Abstract
Purpose :
For spinocerebellar ataxias (SCA), reliable biomarkers with diagnostic and prognostic values are needed for upcoming gene therapy trials. One of the aims of our Integrated Functional Evaluation of the Cerebellum (CERMOI) longitudinal study was to identify ophthalmological biomarkers in SCA type 7 (SCA7).
Methods :
Fifteen ATXN7 pathogenic expansion carriers (7 males, 9 pre-manifest and 6 manifest) were included, all with a scale for the assessment and rating of ataxia (SARA) score <15/40. Three visits (baseline, at month-6, at month-12) were planned, including neurological examination (SARA and Composite cerebellar functional severity score [CCFS]) and ophthalmological examination (visual acuity [VA], microperimetry, full field electroretinogram, optical coherence tomography [OCT] and fundus autofluorescence imaging). Here we report the baseline ophthalmic data from the cohort. A correlation between disease scores and ophthalmic results were attempted.
Results :
Mean age at baseline visit was 34,47 ± 13,14 years (median 38, range 18-60 years). Three patients (20%) had no retinal abnormalities. They all had a SARA score ≤ 1 and a CCFS score <0-850. All other patients presented with a cone dystrophy at variable stages. Both SARA and CCFS scores showed significant correlations (Spearman Rho coefficient [ρ]) with VA (ρ:-0,871 p<0,001 and ρ:-0,772 p=0,001, respectively) and the outer nuclear layer thickness on OCT (ρ:-0,861 p<0,001 AND ρ:-0,560 p=0,037, respectively). The SARA score was also significantly correlated with the function of the cones tested by electrophysiology.
Conclusions :
From these preliminary data of the CERMOI study, neurological scores and ophthalmological functional and structural tests are highly correlated in patients with SCA7, thus the latter have the potential to be good biomarkers for the assessment of the disease. Longitudinal data will be necessary to confirm this hypothesis.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.