Transbulbar B-mode sonography in multiple sclerosis without optic neuritis; clinical relevance

Area of Science:

• Ophthalmology
• Neurology
• Medical Imaging

Background:

• Multiple sclerosis (MS) can affect the optic nerve, even without acute optic neuritis.
• Trans bulbar B-mode sonography (TBS) is a novel imaging technique.
• Diagnostic accuracy of TBS in MS patients without acute optic neuritis is not well-established.

Purpose of the Study:

• To assess the diagnostic accuracy of TBS in detecting optic nerve damage in MS patients.
• To evaluate the correlation between optic nerve diameter (OND), optic nerve sheath diameter (ONSD), and the OND/ONSD ratio with clinical and paraclinical parameters in MS.

Main Methods:

• A comparative study involving 60 MS patients and 60 healthy controls.
• Measurement of OND and ONSD using TBS in both eyes.
• Correlation analysis with clinical factors (gender, age, disease duration, EDSS, P100 latency/amplitude) and MRI findings (T2 lesions).

Main Results:

• MS patients exhibited significantly lower OND, ONSD, and OND/ONSD ratios compared to controls (p < 0.05).
• No significant correlations were found between OND/ONSD and gender, age, P100 amplitude, disease duration, prior optic neuritis, or T2 lesion count.
• Expanded Disability Status Scale (EDSS) and P100 latency showed significant correlations with OND and ONSD (p < 0.05).

Conclusions:

• TBS demonstrated significantly reduced OND, ONSD, and OND/ONSD ratios in MS patients without acute optic neuritis, indicating subclinical axonal loss.
• TBS may serve as a valuable tool for the early detection of optic nerve damage in MS.
• Combining TBS findings with clinical and paraclinical data can enhance the comprehensive assessment of MS patients.