4.3

The Mouse Model of Myopia

Frank Schaeffel*

Introduction

The mouse has recently expanded the spectrum of animal models for studies on myopia,1,2 after chicks,3 tree shrews,4 rhesus monkeys,5 and guinea pigs6 had already been used for a number of years. A driving force for introducing the mouse model was that it offers a number of advantages over the other models. These advantages include the availability of numerous knock-out mutants; most advanced gene microarrays for screening the transcriptome, a completely sequenced genome; the fact that the mouse is the most extensively studied mammalian model for human diseases; the fact that considerable knowledge exists already about biochemical pathways and pharmacology; and finally, that mouse strains can be easily crossed and bred. These advantages are counter-balanced by a number of disadvantages. In particular, compared to chicks and monkeys, mice are not predominantly “visual animals,” and their spatial resolution (around 0.5 cycles/degree) is about 100 times less than in humans, about 80 times less than in the monkey, and 15 times less than in chickens, and still about five times less than in the guinea pig. Furthermore, fast eye growth would be advantageous if the effect of visual input on eye growth is to be studied, and again, the mouse does not seem optimal: its eye grows only 0.15% per day over the first 100 days, which is about 10 times slower than in the chicken (1.1%). Accordingly, significant effects of the deprivation of sharp vision can be observed on eye growth in the chick model

*Section of Neurobiology of the Eye, Ophthalmic Research Institute, Calwerstrasse 7/1, 72076 Tübingen, Germany. E-mail: frank.schaeffel@uni-tuebingen.de.

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