The working threshold approach to Friedmann visual field analyser screening

Area of Science:

• Ophthalmology
• Visual Science
• Medical Devices

Background:

• Central visual field screening is crucial for detecting vision impairments.
• The Friedmann Visual Field Analyser Mark II is a common tool for visual field testing.
• Variability in device settings can affect screening accuracy.

Purpose of the Study:

• To evaluate the performance of the Friedmann Visual Field Analyser Mark II.
• To investigate the impact of individualized working thresholds versus age-predicted filters on screening results.
• To determine if an individualized threshold approach improves the identification of normal visual fields.

Main Methods:

• Central visual field screening of 2223 eyes without known defects using the Friedmann Visual Field Analyser Mark II.
• Comparison of stimuli visibility at various filter settings, including age-predicted filters and individually determined working thresholds.
• Analysis of the difference between mean working thresholds and age filters.

Main Results:

• Significant variation was observed in filter settings and working thresholds among participants.
• 803 eyes (36.1%) could perceive all stimuli at settings above the age-predicted filter.
• The difference between mean working threshold and age filter ranged from 0.22 to 0.40 log units, peaking in middle age groups.

Conclusions:

• An individualized working threshold approach enhances the performance of the Friedmann Visual Field Analyser Mark II.
• Using an individually determined threshold as a criterion for sensitivity depression improves the accuracy of identifying normal visual fields.
• This method offers a more precise assessment of visual field sensitivity compared to standard age-predicted filters.