Korean J Ophthalmol.  1994 Jun;8(1):1-5. 10.3341/kjo.1994.8.1.1.

The luminance-response function of the dark-adapted rabbit electroretinogram

• Chung KH
• Kim SH
• Cho JH

• KMID: 1735114
• DOI: http://doi.org/10.3341/kjo.1994.8.1.1

Abstract

The Naka-Rushton equation of the form, R = R(max) I(n)/(I(n)+K(n)), has been used to describe the b-wave luminance-response function of the scotopic electroretinogram. Rmax is the asymptotic value of the b-wave amplitude as a function of stimulus luminance I, K is the luminance that produces a b-wave amplitude that is one-half R(max), and n is a dimensionless constant that controls the slope of the function. These three parameters are often used in research laboratories, since it can show selective changes in each parameter. The present study describes these parameters (R(max) = 354 +/- 28 uV, n = 0.80 +/- 0.06, log K = -2.26 +/- 0.15 log cd. sec/m2) and the values obtained from the derivative analysis of Naka-Rushton equation (Anastasi et al) in 20 normal pigmented rabbit eyes. However, Naka-Rushton equation accurately describes the function only at low to moderate flash luminances. At high flash luminances, a second amplitude increase appears in the function.

Keyword

rabbit ERG; Naka-Rushton equation parameters; second b-wave amplitude increase; derivative function parameters

MeSH Terms

Animals
*Dark Adaptation
Electroretinography
Light
Rabbits
Retina/*physiology