Abstract
Purpose: :
We have previously reported the efficacy of vitamin A (retinol palmitate (VApal)) eye drops in rabbit models of corneal and conjunctival epithelial damage after n-heptanol treatment (Toshida et al, Curr Eye Res 33,13, 2008). The aim of this study is to investigated the effects of VApal eye drops after corneal and conjunctival epithelial injuries in rabbit dry eye model after removal of lacrimal gland.
Methods: :
Twenty-eight male New Zealand white rabbits without ocular anomaly have used for this study. The lacrimal gland was removed surgically under general anesthesia bilaterally. At least four weeks later, lower tarsal conjunctivae were injured by 0.5% of NaOH solution with filter paper for 30 seconds, then was washed by balanced saline solution. VApal (500, 1,000 or 1,500 IU/mL) or vehicle eye drops were administrated six times a day for 7 days. The eyes were observed by slitlamp microscope with fluorescein and rose bengal staining. After the final observation, histological analysis (HE and PAS staining) were performed.
Results: :
The fluorescein score and the rose bengal score were significantly reduced in the 1,000 IU/mL and 1,500 IU/mL VApal-treated eyes compared with the vehicle-treated eyes at 7 days after treatment (p<0.05). Furthermore, the 1,500 IU/mL VApal-solution tended to be more effective than hyaluronic acid in both scores (fluorescein score: p<0.05, rose bengal score: p<0.01). Histological examination revealed that the wound healing of the corneal and conjunctival epithelium was improved and the number of goblet cells was increased at 7 days after treatment with VApal (1,000 and 1,500 IU/mL) compared to vehicle.
Conclusions: :
VApal eye drops may be useful for treatment of corneal and conjunctival epithelial injury even though dry eye induced by removal of lacrimal gland. It is suggested that VApal may play important rules to stabilize mucin layer at the initial stage of wound healing after corneal and conjunctival epithelial injury.
Keywords: cornea: epithelium • cornea: surface mucins • cornea: tears/tear film/dry eye