A composite measure to explore visual disability in primary progressive multiple sclerosis.

Area of Science:

• Neuroscience
• Ophthalmology
• Radiology

Background:

• Multiple Sclerosis (MS) involves damage to the visual system.
• Optical coherence tomography (OCT) and magnetic resonance imaging (MRI) offer complementary insights into this damage.
• Primary progressive multiple sclerosis (PPMS) is a specific form of MS affecting the visual pathway.

Purpose of the Study:

• To evaluate if a combined OCT/MRI score can predict visual impairments in PPMS patients.
• To assess cumulative damage across the entire visual pathway using a composite score.
• To compare the predictive power of a composite score versus individual metrics.

Main Methods:

• Twenty-five PPMS patients and 20 controls underwent neuro-ophthalmologic exams, spectral-domain OCT, and 3T brain MRI.
• Principal Component Analysis (PCA) was used to create a composite OCT/MRI score from various metrics.
• Linear regression analyzed the relationship between visual acuity (LCVA) and the composite score.

Main Results:

• PCA identified four components explaining 80.69% of data variance.
• Individual metrics like GCIPL thickness, thalamic volume, and OR lesion volume predicted LCVA.
• The composite OCT/MRI score significantly predicted both LCVA 1.25% and LCVA 2.50% (adjusted R² 0.361 and 0.323, respectively).

Conclusions:

• A multiparametric OCT/MRI score provides a more comprehensive assessment of visual disability in PPMS than single measures.
• This composite score is a valuable tool for predicting visual deficits in PPMS.
• The findings highlight the utility of integrating imaging modalities for understanding MS-related visual impairment.