The Friedmann Visual Field Analyser Mark II--technical evaluation and clinical results

Area of Science:

• Ophthalmology
• Medical Devices
• Visual Field Testing

Background:

• The Friedmann Visual Field Analyser Mark II (VFA Mk II) is an advancement over its predecessor, designed for multiple stimulus static campimetry.
• It analyzes the central 25 degrees of the visual field, a critical area for vision.
• The VFA Mk II features an increased number of stimuli (99 vs. 47) and an improved console with LED-monitor display.

Purpose of the Study:

• To evaluate the perimetric concept and technical construction of the Friedmann Visual Field Analyser Mark II (VFA Mk II).
• To assess the clinical utility and performance of the VFA Mk II in visual field testing.

Main Methods:

• Evaluation of the mechanical and electrical construction of the VFA Mk II.
• Testing of 106 eyes from both patients with visual field defects and normal subjects.
• Comparison of the VFA Mk II's performance against its predecessor, the VFA Mk I.

Main Results:

• The mechanical and electrical construction of the VFA Mk II was found to be good.
• The increased number of stimuli enhances the potential for detecting small visual field defects.
• However, the larger number of stimuli complicates manual data registration and interpretation, extending test duration, particularly for patients with significant defects.

Conclusions:

• The VFA Mk II demonstrates good technical construction and improved defect detection capabilities.
• Clinical interpretation and testing efficiency are negatively impacted by the increased stimulus count, posing challenges for practitioners.
• Further refinement may be needed to balance enhanced detection with practical clinical application.