Axonal electrovisiogram or inverse photopic skin electroretinogram?
نویسندگان
چکیده
منابع مشابه
Cone dystrophies with negative photopic electroretinogram.
A scotopic electroretinogram with an a-wave amplitude larger than the b-wave amplitude traditionally is termed 'negative'. Six male patients with negative photopic electroretinograms were examined; three of them suffered from progressive cone dystrophy, in which negative electroretinograms are unusual. Another patient without symptoms was the brother of a patient with cone dystrophy. These pati...
متن کاملPhotopic negative response versus pattern electroretinogram in early glaucoma.
PURPOSE Photopic negative response (PhNR) and pattern electroretinogram (PERG) are electrophysiological markers of retinal ganglion cell function; both are reduced in glaucoma. We compared PhNR and PERG in different stages of the disease. METHODS Eleven eyes with preperimetric glaucoma (glaucomatous optic disc with normal field); 18 with manifest glaucoma; and 26 normals were included. We obt...
متن کاملThe photopic electroretinogram in congenital stationary night blindness with myopia.
Previous studies have reported that subjects affected with congenital stationary night blindness and myopia demonstrated some photopic (cone) abnormalities in their electroretinogram (ERG). By comparing the photopic ERG elicited with a threshold and a suprathreshold stimulus it was found that, at threshold, no significant differences were noted both in the peak time and in the amplitude of ERGs...
متن کاملContribution of post-receptoral cells to the a-wave of the human photopic electroretinogram
ERGs were recorded to red flashes (0.01-50 phcdsm(2)) presented against a steady background (2000 sctd) or 0-300 ms after its suppression. The cone a-wave was altered in form and increased in amplitude in the dark. Peak amplitudes were doubled when the dark period was 50-100 ms and also when it was 150-200 ms. Measurement of the a-wave at fixed times showed that amplitude increase occurred at t...
متن کاملThe contribution of human cone photoreceptors to the photopic flicker electroretinogram.
We aimed to noninvasively estimate the relative contribution of the cone photoreceptors to the photopic flicker electroretinogram (ERG) in humans. Responses to ganzfeld square-wave flicker (15, 30, and 60 Hz) were recorded in the presence of a rod-saturating background. We used a modified paired flash technique in which a bright probe flash was presented at different times during a flicker cycl...
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ژورنال
عنوان ژورنال: Arquivos Brasileiros de Oftalmologia
سال: 2012
ISSN: 0004-2749
DOI: 10.1590/s0004-27492012000500017