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

Area of Science:

• Ophthalmology
• Surgical Outcomes
• Glaucoma Research

Background:

• High intraocular pressure (IOP) is a key factor in glaucoma management.
• Defining surgical success often relies on specific IOP thresholds, but these vary significantly across studies.
• The impact of these varied criteria on reported success rates and their correlation with visual field (VF) progression remain unclear.

Purpose of the Study:

• To review high IOP thresholds used as failure criteria in glaucoma surgery outcome studies.
• To evaluate how these diverse IOP criteria affect reported surgical success rates.
• To examine the relationship between surgical success defined by IOP and actual VF progression.

Main Methods:

• Conducted a systematic literature review to identify high IOP failure criteria.
• Applied identified criteria to two retrospective cohorts (trabeculectomy and deep sclerectomy).
• Estimated success rates using Kaplan-Meier analysis and assessed agreement between criteria with Cohen's kappa; analyzed VF progression using linear mixed models.

Main Results:

• Identified 144 distinct high IOP failure criteria from 277 studies.
• Success rates at 5 years varied dramatically (e.g., 8.7%–74.0% for trabeculectomy) based on different 21-mmHg criteria.
• Agreement among criteria was fair (Cohen's kappa ~0.4), and VF progression rates showed significant overlap between success and failure groups.

Conclusions:

• High IOP failure criteria in glaucoma surgery literature are highly heterogeneous.
• The choice of IOP criterion significantly impacts reported surgical success rates, necessitating standardization.
• IOP-based criteria are poor predictors of long-term VF progression; VF rates are more consistent outcome measures.