Selective laser trabeculoplasty (SLT) has been shown to be useful in the management of primary open angle glaucoma (POAG), but its use in primary angle closure (PAC) / primary angle closure glaucoma (PACG) has yet to be validated. Narayanaswamy et al. present the results of a randomised controlled study involving 100 patients with PAC / PACG having previously undergone laser peripheral iridotomies with subsequent opening of at least 180º of the angles. Fifty participants were randomly allocated to treatment with a topical prostaglandin analogue (PGA) and 50 to treatment with SLT in order to address baseline intraocular pressures (IOP) above 21mmHg. The results after a six month period of follow-up showed a decrease in IOP of 4.0mmHg with SLT vs. 4.2mmHg with PGA (p=0.78), and a percentage decrease in IOP of 16.9% with SLT vs. 18.5% with PGA (0.52). Following treatment, 60.0% of SLT patients had IOPs lower than 21mmHg without medications, compared to 84.0% of PGA patients (p=0.08). And 28.6% of patients receiving SLT were treated repeatedly, to address a reduction in IOP of less than 20%. Side-effects of SLT included a transient post-treatment IOP spike of greater than 5mmHg in one patient (2%), and a significant decrease of 4.8% in mean endothelial cell count (p=0.01). The authors also note the difficulty in performing 360º SLT (known to have the best IOP-lowering effect) owing to the anatomy in PAC / PACG. Side-effects of treatment with PGA included uveitis and allergic uveitis (4%) leading to interruption of treatment. This study shows that SLT does produce a decrease in IOP in patients with PAC / PACG which is comparable to that obtained with a PGA. Treatment with SLT in PAC / PACG presents the advantage of avoiding a long-term treatment with its associated cost, risk of non-compliance and its side-effects. However, a longer follow-up period is required to ascertain the long-term effects of SLT.