Purpose: To evaluate the histopathological changes of pretarsal and orbicularis muscle fibers in trachomatous cicatricial entropion.
Methods: Orbicularis muscle tissue specimens were histopathologically evaluated in 17 eyes of 11 cases in which anterior lamellar reposition and/or wedge-shaped tarsal resection or Wies procedure were performed.
Results: Degeneration of orbicularis muscle fibers, atrophy, connective tissue increase between muscle fibers and edema were observed in 13 tissue specimens. Muscle fiber changes were more commonly observed in cases with severe entropion, in which Wies procedure was performed.
Conclusions: These histopathological changes, which may develop secondary to other structural changes that can cause entropion in the eyelid and weaken the orbicularis muscle, may be a co-factor influencing the severity of entropion more than causing entropion alone.