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):
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Injury
↓Tear production
Foreign body
Respiratory disease (bacteria, virus)
• Causes (in cats it is usually infectious)
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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
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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
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Causes
– Inherited (C Span, Basset, Chow)
– Secondary—obstruction of drainage angle
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Neoplasia
Luxation of lens
Hemorrhage
Uveitis (ciliary body,
iris, choroid)
Signs
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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
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Trauma
Chemical burns
Foreign objects
KCS (Keratoconjunctivitis Sicca)
Conformational abnormalities
Herpes virus (cats)
• Signs
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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