Optokinetic test to evaluate visual acuity of each eye independently

Abstract

A previously described optokinetic testing apparatus [Nat. Neurosci. 5 (2002) 53] was modified to measure vision in each eye separately for evaluation of monocular treatments. This apparatus consists also of a striped rotating drum. Ca. 170• of the drum are illuminated from outside and ca. 190• of the drum move behind a stationary black wall. The rat sits unrestrained in the drum center in a tube so that one eye is unexposed to the rotating stripes. Normal pigmented and retinal degenerate transgenic S334ter-3 rats were tested with the original and the modified apparatus. The usefulness of this method was tested in retinal degenerate rats with retinal transplants in one eye. In retinal degenerate animals, the amount of time (seconds) spent for head-tracking tended to be higher with the original method, possibly due to simultaneous stimulation of both eyes. In rats with retinal transplants, visual responses were significantly preserved in transplanted eyes at late stages of retinal degeneration. In conclusion, contributions from the fellow eye to the optokinetic tracking response can be limited by this testing modification, which is useful for evaluation of treatment effects to one eye.

Independent visual threshold measurements in the two eyes of freely moving rats and mice using a virtual-reality optokinetic system

“…Douglas et al activate the right eye. This has also been reported by Thomas et al 2004!, and is not surprising, if as we argue below, the behavior is solely due to the crossed subcortical projections from the eyes. A similar pattern has been seen in optokinetic eye movements in rabbits~Hobbelen & Collewijn, 1971!…”

Early Visual Deficits in Streptozotocin-Induced Diabetic Long Evans Rats

“…48 The AOS originates from the retina, with directionselective and velocity-selective ganglion cells projecting to various nuclei in the midbrain region. 9,48,49 The goal of AOS is to detect slip of the visual world on the retina, which then triggers corrective eye and head movements to stabilize the images. 48 Therefore, it is not surprising that defects in OKT response occur at a similar time point as OP abnormalities, as retinal ganglion cells and amacrine cells are potential generators of OPs.…”

“…An effective behavioral test of visual performance in animals is the assessment of optokinetic response, the ability of an animal to track moving stimuli by moving its head. 8,9 Both visual acuity and contrast sensitivity can be measured by varying spatial frequency or contrast of the projected gratings. Assessment of optokinetic tracking (OKT) response with head movement has been reliably quantified in rodents [8][9][10][11] and can readily distinguish mice with normal vision from those with retinal degeneration.…”

“…8,9 Both visual acuity and contrast sensitivity can be measured by varying spatial frequency or contrast of the projected gratings. Assessment of optokinetic tracking (OKT) response with head movement has been reliably quantified in rodents [8][9][10][11] and can readily distinguish mice with normal vision from those with retinal degeneration. 12 A recent report using OKT to evaluate visual function of streptozotocin (STZ)-induced DM rats found reduction in visual acuity at 4 weeks post-STZ, which the authors attributed to reduced expression of visual cycle enzymes.…”

A Novel Method for Objective Vision Testing in Canine Models of Inherited Retinal Disease

“…The dogs' large size and behavioral differences from mice limit the ability to use such a forced-choice testing apparatus as a water maze. Optokinetic devices can be devised and used to measure visual function of small subjects such as rodents 9 and chickens. 10 Dogs will exhibit a postural change in response to optokinetic stimulation 11 ; however, these studies used small numbers of dogs that were painstakingly trained to stand still on a platform before testing could take place.…”