Colour vision impairment is associated with disease severity in multiple sclerosis
This interesting study investigated the association between impaired colour vision and MS disease severity as damage of the visual pathway might be informative of overall brain damage in MS.
The study included 108 patients who underwent neurological and ophthalmic examinations, MRI and OCT at baseline and at 12 months follow-up. Colour vision was assessed using Hardy, Rand and Rittler plates.
Dyschromatopsia was defined if colour vision was impaired in either eye, except in individuals with optic neuritis, as only the unaffected eye was considered. The researchers found that impaired colour vision was detected in 21 out of 108 patients at baseline (in non-ON eyes). Patients with impaired colour vision had lower MSFC (Multiple Sclerosis Functional Composite) scores and BRB (Brief Repeatable Battery) Neuropsychology executive function scores when compared to individuals with normal colour vision. In addition to this, these patients also had a thinner retinal nerve fibre layer (RNFL), smaller macular volume, normalised brain volume and normalised grey matter volume (NGMV) at baseline. Patients with dyschromatopsia after one year of follow-up had a greater disability measured by the EDSS and MSFC-20, as well as a greater reduction in NGMV than patients with normal vision.
In conclusion, this study demonstrates that impaired colour vision is associated with greater clinical disability in MS subjects and with surrogate brain and retinal markers of axonal damage.
Martínez-Lapiscina EH, Ortiz-Pérez S
Mult Scler. 2014 Jan 7. [Epub ahead of print]
Read the abstract