Morphometric Analysis of the Eye by Magnetic Resonance Imaging in Gene-Deficient Mice.

Strabismus, a neuro-ophthalmological condition characterized by misalignment of the eyes, is a common ophthalmic disorder affecting both children and adults. In our previous study, we identified the microsomal glutathione -transferase 2 () gene as one of the potential candidates for comitant strabismus susceptibility in a Japanese population. The gene belongs to the membrane-associated protein involved in the generation of pro-inflammatory mediators, and it is also found in the protection against oxidative stress by decreasing the reactivity of oxidized lipids. To look for the roles of the gene in the development, eye alignment, and overall morphology of the eye as the possible background of strabismus, gene knockout (KO) mice were generated by CRISPR/Cas9-mediated gene editing with guide RNAs targeting the exon 2. The ocular morphology of the KO mice was analyzed through high-resolution images obtained by a magnetic resonance imaging (MRI) machine for small animals. The morphometric analyses showed that the height, width, and volume of the eyeballs in KO homozygous mice were significantly greater than those of wild-type mice, indicating that the eyes of KO homozygous mice were significantly enlarged. There were no significant differences in the axis length and axis angle. These morphological changes may potentially contribute to the development of a subgroup of strabismus.