Optical Coherence Tomography and Visual Field Findings in Patients With Friedreich Ataxia

Abstract

To investigate the optical coherence tomography (OCT) and visual field findings in Friedreich ataxia (FRDA). Ten eyes of 10 patients with genetically confirmed FRDA were included in this study. Twenty-two eyes of 22 age- and sex-matched volunteers served as controls. All eyes were examined with spectral domain OCT (Retinascan Advanced RS-3000; NIDEK) and Humphrey Field Analyzer (HFA II 750; Zeiss-Humphrey Systems). OCT measurements of the average peripapillary retinal nerve fiber layer (RNFL) thickness, average peripapillary retinal thickness (RT), and foveal RT showed a statistically significant reduction in patients with FRDA (P < 0.0001). There was no statistically significant difference in choroidal thickness. OCT measurements of horizontal cup-to-disc (C/D) ratio, vertical C/D ratio, and average cup area were significantly increased in patients with FRDA. Visual acuity was significantly correlated with age at onset (P = 0.021) and average RNFL value (P = 0.045). There was a significant correlation between foveal thickness and disease duration (P = 0.014). Mean RNFL thickness was significantly correlated with the severity of neurological involvement (P = 0.039). Visual field testing (VFT) revealed a generalized reduction of sensitivity in the patients. Patients with FRDA may have a measurable degree of retinal thinning as determined by OCT and a generalized reduction of sensitivity in VFT. Combining structural and functional findings may be used in the follow-up of patients with FRDA.