Abstract
Unilateral hypoplasia of the retina and optic nerve was found in a male Sprague-Dawley rats. The lesion was first suspected on the electroretinographic examination. There was very little response from the left eye to the light stimulus, whereas the right eye was normal. On the ophthalmic examination, the fundus of the left eye had faint retinal vessels. At necropsy, the left optic nerve and right optic tract were thin. Microscopically, the retina of the left eye was not fully developed showing undifferentiated photoreceptor, outer and inner granular, inner plexiform and ganglion cell layers, and a complete lack of the outer plexiform layer.
