Rabbits were randomized to group 1, full cautery OD and no treatment OS (
n = 5 rabbits), or group 2, full cautery OD and OS (
n = 5 rabbits). Group 1 was considered the control. Group 2 received drop A (30 µL hyaluronic acid [HA]-containing eye drop; Johnson & Johnson, Jacksonville, FL) in OS and drop B (30 µL HA and castor oil–containing eye drop; Johnson & Johnson) in OD, three times a day from day 15 to day 47. The eye drops were applied using a micropipette (Pipetman G Pipette tips, 200 µL; Gilson, Middleton, WI). The interval between each dose was approximately 4 hours. Rabbits were observed daily for clinical signs of toxicity, moribundity, and mortality, and they were weighed prior to cauterization and the end of the study. Draize scoring was performed daily beginning on day −2. NIBUT was performed bilaterally on days −2, −1, 7, 9, and 14 prior to eye drop administration and after each drop administration on days 15, 19, 22, 26, 29, 33, 36, 40, 43, and 47. Fluorescein staining and imaging for ophthalmic examinations were performed on days −1, 7, 9, and 14 prior to administering the combined Draize and McDonald–Shadduck scoring system
18 and also on days 15, 19, 22, 26, 29, 33, 36, 40, 43, and 47. Histopathology was assessed at day 48. This was a 51-day study, including the 2 days pre-cautery, the day of cautery (day 0), and the 48 days post-cautery.