Short-term safety and efficacy of Preserflo™ Microshunt in glaucoma patients: a multicentre retrospective cohort study

Abstract

Background/aims: To evaluate 1-year success rates and safety profile of Preserflo™ Microshunt in glaucoma patients.

Methods: Retrospective multicentre cohort study of 100 consecutive eyes (91 patients) from four tertiary-referral glaucoma centres. Four intraocular pressure (IOP) criteria were defined: A: IOP ≤ 21 mmHg+IOP reduction ≥20% from baseline; B: IOP ≤ 18 mmHg+IOP reduction ≥20%; C: IOP ≤ 15 mmHg+IOP reduction ≥25%; D: IOP≤12 mmHg+IOP reduction ≥30%. Success was defined as qualified or complete based on whether reached with or without medication. Primary outcome was success according to the above criteria. Secondary outcomes included: IOP, best-corrected visual acuity (BCVA), medication use, complications, postoperative interventions, and failure-associated factors.

Results: Qualified and complete success rates (95% CI) at 12 months were 74%(66-83%) and 58%(49-69%) for criterion A, 72%(63-82%) and 57%(48-68%) for B, 52%(43-63%) and 47%(38-58%) for C, 29%(21-40%) and 26%(19-36%) for D. Overall median (interquartile range (IQR)) preoperative IOP decreased from 21.5(19-28) mmHg to 13(11-16) mmHg at 12 months. BCVA was not significantly different up to 12 months (p = 0.79). Preoperative median (IQR) number of medications decreased from 3 (2-3) to 0 (0-1) at 12 months. Twelve eyes underwent needling, five surgical revision and one device removal due to corneal oedema. There were no hypotony-related complications. Non-Caucasian ethnicity was the only risk factor consistently associated with increased failure.

Conclusions: Preserflo™ Microshunt is a viable surgical option in glaucoma patients, with reasonable short-term success rates, decreased medications use, excellent safety profile, smooth postoperative care, and rapid learning curve. Success rates for the most stringent IOP cutoffs were modest, indicating that it may not be the optimal surgery when very low target IOP is required.

Fig. 1. Post-operative outcomes.

a Intraocular pressure (IOP) readings (left panel), number of medications (middle panel), and best-corrected visual acuity (BCVA) values (right panel) over time in patients undergoing Preserflo MicroShunt. Black diamonds on the boxplots represent mean values. b Scatterplot of the preoperative versus postoperative 1-year intraocular pressure values. Dots represent eyes, the diagonal solid line represents the no difference line, and the various horizontal lines indicates the various IOP thresholds (i.e., 21, 18, 15, and 12) used in this study. c Kaplan-Meier curves for the qualified (with glaucoma medications) and complete (without medications) success according to the various study criteria. Criterion A: IOP ≤ 21 and IOP reduction ≥20% from baseline; Criterion B: IOP ≤18 and IOP reduction ≥20% from baseline; Criterion C: IOP ≤ 15 and IOP reduction ≥25% from baseline; Criterion D: IOP ≤ 12 and IOP reduction ≥30% from baseline. d Kaplan-Meier cumulative incidence for postoperative needling.