149 Optical coherence tomography in an irish SPG7 cohort

Reduction of retinal nerve fibre layer (RNFL) thickness has been reported in neurodegenerative conditions, including inherited ataxias and hereditary spastic paraparesis. Mutations in SPG7 are increasingly identified as a common cause of spastic ataxia. Spectral domain optical coherence tomography (OCT) was performed in 25 individuals (six females) with genetically confirmed SPG7-related spastic ataxia to quantify peripapillary RNFL thickness. Standardized examination included age of onset, mean: 40 years (range 12–61); disease duration, mean: 19.6 years (range 6–42 years) and disease severity as quantified with Scale for the Assessment and Rating of Ataxia (SARA), mean: 10.2/40 (range 3–29). Abnormal RNFL thickness in comparison to controls was detected in 12/22 patients. 3/12 patients had disease duration of less than 10 years and demonstrated predominantly temporal inferior RNFL loss. There was no significant correlation between global RNFL thickness with disease severity (R=-0.13, p=0.75) or disease duration (R=-0.31, p=0.41). RNFL abnormalities in patients with spastic paraparesis/ataxia may be suggestive of SPG7-associated disease. OCT, non-invasive and quick, should be considered part of the neurological assessment, especially in patients with late-onset spastic ataxias. Further longitudinal studies are needed to determine whether RNFL thickness could be used as a potential biomarker for disease progression in the SPG7 cohort.