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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
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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
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
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 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) • 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
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
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
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 – 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 – blood-aqueous 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