Original Reports
Simple Corneal Epithelial Abrasion Model in Rabbit
1997 Volume 16 Issue 1-2 Pages 1-2_15-1-2_19
Details
1997 Volume 16 Issue 1-2 Pages 1-2_15-1-2_19
Corneal epithelial abrasion model in rabbit is an important technique for evaluation of effect on corneal healing. In published studies, the corneal epithelium is usually abraded using a trephine and a spatula or scalpel blade operating under a microscope. In the present study, the technique was simplified to remove the corneal epithelium.
Oxybuprocaine hydrochloride was used for surface anesthesia of the cornea under general anesthesia. A circular incision of 5.5 mm in diameter and 50 μm in depth was made in the center of the cornea by sterile trephine. With the aid of fluorescien dyeing to ascertain the site of the circular incision, fine forceps and a sterile wet cotton swab were used to remove the corneal epithelium with rubbing the area surrounded by the circular imprint. The extent of abrasion was confirmed by the further staining with fluorescein dye. The abrasion site was washed with saline solution to remove debris and residual topical anesthetic.
The availability of the present model was assessed by evaluating the effect of benzalkonium chloride (BAC) on healing of mechanically produced corneal abrasion as mentioned above. BAC solution of 0.015% or 0.050% was instilled three times a day for 2 days after abrasion, and saline was used as a negative control. The abrasion site of the corneal epithelium stained with fluorescein was examined twice a day. Observation was terminated when the abrasion site was not detected by staining with fluorescein. The area of the abrasion site was calculated by multiplying the minimal span and the maximal span of the stained site. A area under the time response curve (AUC; a percentage of the abrasion area compared to the initial one) was calculated using the trapezoidal rule to characterize the time response pattern.
The abrasion sites of the corneal epithelium were completely healed within 72 hours not only in the animals of the control group, but also in those of the BAC treatment groups. Following BAC treatment, the AUC of the abrasion area in the 0.050% BAC group became statistically significantly (P<0.05) greater than that of controls.
In summary, this model for the corneal epithelial abrasion healing studies in rabbit is applicable for routine use in testing of effects of ophthalmic solution on corneal healing.
