Neuroprotection with phenytoin in optic neuritis

• Research type

  Research Study

• Full title

  A phase II double-blind, randomised, placebo-controlled trial of neuroprotection with phenytoin in acute optic neuritis

• IRAS ID

  83220

• Contact name

  Raju Kapoor

• Eudract number

  2011-003475-11

• ISRCTN Number

  N/A

• Research summary

  People who develop acute optic neuritis lose vision in the affected eye, and recovery can sometimes be poor. Current treatment with corticosteroids helps vision to recover more quickly, but does not improve on the extent to which it would recover if left untreated. This means that there is an unmet need for a treatment which can improve eventual recovery of vision. This clinical trial directly addresses this need. Moreover, optic neuritis is usually a manifestation of multiple sclerosis, so treatment which works there is likely to work for relapses of all kinds in multiple sclerosis. Optic neuritis affects vision primarily by damaging nerve fibers (axons) in the optic nerve, partly by flooding them with toxic levels of sodium from the surrounding tissuflud. Experiments show that axonal damage can be prevented by drugs which reduce the entry of sodium. As it happens, these drugs (including phenytoin) are already used safely to treat some of the symptoms of multiple sclerosis. We will test the potential benefits of phenytoin in optic neuritis by carrying out a randomised controlled clinical trial of treatment with phenytoin compared to placebo. We will assess the extent of axonal degeneration because it causes the retina ?? the light-sensitive nerve layer at the back of the eye - to shrink, and this shrinkage can be measured using a method (optical coherence tomography) which is already in safe, widespread use. We will also measure visual function to assess the extent to which the treatment improves recovery. This is a novel idea for preventing damage, and if we are successful, our results will allow us to progress to full-scale clinical trials of the treatment in people with optic neuritis and other relapses of multiple sclerosis, and will help to prevent disability in these conditions.

• REC name

  London - South East Research Ethics Committee

• REC reference

  11/LO/1374

• Date of REC Opinion

  15 Nov 2011

• REC opinion

  Further Information Favourable Opinion