Naka-Rushton Equation Parameters in Normal Pigmented Rabbit ERG.

Chung, Kee Ha; Kim, Jae Hong; Kim, Sang Ha

Original Article

Journal of the Korean Ophthalmological Society 1995;36(3):473-478.
Published online March 1, 1995.

Naka-Rushton Equation Parameters in Normal Pigmented Rabbit ERG.

¹Department of Ophthalmology, Kyungpook National University, College of Medicine, Taegu, Korea.
²Department of Ophthalmology, Maryknoll Hospital, Pusan, Korea.

정상 유색가토 ERG 의 Naka - Rushton 공식의 매개변수

김재홍(Jae Hong Kim),김상하(Sang Ha Kim),정기하(Kee Ha Chung)

Abstract

The Naka-Rushton equation, R=R(max) I(n)/(I(n)+K(n)), has been used to describe the luminance-response function of the scotopic electroretinogram. R(max) is the asymptotic value of the b-wave amplitude as a function of stimulus luminance, K is the intensity that produces a b-wave amplitude that is one-half R(max) and n is a dimensionless contant that controls the slope of the function and represents the degree of homogeneity of retinal sensitivity. These three parameters are often used in experimental laboratories, since it can show selective changes in each parameter. The present study describes and compares the parameters of Naka-Rushton equation obtained by using ganzfeld stimuli(R(max)=363+/-32 uv, n=0.86+/-0.06, log K=-2.39+/-0.19 log cd.sec/m2) and direct flash stimuli(R(max)=354+/-28 uv, n=0.80+/-0.06, log K=-2.26+/-0.15 log cd.sec/m2) in 20 eyes of the normal pigmented rabbits respectively. The n values were significantly increased by the ganzfeld light stimuli than by the direct flash stimuli(p<0.05).

Key Words: Ganzfeld stimulus;Naka-Rushton equation parameters;Rabbit ERG