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Phenotyping parallel visual pathways in autosomal dominant optic atrophy
Author(s) -
REIS AA,
VIEGAS T,
MATEUS CD,
SILVA ED,
CASTELOBRANCO M
Publication year - 2008
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2008.6357.x
Subject(s) - parvocellular cell , atrophy , electrophysiology , neuroscience , electroretinography , audiology , visual system , ophthalmology , achromatopsia , psychology , population , optic nerve , contrast (vision) , retina , medicine , retinal , pathology , physics , central nervous system , optics , environmental health
Purpose To characterize different phenotypes of Kjer optic atrophy along different visual pathways. Methods Novel computerized psychophysical assessment methods (CCT ‐ Cambridge Colour Test and CSF ‐ Metropsis Contrast Sensitivity Function Test) were used to evaluate visual function in a population of 13 subjects (26 eyes) from 8 families with Autosomal Dominant Optic Atrophy (ADOA). This evaluation was completed with electrophysiological assessment (Pattern ERG, Pattern and Multifocal VEP) and Automated Static Perimetry (ASP). Results CCT shows evidence for severe damage of all cone populations (p<<0.0001), and of similar magnitude, implying concomitant damage of parvo and koniocellular pathways. Achromatic contrast sensitivity is severely impaired for all six spatial frequency channels studied (p<0.002), suggesting mixed magno/parvocellular impairment. A decrease of both P‐50 and N‐95 amplitudes of PERG is found (p<<0.001), while implicit times are normal. MfVEP results show significant impairment in amplitudes of the most central rings (1, 2 ‐ p<0.001), with concomitant local increased implicit times, no significant changes being found at most eccentric rings. Pattern VEP impairment is consistent with these results. Amplitude values of MfVEP in visual quadrants are significantly correlated with the decreased retinal sensitivity obtained in the 4 quadrants by ASP. Conclusion Our results suggest that all functional types of nerve fibers are damaged in ADOA, with a predominance of the parvocellular ones. Multimodal psychophysical and electrophysiological methods are good quantitative markers to understand the pathophysiology of damage of central and peripheral pathways in this condition.