Can SLT safely delay surgery in presurgical primary open angle glaucoma?

ABSTRACT

Purpose: Selective laser trabeculoplasty (SLT) has been widely used as both a primary and adjunct treatment in glaucoma. Glaucoma surgery was significantly affected during the Covid-19 pandemic due to reduced theatre and clinic capacity. We looked at SLT as a temporary alternative to safely delay surgical intervention in presurgical primary open angle glaucoma (POAG). Methods: This is a retrospective study that included 104 patients who had a diagnosis of POAG and received SLT treatment, with at least 1 year follow-up. Primary outcomes included reduction in intraocular pressure (IOP), and number of glaucoma medications (NGM). The endpoint was defined as time to be listed for glaucoma surgery. All eyes that had progressive or advanced visual fields and were on 2 or more medications were included. Eyes with previous glaucoma filtration surgery or argon laser trabeculoplasty, diagnosed with normal tension glaucoma or that had significant angle closure disease (peripheral anterior synechiae >180) were excluded. Results: The mean patient age was 73.4 ± years. At baseline, the mean IOP and NGM were 20.5 ± 4.9 and 2.8 ± 0.9 mmHg, respectively. At 12 months, the mean IOP was 16.5 ± 3.3 mmHg and the NGM was 2.7 ± 1.0. The IOP reduction was 3.7 ± 5.8 mmHg (14.5%, p<0.01) at 12 months follow-up, 3.4 ± 4.7 mmHg (15.5%, p<0.01) at 24 months follow-up, 3.7 ± 5.2mmHg (15.2%, p<0.01) at 36 months follow-up and 2.5 ± 5.9 mmHg (10.1%, p=0.04) at 48 months follow-up. No surgical intervention was needed in 96% of eyes within the first year of SLT. There was no significant difference in the NGM pre- and post- SLT. Conclusions: With the current pandemic limiting the surgical capacities of eye hospitals, SLT can safely delay the need for glaucoma surgery for at least 1 year by reducing the IOP. This is particularly apparent in elderly patients or those poorly compliant to medical therapy. In addition, this could increase ophthalmology clinic capacity by reducing the number of post-operative follow ups.