[Selective laser trabeculoplasty (SLT): our experience in African blacks]

Abstract

Introduction: The purpose of our study was to evaluate in the short and medium term, intraocular pressure results after selective laser trabeculoplasty in black patients with chronic open angle glaucoma or isolated ocular hypertension.

Materials and methods: We conducted a retrospective study with a mean 12.5-month follow-up in black patients who underwent SLT. Inclusion criteria were: an open iridocorneal angle greater than or equal to Schaeffer grade 3, data recorded and available on trabecular pigmentation, data on SLT parameters available, and intraocular pressure by Goldmann applanation tonometry recorded.A positive result was defined as a post-laser IntraOcular Pressure (IOP) less than 21 mmHg after 1-month follow-up. The main motivation was the reduction of number of eye drops used. Performed first was a treatment of the inferior 180° (3:00-9:00), possibly supplemented by a second session at 15 days or 1 month if a pressure decrease was noted after the first session. IOP results were evaluated prior to SLT, immediately following SLT and then depending on the drop in pressure. Statistical analysis was performed using the EPI.info 7 software.

Results: A total of 69 eyes of 40 patients treated with SLT were identified. The mean IOP prior to SLT was 18.3 mmHg ± 4. Our results showed 90% of patients who positively responded to the treatment (10% failure) with a mean IOP decrease of 2.3 ± 1 mmHg, that is 13%, by the second week. The mean pressure decrease continued to 4.78 ± 1 mmHg for patients (30%) in the group treated for 360°, that is 27% in the same period of time. SLT permitted discontinuation of a prostaglandin in 60% (42 cases). Eyes on triple-drug therapy went from 23 before SLT to 5 following SLT (a 26% decline), eyes on two medications went from 32 to 16 (24% decline). In result association tests, only pigmentation of the angle and visual field stage had a statistically significant probability.

Discussion: In our experience, SLT is indicated in black patients to potentiate less effective treatments, to reduce the number of drops in order to limit side effects, but also to avoid or delay monotherapy treatment-naïve, hypertensive eyes.

Conclusion: In the short and medium term, SLT brought about an IOP decrease in 90% of black patients, and discontinuation of a prostaglandin in 60% of our patients. In addition, the iridocorneal angle in blacks appears to be less pigmented than previously thought, and a protocol systematically treating 360° seems to provide better results.

Keywords: Black; Glaucoma; Glaucome; Mélanoderme; Selective trabeculoplasty; Trabéculoplastie sélective.