A cross-linked hyaluronan gel accelerates healing of corneal epithelial abrasion and alkali burn injuries in rabbits

Objective To evaluate the efficacy of a chemically modified and cross-linked derivative of hyaluronan (CMHA-SX) for treatment of corneal epithelial abrasion and standardized alkali burn injuries. Animals Twelve female New Zealand white rabbits in two groups were used. Procedures Bilateral 6-mm diameter corneal epithelial abrasions were made in each of six rabbits in one group and 6-mm standardized alkali burn injuries were made in the second group. A 1% CMHA-SX formulation was applied topically four times per day in right eye of each rabbit for 1 week, and phosphate buffered saline (PBS) was placed in left (control) eye of each rabbit. The wound size was determined by staining with 1% fluorescein and photographed at the slit lamp with a digital camera at 0, 1, 2, 3 days postoperatively in the first group and 0, 1, 2, 3, 7, 12 days in the second group. Rabbit corneas were collected for histological examination on day 7 in the first group and day 12 in the second group. Results Closure of corneal wound in the abrasion model was complete in the CMHA-SX treated eye by 48 h. The wound closure rate and thickness of the central corneal epithelium in the CMHA-SX treated group was greater than in control eyes for both the abrasion and alkali burn injuries. Moreover, the CMHA-SX treated cornea exhibited better epithelial and stromal organization than the untreated control cornea. Conclusions Chemically modified and cross-linked derivative of hyaluronan improved corneal wound healing and could be useful for treating noninfectious corneal injuries.