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/

http://vanat.cvm.umn.edu/carnLabs/Lab24/Lab24.html

Alleice Summers, Common Diseases of Companion Animals

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