Michael Butler

Introduction
Selective laser trabeculoplasty has been carried out at Lancashire Teaching Hospitals over the past seven years. This work aimed to review the use of SLT in this Trust. The primary objectives were to establish the efficacy of SLT in reducing intraocular pressure, to analyse how prior treatment with different topical medications can influence SLT outcomes and to analyse the outcomes in revisionary patients.

Method
We conducted a retrospective review of 288 eyes, with a known history of glaucoma or ocular hypertension and who underwent initial SLT laser treatment between October 2018 and January 2020. SLT was performed on known glaucoma and treatment naïve patients where IOP control was deemed sub-optimal. All patient data was fully anonymised.

Results
We found that SLT was effective in lowering IOP. Around two-thirds of the eyes (181/280, 65%) achieved a reduction in IOP of 10% or more. Just under half (127/280, 45%) achieved a reduction of 20% or more. For a pre-SLT IOP of 14.6 mmHg, we found that no mean change in IOP is expected, and for each 1 mmHg by which the pre-SLT IOP exceeds this threshold, the mean reduction in IOP is expected to be 0.61 mmHg. We also found that combination therapies of PGA plus aqueous suppressants gave better outcomes compared with PGA alone. We found that revisionary SLT compared favourably with the first treatment, although first-time outcomes were not a good predictor of success with revisionary SLT.

Conclusion
Primary and revisionary SLT has been shown to be effective across the cohort of patients in this study.