Retinal nerve fibre thickness studied
The nerve fibre layer in the retina of the eye is known to be thinner in people with complicated HSP. This study investigated the potential for the varying thickness of this layer to be used as a biomarker of disease status and progression. Thinning was found to be correlated with age and disease duration but not with clinical severity, meaning that it may not be suitable as a biomarker.
Introduction: In-vivo objective documentation of pathological changes in neurodegenerative disease is a major aim to possibly improve our ability to monitor disease progression and response to treatment. Temporal thinning of the retinal nerve fiber layer (RNFL) thickness shown by spectral domain optical coherence tomography (SD-OCT) has been reported in association with the complex forms in hereditary spastic paraplegia (HSP). We performed an assessment of the RNFL thickness in a group of HSP patients, including a longitudinal follow-up in a subgroup. Our aim was to measure and compare the changes and correlate them to clinical progression.
Materials and Methods: Twenty-three HSP patients were recruited and studied with the SD-OCT including papillary and macular scan by Spectralis. The clinical severity was assessed using the Spastic Paraplegia Rating Scale.
Results: Thinning of the superior, nasal and inferior quadrants bilaterally were observed compared to the normative data in both pure and complicated forms, but were clearly pathological only in a proportion of cases. Thinning correlated with age and disease duration, but not with clinical severity. The longitudinal study (n = 9) showed no significant change compared to the baseline data for the period of observation (mean 10.7 months).
Conclusions: RFNL is frequently thinned in HSP with no specific recognizable pattern of quadrants involved and SPG types. The small sample size and the short follow-up time showed no clear progression. Although SD-OCT appraisal of RFNL deserves to be explored in neurodegenerative conditions, it might not be suitable for use as a biomarker in HSP as it appears not to be specific to this condition and can be a feature of aging.
SOURCE: Front Neurol. 2019 Nov 22;10:1193. doi: 10.3389/fneur.2019.01193. eCollection 2019. PMID: 31824395 Copyright © 2019 Vavla, Paparella, Papayannis, Pascuzzo, Girardi, Pellegrini, Capello, Prosdocimo and Martinuzzi.
Optical Coherence Tomography in a Cohort of Genetically Defined Hereditary Spastic Paraplegia: A Brief Research Report.
Vavla M1, Paparella G1, Papayannis A2, Pascuzzo R3, Girardi G1, Pellegrini F2, Capello G3, Prosdocimo G2, Martinuzzi A1.
1 SOS Neuromotor Unit, Scientific Institute, IRCCS E. Medea, Conegliano, Italy.
2 Department of Ophthalmology, AULSS2 Marca Trevigiana, Treviso, Italy.
3 Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.