Effects of Amniotic Membrane Extraction on Rabbit Corneas with Herpes Simplex Keratitis

The amniotic membrane exhibits many biological properties that may be helpful in treating ocular surface diseases. In this study, we investigated the effect of topical amniotic membrane extraction on herpes simplex keratitis (HSK) in a rabbit model. The corneas of rabbits were infected with herpes simplex type 1 virus. The rabbits were divided into 2 groups according to topical treatment methods: saline and AM extraction. The corneal lesions and angiogenesis severity were measured and graded at 0,1,3,5,7, and 14 days after treatment. Histologic examination was performed and the expression of interleukin (IL)-2, IL-10 and vascular endothelial growth factor (VEGF) were determined by enzyme-linked immunosorbent assay at 7 or 14 days after treatment. The severity of keratitis treated with AM extraction was less than saline treated eyes after 5 days of treatment (P<0.05). The extent of angiogenesis in the eyes of AM extraction treatment revealed greater reduction than the control ones after 3 days of treatment (P<0.05). The amount of IL-2 and VEGF were decreased after treatment of AM extraction, whereas the amount of IL-10 was increased. The present study showed the extraction from fresh human amniotic membrane dramatically decreased the corneal inflammation and angiogenesis in experimental HSK by modulating the expression of proinflammatory cytokines and VEGF in the infected corneas.