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LIVE IN THE MOMENT! “The secret of health for both mind and body is not to mourn for the past, not to worry about the future, or not to anticipate troubles, but to live in the present moment wisely and earnestly.” -Buddha Ophthalmic Diseases Chapter 4 Common Diseases of Companion Animals Ophthalmic Diseases Conjunctivitis • CONJUNCTIVA: pink tissue that lines the inner surface of the eyelids and covers the front portion of the eyeball except for the cornea • Causes – Allergy (atopy) – Anatomic (ectropion, entropion) – Bacterial infection (predisposed by): • • • • Injury ↓Tear production Foreign body Respiratory disease (bacteria, virus) • Causes (in cats it is usually infectious) – – – – Feline herpes virus (most common cause of bilateral conjunctivitis) Calicivirus Chlamydia psittaci bacteria Mycoplasma Red, congested/swollen, painful Conjunctivitis • Signs – Redness – Chemosis (swelling of conjunctiva) – Ocular discharge (tears, mucus) • Diagnosis – Determine 1º disease, if any – Rule out FB – Rule out ‘dry eye’ in recurrent cases • Schirmer tear test – 1 min- tears show as blue dye SCHIRMER TEAR TEST Cats: 11-23mm Conjunctivitis • Rx – Topical antibiotic ointment • neomycin/bacitracin/polymyxin B(BNP or triple antibiotic) • Gentamicin ophthalmic ointment • Antibiotic w/ cortisone (if cornea is intact) • Client info – – – – – Do not allow dogs to ride with head out window Keep medial canthus of eye clean (warm water, clip hair) Vaccinate kittens to prevent URI Do not touch eye with applicator Discard unused medication Epiphora • EPIPHORA: excessive tearing • Causes (2 causes) – Overproduction of tears • Ocular pain, irritation (from hair, etc) – Faulty drainage by lacrimal system • Blockage of duct (swelling, inflam) • Blockage of puncta (hair, debris) • Imperforate puncta (no opening) – Cockers – Poodles • Trauma Epiphora • Signs – Watering of eye – Discoloration of hair • Dx – Fluorescein dye test • Dye at nose shows duct is open • Rx – Treat 1º cause • • • • Flush lacrimal ducts Surgically open imperforate puncta Topical antibiotic ointment Keep hair trimmed around eyes – May act as a wick • Client info – Staining due to pigment in tears, not blood – Some dogs have life-long problem EPIPHORA FLUSHING THE NASOLACRIMAL DUCT Entropion: eyelids that roll in against the cornea • Causes – Congenital • large orbits w/ deep-set eyes (poor lid support) – Collies, G. Dane, I. Set, Dobe, G. Ret, Rott, Weim • Poor ocular muscle development – Chesapeake, Labs, Chow, Samoyed – Trauma → scarring with distortion of lid – 2º to painful corneal lesion, conjunctiva inflammation (most common cause in cats) • Signs – – – – – – Epiphora (tearing) Chemosis (swelling of conjunctiva) Conjunctivitis Pain Corneal ulceration (±) Photophobia Entropion • Treatment – Surgical correction is treatment of choice • Temporary mattress suture to evert eye (young animal) • Lateral canthoplasty (to shorten eye lid) • Hotz-Celsus: Remove elliptical piece of tissue from under eye Ectropion • Causes – Congenital • Bassets, Blood, C Span, E Bull, St Bern • Signs – – – – Conjunctivitis Epiphora Keratitis (corneal inflammation/scarring), usually from exposure Purulent exudate • Rx – Surgery to shorten eye lid – Other procedures Hypertrophy and Prolapse of 3rd eyelid gland Hypertrophy and Prolapse of Nictitans Gland (Cherry Eye) Nictitating membrane is the 3rd eyelid; is a protective structure Produces ~30% of tears • Cause is unknown – Bassets, Beagle, Bos. Terr, C. Span • Signs – Young dog (<2 y) – Epiphora – Usually no pain • Dx – r/o tumor in older dogs and cats • Rx – Sx to remove gland is an option , but not recommended – Suture back in place Glaucoma Aqueous humor provides nourishment to lens and cornea Increased intraocular pressure; → Blindness Normally, the amt of fluid produced = amt of fluid leaving eye Normal: Dog/Cat—12-22 mm Hg • Causes – Inherited (C Span, Basset, Chow) – Secondary—obstruction of drainage angle • • • • Neoplasia Luxation of lens Hemorrhage Uveitis (ciliary body, iris, choroid) • Signs – – – – – Ocular pain Episcleral injection Corneal edema Dilated pupil (unresponsive to light) Blind (±) Glaucoma • Dx – IOP>30 mm Hg • Rx – Acute (this is an emergency; prevent blindness) • Latanoprost (Xalatan 0.005%) – Facilitates aqueous outflow • Dichlorphenamide (Daranide) – Decreases aqueous production • Surgical – Cryosurgery or laser (destroys part of ciliary body) » Decreases aqueous production – Chronic • Enucleation to relieve pain Schiotz Tonometer Tono-Pen Ulcerative Keratitis (Corneal Ulcers) Ulcers usually heal within a few days • Causes – – – – – – Trauma Chemical burns Foreign objects KCS (Keratoconjunctivitis Sicca) Conformational abnormalities Herpes virus (cats) • Signs – – – – Pain Epiphora Blepharospasm (eyelid spasm) Hyperemia of conjunctiva • Dx—Fluorescein dye to cornea Herpes virus Ulcerative Keratitis (Corneal Ulcers) • Rx – Topical atropine (1%) ointment (Debate over benefits and how long to use) • Decrease pain, blepharospasm – Topical broad-spectrum antibiotic ointment – Viral ointments or solutions (Viroptic for cats with herpes virus) – Surgery • Eyelid flap, conjunctival flap – Serum (autologous) • Blocks proteases