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

OBJECTIVE

Trans bulbar B-mode sonography (TBS) is a recently proposed method but there is little known about its diagnostic accuracy in patients with multiple sclerosis without acute optic neuritis. Therefore we assessed the correlation between OND, ONSD and OND/ONSD ratio with clinical/para clinical parameters.

METHODS

In a comparative study, we intended to examine possible differences in optic nerve diameter (OND) and optic nerve sheath diameter (ONSD) between 60 patients with multiple sclerosis (MS) and 60 individuals as matched healthy controls.

RESULTS

The OND, ONSD and OND/ONSD ratio in both eyes showed significantly lower amounts in patients compared to healthy controls (p < 0.05). There were no correlations, between either OND or ONSD and factors including gender, age, P100 amplitude, disease duration, history of optic neuritis and number of T2 lesions in MRI (P ≥ 0.05). Expanded disability status scale (EDSS) and p100 Latency were correlated with both OND and ONSD values (P < 0.05).

CONCLUSIONS

TBS showed significantly lower amounts of OND, ONSD and OND/ONSD ratio in MS patients without current attack compared to their healthy controls indicating a subclinical axonal loss over time. It is suggested that TBS could be an applicable tool for early detection of optic nerve damages along with clinical and para-clinical findings.