King's College London

Optic neuritis is a condition that affects people of all ages, but especially young adults, usually manifesting in blurred vision and sometimes pain when moving the eyes. Up to half of people affected in the UK eventually go on to develop MS – often many years later. Emerging evidence indicates that starting the very effective MS treatments earlier may improve long term health.

Optic neuritis occurs because of swelling in or around the optic nerve. For those with MS-related optic neuritis, the swelling subsides on its own, and vision usually recovers. For many people whose optic neuritis does not result from MS, the optic nerve can be permanently damaged unless high doses of steroids are given quickly, resulting in loss of sight. However, steroids can result in harmful side effects. When people first develop optic neuritis, it can be difficult for patients and their doctors to decide whether the possible benefits of steroid outweigh the possible harms, when the likely cause of the optic neuritis is unclear.

Identifying whether there is an underlying cause of optic neuritis can be challenging for clinicians, with many important test results taking weeks to return. Now, new research, published in Nature Communications and led by the University of Exeter and King’s, has shown for the first time that combining genetic risk for MS with demographic factors significantly improves MS risk prediction in people presenting with optic neuritis.

The team analysed more than 300 common genetic variants linked to developing MS, combining them into a genetic risk score that helps clinicians understand an individual’s chance of developing MS. They analysed data from 500,000 people in the UK Biobank, who have shared genetic samples, questionnaires and linked health information from their electronic medical records.

The researchers found 2,369 people who had MS in the UK Biobank, and 687 people with optic neuritis. Of those, 545 had no identifiable cause for their optic neuritis at the start of the study, and 124 went on to develop MS.

Applying the genetic risk score effectively helped separate those at lowest risk from those at high risk. Whilst the MS genetic risk score is not a diagnostic test, this study highlights that it could add one valuable additional piece of information to support doctors and patients to make better decisions.

Co-author Professor Richard Oram, of the University of Exeter Medical School, said: “Since the first genome was sequenced three decades ago, we’ve been working towards the promise of being able to use genetics to improve outcomes for individual patients. This research is an excellent example of precision genetic diagnosis in practice.”

The research stemmed from a summer project led by University of Exeter Medicine student Pavel Loginovic. With funding from the University of Exeter, it expanded into a research collaboration involving academics in Finland and the US. The research was further funded through Fight for Sight and the Royal College of Ophthalmologists, who awarded Dr Braithwaite a Zakarian Award to support this work.