What is MS risk after optic neuritis?
A Optic neuritis associated with demyelination presents with a variable reduction in vision, loss of colour vision and, in over 90 per cent of patients, pain with eye movements.
Typically the vision gets worse over the first week and begins to improve after the second week. Patients can be told their vision should start to improve after this time – if it does not, the patient needs to see the ophthalmologist again for consideration of alternative diagnoses.
A clinical diagnosis of MS is made when neurological events are separated in space and time and for this reason, until recently, many ophthalmologists will not inform the patient of their risks of getting MS unless specifically asked or unless a second event occurs. This is now changing because of the prognostic ability of MRI scanning and the increasing number of potential treatments available for MS.
In this man's situation, it is possible to tell him a number of things. First, that he does not yet fit the clinical criteria for MS and may never do so. Second, although it depends on a number of factors such as age and gender, he has around a 50 per cent risk of having a further attack of optic neuritis or other demyelinating phenomena in the next 15 years.
Third, although opinions do vary, many neurologists and an increasing number of ophthalmologists will order an MRI scan for prognostic reasons. The number of active and inactive lesions seen, along with the clinical picture, will allow accurate assessment of the risks of further attacks to be given to the patient – if they want to know this.
Mr Scott Fraser is
consultant ophthalmologist at
Sunderland Eye Infirmary