title: Postanaesthetic tear production and ocular irritation in cats.
abstract: OBJECTIVE
  General anaesthesia significantly reduces tear production and normal values are not immediately re-established on ending anaesthesia. Therefore, adequate protection of the cornea has to be assured during the perianaesthetic period. There are various methods available, including taping of the eyelids and the application of eye ointments, gels and drops. In human medicine studies, different formulations were found to induce signs of ocular irritation. The aim of the present study was to determine tear production in cats after general anaesthesia, and to identify possible causes of irritation.
  
  
  METHODS
  Tear production was determined in 41 cats after general anaesthesia and eyes were examined for signs of irritation. Two different anaesthetic protocols were used. To protect the cornea, an ointment and gel were applied to the right and left eyes, respectively.
  
  
  RESULTS
  Postoperatively, tear production was significantly reduced for 6 hours and 18 hours in the right and left eyes, respectively. Two hours after anaesthesia, blepharospasm of the right eye was observed in 92.7% (n = 38) of the cats. In contrast, the left eye was always held open.
  
  
  CONCLUSIONS
  This study demonstrated that tear production in cats is significantly decreased both during and after anaesthesia. The degree of reduction was independent of the anaesthetic protocol. Both the eye ointment and gel proved effective in protecting the corneal surface. However, eye gel use is recommended because the eye ointment consistently caused an irritation comparable to the foreign-body sensation reported in humans.
authors.affiliation: Dr. Nina Peche, Klinik und Poliklinik für kleine Haustiere, Freie Universität Berlin, Oertzenweg 19b, 14163 Berlin, E-Mail: nina.peche@fu-berlin.de.
authors.forename: N
authors.initials: N
authors.lastname: Peche
authors.forename: R
authors.initials: R
authors.lastname: Köstlin
authors.forename: S
authors.initials: S
authors.lastname: Reese
authors.forename: K
authors.initials: K
authors.lastname: Pieper
mesh_terms: D000768:Anesthesia, General / Q000009:adverse effects / Q000662:veterinary*; D000818:Animals; D002371:Cat Diseases / Q000209:etiology*; D002415:Cats; D015352:Dry Eye Syndromes / Q000209:etiology / Q000662:veterinary*; D065346:Lubricant Eye Drops / Q000008:administration & dosage; D013666:Tears / Q000187:drug effects / Q000502:physiology
chemical_list: D065346:Lubricant Eye Drops
keywords: Anaesthesia; Schirmer tear test; dry eye; eye irritation; feline