Senile ectropion and entropion: a comparative histopathological study.

A microscopic histopathological study was done on 500 full-eyelid-thickness surgical specimens: 25 with the diagnosis of senile ectropion and 25 with that of senile entropion. Five different staining techniques were used. There appears to be significantly more orbicularis and Riolan's muscle ischemia, atrophy, and collagen fragmentation with ectropion than with entropion. Entropion shows more septal and tarsal atrophy. In both conditions, the skin and conjunctiva show chronic inflammation and scarring as a constant feature. Statistical significance at the 1% level was present for all six characteristics studied. These histopathological changes, if not etiological, are at least concomitant features differentiating senile ectropion from entropion at the microscopic tissue level.