Rabbit Corneal Alkali Burn Model

A total of 65 healthy New Zealand white rabbits (34 females and 31 males, aged 80–90 days, weight 1.8–2.5 kg) were purchased from Shanghai Slack Laboratory Animal Co., Ltd. (Shanghai, China). The rabbits were anesthetized with 20 mg/kg ketamine. The eyeballs of rabbits were normal and healthy without corneal damage or scar under a slit-lamp microscope. Among the 65 white rabbits, 15 were randomly selected as the controls, and the remaining 45 were used for the alkali burn model establishment. The filter paper (5 mm in diameter) was immersed in 2 mol/L NaOH solution and then put on the eyeballs of the white rabbits for 40 seconds. Thereafter, the filter paper was removed and residual NaOH solution was washed away with normal saline. Subsequently, the rabbits with corneal alkali burn were randomly divided into the alkali treatment (AT) group, empty vector (EV) group, and shRNA-S100A4 group (sh group for short), with 15 rabbits in each group. The cornea of each rabbit in the sh group was injected with 10 µL S100A4 shRNA. Eight quadrant bulbar conjunctiva of each rabbit in the EV group were injected with 10 µL empty plasmid. Each rabbit in the AT group was injected with 10 µL normal saline. On days 1, 3, 7, 14, and 28 after the Schirmer test, the corneas were excised from three white rabbits: corneas from one eye of the three rabbits were used for frozen sections, and corneas from the other eye of the three rabbits were used for extraction and quantification of protein and RNA, as well as extraction of the aqueous humor for ELISA.