| The dysfunction of conjunctiva is often noticed after ocular surface alkali burns, large amounts of goblet cells are destroyed, the secretion of mucoprotein -one of the important components of preocular tear film -is deficient. So, tear film is unstable and easy to break and tear break-up time becomes shorter. As the surface of cornea and conjunctiva are always in a dry condition , epithelia will be erosible and keratinized , which will lead to secondary dry eye . Xerophthalmia, also called dry eye syndrome, is the disorder of the quality, quantity or dynamics of the tear ,which results from any possible reasons . It leads to the disability of the tear film and /or abnormality in ocular surface , and the discomfort of eyes is often concomitant symptom. Although the exact etiologies of dry eye are varied and still unclear, it has been agreed that underlying inflammatory process and the deficiency of mucoprotein play a important role in dry eye syndrome. How to interrupt these processes has been a hotspot in the treatment of dry eye.Objective: To establish a dry eye model; to study the effect of gefarnate eye drops on experimental dry eye and investigate whether it has any cooperative interactions with ketorolac tromethamine-one of a nonsteroidal anti-inflammatory drugs. Material and Methods: 40 New Zealand rabbits (2-2.5kg, 20 male and 20 female), were induced into models whose goblet cells are destroyed by alkali burns. Then, they were randomized into the following four groups, each group having 10 rabitts:control group (dripped 0.9%sodium chloride) -1, the second-2 ,third-3 and forth-4 group, they were dealed with l%gefarnate ,0.5% ketorolac tromethmine and l%gefarnate combined with 0.5% ketorolac tromethamine respectively, 4 times a day for 4 weeks. Fluorescence stain, rose Bengal stain, BUT test, TFT test and conjunctival impression cytology test were performed after the 1st day of operation, and 1,2,3,4 weeks after dripping drugs. 4 weeks later, 12 rabbits were chosen randomly and killed , eyes were extirpated , eyelid, conjunctiva and cornea tissuebiopsy were carried out, in order to observe MUC5AC with immunohistochemistry under optical microscope, and the super-micro structure of goblet cell. Results: All the following results are compared with that of the first day after the operation. Slit-lamp examination: the signs of 3 and 4 were relieved after the first week of treatment while the 2 group were in the second week and the 1 group in the third week; Scores of fluorescence and rose bangle stain: The scores of 2 and 4 group are significantly lower than that of 1 group (P<0.05), but no difference were found among 2, 4, 3 or 3, 1 group (P>0.05) . BUT test : Statistical difference were observed among 1 and other there groups (P= 0.020, 0.014, 0.033<0.05), and the same conclusion was drawn from the comparison of 2, 4 and 3 group (P<0.05); TFT test: Statistical difference were found among 2,4 and 3, 1 group (P<0.05). Schirmer I test : No significant difference were observed among four groups (P>0.05). Conjunctival impression cytology and immunohistochemistry test : The density of goblet cells and quantity of MUC5AC of 2,4 group are significantly higher than that of 1,3 group and there are fewer neutrophils in tissue of 3, 4 group than that of 1, 3 group at the same time in the 1st and 4th week after treatment (P<0.05). Conclusions: The secondary dry eye model established by alkali burns, is a good model for the study of the mechanism and treatment of dry eye syndrome; It is obviously that Gefarnate can stimulate goblet cell to proliferate and secret MUC5AC , but the inhibition on exudation of neutrophils in inflammation is not noticed. Compare with gefarnate, Ketorolac Tromethamine exerts a more stronger anti-inflammation effect on burned conjunctiva though its effect on goblet cell is weaker .It is also demonstrated that gefarnate combined with Ketorolac Tromethamine is a better and more efficient approach for the treatment of dry eye syndrome induced by alkali burns.
|
PDF Full Text Request