Abstract
Purpose:
The purposes of this study were 1) to evaluate visual function in a three week period of the bugeye zebra fish (Danio rerio), 2) to determine if the multiple measurements are needed to establish a baseline measure of visual function in the bugeye zebra fish. 3) to assess short term limits of agreement of visual function.
Methods:
Adult bugeye zebrafish (15 fish, age 8 months) were anesthetized in tricaine and placed on a styrofoam bed with a magnetic base. Once secured the animal was placed in a water tank with a metal holder at the center. The animal was allowed to regain complete consciousness and visual function was assessed using an optokinetic response (OKR with large gratings to elicit an OKR movement), which was also recorded using a video camera. Further testing was continued using lower spatial frequency gratings until an OKR was not elicited.<br /> OKR measurements were obtained three times in the bugeye zebrafish one week apart. The baseline measurements were compared with second and third measurements using a paired t-test. Additionally, baseline, average of two measures and average of three measures were compared using a paired t-test. The Altman and Bland plots were created to obtain limits of agreement.
Results:
The mean values of baseline measurements were not significantly different when compared to second or third measurements (paired t-test p-value= 0.23 and 0.56 respectively). The baseline mean values were not significantly different when compared to the average of two measurements or average of three measurements (paired t-test p-value= 0.23 and 0.34 respectively). The limits of agreement between baseline and first measurement and baseline and second measurement were -0.26 to + 0.36 cpd and -0.47 to 0.55 cpd respectively.
Conclusions:
The visual function in eight month old the bugeye zebrafish on average does not seem to vary in a three week period. One visual function measure is sufficient to establish baseline and obtaining multiple measures and averaging does not seem to provide significant additional benefit. The limits of agreement are wide because the level of retinal damage and visual function vary significantly in-between animals.