ANOPHTHALMOS. ATROPHY OF THE EYEBALL. PHTHISIS BULBI. MICROPHTHALMOS.
In some cases the eye is congenitally absent (Anophthalmos). In others it is abnormally small. One such case came under the notice of the author in which the eyeball was represented by a small black sphere about half an inch in diameter moved by the ocular muscles. The dam of the filly, born with this defect, had, during the pregnancy, a burdock entangled in the forelock and causing a violent ophthalmia which was supposed to have lasted for months. In other cases there is a fistula opening from the vitreous behind.
Cases of wasting and atrophy of the eye follow on exudates into the vitreous and their subsequent contraction, or on suppuration and granulation as noted under internal ophthalmia, recurrent ophthalmia, and panophthalmia. The condition may also result from atrophy or degeneration of the optic nerve or of its cerebral ganglia (thalamus, corpora quadrigemini, geniculata, etc.). These conditions are irremediable.