Presence of visual head tracking differentiates normal sighted from retinal degenerate mice.

We have generated a large number of potential eye and vision mutants by a mouse mutagenesis programme and sought to develop a rapid method for testing vision. This experiment assesses whether the visual tracking drum can differentiate between mice with and without retinal degeneration. The population of mice tested had a proportion with retinal degeneration, the remainder having normal retinas. Mice were observed in the visual tracking drum for a head tracking response to a visual stimulus. They were then examined for retinal degeneration. Of 204 animals tested, 138 had retinal degeneration. None of these showed any head tracking response. Of the remaining 66 with normal retinas, 45 showed a normal response, and 19 of the 21 mice which did not respond on a first test showed a normal response when the test was repeated. The visual tracking drum differentiates reliably between mice with normal vision and mice with severely decreased vision. There was a relatively high rate of non-responders among the normal sighted mice on a first test, but the test is rapid enough to be repeated easily.