Evaluating High Intraocular Pressure Criteria for Failure in Glaucoma Surgery: Impact on Estimated Success and Visual Field Rates

Purpose: Review high intraocular pressure (IOP) thresholds used as failure criteria in glaucoma surgical outcome studies, evaluate their impact on success rates, and examine the relationship between surgical success criteria and visual field (VF) progression rates.

Design: Systematic literature review and application of high IOP failure criteria to 2 retrospective cohorts.

Participants: Two cohorts of 934 and 1765 eyes underwent trabeculectomy and deep sclerectomy (DS), respectively, with a median follow-up of 41.4 months for trabeculectomy and 45.4 months for DS. Visual field analysis was conducted on patients in the trabeculectomy cohort with ≥4 VFs in ≥2 years post-surgery.

Methods: We applied literature-based high IOP fail- ure criteria to the patient cohorts, defining failure as exceeding these IOP thresholds, loss of light percep- tion, hypotony revision surgery, or need for additional IOP-lowering surgery. Success rates were estimated with Kaplan–Meier statistics, and Cohen’s kappa statistic as- sessed the agreement among criteria in defining failure at 5 years. Linear mixed models estimated VF mean devia- tion (MD) progression rates based on success or failure status.

Main Outcome Measures: Kaplan–Meier success rates, Cohen’s kappa, and MD progression rates.

Results: From 2503 initial studies, 277 were in- cluded, identifying 144 high IOP failure criteria. The 21-mmHg criterion variations showed success rates at 5 years ranging from 8.7% to 74.0% for trabeculec- tomy and 22.1% to 89.9% for DS. The median Co- hen’s kappa for 21-mmHg criteria indicated fair agree- ment (0.39 for trabeculectomy, 0.42 for DS). A sub- set of 339 trabeculectomy eyes were eligible for the VF analysis. Overall, the median (interquartile range) post- operative progression rate was−0.36 (−0.09 to−0.74) dB/year. Distributions of progression rates greatly over- lapped between failure and success groups as defined by the various criteria.

Conclusions: The criteria for defining high IOP fail- ure in glaucoma surgery are highly heterogeneous in the current literature. Varying high IOP criteria has a large impact on glaucoma surgery success rates, highlighting the need for standardized failure criteria to enable consis- tent interpretation and comparison across studies. IOP- based classifications are poor surrogates for postoperative VF progression rates. Long-term visual field rates pro- vide a more consistent primary outcome measure and may be incorporated into composite success criteria.

Authors: Alessandro Rabiolo, Giacinto Triolo, Andrea Servillo, Daniela Khaliliyeh, Sang W Jin, Esteban Morales, Luca Rossetti, Nitin Anand, Giovanni Montesano, Gianni Virgili, Joseph Caprioli, and satefano de Cillà.

Link: https://www.sciencedirect.com/science/article/abs/pii/S0002939425003460/

Doi: 10.1016/j.ajo.2025.05.054

NGP Papers Manager: Carlo Cutolo