The flight of colors test in multiple sclerosis

Area of Science:

• Ophthalmology
• Neuro-ophthalmology
• Visual electrophysiology

Background:

• Flight of colors (FOC) is a visual phenomenon sensitive to central visual field defects.
• Optic neuropathies (ONs) often impair or abolish FOC, particularly in conditions like multiple sclerosis (MS).
• Assessing FOC at the bedside could offer a rapid diagnostic tool for visual pathway dysfunction.

Purpose of the Study:

• To evaluate the diagnostic effectiveness of a bedside FOC test.
• To compare the FOC test's performance against pattern-reversal visual evoked responses (PRVERs).
• To determine the utility of FOC in detecting subclinical optic neuropathies.

Main Methods:

• A cohort of 74 subjects, including controls and patients with various stages of MS and ON, was studied.
• A bedside FOC test using a pocket flashlight was administered.
• Results were compared with those obtained from PRVERs in a subset of eyes.

Main Results:

• The FOC test demonstrated high accuracy, correctly identifying 95 of 99 normal eyes and 45 of 49 eyes with ON.
• Overall diagnostic accuracy for the FOC test was 95% (140 out of 148 eyes).
• FOC and PRVER results agreed in 87% of cases, including detection of subclinical ON.

Conclusions:

• A bedside FOC test is a sensitive and specific method for detecting optic neuropathies.
• FOC testing offers a valuable, accessible alternative or adjunct to electrophysiological methods like PRVERs.
• This bedside test can identify both clinical and subclinical ON, aiding in early diagnosis and management.