Corneal abrasion and microbial contamination in horses following general anaesthesia for non-ocular surgery

  • Stefania Scarabelli
    Correspondence: Scarabelli Stefania, Institute of Veterinary Science, University of Liverpool, Chester High Road, Neston CH64 7TE, UK.
    Phillip Leverhulme Equine Hospital, Institute of Veterinary Science, University of Liverpool, Liverpool, UK
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  • Dorina Timofte
    Veterinary Pathology and Public Health Department, Institute of Veterinary Science, University of Liverpool, Liverpool, UK

    Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
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  • Fernando Malalana
    Phillip Leverhulme Equine Hospital, Institute of Veterinary Science, University of Liverpool, Liverpool, UK
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  • David Bardell
    Phillip Leverhulme Equine Hospital, Institute of Veterinary Science, University of Liverpool, Liverpool, UK

    Institute of Aging and Chronic Disease, University of Liverpool, Liverpool, UK
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Published:January 08, 2018DOI:



      To evaluate the incidence of corneal abrasions/ulceration and microbial contamination in horses undergoing general anaesthesia.

      Study design

      Prospective, observational, clinical study.


      A total of 40 client-owned healthy horses scheduled for elective non-ophthalmic procedures.


      Conjunctival sac swabs were taken, fluorescein dye applied and digital images recorded from both eyes of the horses after preanaesthetic medication and 24 hours after recovery from general anaesthesia. A paraffin-based bland ophthalmic ointment was applied on the ocular surface intraoperatively following collection of a sample into a sterile container. All samples underwent aerobic, anaerobic and fungal culture. Subject demographics, chronology of ophthalmic ointment use, anaesthesia duration, recumbency after induction, during surgery and recovery, fluorescein uptake and culture results were recorded. Descriptive statistics were performed.


      Complete data were collected from 34 horses; six (17.6%) developed mild unilateral generalized fluorescein uptake consistent with corneal abrasions. Recumbency on the operating table was the only risk factor significantly associated with corneal abrasions. A total of 11 bacterial species were identified; Staphylococcus spp. (15 eyes) and Micrococcus spp. (eight eyes) were the most frequently isolated bacteria. Two fungal species were isolated postoperatively (Aspergillus spp., Saccharomyces spp.) in two eyes. Ointment contamination was recorded in two cases (5%) but cross-contamination was not recognized.

      Conclusionsand clinical relevance

      Incidence of corneal abrasion/ulceration in horses undergoing general anaesthesia and contamination rate of ophthalmic solutions are similar to those previously reported in dogs.


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        • Andrew S.E.
        • Nguyen A.
        • Jones G.L.
        • Brooks D.E.
        Seasonal effects on the aerobic bacterial and fungal conjunctival flora of normal thoroughbred brood mares in Florida.
        Vet Ophtalmol. 2003; 6: 45-50
        • Barsotti G.
        • Sgorbini M.
        • Nardoni S.
        • et al.
        Occurrence of fungi from conjunctiva of healthy horses in Tuscany, Italy.
        Vet Res Commun. 2006; 30: 903-906
        • Batra Y.K.
        • Bali I.M.
        Corneal abrasions during general anesthesia.
        Anesth Analg. 1997; 56: 363-365
        • Betbeze C.M.
        • Stiles J.
        • Krohne S.G.
        Assessment of bacterial contamination of three multidose ophthalmic solutions.
        Vet Ophthalmol. 2007; 10: 81-83
        • Brightman A.H.
        • Manning J.P.
        • Benson G.J.
        • et al.
        Decreased tear production associated with general anaesthesia in the horse.
        J Am Vet Med Assoc. 1983; 182: 182-243
        • Dawson C.
        • Sanchez R.F.
        A prospective study of the prevalence of corneal surface disease in dogs receiving prophylactic topical lubrication under general anesthesia.
        Vet Ophthalmol. 2016; 19: 124-129
        • Fazeli M.R.
        • Nejad H.B.
        • Mehrgan H.
        • Elahian L.
        Microbial contamination of preserved ophthalmic drops in outpatient departments: possibility of an extended period of use.
        Daru. 2004; 12: 151-155
        • Ferreira A.R.A.
        • Santana A.F.
        • da Veiga Rodarte de Almeida A.C.
        • et al.
        Bacterial culture and antibiotic sensitivity from the ocular conjunctiva of horses.
        Ciência Rural. 2017; 47e20160753
        • Grixti A.
        • Watts M.T.
        Corneal protection during general anesthesia for nonocular surgery.
        Ocul Surf. 2013; 11: 109-118
        • Johns I.C.
        • Baxter K.
        • Booler H.
        • et al.
        Conjunctival bacterial and fungal flora in healthy horses in UK.
        Vet Ophtalmol. 2011; 14: 195-199
        • Kim M.S.
        • Choi C.Y.
        • Kim J.M.
        • et al.
        Microbial contamination of multiply used preservative-free artificial tears packed in reclosable containers.
        Br J Ophthalmol. 2008; 92: 1518-1521
        • Kocaturk O.
        • Kocaturk T.
        • Kaan N.
        • et al.
        The comparison of four different methods of perioperative eye protection under general anaesthesia in prone position.
        J Clin Anal Med. 2012; 3: 163-165
        • Livingstone D.J.
        • Hanlon G.W.
        • Dyke S.
        Evaluation of an extended period of use for preserved eye drops in hospital practice.
        Br J Ophtalmol. 1998; 82: 473-475
        • Martin D.P.
        • Weingarten T.N.
        • Gunn P.W.
        • et al.
        Performance improvement system and postoperative corneal injuries.
        Anesthesiology. 2009; 111: 320-326
        • Moore C.P.
        • Heller N.
        • Majors L.J.
        • et al.
        Prevalence of ocular microorganisms in hospitalised and stabled horses.
        Am J Vet Res. 1988; 49: 773-779
        • Moos D.D.
        • Lind D.M.
        Detection and treatment of perioperative corneal abrasions.
        J Perianesth Nurs. 2006; 21: 332-338
        • Park Y.W.
        • Son W.G.
        • Jeong M.B.
        • et al.
        Evaluation of risk factors for development of corneal ulcer after nonocular surgery in dogs: 14 cases.
        J Am Vet Med Assoc. 2013; 24: 1544-1548
        • Punch P.I.
        • Costa N.D.
        • Chambers E.D.
        • et al.
        Plasma and tear concentrations of antibiotic administered parenterally to cattle.
        Res Vet Sci. 1985; 39: 179-187
        • Rahman M.Q.
        • Tejwani D.
        • Wilson J.A.
        • et al.
        Microbial contamination of preservative free eye drops in multiple application containers.
        Br J Ophthalmol. 2006; 90: 139-141
        • Roth S.
        • Thisted R.A.
        • Erickson J.P.
        • et al.
        Eye injuries after nonocular surgery. A study of 60,965 anesthetics from 1988 to 1992.
        Anesthesiology. 1996; 85: 1020-1027
        • White E.
        • Crosse M.M.
        The aetiology and prevention of peri-opertaive corneal abrasions.
        Anaesthesia. 1998; 53: 157-161
        • Whitley R.D.
        • Burgess E.C.
        • Moore C.P.
        Microbial isolates of the normal equine eye.
        Equine Vet J suppl. 1983; 2: 138-140
        • Yu H.D.
        • Chou A.H.
        • Yang M.W.
        • Chang C.J.
        An analysis of perioperative eye injuries after nonocular surgery.
        Acta Anaesthesiol Taiwan. 2010; 48: 122-129