, laser trabeculoplasty, intraocular pressure