Subconjunctival amniotic membrane free graft in rabbit eyes: effects on fibrovascular reaction

The purpose of our study is to investigate the effect of subconjunctival amniotic membrane free graft on subconjunctival fibrovascular reaction.

Twelve healthy male white New Zealand rabbits were used for the study. The rabbits were divided randomly into two groups: Study Group (n=6) and Control Group (n=6). In the Study Group, a 4mm limbal incision was made and a 4×4mm subconjunctival pocket was created with blunt dissection. A 4×4mm single layer of free amniotic membrane was placed in the pocket in an epithelium-up fashion without suturing. The limbal opening was secured with 10-0 nylon sutures on both sides. In the Control Group, a 4mm limbal incision was made, a 4×4mm subconjunctival pocket was created with blunt dissection, and the limbal opening was closed with 10-0 nylon sutures on both sides. After the first month, sclero-conjunctival blocks were obtained from the operated area and sections were stained with hematoxylin and eosin, Masson trichrome, and Ki67, SMA and CD34 antibodies.

The number of fibroblasts, lymphocytes and macrophages was significantly higher in the Study Group than in the Control Group. The number of Ki67- and SMA-positive cells, and CD34-positive vessels was also significantly higher in the Study Group. Amniotic membrane appeared to form folds in all the specimens.

The higher fibrovascular reaction shown by our histopathological examination indicates that free human amniotic membrane grafting without suturing is not useful in decreasing the subconjunctival fibrovascular reaction at the first postoperative month in rabbit eyes.