Congenital anophthalmia, complete absence of the eyeball, refers to the absence at birth of the structures of the eye derived from the neural ectoderm. In a strict sense true anophthalmia can only be diagnosed after careful histological examination of the entire contents of the orbit demonstrating the complete absence of any rudiments of neuroectodermal structures, because it is possible that the presence of such structures, while clinically not visible or palpable, indicates an extreme degree of microphthalmia. The terms anophthalmia and microphthalmia are therefore often used interchangeably1,2 or an extreme form of microphthalmia is referred to as pseudoanophthalmia. In the absence of histological verification the terms apparent or clinical anophthalmia are used.
Several reports of single cases of unilateral anophthalmia have been published, and in about half of these cases some other congenital defect has been present in the other eye.3 Familial cases of unilateral anophthalmia have also
HOEFNAGEL D, KEENAN ME, ALLEN FH. Heredofamilial Bilateral Anophthalmia. Arch Ophthalmol. 1963;69(6):760-764. doi:10.1001/archopht.1963.00960040766015