Chronic Superficial Keratitis (Pannus)

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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)
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 healing
Tears from 2 glands: 70%--Lacrimal gland; 30%--Nictitans gland
• Signs
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–
–
–
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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
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•
•
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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
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 – hyphema
Anterior Uveitis
Anterior Uveitis – keratic precipitates
Anterior Uveitis – Treatment
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•
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•
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Topical steroids or
Topical Anti-inflmmatory drugs (ocufen)
Or systemic steroids
Atropine – dilates eye, decreases pain
Antibiotics – topically +/- systemically
Anterior Uveitis – Client Info
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•
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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
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–
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–
–
–
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/L
ab24.html
 Alleice Summers, Common Diseases of
Companion Animals
 http://www.vetmed.wisc.edu/Data/CourseM
aterial/Miller/Emergencies.pdf
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