Effect of cryopreserved amniotic membrane on the development of adhesions and fibrosis after extraocular muscle surgery in rabbits

Abstract

. Purpose: To histopathologically evaluate the effect of cryopreserved human amniotic membrane (AM) transplant on preventing the development of postoperative adhesions after extraocular muscle surgery. Methods: Ten albino rabbits were used. The superior rectus muscles were bilaterally resected. In right eyes, the muscle was wrapped with cryopreserved human AM (group AM). In left eyes, the muscle was not wrapped with AM and served as a control group (group C). The rabbits were killed, and the eyes were enucleated 6 weeks after surgery to perform histopathological examination. Results: On histopathological examination, the AM was present in eight eyes, surrounded by periamniotic inflammation, with no adhesions detected between rectus muscle and sclera, conjunctiva and Tenon’s capsule in the segment where the AM was present, but detected elsewhere. Adhesions were detected in the other two eyes of group AM, in which the AM was absent, and in all group C eyes. When comparing eye pairs of each rabbit, AM eyes showed significantly less adhesions between the muscle and sclera (p = 0.009) and between the muscle and Tenon’s capsule and conjunctiva (p = 0.008), in the region of AM application, and significantly more foreign body inflammation (p = 0.031), than C eyes. The differences between AM and C eye pairs, in terms of conjunctival inflammation and vascularity and muscle fibrosis, were insignificant (p > 0.05). Conclusions: Cryopreserved AM is effective in reducing postoperative extraocular muscle adhesions. Its application is, therefore, recommended during strabismus reoperations.

Tissue Response to Implanted Ahmed Glaucoma Valve with Adjunctive Amniotic Membrane in Rabbit Eyes

“…However, amniotic membrane significantly reduced the thickness of the fibrous capsule and α-SMA expression in spite of its failure to prevent inflammation in this study. These findings are in agreement with a previous animal study [33]. Kassem et al [33] noticed that human amniotic membrane was effective in reducing postoperative extraocular muscle adhesion in rabbits, although significantly more foreign body inflammation was found in amniotic membrane eyes compared with control eyes.…”

“…These findings are in agreement with a previous animal study [33]. Kassem et al [33] noticed that human amniotic membrane was effective in reducing postoperative extraocular muscle adhesion in rabbits, although significantly more foreign body inflammation was found in amniotic membrane eyes compared with control eyes. In addition, Tseng et al [37] reported that the antiscarring action of amniotic membrane is not caused indirectly by suppressing inflammation but by directly suppressing TGF-β signaling at the transcriptional level.…”

“…Kassem et al [33] reported that significant foreign body inflammation was observed in rabbit eyes 6 weeks after cryopreserved human amniotic membrane implantation. We presumed that the inflammatory response observed 2 months after surgery in our study group was related to the xenogenic nature of human amniotic membrane used in rabbits.…”

Restrictive problems related to strabismus surgery

“…The use of such agents should be regarded with caution as they may also decrease the reattachment of the extraocular muscle to the scleral tissue. The role of amniotic membrane to reduce postoperative scarring is studied by different groups and conflicting results are reported about the effect of reducing postoperative scarring161718192021222324.…”

Amniotic Membrane in the Treatment of Spinal Cord Injuries

“…In clinical practice, it has also been applied in ophthalmology since 1997 [28]. It is used therapeutically for defects of the cornea and conjunctiva [29]; prevention of postoperative adhesions [30]; reconstruction of defects of the pharynx and oral mucosa [31] and in bone defects [32]. In general, AM patching has shown interesting results when applied in injured tissue, with low incidence of side effects, encouraging the development of new experimental research aimed at the treatment of SCI.…”