Twelve-month outcomes after open bleb revision for Preserflo^® microshunt bleb failure in refractory glaucoma patients

Purpose: To evaluate the 12-month efficacy and safety of open bleb revision (OBR) for Preserflo^® MicroShunt (PMS) (Santen, Osaka, Japan) bleb failure. Patients and Methods: All consecutive patients who underwent PMS OBR for primary bleb failure between April 2019 and July 2024 at the Hôpital National des Quinze-Vingts (Paris, France) were retrospectively included. The primary endpoint was assessed at 6 and 12 months as surgical success, defined as an intraocular pressure (IOP) ≤ 21 mmHg with a ≥ 20% reduction in IOP using the same or fewer hypotensive treatments, with no additional glaucoma surgery, no chronic hypotony, and no loss of light perception. All complications during follow-up were analyzed. Results: A total of 87 patients who underwent PMS OBR for primary bleb failure were evaluated. Most patients presented with severe, refractory, glaucoma, as the mean number of glaucoma surgical procedures prior to the first PMS implant was 1.9 ± 1.4. 97% of patients had previously undergone major bleb-forming glaucoma surgery. The mean preoperative IOP was 30.2 mmHg with 1.8 ± 1.5 hypotensive treatments. OBR was performed after a median interval of 157 days. Success rate was 40.7% at 6 months, and dropped to 20.9% at 12 months. The mean IOP decreased to 20.2 ± 7.6 mmHg at 12 months, representing a significant decrease of 9.8 ± 9.3 mmHg (33%), with 1.7 ± 1.5 hypotensive treatments (p = 0.82). Transient postoperative hypotony was observed in 3 patients (3.5%). No serious complications were reported during follow-up, in particular no chronic hypotony. Conclusion: Following OBR for PMS bleb failure, approximately 40% of patients achieved surgical success at 6 months, compared with 20% at 12 months. However, a significant reduction in intraocular pressure was maintained at 12 months, without a statistically significant reduction in medication burden.