Factors Associated with Midterm Visual Field Variability in Patients with Stable Glaucoma

Area of Science:

• Ophthalmology
• Medical Research
• Glaucoma Studies

Background:

• Glaucoma is a progressive optic neuropathy characterized by visual field (VF) loss.
• Monitoring VF changes is crucial for managing glaucoma, but test variability can complicate interpretation.
• Identifying factors influencing VF variability is essential for accurate disease assessment.

Purpose of the Study:

• To investigate factors associated with midterm visual field variability in stable glaucoma patients in Brazil.
• To determine the relationship between visual field test variability and glaucoma severity.

Main Methods:

• Retrospective observational study of 59 eyes from 39 stable glaucoma patients.
• Collected demographic and clinical data, including intraocular pressure, number of medications, and glaucoma type.
• Analyzed 5 latest standard automated perimetry (SAP) visual field tests to calculate mean, standard deviation, and coefficient of variation (CV) of the visual field index (VFI).
• Compared groups with low and high CV using Generalized Estimating Equations (GEE) models.

Main Results:

• Patients with higher VF variability (higher CV) had significantly worse mean deviation (MD) and VFI scores.
• A statistically significant association was found between CV and SAP MD (P=0.006) and VFI (P=0.002).
• This association remained significant even after adjusting for age and educational level.

Conclusions:

• Worse visual field sensitivity in glaucoma patients, reflected by lower MD and VFI, is associated with increased VF test variability.
• Higher variability in visual field tests may indicate less stable disease or greater difficulty in obtaining reliable measurements in more advanced glaucoma.