Systematic review and meta-analysis of the development of multiple sclerosis in clinically isolated syndrome.

Clinically isolated syndrome (CIS) usually describes a first clinical episode that suggest multiple sclerosis. One of the signs and symptoms of CIS is Optic neuritis (ON). Several early intervention drugs are being tested in clinical trials for the early intervention in CIS patients which may lead to multiple sclerosis (MS). This study aim (1) early intervention of the CIS progression to MS delay slow down the MS progression, (2) since that ON affects 30%-70% of MS patients, the available ON intervention delay the MS progression. PubMed was used as a search engine. Summary relative risks (RRs) and 95 % confidence intervals (CIs) were estimated using a random-effect model. For aim 1, it showed lower risk of progression to MS compared to non-treated group (Risk Ratio (RR) 0.64; 95%CI: 0.58, 0.69;  < 0.001). For aim 2, drug treated group showed lower risk of progression compared to non-treated group (RR 0.19, 95%CI: 0.06, 0.54,  < 0.002. Statistical heterogeneity was not significant in both outcomes and bias of publication was not found using inspection of funnel plot and Egger's statistical test in both outcomes. In conclusion, early treatment should be considered in CIS patients to prevent the progression of MS. Moreover, this data shows that early intervention (Erythropoietin, Ery) of ON decreases the conversion risk to MS.