Introduction
- Corneal disease resulting from deficiency of aqueous phase of precorneal tear film.
- Cause : secondary to systemic metabolic disease, drug induced, traumatic; auto-immune destruction of lacrimal gland; congenital; idiopathic.
- Signs : tacky discharge and conjunctival hyperemia, unresponsive to antibiotics; corneal edema; deep circular subcentral ulceration; pigmentation and vascularization as chronic change; dull, lustreless cornea; conjunctival hyperplasia and corrugation
. - Diagnosis : clinical signs, Schirmer tear test.
- Treatment : palliative medical therapy - artificial tears, prophylactic antibiotics, anti-inflammatories. Treat underlying cause if appropriate. Topical cyclosporin A stimulates tear production in the majority of cases. Surgical therapy - parotid duct transposition.
- Prognosis : may be reversible if secondary to systemic disease. Iatrogenic/auto-immune cases in susceptible breeds generally progressive, life-long treatment necessary. Loss of eye rare, with good owner compliance and monitoring.
Print off the owner factsheet Keratoconjunctivitis sicca ('Dry eye')
to give to your client.
Diagnosis
Clinical signs
- Unilateral or bilateral.
- Acute:
- Chronic:
- Ocular discharge.
- Conjunctival hyperplasia/corrugation/chemosis.
- Corneal pigmentation/vascularization/xerosis.
- Discharge typically adherent to cornea, forms ropy deposits in upper and lower conjunctival fornices
.
- Ulcer typically deep, non-vascularised, circular, subcentral .
- May progress rapidly to perforation.
- Corneal malacia possible, resulting in dehiscence, iris prolapse.
Needs emergency intensive treatment.
Diagnosis
Differential diagnosis
- Abnormalities in spreading of precorneal tear film due to contenital/acquired lid defects:
- Bacterial conjunctivitis.
- Corneal epithelial cell degeneration, keratinization, pigmentation and vascularization. Epithelial pegs form in chronic cases with plasma cells and lymphocytes in the anterior stroma.
- Lymphocytic/plasmacytic infiltration of the lacrimal gland with acute atrophy.
Sequelae
Prognosis
- Depends on etiology.
- May resolve if secondary to systemic or metabolic disease.
- If permanent, can be well controlled if adequately treated and regularly monitored.
- Post-duct transposition usually successful but eyes still need daily attention.
Not suitable for very greedy dogs or dogs producing copious saliva - overflow may result in calcium deposits on cornea/periorbital skin/hair → periorbital dermatitis.
Expected response to treatment
- Return of tear production.
- Resolution of tacky ocular discharge, conjunctival hyperemia, corneal pigmentation and vascularization.
Reasons for treatment failure
- Advise owner permanent care necessary even with successful treatment.
- Cyclosporin failure.
- Lack of saliva prevents surgical correction of KCS.
- Anatomical abnormalities resulting in lagophthalmos and permanent exposure of central cornea.
Sources
Publications
Refereed papers
- Sansom J, Barnett K C, Neuman W et al(1995) Treatment of KCS in dogs with cyclosporine ophthalmic ointment- a European clinical trial field. Vet Rec 11 , 504-507.
- Stiles J, Carmicheal P, Kaswan R et al(1995) Keratectomy for corneal pigmentation in dogs with cyclosporine responsive chronic KVS. Vet Comp Ophthal 5 , 25-34
- Morgan R V & Abrams K L (1991) Topical administration of cyclosporine for treatment of keratoconjunctivitis sicca in dogs. JAVMA 199 , 1043.
- Salisbury M A, Kaswan R L & Ward D A et al(1990) Topical application of cyclosporine in the management of keratoconjunctivitis sicca in dogs. JAAHA 26 , 269.
Other sources of information
- Gelatt K N (1999) Veterinary Ophthamology. 3rd edn. Williams & Wilkins.














