Dry Eye and Related Corneal Issues Brad Graham DVM, MS, DACVO Definitions Evaluation for dry eye Dog Cat Treatment Medication Surgery Future Outline Dry Eye Syndrome (DES) Inadequate production or enhanced loss of tears When the eye is unable to maintain a healthy coating of tears Irritation, grittiness, burning, sensitivity to light 1
Keratoconjunctivitis Sicca Tear Film Anatomy Tear Film Anatomy 2
Immune mediated Types of Dry Eye Neurogenic Qualitative deficiencies Immune mediated Tissue specific, immune mediated disorder Histo varying degrees of monocellular (lymphoplasmacytic) infiltrates associated with acinar atrophy May be associated with systemic autoimmune conditions Neurogenic Nerve damage along facial nerve Ipsilateral xeromycteria Some idiopathic cases may enter spontaneous remission Unlikely to respond to immuno-modulating drugs Consider pilocarpine 3
Qualitative Deficiencies Disturbances of the meibomian glands Insufficient production of preocular mucin Genetic predispositions Gender predispositions Often idiopathic (thought to be immune-mediated) Causes in Dogs Infectious causes Canine distemper virus Chronic blepharoconjunctivitis Congenital conditions Causes in Dogs Lacrimal gland hypoplasia often unilateral, extreme dryness miniature breeds 4
Causes in Dogs Trauma, inflammatory orbital conditions, neurogenic causes, metabolic diseases (hypothyroidism, DM, Cushing s disease), ear infections, corneal inflammation and scars Causes in Dogs Drug-toxicities Sulfonamides, atropine, antihistamines, etodolac Pre-anesthetic and anesthetic agents Iatrogenic Removal of gland of the third eyelid Laser eyelid treatment Causes in cats Immune mediated component not yet identified Most commonly secondary to chronic blepharoconjunctivitis Other secondary causes similar to the dog Treat underlying cause Treat symptoms Parotid duct transposition 5
Dry Eye Evaluation Quantitative DES Quantitative tear tests Test Dog Cat STT 18.9 ± 2.62 mm/60s 16.2 ± 3.8mm/60s Quantitative DES Quantitative tear tests Test Dog Cat STT 18.9 ± 2.62 mm/60s 16.2 ± 3.8mm/60s PRT 29.3 ± 3.45 mm/15s 23.0 ± 2.2mm/15s 6
Qualitative tear tests Tear film break-up time (TFBUT) Lactoferrin Tear film meniscus height Osmolarity Qualitative DES Osmolarity Tear film osmolarity measurements using the TearLabTM osmometer in normal dogs and dogs with dry eye disease ARVO Annual Meeting Abstract April 2014Lionel Sebbag; Shin Ae Park; Philip H Kass; David J Maggs; Christopher J Murphy Treatment Dry Eye Syndrome Phase 1: artificial tears and treatment of associated conditions Artificial tears Hot compresses Lid hygiene Antibiotics Anti-inflammatories Nutrition supplements essential fatty acids 7
Dry Eye Syndrome Treatment Phase 2: additional measures to lower elevated tear osmolarity Punctal occlusion Ointments Humidifiers and moist chambers Tarsorrhaphy Treatment in Dogs Treat underlying cause Cyclosporine, tacrolimus, pilocarpine, artificial tears Severin s KCS solution (modified) (antibiotic, acetylcysteine, artificial tears) Parotid duct transposition Cyclosporine Inhibits T cell proliferation by inhibiting IL-2 transcription Compounded Oil Aqueous Optimmune Episcleral Implant 8
Tacrolimus Macrolide antibiotic immunosuppressant Similar mechanism of action as cyclosporine 0.02-0.03% 1% Pilocarpine Parasympathomimetic (muscarinic cholinergic agonist) Not many studies No detectable effect topically in normal dogs (1994) Anecdotal support for oral administration Systemic toxicities Severin s KCS Solution (modified) 0.45 cc tobramycin (40mg/ml injectable) 1.5 cc acetyl L cysteine (20% injectable) 4.5 cc artificial tear drops 9
Remend Cross-linked, modified hyaluronic acid No antibiotic, no steroid, no preservatives Artificial Tears Parotid Duct Transposition 10
Parotid Duct Transposition Doggles RexSpecs 11
Diquafosol Future Directions LipiFlow Acupuncture Episcleral implants Questions/Comments 12