Changes of Tear Secretion and Morphology of Corneal Epithelium after Lacrimal Gland Extirpation in Rabbits

Objective To observe the changes of Schirmer I test value(SIT),corneal fluorescein and rose Bengal staining,and morphological alterations of corneal epithelium after lacrimal gland extirpation in rabbits.To evaluate the characteristics of the rabbit dry eye model.Method The S1T value,corneal fluorescein and rose Bengal staining before and after lacrimal gland extirpation were graded.The cornea was taken for transmission electron microscopic examination.Result After lacrimal gland extirpation,the S1T was statistically significantly decreased(20.25±5.52 mm/5 min before and 15.88±6.29 mm/5 min after extirpation,P=0.0062).The average grade point of the corneal fluorescein and rose bengal staining(8.22±1.99 and 7.67±0.87,respectively)was significantly higher than that before the model establishment(0.22±0.44 and 0.67±0.5,respectively,P0.0001).The variation of the above mentioned three testing indexes indicated that tear deficient dry eye after the extirpation of lacrimal gland caused punctate erosions and necrosis of the corneal epithelium.Transmission electron microscopic observation revealed liquidation of superficial epithelial cells and break of basement membrane in the cornea after the model establishment.Those changes were characteristic of dry eye.Conclusion After lacrimal gland extirpation,the tear secretion decreases and punctate erosion and necrosis of corneal epithelium occurs.Thus,a rabbit model of dry eye with decresed tear secretion and punctate erosion and necrosis of corneal epithelium can be successfully established by lacrimal gland extirpation.