Midterm Survival Results of Preserflo in a Real-World Setting.

Prcis: Preserflo surgery is a safe procedure, effective in reducing intraocular pressure into the "low teens," surgical survival is greatest in cases of high baseline intraocular pressure (above 21 mm Hg) and when performed as a standalone procedure.

Purpose: To evaluate midterm surgical survival and safety profile of Preserflo filtering surgery.

Methods: In this retrospective, cohort study, consecutive patients who underwent standardized Preserflo implantation with mitomycin C from December 2019 to April 2021 were included. Clinical data were retrieved from patient charts. The primary outcome was surgical survival at 24 months in accordance with World Glaucoma Association guidelines. Survival was evaluated using Kaplan-Meier statistics. Analysis was performed at the eye level and as intention to treat.

Results: Ninety-five eyes were included in this study (18 cases combined with cataract surgery). More than half of cases (n=51) were primary open angle glaucoma, with over a fifth having a prior filtering glaucoma procedure. Intraocular pressure at 24 months was significantly decreased from baseline (22.4±6.28 vs. 12.0±3.43 mm Hg), as well as the need for IOP-lowering medication [2.88 (±0.92) vs. 0.79 (±1.3), P <0.001 all comparisons]. Standalone Preserflo achieved a qualified survival (irrespective of medication) of 71% (95% CI, 62%-83%) and 44% (95% CI, 27%-75%) in the combined procedure subgroup ( P <0.05 when considering absolute survival). Eyes with baseline intraocular pressure ≥21 mm Hg showed a greater qualified survival when compared with eyes with baseline ≤18 mm Hg [80% (95% CI, 65%-100%) vs. 50% (95% CI, 32%-76%); P <0.05]. Intra and early operative complications were few, self-limited, and did not require surgical management. The reoperation rate was low (18%).

Conclusions: Preserflo filtering surgery was effective in reducing intraocular pressure into the "low teens" and presents an adequate surgical survival and safety profile. Surgical survival appeared greatest when performed as standalone and when preoperative intraocular pressure was high.