Latex Biomembrane with Polylysine in Lamellar and Penetrating Scleral Lesions Repair in Rabbits
Inflammatory diseases scleral may progress to complete perforation or require specific therapy to prevent perforation (1). The purpose of this research was study the effects of latex biomembrane with polylysine graft on scleral healing of rabbits submitted to lamellar and penetrating sclerectomies. The latex biomembrane is believed to promote neoformation of biological tissues (2,3).
Latex biomembrane was prepared by Department of Biochemistry of Medicine College of Ribeirão Preto, University of São Paulo. Twenty-four healthy rabbits were used and randomized into two groups and evaluated at the first, third, seventh, 15th, 30th and 60th day after surgery, under clinical and morphological aspects. After general anesthesia the conjunctiva was deviated and scleral square incisions of 0.4X0.4 cm were carried out in eleven o'clock position near the limbus, being a full-thickness resection on G1 (n=12) and a lamellar deep resection on G2 (n=12). All eyes underwent latex biomembrane with polylysine transplantation to restore thickness and promote healing. The preplaced biomembrane graft was positioned and sutured with interrupted 9-0 nylon. The conjunctiva was pulled forward to cover the area of graft. Postoperative evolution was analyzed every day: intensity of hyperemia and edema, blepharospasm, presence of infection, secretion, rejection and tonicity of the eyes by applanation tonometry.
There were not signs of graft extrusion in all animals. No cases of blepharospasm or infection were observed. All the eyes maintained normal intraocular pressure and anterior and posterior segments did not reveal clinical signs of inflammation. Mucoid ocular discharge was sustained until 5th day after surgery. Hyperemia was observed until the third day after surgery. Congestion of conjunctival vessels on area was observed until the end of the evaluation period in G1. The histopathological findings showed that the healing tissue is primarily dependent on help from highly vascularized tissues on one side or the other, the episclera or the choroid. The proliferating fibrous tissue, composed essentially by many fibroblasts, neovessels and few leucocytes, runs between the edges of the wound, being complete at seventh day in animals of G1. There was a good adhesion of the biomembrane by recipient's sclera.
The use of latex biomembrane with polylysine represents a useful alternative to scleral reconstruction and could be an alternative graft to repair scleral lesions in animals and humans when donor tissue is not available. Moreover, it showed some advantages such as easy obtention, good handling and durability.
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2. Frade, M. A. C., et al. Chronic phlebophatic cutaneous ulcer: a therapeutic proposal. Int. J. Dermatol., v.40, p.237-40, 2001.
3. Poterio Filho, J., et al. O uso de látex natural com polilisina 0,1% na cicatrização de úlceras isquêmicas. Rev. Soc. Bras. Angiol. Cir. Vasc., suplemento, p.S-156, 1999.