Comparative study of early safety and effectiveness outcomes of the PreserFlo MicroShunt with and without an intraluminal suture stent

Abstract

Objective: -To assess the early safety and effectiveness outcomes of the PreserFlo MicroShunt with and without an intraluminal suture stent.

Design: -Multicenter observational retrospective study using data from the Fight Glaucoma Blindness registry.

Participants: -A total of 183 eyes in 172 patients, with a mean age of 73 ± 14 years, who underwent PreserFlo MicroShunt surgery with/without intraluminal stent suture placement, and with at least 6 months of follow up. Eyes were divided into two groups: stent (68 eyes) and no stent (115 eyes).

Methods: -Baseline and post-operative measurements of intraocular pressure (IOP), visual acuity, number of glaucoma medications and adverse events were recorded at 1, 3, and 6 months. Outcomes were compared between stent and no-stent groups using t-tests for continuous variables and Fisher's exact tests for categorical variables.

Main outcome measures: -The primary outcome measures were the incidence of numerical hypotony (IOP ≤ 5 mmHg) and symptomatic hypotony (numerical hypotony plus ≥10 letters of visual acuity loss) within 1 month, 1-3 months, and 3-6 months postoperatively. Secondary outcome measures included surgical success rates (defined as IOP ≤12, ≤15, ≤18, or ≤21 mmHg and ≥20% IOP reduction without hypotony and without additional glaucoma medications) and the need for secondary surgical interventions.

Results: -In the first post-operative month, the stent group had significantly lower rates of numerical hypotony (24% vs 44%; p = 0.007) and symptomatic hypotony (15% vs 30%; p = 0.04) than the no-stent group. The rate of device revision, explant, or replacement with an alternative shunt was also significantly lower in the stent group (3 eyes; 4.4%) compared to the no stent group (17 eyes; 14.8%; p = 0.047). No significant differences in hypotony rates were observed in the later follow-up windows (1-3 months and 3-6 months), nor were there significant differences in surgical success rates between the stent and no-stent groups at any time point.

Conclusions: -The use of an intraluminal suture stent in PreserFlo MicroShunt surgery reduces the incidence of early hypotony without compromising surgical success. These findings suggest that routine use of intraluminal sutures may improve early post-operative safety.