Risk Factors for Visual Field Progression in Primary Angle Closure Disease Over 10 Years: The CUPAL Study

Purpose: To identify associated long-term risk factors of visual field (VF) progression among eyes of primary angle-closure disease (PACD), including primary angle-closure suspect (PACS), primary angle-closure (PAC), and primary angle-closure glaucoma (PACG). Methods: PACD eyes with at least a 10-year follow-up duration were included. VF was tested every 6 months using the 24-2 pattern standard on the Humphrey Field Analyzer. The initial intraocular pressure (IOP) fluctuation and initial visual field index (VFI) slope were calculated based on the first-year follow-up data. Univariable and multivariable Cox proportional hazards regression models were calculated to determine potential risk factors associated with VF progression, as assessed by guided progression analysis. Results: Forty out of 129 eyes with PACD (31.0%) developed VF progression, including two out of 11 PACS eyes (18.2%), nine out of 52 PAC eyes (17.3%), and 29 out of 66 PACG eyes (43.9%). In multivariable Cox models, among PACG eyes, higher IOP fluctuation (hazard ratio [HR] = 1.591; 95% confidence interval [CI], 1.128-2.245) and steeper initial VFI slope (HR = 3.325; 95% CI, 2.046-5.404) were associated with VF progression. Among PACS/PAC eyes, a steeper initial VFI slope (HR = 4.848; 95% CI, 1.627-14.448) was associated with VF progression (P ≤ 0.008). Conclusions: Our findings underscore the importance of monitoring IOP fluctuation in PACG eyes and initial VFI slope in PACD eyes, supporting the implementation of tailored management strategies based on disease severity and refractive status.