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 structureProduces ~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 corneaIncreased intraocular pressure; → Blindness Normally, the amt of fluid produced = amt of fluid leaving eyeNormal: 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 tissueProgressive, 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 healingTears 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

Normal canine retina PRA, optic nerve atropy and vesselattenuation

PROGRESSIVE RETINAL ATROPHY

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 – 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

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_eyes/

• Alleice Summers, Common Diseases of Companion Animals

• http://www.vetmed.wisc.edu/Data/CourseMaterial/Miller/Emergencies.pdf