Ocular Involvement in Friedreich Ataxia Patients and Its Relationship with Neurological Disability, a Follow-Up Study

Abstract

Background: This study compared functional and structural visual changes in Friedreich ataxia (FRDA) patients with healthy controls (HC) and correlated these changes with neurological disability. Methods: Eight FRDA Spanish patients and eight HC were selected from 2014 to 2018. Best corrected visual acuity (BCVA), visual field (VF), optic coherence tomography (OCT), and neurological disability measured by “scale for the assessment and rating of ataxia” (SARA) were taken in a basal exploration and repeated after 6 months. A linear mixed analysis and Bonferroni p-value correction were performed. Results: FRDA baseline and follow-up patients showed statistically significant decreases in BCVA, VF, and OCT parameters compared with the HC. Some of the VF measurements and most of the OCT parameters had an inverse mild-to-strong correlation with SARA. Moreover, the analysis of the ROC curve demonstrated that the peripapillary retinal nerve fiber layer (pRNFL) average thickness was the best parameter to discriminate between FRDA patients and HC. Conclusions: The follow-up study showed a progression in OCT parameters. Findings showed a sequential effect in pRNFL, ganglion cell complex (GCC), and macula. The VF and the OCT could be useful biomarkers in FRDA, both for their correlation with neurological disease as well as for their ability to evaluate disease progression.

Sensitivity of Neuroimaging Indicators in Monitoring the Effects of Interferon Gamma Treatment in Friedreich’s Ataxia

“…This could indicate that RNFL thickness would not appear to be an efficient marker for response to treatment in such a short period. So far, only one study has longitudinally investigated this measure in FRDA, with a surprising progression of RNFL thinning over a 6-month period ( Rojas et al, 2020 ). These different results could be due to the fact that the cohort of Rojas et al (2020) included older patients when compared to ours.…”

“…So far, only one study has longitudinally investigated this measure in FRDA, with a surprising progression of RNFL thinning over a 6-month period ( Rojas et al, 2020 ). These different results could be due to the fact that the cohort of Rojas et al (2020) included older patients when compared to ours. Perhaps the RNFL impairment and the ocular involvement are age-related events that progress over time.…”

Neuro-Ophthalmological Findings in Friedreich’s Ataxia

“…There are very few studies using OCT in patients with FRDA [4,11,22,55,80] and only one that included OCT follow-up [79] (Table 3, Figure 1). Abbreviations: ↓: decrease; OCT: optical coherence tomography; TD-OCT: temporal domain OCT; SD-OCT: spectral-domain OCT; SD standard deviation; pRNFL: peripapillary retinal nerve fiber layer; CMT: central macular thickness; IMR: inner macular ring; OMR: outer macular ring; GCC: ganglion cell complex; ICARS: International Cooperative Ataxia Rating Scale; FARS: Friedreich Ataxia Rating Scale; SARA: Scale for the Assessment and Rating of Ataxia.…”

“…In FRDA, the axons of the papillary-macular bundle, which constitute the anatomical substrate of central vision, color, and high spatial frequency contrast sensitivity [ 12 , 76 , 77 , 78 ], seem to be preserved [ 11 , 12 , 13 , 55 ]. Loss of visual acuity is therefore uncommon [ 11 , 53 ] or occurs at later stages of the disease [ 4 , 11 , 22 , 55 , 79 ]. Over an average of 4.4 years of follow-up, visual acuity at 100% contrast decreases (−0.37 letters/year) [ 56 ].…”

The Value of OCT and OCTA as Potential Biomarkers for Preclinical Alzheimer’s Disease: A Review Study

“…The retina is an extension of the central nervous system (CNS), providing a window through which to observe both neuronal and vascular changes in the brain [ 10 ]. The importance of monitoring retinal changes in various neurodegenerative diseases has become evident in the last few decades [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ], suggesting that the data collected may be useful as biomarkers for the diagnosis and treatment of these diseases [ 18 ]. Ophthalmologists now use in vivo imaging techniques that can detect and quantify findings compatible with the histopathologic changes reported in the retinas of AD patients many years ago [ 19 ].…”