Eye problems are seen in ∼60–70% of patients with FA. Disease severity and progression have both previously been shown to be correlated to changes to a part of the eye called the retina. Professor Giunti and her team at the London Ataxia Centre have been attempting to identify potential biomarkers based upon the eye problems commonly found in patients with FA. They previously used an imaging technique called OCT (optical coherence tomography) to measure damage to the retina in a group of subjects with a range of genetically proven ataxias. They discovered that out of all the forms of ataxia studied, FA was associated with the greatest amount of damage to a part of the retina called the retinal nerve fibre layer (RNFL).

In their most recent study, fifty-two patients with FA were recruited from the London Ataxia Centre. Each participant with FA underwent a full neurological examination, which included a measure of ataxia known as the SARA (Scale for Assessment and Rating of Ataxia). The damage to the RNFL was also measured, using OCT. They discovered that the SARA score correlated with the amount of damage to the RNFL. This suggests that as the function of the cerebellum deteriorates, the amount of damage to the RNFL increases.

According to Professor Giunti: 'This is the first time a correlation between the damage to the RNFL and both SARA score and activity of daily living in FA patients has been demonstrated. The results from this study show using OCT to measure the amount of damage to the RNFL has the potential to become a robust, ready available and inexpensive biomarker for future treatment trials in FA'.

In the future, the team will focus on exploring the possibility that the damage to the RNLF changes with the progression of the disease. If this proves to be the case, measuring damage to the RNFL will be the first quantifiable biomarker that is readily available and cost-effective, thus suitable for large-scale trials in FA.

The paper was published in the neurology journal Brain, you can view the abstract here

Posted on 24/05/19