The photopic ERG luminance-response function (photopic hill): method of analysis and clinical application.
With progressively brighter stimuli, the amplitude of the photopic b-wave first increases, briefly saturates and then decreases gradually to reach a plateau, where the amplitude of the b-wave equals that of the a-wave; a phenomenon previously presented as the photopic hill. The unique presentation of this luminance-response function seriously complicates its analysis with curve fitting equations such as that of Naka-Rushton used for scotopic electroretinogram. We report a method of analysis of the photopic hill based on easily identifiable and reproducible features of the ascending and descending limbs of this function. The clinical usefulness of these parameters is illustrated with selected cases of retinal disorders.
Department of Ophthalmology (D-164), McGill University, Montreal Children's Hospital Research Institute, 2300 Tupper Street, Que., H3H 1P3, Montreal, Canada.
Marianne
M
Rufiange
Justine
J
Dassa
Olga
O
Dembinska
Robert K
RK
Koenekoop
John M
JM
Little
Robert C
RC
Polomeno
Marie
M
Dumont
Sylvain
S
Chemtob
Pierre
P
Lachapelle
D000221:Adaptation, Ocular / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D004596:Electroretinography / Q000379:methods; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D010775:Photic Stimulation; D012160:Retina / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*