Estimating progression of visual field loss in glaucoma

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Glaucoma is a leading cause of irreversible blindness worldwide.
• Early detection and monitoring of visual field loss are crucial for managing glaucoma.
• Progressive visual field loss indicates ongoing optic nerve damage and disease advancement.

Purpose of the Study:

• To estimate the prevalence and rate of progressive visual field loss in glaucoma patients.
• To analyze the progression of specific visual field parameters over time.
• To identify factors associated with visual field deterioration in glaucoma.

Main Methods:

• Annual visual field testing using Humphrey Analyzer C-30-2 fields over a median of 6.3 years.
• Linear regression analysis to quantify rates of change in mean deviation, corrected pattern standard deviation (CPSD), and Glaucoma Hemifield Test (GHT) clusters.
• Assessment of location-specific visual field changes and association with optic nerve head parameters.

Main Results:

• Twenty-eight percent (19/67 eyes) of glaucoma patients exhibited progressive visual field loss.
• Rates of deterioration varied: CPSD increased by 0.9 dB/year, GHT clusters declined by 1.4-2.4 dB/year, and individual locations worsened by 1.0-5.0 dB/year.
• Patient age was a predictor of visual field loss, while baseline severity was not; optic disc changes showed a trend towards association with progression.

Conclusions:

• Less than one-third of glaucoma eyes showed progressive visual field loss over the study period.
• Standard follow-up intervals may not detect subtle visual field changes (<1 dB/year) over 6 years.
• Increased testing frequency or detection of larger changes is necessary to statistically identify smaller rates of visual field progression.