In this study, ten patients underwent combined phacoemulsification cataract surgery with a permanent supraciliary biostent implantation. The biostent comprised decellularized scleral allograft tissue microtrephined into a polymer tubular implant. Patients enrolled in the study had been diagnosed with POAG (angle 3+ in all four quadrants) cataracts and did not previously undergo glaucoma surgery. Significant corneal opacities and visual field loss within central 10° were exclusion criteria. Patients were visited at one week, one month, six months, and 12 months after surgery. All patients at 12 months reached a sustained IOP reduction (40% from baseline) and a significative reduction in IOP medication use (62%). Mean IOP at baseline was 24.2 mmHg, at 12 months follow-up 14.6 mmHg. No stent displacement or corneal touch was reported; no significant hyphema, anterior segment inflammation, or peripheral anterior synechiae were observed post-operatory follow-up. Endothelial cell density was 2619 ± 228 (cells/mm2) at baseline, 2312 ± 210 cells/ mm2 at 12 months follow-up. Mean BCVA was 0,81 logMAR at baseline (20/130) and 0,26 logMAR at 12 months follow-up (20/36).
The authors adequately disclose the limits of this study: the relatively short duration of follow-up and the small number of subjects enrolled. The authors tried to compare the endothelial cell loss of the biostent with other MIGS. However, the follow-up duration in the current study is shorter, and the comparison may be misleading. Furthermore, endothelial cell loss may become evident well after one year, as with the Cypass. The biostent softness, biocompatibility, and the observation that it did not dislodge nor move during the one-year follow-up are reassuring. The short-term follow-up needs further investigation to answer questions on the biocompatibility and tolerability of the device.
Despite the small number of patients enrolled in this study, this new supraciliary biostent combined cataract surgery results are promising. IOP control, tolerability, safety, and one-year biostent stability of the device are essential and valuable points.