The development of eye alignment in normal and naturally microstrabismic kittens.

The development of interocular alignment was pupillographically measured from eye opening throughout the first half year of life in normal kittens and in kittens deriving from a naturally strabismic cat colony. Whereas the cyclorotatory component of age dependent changes did not differ between the two groups, the horizontal divergence of the optical axes was increased in the future esotropes during the whole observation period. Surprisingly the divergence angle of the optical axes was correlated with the convergence angle of the visual axes as determined during cortical receptive field analysis at 7-9 months of age. The authors suggest a theory that might explain the microstrabismic misalignment of the visual axes with an intraretinal defect.