released from leukocytes and bacteria (helps prevent continued collagen loss) – keep in refrigerator (throw out after 72 hours) Deep Corneal Ulcer • Desmetocele – erosion to membrane Ulcerative Keratitis (Corneal Ulcers) • Client info – – – – Most ulcers heal quickly with treatment Avoid using old medications Rx with cortisone will inhibit healing of ulcer Do not touch eye with ointment applicator Chronic Superficial Keratitis (Pannus) Pannus—superficial corneal vascularization/scar tissue Progressive, bilateral, can result in blindness • Cause – Thought to be immune-mediated (Infiltration of cornea with lymphocytes, plasma cells) – Increased ultraviolet light/high altitudes increases incidence • Signs – Opaque lesions that begin at limbus and extend into cornea • Milky, pink, or tan Chronic Superficial Keratitis (Pannus) Chronic Superficial Keratitis (Pannus) • Breeds – Ger. Shep, B. Collie, greyhound, Sib. Husky • Dx – r/o KCS, corneal ulcers • Rx – Corticosteroids often lifelong – Cyclosporine often lifelong – Antibiotic eye ointment • Client info – No cure – If Rx is stopped, disease will return and progress – High altitudes and ↑sun predispose animals DOGGLES!!!! Keratoconjunctivitis Sicca (KCS) Lack of tear production; tears lubricate, nourish, ↓bacteria, aid in healing Tears from 2 glands: 70%--Lacrimal gland; 30%--Nictitans gland • Signs – – – – – Recurrent conjunctivitis, corneal ulcers, keratitis Dull, dry, irregular cornea, conjunctiva Tenacious, mucoid ocular discharge Blepharospasm Crusty nares • Rx – Tear stimulation—cyclosporine, pilocarpine – Artificial tears • Client info – Px is guarded for resolution – Failure to treat → blindness KCS Cataracts Opacity of lens that causes reduced vision; most common disease of lens • Cause – Genetic – 2º to: • Diabetes mellitus (bilat; within 1 y of disease; ↑glucose → ↑fluid in lens) – Most common cause • • • • • • Trauma (unilateral; HBC, thorn penetration, shotgun pellet) Lens luxation Nutritional deficiency Uveitis Hypocalcemia Electrical shock • Rx – Surgical removal of lens – Treat underlying cause (e.g., Diabetes) • Client info – Most cataracts are inherited, so don’t breed affected dogs – Dogs can live quality lives even with bilat. cataracts Cataracts • Signs – Progressive loss of vision – Opaque pupillary opening • Dx – Must be distinguished from senile nuclear sclerosis • Normal old age change; graying of lens; bilat; usually does not affect sight CATARACTS Progressive Retinal Atrophy • A group of hereditary disorders causing loss of rods, cones, and/or blood supply – Breeds • Toy/min. Poodle, G. Ret, I. Set, C. Span, Schnauzer, Collie, Samoyed, N. Elkhound • Recessive gene isolated in some breeds • Signs—slow onset of blindness – Loss of night vision (rods) → loss of day vision (cones) → cataracts (±) • Dx – r/o metabolic disorders that could cause cataracts – Ophth exam • gray, granular appearance of retina • Hyperreflective retina • Vascular attenuation, optic nerve atrophy PROGRESSIVE RETINAL ATROPHY Normal canine retina PRA, optic nerve atropy and vessel attenuation Progressive Retinal Atrophy • Rx – None • Client info – This is an inherited disease – Avoid buying affected breeds • Have ophth exam by board certified ophth to r/o PRA – Blind animals adapt well • Have trouble in strange surroundings – Cats need well balanced diet • Taurine deficiency can lead to PRA Anterior Uveitis • Inflammation of uvea: ciliary body, iris, choroid • Causes – Inflammation/infection – FeLV/FIP, fungal, bacterial – Neoplasia – Trauma Uveitis – Clinical Signs • • • • • • • • Blepharospasm Aqueous flare – increased turbidity of aqueous humor Miosis of affected eye Iridal swelling or congestion Keratic precipitates Ciliary flush in limbal region +/- Corneal edema +/- hyphema Anterior Uveitis – hyphema Anterior Uveitis Anterior Uveitis – keratic precipitates Anterior Uveitis – Treatment • • • • • Topical steroids or Topical Anti-inflmmatory drugs (ocufen) Or systemic steroids Atropine – dilates eye, decreases pain Antibiotics – topically +/- systemically Anterior Uveitis – Client Info • • • • Recheck within 3 days Secondary glaucoma is frequent complication Prognosis depends on cause Treat for 2 months regardless of cause – bloodaqueous barrier disrupted for 6 weeks Proptosed Globe • Cause – Trauma – Conformation – Retrobulbar abscess or neoplasia • Clinical Signs – Protrusion of the globe, – Eyelids unable to close, may be trapped behind globe Prognosis • Favorable – brachycephalic dog, – positive direct or consensual pupillary light response – normal findings on posterior segment exam – proptosed eye with vision on initial presentation • Unfavorable indicators – – – – – – non-brachycephalic cat breed hyphema, no visible pupil facial fractures optic nerve damage and avulsion of 3 or more extraocular muscles Proptosed Globe Proptosed Globe – Treatment • Lubricate immediately • Reduce the globe into the socket ASAP to reduce trauma to optic nerve • Enucleation if optic nerve severed • Systemic and topical antibitics • +/- Steroids Proptosed Globe References • http://www.vetmed.ucdavis.edu/courses/vet_ey es/ • Alleice Summers, Common Diseases of Companion Animals • http://www.vetmed.wisc.edu/Data/CourseMate rial/Miller/Emergencies.pdf