Dried Human Amniotic Membrane Does Not Alleviate Inflammation and Fibrosis in Experimental Strabismus Surgery

Abstract

Purpose. The purpose of this study was to evaluate the efficacy of dried human amniotic membrane (AM) in reducing the postoperative inflammatory response and scarring after strabismus surgery. Methods. The inflammatory response at the extraocular muscle reattachment site was analyzed after superior rectus (SR) resection in 12 rabbits. Dried human AM (Ambiodry2) was applied between the resected SR muscle plane and Tenon's capsule of the left eyes of rabbits. As a control, the right eyes of rabbits underwent SR resection only. The surgeon randomly ordered which eye gets operated first during the experiment. Two weeks later, enucleation was performed. Six sagittal sections were made for each eye at the insertion of the SR muscle. The grade of postoperative inflammation and the presence of fibrosis were evaluated in histological examinations. Results. There was no statistically significant difference in the intensity of inflammation and fibrous proliferation between the eyes treated with dried human AM after SR resection and those treated with SR resection only. Conclusions. The use of dried human AM was not effective in controlling the postoperative inflammation and scarring in rabbit eyes after extraocular muscle surgery. However, this may be due to the devitalized dry preparation of human AM (Ambiodry2), which may have lost the expected anti-inflammatory and anti-scarring properties, and further studies on humans may be necessary.

Cryopreserved rabbit amniotic membrane alleviated inflammatory response and fibrosis following experimental strabismus surgery in rabbits

“…Thus, several researches have been performed on the role of the AM as a biological barrier in strabismus surgery by reducing postoperative inflammation and scarring. However, our previous research demonstrated that lyophilized human AM was not efficient in alleviating postoperative inflammation and fibrosis following strabismus surgery in rabbits, and those data corresponded with the results reported by Kassem et al [ 17 , 18 ] We speculated that these results might be due to the limited benefit of lyophilized human AM [ 19 ]. Kassem et al [ 20 ] reported that cryopreserved human AM was effective in reducing postoperative adhesions in rabbits.…”

“…A 6–0 absorbable polyglactin (Vicryl ® ) was sutured on the SR muscle 1 mm behind the resection point, and the SR muscle resection of 4 mm was performed. To aggravate the inflammatory response following this experimental strabismus surgery, cauterization of the underlying sclera (1 × 0.5 cm 2 , 10 times) was done prior to suturing of the resected SR muscle to its original insertion [ 17 , 22 ]. The reason for this additional cauterization is that the average degree of inflammation following strabismus surgery is unknown in rabbits, although De Carvalho et al [ 7 ] demonstrated that postoperative inflammation following uncomplicated strabismus surgery was minimal in this species.…”

Cryopreserved Ultra-Thick Human Amniotic Membrane for Conjunctival Surface Reconstruction After Excision of Conjunctival Tumors

“…[10][11][12][16][17][18] Similarly, we observed symblepharon with no interference in ocular motility or eyelid function in 11% of patients and partial limbal stem cell deficiency in 18% of patients. None of the patients experienced dehiscence or folding of the ultra-thick cryopreserved AM.…”

“…3,12,14 Cryopreserved AM is the most commonly used form because it preserves the intact basement membrane and contains a higher amount of soluble, wound-healing modulating factors. 7,15,16 Studies show that it facilitated complete epithelial healing, with good or excellent cosmesis, in patients with ocular surface neoplasia. [17][18][19] Similar to commercially available cryopreserved AM, ultra-thick cryopreserved AM also facilitated complete epithelial healing and good cosmesis in all patients.…”

Effect of Cryopreserved Amniotic Membrane on the Mechanical Properties of Skeletal Muscle after Strabismus Surgery in Rabbits

“…However, in their studies, Kassem et al (17,18), revealed that lyophilized AM is not able to prevent adhesion formation or reduce EOM fibrosis. Moreover, Chun et al (19) described a similar inflammation level between operated eyes with and without lyophilized membrane. Thus, cryopreserved AM, stored in glycogen and frozen at -80ºC, has been reported as the best method to avoid membrane damage and maintain its properties (20).…”