Clinical Effectiveness And Safety Of Preserflo Microshunt Surgery: A 2-Year Follow-Up Study

Glaucoma is a multi-factorial disease which causes progressive irreversible damage to optic nerve and visual field. Lowering IOP can slow glaucoma progression and is the only treatment available. Preserflo Microshunt is device which has been classified as microinvasive glaucoma surgery (MIGS). We conducted a study to analyse the clinical effectiveness and safety of Preserflo surgery at a tertiary care hospital in the UK over a 24-month follow-up period.

Ophthalmology department of a tertiary care hospital in the West Midlands, United Kingdom

Ambispective clinical data was collected from electronic medical records for 50 Preserflo operations performed by two glaucoma consultants in the West Midlands, United Kingdom. Surgeries were performed from April 2022 to June 2023. Intraocular pressure (IOP) while listing for surgery and up to 24 months after surgery was noted. The average number of glaucoma medications patients were on before and after surgery was calculated. Any drop in best-corrected visual acuity (BCVA) possibly related to the surgery, and other complications were analysed.

The study captured 50 Preserflo operations across 40 patients. The primary indication was POAG (78%), followed by NTG (8%). Mean pre-operative IOP was 22.2 mmHg and mean number of glaucoma drops was 2.74/eye, with 26% on concurrent oral acetazolamide. By 24 months (n=49) mean IOP was 12.2 mmHg (45% reduction), and mean number of drops was 0.35/eye. 40 eyes of 50(80%) were not on any glaucoma medication up to their last follow-up. Acetazolamide was stopped in all patients. There were no major complications. Minor complications were transient such as hypotony and microhyphema which resolved spontaneously. 9 patients were noted to have a drop in BCVA by 1 line during follow-up, however, none of them were attributed to Preserflo surgery.

Our study found Preserflo surgery to be safe and effective, with results comparable/superior to trabeculectomy. Other studies have also shown similar encouraging results. Apart from lesser surgical interventions, other potential advantages include lesser surgical time, faster recovery and reduced risk of damaging other ocular structures. Thus, it may help facilitate a more efficient service delivery for patients requiring surgery. A larger patient cohort and longer-term follow-up are needed to better assess the sustainability of the IOP reduction.