Characterising eye movement dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome

Area of Science:

• Ophthalmology
• Neurology
• Neuroscience

Background:

• Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients report visual disturbances like sluggish eye movements.
• Subjective reports lack objective verification, necessitating empirical research into ME/CFS-related visual dysfunction.
• This study provides the first objective examination of eye movement abnormalities in ME/CFS.

Purpose of the Study:

• To objectively assess and compare eye movement control in ME/CFS patients versus healthy controls.
• To investigate saccadic and smooth pursuit eye movement capabilities in individuals with ME/CFS.

Main Methods:

• ME/CFS patients and matched controls underwent assessments of saccade and smooth pursuit eye movements.
• Performance was evaluated using prosaccade, antisaccade, and smooth pursuit tasks.

Main Results:

• No significant differences in error rates or saccade latencies were observed between groups for prosaccade and antisaccade tasks.
• ME/CFS patients demonstrated intact fixation (prosaccades) but were impaired in antisaccade tasks.
• Marked impairment was observed in ME/CFS patients during smooth pursuit eye movements.

Conclusions:

• Saccadic eye movements may be briefly compensated for in ME/CFS, but smooth pursuit reveals significant dysfunction.
• Continuous visual tracking challenges highlight abnormal eye movement behavior in ME/CFS.
• Further smooth pursuit research could enhance ME/CFS diagnosis and understanding.