A prospective, masked, randomized, controlled superiority study comparing the incidence of corneal injury following general anesthesia in dogs with two methods of corneal protection

Objective To compare the incidence of corneal injury during general anesthesia (GA) and the immediate post-operative period in eyes protected with topical ocular lubricant alone with eyes protected with topical lubricant followed by complete eyelid closure using tape. Animals Studied One hundred client-owned dogs (200 eyes) undergoing GA for MRI scan. Methods Patients had ocular lubricant applied to both eyes upon induction of anesthesia. One eye was taped closed immediately after induction for the duration of anesthesia using Strappal (R) tape (BSN medical (TM); treatment group), and the other eye was not taped (control group). Eyes were randomly allocated to a treatment group. Ophthalmic examination was performed before and after anesthesia; the examiner was masked to eye treatment groups. Corneal injury was defined as corneal ulceration or corneal erosion. A McNemar's test was used to compare the incidence of corneal injury between groups. A paired-samples t-test was used to compare Schirmer-1 tear test (STT-1) readings between groups. Results Sixteen eyes (8%) developed corneal erosion. No corneal ulceration occurred. There was no significant difference between incidence of corneal erosion between groups (p = .454). There was a significant decrease in STT-1 readings following GA in both groups (p < .001), with no significant difference in STT-1 between groups (p = .687). No adverse effects of taping the eye closed were observed. Conclusion Taping the eyes closed during GA had no additional benefit to the lubrication protocol used in this study.