J Glaucoma
J GlaucomaNovember 2025Review

Impact of Different Intraocular Pressure and Medication Endpoint Criteria on Success Rates in Subconjunctival Minimally Invasive Glaucoma Surgery.

Glaucoma SurgeryIOP & Medical Therapy

Summary

Using different IOP and medication criteria to define success can have a significant influence on the apparent risk of failure, particularly at the 21 mm Hg threshold and when incorporating a minimum 20% IOP reduction from baseline.

Abstract

PRCIS

Applying different combinations of intraocular pressure and medication endpoint criteria recommended by the World Glaucoma Association can have a significant influence on the risk of failure following glaucoma surgery, which hinders the comparison of outcomes.

PURPOSE

The definition of success in glaucoma surgical trials lacks standardization, leading to difficulty comparing outcomes across studies. This study evaluates how different intraocular pressure (IOP) and medication criteria affect success in a representative subconjunctival minimally invasive glaucoma surgery (MIGS) dataset.

METHODS

A literature review identified the range of criteria used to define surgical success in studies of Xen gel stent, which were summarized into 4 definitions: (A) final IOP within upper and lower thresholds only, (B) criteria A plus ≥20% decrease in IOP verssus baseline, (C) ≥20% IOP decrease plus no increase in medications versus baseline, (D) all 3 criteria combined. These definitions were then applied to a cohort of 308 eyes that underwent Xen surgery to compare the apparent risks of failure.

RESULTS

Success rates at 12 months across studies reviewed ranged from 18.5% to 33.4% for complete and 22.4% to 64.6% for qualified success. In our cohort, the hazard ratios of failure ranged from 0.27 to 5.87 (95%

CI

0.21-7.63, P <0.001) across the 4 definitions. The greatest degree of difference in apparent failure rates was observed at the upper IOP threshold of 21 mm Hg, and when evaluating qualified success.

CONCLUSION

Using different IOP and medication criteria to define success can have a significant influence on the apparent risk of failure, particularly at the 21 mm Hg threshold and when incorporating a minimum 20% IOP reduction from baseline. Reporting success using guidelines-recommended criteria-and at multiple upper IOP thresholds may enable better comparison of outcomes between studies.

Keywords

Xen45 gel stentdefinitionsglaucomaglaucoma filtration surgeryminimally invasive glaucoma surgerysurgical success

In the Knowledge Library

Discussion

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