Comparative outcomes of Selective Laser Trabeculoplasty (SLT) delivered by optometrists compared to Ophthalmologists in the United Kingdom (UK): a multi-centre observational study.

Abstract

Purpose : SLT in the UK national health service (NHS) is increasingly undertaken by optometrists (OPTs) but studies comparing outcomes of SLT delivered by OPTs to ophthalmologists (OPHs) are lacking. We have undertaken a multi-centre observational study to evaluate this.

Methods : We analysed fully anonymised medical records of adult patients (aged 40 and above) with no previous laser interventions or glaucoma surgery receiving first treatment of SLT at 3 regional eye units between 1st August 2018 and 1st August 2021. Primary outcome was mean reduction in intraocular pressure (IOP) at 12 months. Secondary outcomes were mean change in visual acuity (VA) and glaucoma medications, and composite failure outcomes including repeat laser, surgery, or increased medication. Safety outcomes were loss of ≥2 lines of VA, registration as sight impaired (SI), and complications. Two-tailed t-test was used to compare means and mean differences, Chi squared test was used to compare categorical proportions.

Results : 69 eyes of 45 patients treated by OPTs were compared to 125 eyes of 75 patients treated by OPHs. Baseline characteristics and variables were well matched between both groups (Table 1). There were significantly more patients with normal tension glaucoma in the OPH-treated group, and open angle glaucoma in the OPT-treated group respectively. There was a statistically significant reduction in mean [95% confidence interval] IOP from baseline in both groups, (OPTs -5.6mmHg [3.6-6.5] vs OPHs -4.4mmHg [3.3-5.6], p<0.05) but no statistically significant difference (p>0.05) in mean IOP reduction (0.58 [-1.4-2.5]) or change in mean VA, medication use or duration to subsequent glaucoma surgery comparing both groups (Table 2). A similar proportion of eyes in both groups reached at least 1 measure of composite treatment failure at 12 months (58% vs 58.4%). No OPT-treated patients required SI registration, compared to 1 OPH-treated patient (Table 3). The relative risk of post-SLT IOP >21mmHg was 3.3 times greater in OPH-treated eyes compared to OPT.

Conclusions : Efficacy outcomes of SLT are comparable between eyes treated by OPTs compared to OPHs. There was a higher risk of raised IOP in eyes treated by OPHs - this may be due to differences in baseline case mix with OPHs opting to treat patients at higher risk of complications or progression.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.