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 4Common 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 (±) IRIDOCORNEAL ANGLE

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