Evaluation of relation between the retinal nerve fiber layer and Expanded Disability Status Scale (EDSS) in patients with relapsing-remitting form of multiple sclerosis referring to Rasool Akram Hospital

Early diagnosis of multiple sclerosis disability is very important in managing patients. The aim of this study is to use Heidelberg Retinal Tomography (HRT) to evaluate the Retinal Nerve Fiber Layer (RNFL) of MS patient as a predictor factor of their disability scales.

In this cross-sectional study a total of 69 patients with RR.MS were included on the revised McDonald criteria. They were examined by a neurologist to calculate their EDSS scores. Demographic information and related data of patients such as history of Optic Neuritis (ON) and using Interferones were taken. Patients were referred to ophthalmology department of Rasool Akram hospital to assess their RNFL thickness using HRT method. Data Analyzed by SPSS software level of significance was below 0.05.

The range of patient’s age was 17 to 59 years. The mean of EDSS scores of men and respecting women was 2.69 micrometer and 2.86 micrometer that show no significant difference (P=0.63). Spearman Correlation showed that there is no statistically significant correlation between EDSS and mean RNFL thickness in both left and right eyes (P=0.081 for right and P=0.052 for left). Also there was no statistically significant correlation between EDSS and mean RNFL thickness of both eyes in patients with or without optic neuritis (P=0.66, 0.28). Mean RNFL thickness of both eyes showed no significant difference in patients with and without optic neuritis (0.209).

This study pointed out that no decrease was detected in RNFL thickness by increasing EDSS scores using HRT method. There are evidences that both HRT and Optical Coherence Tomography (OCT) methods can show decreasing of RNFL but OCT appears to be more sensitive.