Schirmer Tear Test Value and Corneal Lesions' Incidence during General Anesthesia for Non-Ophthalmic Surgery in Non-Brachycephalic Dogs: A Pilot Study Comparing Three Different Lubricant Eye Drop Formulations.

Cristina Di Palma,Giancarlo Vesce,Fabiana Micieli,Gerardo Fatone,Valeria Uccello,Annalisa Nieddu,Barbara Lamagna

doi:10.3390/vetsci7010025

Cristina Di Palma, Giancarlo Vesce + Show 5 more

Open Access

https://doi.org/10.3390/vetsci7010025

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Journal: Veterinary sciences	Publication Date: Feb 18, 2020
Citations: 6	License type: CC BY 4.0

Affiliation: University of Naples Federico II

Abstract

Aim of this blinded, prospective, randomized clinical study was to compare three different lubricant eye drops (LED) in healthy adult dogs undergoing general anaesthesia (GA) for non-ophthalmic surgery. Tear production rate was monitored by means of Schirmer tear test-1 (STT-1), and incidence of post-operative corneal abrasions/ulcerations was detected by corneal staining. A complete ophthalmic examination was performed before premedication, at extubation time and 24 h after GA in twenty-five non-brachycephalic dogs (fifty eyes) undergoing elective orthopaedic or spinal surgery procedures. Dogs were randomly allocated to one of three groups receiving as prophylactic LED either carmellose sodium (GC), or 1% hyaluronic acid (GH), or 0.25% hyaluronic acid (GL). In each eye STT-1 was repeated every hour during GA, before instilling one drop of the assigned LED. In all groups STT-1 values drastically decreased during GA, while 24 h later nine eyes (18%) had STT-1 values lower than 15 mm/minute. All of the three formulations tested were fully effective in preventing corneal ulceration (0% in all groups), while 10% of eyes reported superficial de-epithelialization. Fluorescein staining demonstrated that hourly prophylactic LED application prevented exposure keratopathy during general anesthesia in 90% of the eyes in non-brachycephalic dogs.

Highlights

Corneal abrasions are the most common ocular complication in humans during general anesthesia (GA) for non-ophthalmic surgery [1]
Our results demonstrate that all of the three formulations tested in healthy dogs’ eyes, when administered hourly during GA, are effective in preventing corneal ulceration and in reducing the incidence of corneal abrasions
The present study compares the incidence of perioperative corneal lesions following instillation of three different lubricant eye drops (LED) in non-brachycephalic dogs undergoing elective orthopaedic or spinal procedures

Summary

Introduction

Corneal abrasions are the most common ocular complication in humans during general anesthesia (GA) for non-ophthalmic surgery [1]. Adverse ocular side effects of GA are lagophthalmos, leading to exposure keratopathy (EK); loss of eyelid reflex; decreased basal tear production and reduced stability of the corneal tear film [2]. Anesthesia induced corneal lesions have been reported in dogs [3,4,5,6,7,8], cats [9,10] and horses [11]. Eye damage under anesthesia is a preventable complication. As early as 1981 Schimidt et al [12]. Reported that ocular application of a water-based 4% methylcellulose ointment could allow eye protection during GA in humans.

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