Hypotensive effect of selective laser trabeculoplasty in patients with medically uncontrolled primary open-angle glaucoma

Abstract

Introduction. Glaucoma is a chronic, progressive disease of the optic nerve which if left untreated can lead to blindness at end stages. A decrease of intraocular pressure (IOP) has proven to slow down the progression of the disease. IOP decrease can be achieved by medical, laser and surgical treatment. Objective. The aim of this study was to evaluate the response of patients with medically uncontrolled primary open angle glaucoma to selective laser trabeculoplasty (SLT). Methods. The study involved baseline characteristics recorded for each of 35 patients (48 eyes) in whom, despite being under full medication we could not achieve a satisfactory IOP. Patients, who had pressure above 25 mmHg under the maximal medication therapy, were not included into the study and were referred for surgical treatment. IOP was measured on admission, 1 hour, 7 days, 1, 3, 6 and 12 months after SLT. We considered satisfactory surgical result if IOP was decreased more than 20% of the initial value. Also, we investigated the influence of baseline IOP on SLT outcome after 12 months. Patient inclusion criteria were inability to reach target IOP with maximal medical therapy. Exclusion criteria were congenital glaucoma, any type of angle closure glaucoma, advanced-stage glaucoma, eyes with previous laser or surgical glaucoma applications and patients with baseline IOP >25 while fully medicated. Patients who could not be followed for at least 12 months were also excluded. Results. The mean age of our patients was 73?12 years. The mean baseline IOP was 20.48 mmHg (SD=1.91), and the mean change in IOP from baseline of the treated eye after one year was 4.47 mmHg (SD=2.12). In eyes with a higher baseline IOP the reduction of pressure at the end of the study was significantly higher. Satisfactory effect of IOP reduction after one year was achieved in 64.58% of eyes. The IOP reduction did not show to be dependent as regarding age and gender. Conclusion. SLT effectively lowers IOP in patients with primary open-angle glaucoma, and the intervention is not followed by significant complications. Our results confirm that the IOP reduction is more significant if the initial value is higher. Our first reliable results of IOP reduction were confirmed one month after the procedure so that the procedure should not be repeated before one month has elapsed. The study is limited by a small number of eyes, which is insufficient to make a complete case analysis.