Dyschromatopsia in Multiple Sclerosis Patients: A Marker of Subclinical Involvement?
In multiple sclerosis (MS), even in the absence of a clinical episode of optic neuritis (ON), the optic nerve and retinal nerve fiber layer (RNFL) may be damaged leading to dyschromatopsia. Subclinical dyschromatopsia has been described in MS associated with lower motor and cognitive performances.



To set the prevalence of dyschromatopsia in eyes of MS patients without a history of ON, to compare its prevalence in patients with and without ON history, and to explore the association between dyschromatopsia and disease duration, average peripapillary RNFL thickness, macular volume, and cognitive and motor performances.



An observational cross-sectional study was conducted at multiple medical centers. Data were collected after single neurological and ophthalmological evaluations. Dyschromatopsia was defined by the presence of at least 1 error using Hardy-Rand-Rittler plates.



In our population of 125 patients, 79 patients (63.2%) never had ON and 35 (28.8%) had unilateral ON. The prevalence of dyschromatopsia in eyes of patients without ON was 25.7%. Patients with dyschromatopsia had a statistically significant lower RNFL thickness (P = 0.004 and P = 0.040, right and left eyes, respectively) and worse performance in symbol digit modalities test (P = 0.012). No differences were found in macular volume or motor function tasks.



Dyschromatopsia occurs frequently in MS patients. It may be associated with a worse disease status and possibly serve as a marker for the detection of subclinical disease progression since it was detected even in the absence of ON. It correlated with thinner peripapillary RNFL thickness and inferior cognitive performance.
Neurology Department (HF), Centro Hospitalar de Vila Nova de Gaia/Espinho, Vila Nova de Gaia, Portugal; Neurology Department (JP), Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal; Neurology Department (SC), Hospital Fernando Fonseca, Lisboa, Portugal; Neurology Department (PP), Hospital Garcia de Orta, Almada, Portugal; Neurology Department (AFS), Hospital de Braga, Braga, Portugal; Neurology Department (AR), Centro Hospitalar do Porto, Porto, Portugal; Ophthalmology Department (DM), Centro Hospitalar de Vila Nova de Gaia/Espinho, Vila Nova de Gaia, Portugal; Ophthalmology Department (PF), Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal; Ophthalmology Department (CP), Hospital Fernando Fonseca, Lisboa, Portugal; Ophthalmology Department (JNC), Hospital Garcia de Orta, Almada, Portugal; Ophthalmology Department (CA), Hospital de Braga, Braga, Portugal; Ophthalmology Department (MA), Centro Hospitalar do Porto, Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar da Universidade do Porto (ES), Porto, Portugal.
Helena
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Felgueiras
Joana
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Parra
Simão
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Cruz
Pedro
P
Pereira
Ana F
AF
Santos
Adriana
A
Rua
Dália
D
Meira
Pedro
P
Fonseca
Catarina
C
Pedrosa
João N
JN
Cardoso
Cristina
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Almeida
Maria
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Araújo
Ernestina
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Santos
D000293:Adolescent; D000328:Adult; D055253:Color Vision / Q000502:physiology*; D003117:Color Vision Defects / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications* / Q000175:diagnosis; D009412:Nerve Fibers / Q000473:pathology; D009900:Optic Nerve / Q000473:pathology; D009902:Optic Neuritis / Q000150:complications* / Q000175:diagnosis; D012165:Retinal Ganglion Cells / Q000473:pathology; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity; D055815:Young Adult