I started a 5 day course of IVSM within about 12 hours onset of ON. Vision blurry, pain horrible. Vision 100% back to normal within a few days, pain eased the first day. Both my neuro and neuro-ophtha said that it's possible my recovery was so complete because of how promptly I started on steroids. They said this result hasn't been proven in studies, but they notice this anecdotally in case after case.
For myself yes it worked to clear vision... And cleared my color blindness. It was significantly better withing the first 2 doses. Gradually better over time to its almost original sight.
As far as the earlier the better?? Yes your doc should know ASAP however I am told that weather you have steroids or not have steroids the sight will come back (faster or slower) to the point it will either way. The steroids will not make the vision be better... Just come back faster!!
However I think maybe the fact that steroids reduce inflammation maybe that can reduce the amount of damage... ?!?! I will never know (I am by far an expert opinion)....... but if I have to have steroids anyway.. The sooner the better bc "what if" if helps
If your symptoms are caused by inflammation yes steroids can help. Steroids do not help with nerve damage only inflammation. It is important to let your Neurologist know as soon as you feel you have ON.
Alex