Color vision testing versus pattern visual evoked potentials and optical coherence tomography parameters in...

Area of Science:

• Neuro-ophthalmology
• Neuroimmunology
• Ophthalmology

Background:

• Acute idiopathic demyelinating optic neuritis is a common initial symptom of multiple sclerosis (MS).
• Early detection of optic nerve involvement is crucial for managing MS, even in patients without a history of optic neuritis.

Purpose of the Study:

• To evaluate the utility of color vision testing as a simple biomarker for detecting subclinical optic nerve damage in MS patients.
• To compare the effectiveness of color vision testing with pattern visual evoked potentials (PVEP) and spectral domain optical coherence tomography (SD-OCT) parameters in identifying optic nerve involvement.

Main Methods:

• Color vision was assessed using the Farnsworth-Munsell 100 (FM-100) hue test, calculating total error scores (TES), red-green axis (RGS), and blue-yellow axis (BYS).
• Ocular imaging included SD-OCT for retinal nerve fiber layer (RNFL), optic disc parameters, macular volume, central macular thickness, and retinal ganglion cell layer, and enhanced depth imaging OCT for choroidal thickness (CT).
• Pattern visual evoked potentials (PVEP) were recorded, and data were compared between 28 RRMS patients and 25 healthy controls.

Main Results:

• PVEP showed significantly delayed P100 latencies and reduced amplitudes in MS patients compared to controls.
• SD-OCT revealed statistically significant thinning in the temporal quadrant of the RNFL in MS patients.
• While color vision test scores (TES, RGS, BYS) were higher in MS patients, the differences were not statistically significant, and no correlation was found with PVEP or OCT parameters.

Conclusions:

• Color vision testing, using the FM-100 hue test, is not a sensitive biomarker for detecting subclinical optic nerve damage in MS patients without prior optic neuritis.
• PVEP and OCT-measured RNFL thickness are more valuable and reliable biomarkers for assessing neurodegeneration in the anterior visual pathway in MS.
• These findings suggest that PVEP and OCT should be prioritized over color vision testing for early detection of optic nerve involvement in MS.