Selective laser trabeculoplasty (SLT) after glaucoma surgery in moderate and advanced primary open-angle glaucoma

Purpose. To study the hypotensive effect of selective laser trabeculoplasty (SLT) treatment in cases of insufficient effectiveness or reduced hypotensive effect of glaucoma surgery in patients with moderate and advanced primary open-angle glaucoma (POAG). Material and methods. A retrospective study was conducted of 32 patients (32 eyes) with POAG after previous glaucoma surgery and uncompensated intraocular pressure (IOP), who underwent SLT due to the impossibility of reoperation. Changes in IOP were studied 1 day, 1, 3, 6 and 12 months after SLT. Results. After SLT, the IOP level decreased from 24.5±4.4 to 19.3±3.8 mm Hg after 1 day (p<0.001), the hypotensive effect was 5.2±5.1 mm Hg (21.2% of the baseline IOP) and did not change significantly within 3 months after laser treatment. After 6 and 12 months, a decrease in the hypotensive effect was revealed compared with the primary response 1 day after SLT (3.0±2.9 and 1.9±5.4 mm Hg, p=0.02). 12 months after SLT, the IOP level remained below the baseline IOP only in 46.9% of cases. There were no significant differences in the results of SLT at different stages of POAG, different types of glaucoma surgery, different medication regimens (p>0.05), and there was no dependence on the timing after previous glaucoma surgery. Conclusion. SLT can be used after previous glaucoma surgery when IOP reduction is insufficient in patients with moderate and advanced POAG. However, the hypotensive effect of SLT in such cases is unstable, so this method of treatment should be considered only as an auxiliary one and if repeated surgery is not possible, as well as providing more frequent control of IOP in patients. Key words: glaucoma, selective laser trabeculoplasty, intraocular pressure, glaucoma surgery, ophthalmic surgery