Pretarsal and marginal orbicularis oculi muscle fiber changes in trachomatous cicatricial entropion: histopathological evaluation

Purpose. To evaluate the histopathological changes of pretarsal and orbicul aris muscle fibers in trachomatous cicatricial entropion. Methods. Orbicularis muscle tissue specimens were histopathologically evalu ated in 17 eyes of II cases in which anterior lamellar reposition and/or we dge-shaped tarsal resection or Wies procedure were performed. Results. Degeneration of orbicularis muscle fibers, atrophy, connective tis sue increase between muscle fibers and edema were observed in 13 tissue spe cimens. Muscle fiber changes were more commonly observed in cases with seve re entropion, in which Wies procedure was performed. Conclusions. These histopathological changes, which may develop secondary t o other structural changes that can cause entropion in the eyelid and weake n the orbicularis muscle, may be a co-factor influencing the severity of en tropion more than causing entropion alone.