Efficacy of topically applied liposome‐bound tetracycline in the treatment of dry eye model

OBJECTIVE: To evaluate the effects of liposome-bound tetracycline eye drops in a rabbit dry eye model evaluating their advantage of being less allergic, preservative free and prolonged action compared with other tear substitutes. PROCEDURES: New Zealand albino rabbits were equally divided into control group and dry eye induced groups. Dryness was induced in 24 eyes of 12 healthy adult male albino rabbits by instilling atropine sulfate eye drops 1% three times daily for 1 week, then animals were subdivided into four groups; group 1 (rabbits with dry eye model), groups 2, 3, and 4: rabbits with dry eye model treated for 7 days starting on 7th day of dryness induction with either tetracycline, empty liposome, or combined tetracycline with liposome as topical eye drops respectively. Schirmer (STT) test and tear break up time (TBUT) were assessed on days 0, 2, 4, 7, 9, 11, and 14. Animals were sacrificed on day 14 and histopathological examination of the cornea and conjunctiva was performed. RESULTS: Tear break up time and STT test values were significantly improved in groups 2, 3, 4 as compared with group 1. The histopathological examination showed normal cytoarchitecture of corneas and conjunctivae in groups 2, 3, 4 against the dryness effect that continued to affect the cornea and conjunctival epithelium in group 1. There was a significant improvement in the group treated with liposome-bound tetracycline eye drops (group 4) as compared with tetracycline alone (group 2) and empty liposome (group 3). CONCLUSION: The use of liposome encapsulated tetracycline significantly improved STT and TBUT values as well as reverse surface ocular pathology.