Selective reduction of S-cone response and on-response in the cone electroretinograms of patients with X-linked retinoschisis.
OBJECTIVE
To examine the electroretinograms (ERGs) of the short-wavelength-sensitive (S-) and the mixed long- and middle-wavelength-sensitive (L,M-) cones, and the ON- and OFF-responses of the cone ERGs in three patients with X-linked juvenile retinoschisis (XLRS).


METHODS
Cone ERGs elicited by different color flashes and those elicited by long duration stimuli under Ganzfeld conditions were recorded from three patients with XLRS.


RESULTS
The S-cone b-waves were undetectable to short-wavelength stimuli in all three XLRS patients, while the L,M-cone ERG b-waves were within the normal range. To long-duration white stimuli, the ON-response (b-wave) was reduced and delayed in all patients compared with that of the normal subjects, while the d-wave or OFF-response appeared normal in amplitude and implicit time.


CONCLUSIONS
These results support the hypothesis that the normal S-cone ERG arises primarily from the ON-pathway of the cone ERGs and the hypothesis that ON-bipolar cells are predominant in the S-cone system.
Yamamoto
Shuichi
S
Department of Ophthalmology, Toho University Sakura Hospital, 564-1 Shimoshizu, Sakura, Chiba 285-8741, Japan. shuyama@med.toho-u.ac.jp
Hayashi
Masanori
M
Tsuruoka
Mieko
M
Ogata
Kazuha
K
Tsukahara
Itsuro
I
Yamamoto
Teiko
T
Takeuchi
Shinobu
S
D000328:Adult; D002648:Child; D004596:Electroretinography; D008040:Genetic Linkage; D006801:Humans; D007395:Interneurons / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D017949:Retinal Cone Photoreceptor Cells / Q000503:physiopathology*; D012162:Retinal Degeneration / Q000235:genetics / Q000503:physiopathology*; D014960:X Chromosome