Persistent ocular motor manifestations and related visual consequences in multiple sclerosis

Area of Science:

• Ophthalmology
• Neurology
• Neuroscience

Background:

• Abnormal eye movements are common in multiple sclerosis (MS) and linked to disability.
• The precise incidence and visual impact of these ocular motor manifestations remain unclear.
• Understanding these deficits is crucial for managing MS-related visual handicap.

Purpose of the Study:

• To characterize persistent ocular motor abnormalities in MS patients.
• To correlate these eye movement disorders with visual functions, including visual acuity and patient-reported outcomes.
• To investigate the relationship between the number of abnormal eye movements and visual function.

Main Methods:

• Selected 24 MS patients with persistent visual disability and ocular motor symptoms, excluding anterior visual pathway deficits.
• Assessed visual acuity and utilized a vision-related questionnaire for functional assessment.
• Documented specific ocular motor manifestations such as internuclear ophthalmoplegia, gaze-evoked nystagmus, saccadic hypermetria, and pendular nystagmus.

Main Results:

• Internuclear ophthalmoplegia was the most frequent symptom, followed by gaze-evoked nystagmus, saccadic hypermetria, and pendular nystagmus.
• Pendular nystagmus, saccadic hypermetria, and combined internuclear ophthalmoplegia with gaze-evoked nystagmus correlated with lower visual acuity and functional scores.
• A direct correlation was observed between the number of abnormal eye movements and the degree of visual dysfunction.

Conclusions:

• Ocular motor dysfunction in MS significantly contributes to specific visual deficits and handicap.
• Persistent abnormal eye movements in MS patients lead to measurable visual impairment.
• Targeting ocular motor symptoms may be important in improving visual function for MS patients.