Duration 5min, Q&A 3min
A New Non-Human Primate Model of Severe Dry Eye
To establish a new rhesus monkey model of severe dry eye.
A total of eight rhesus monkeys were used for the study.
Four monkeys had the main lacrimal gland and nictitating membrane surgically removed (group one). Another four monkeys had similar surgery with further application of fifty percent trichloroacetic acid on the bulbar conjunctiva (group two). The ocular surface was evaluated before and after surgery (first, forth, eighth, twelfth and twenty-forth weeks) using Schirmer test, corneal fluorescein staining and lissamine green test. Conjunctival impression cytology was also performed before and twenty-forth weeks after surgery. Finally, the cornea and conjunctiva were evaluated under light microscopy.
Results and Conclusion
A significant and important decrease in tear secretion was observed in all operated eyes. Schirmer tests were measured less than four mm in all operated eyes. Slit-lamp examination also revealed abnormal staining in all operated eyes that remained stable until the end of experiment. In group two, corneal fluorescein staining and lissamine green test were always more than five (max. twelve) and more four (max. nine), respectively. Impression cytology specimens of both treated groups showed conjunctival squamous metaplasia and decreased number of goblet cells. Under light microscopy, the corneal epithelium was irregular with edematous basal epithelial cells and the conjunctiva showed a decreased goblet cell density.
Complete removal of the principal lacrimal gland and nictitating membrane associated with application of 50% trichloroacetic acid on the conjunctiva could induce severe keratoconjunctivitis sicca in rhesus monkeys.
[ Keyword ]
Dry eye / animal model / rhesus monkey / impression cytology / lacrimal gland
[ Conflict of Interest ]