Mega-analysis
Ticiana De Francesco, MD,¹⁻⁴; James J. Armstrong, MD, PhD,⁵; Isra M. Hussein, MD, MSc,⁶; Vital P. Costa, MD, PhD,²; Iqbal Ike K. Ahmed, MD, FRCSC¹,⁷⁻⁸
Purpose: To compare the effectiveness and adverse event profile of standalone polystyrene-isobutylene-styrene (SIBS) microshunt implantation with adjunctive mitomycin C (MMC) at concentrations of 0.2 mg/ml and 0.4 mg/ml.
Design: Mega-analysis using individual patient data from international prospective and retrospective clinical studies.
Participants: Patients with glaucoma who underwent implantation of a SIBS microshunt with MMC as a standalone procedure.
Methods: Eyes receiving MMC at concentrations of 0.2 mg/ml or 0.4 mg/ml were compared.
Main Outcome Measures: The primary outcome was complete success at 1 year, defined as the proportion of eyes meeting all of the following criteria: (1) no two consecutive intraocular pressure (IOP) measurements >17 mmHg; (2) absence of clinical hypotony; (3) ≥20% reduction in IOP from baseline; and (4) no use of glaucoma medications.
Secondary outcomes included IOP thresholds of 12, 14, and 21 mmHg; median IOP; number of glaucoma medications; risk factors for failure; interventions; adverse events; and reoperations.
Results: At 1 year, the complete success rate was significantly higher in the MMC 0.4 mg/ml group compared with the MMC 0.2 mg/ml group (71.3% vs. 50.46%; P < 0.001). The median IOP was also significantly lower in the 0.4 mg/ml group (13.0 vs. 14.2 mmHg; P < 0.05).
The use of MMC at 0.2 mg/ml was identified as a significant risk factor for treatment failure, with a hazard ratio of 1.75 (95% confidence interval, 1.14–2.67).
Needling procedures and surgical revisions occurred at lower rates in the MMC 0.4 mg/ml group compared with the MMC 0.2 mg/ml group (7% vs. 18.8%; P = 0.002, and 4.3% vs. 13.7%; P = 0.0087, respectively).
Adverse events occurred at similar frequencies between the groups: 26.6% in the MMC 0.2 mg/ml group and 29.6% in the MMC 0.4 mg/ml group (P = 0.46). Most adverse events were early and transient.
Conclusion: Standalone implantation of a polystyrene-isobutylene-styrene (SIBS) microshunt with MMC at 0.4 mg/ml resulted in a higher success rate and greater IOP reduction compared with the use of MMC at 0.2 mg/ml. The higher MMC concentration was not associated with an increased frequency of serious adverse events.
Financial Disclosure(s): Proprietary or commercial disclosures may be found in the Footnotes and Disclosures section at the end of the article.
Reference: Ophthalmology Glaucoma. 2024;7:454–465. © 2024 by the American Academy of Ophthalmology.