Posterior conical cornea.

SINCE this condition was first described (Butler, 1930), only a handful ofcases has been added to the literature. In view of its infrequency, some cases are presented and compared with previous descriptions. Perhaps the name, although anatomically descriptive, is unfortunate, for it would imply that the condition has some relationship with the better-known conical cornea. In fact, there is no evident relationship beyond the unsubstantiated statement that the posterior form is a precursor of the ordinary form. The two conditions are so named merely because the cornea tends to become cone-shaped-throughout its thickness in ordinary keratoconus and solely in its posterior surface in keratoconus posticus. Two forms of the latter condition occur: (A) Localized-keratoconus posticus circumscriptus. (B) Generalized-keratoconus posticus totalis.