Retinal thinning correlates with clinical severity in multiple system atrophy.

To analyze retinal thickness changes in multiple system atrophy (MSA) and correlate changes with disease severity and subtypes of MSA. A total of 36 MSA (27 MSA-P and 9 MSA-C) patients and 71 healthy control subjects underwent general ophthalmologic examination and optical coherence tomography (OCT) scans. Peripapillary retinal nerve fiber layer (RNFL) thickness and perifoveal retinal thickness were analyzed separately. The generalized estimating equation model was used with age as a covariate to adjust for within-patient inter-eye correlations and the effect of age on retinal or RNFL thickness. Correlation analysis between RNFL, perifoveal thickness, and clinical parameters, the Unified MSA Rating Scale (UMSARS) and Global Disability Score (GDS), was also done. MSA patients showed significantly decreased peripapillary RNFL thickness in the inferior (P = 0.047) and inferotemporal (P = 0.017) sectors and significant perifoveal thinning in the superior outer sector (P = 0.042) compared to healthy controls. Both RNFL and perifoveal thinning were more marked and widespread in MSA-P than MSA-C patients. The UMSARS and GDS showed significant negative correlation with center and total macular perifoveal thickness and also the inferior and nasal outer sectors. Peripapillary RNFL and perifoveal retinal thinning were observed in MSA patients and retinal thinning correlated with the clinical severity of MSA. Structural changes in the retina may reflect the degree and pattern of neurodegeneration occurring in MSA.