To evaluate the efficacy and safety of micropulse transscleral laser therapy (MP-TLT) in lowering intraocular pressure (IOP) in eyes with primary glaucoma at different stages.

In this retrospective longitudinal cohort study, data were collected from the charts of patients who undergo MP-TLT. Information regarding medication burden (including oral carbonic anhydrase inhibitor use), IOP, and visual acuity, were gathered prior to the procedure and at day 1, week 1 and at 1, 3, 6, 12, 18, and 24mo follow-up. Glaucoma severity staging was performed according to the Hodapp-Parrish-Anderson classification system based on visual field parameters assessed with standardized automated perimetry. Early glaucoma was defined as mean deviation (MD) better than -6 dB, moderate glaucoma as MD between -6 and -12 dB, and advanced glaucoma as MD worse than -12 dB.

Totally 84 eyes of 53 patients (22 females), with a mean age of 67.14±11.39y affected by progressive primary open angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) were included. Before treatment, mean best corrected visual acuity was 0.26±0.36 logMAR, mean IOP was 22.32±6.64 mm Hg and patients took a mean of 2.96±0.75 topical IOP lowering molecules; moreover, 18 patients also required acetazolamide tablets. At 1mo follow-up, a significant (P<0.001) reduction of mean IOP was detected both in POAG (-7.16±2.92 mm Hg) and PACG (-6.89±3.12 mm Hg) eyes, remaining stable during the further follow-up. A significant (P<0.01) reduction in the number of drugs taken was observed at 3-month follow-up both in POAG (-0.59±0.32) and PACG (-1.06±0.73) eyes. These effects persisted over time during the further follow-up. Furthermore, marked decreases in IOP and IOP-lowering drugs were seen in patients with early, moderate, and advanced glaucoma, and these results closely matched the findings from the entire study cohort.

The results obtained suggest that MP-TLT may be an effective and safe option for managing patients with POAG and PACG at every stage of the disease.