Multifocal ERG findings in carriers of X-linked retinoschisis.
OBJECTIVE
To determine whether retinal dysfunction in obligate carriers of X-linked retinoschisis (XLRS) could be observed in local electroretinographic responses obtained with the multifocal electroretinogram (mfERG).


METHODS
Nine obligate carriers of XLRS (mean age, 46.2 years) were examined for the study. Examination of each carrier included an ocular examination and mfERG testing. For the mfERG, we used a 103-scaled hexagonal stimulus array that subtended a retinal area of approximately 40 degrees in diameter. The amplitudes and implicit times in each location for the mfERG were compared with the corresponding values determined for a group of 34 normally-sighted, age-similar control subjects.


RESULTS
Mapping of 103 local electroretinographic response amplitudes and implicit times within a central 40 degrees area with the mfERG showed regions of reduced mfERG amplitudes and delayed implicit times in two of nine carriers.


CONCLUSIONS
The mfERG demonstrated areas of retinal dysfunction in two carriers of XLRS. When present, retinal dysfunction was evident in the presence of a normal-appearing fundus. Multifocal ERG testing can be useful for identifying some carriers of XLRS.
Kim
Linda S
LS
Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois at Chicago, Eye and Ear Infirmary, 1855 West Taylor Street, Chicago, IL 60612-7234, USA.
Seiple
William
W
Fishman
Gerald A
GA
Szlyk
Janet P
JP
D000328:Adult; D000368:Aged; D004596:Electroretinography / Q000379:methods*; D005260:Female; D006579:Heterozygote; D006801:Humans; D008875:Middle Aged; D012160:Retina / Q000503:physiopathology*; D041441:Retinoschisis / Q000235:genetics / Q000503:physiopathology*