Exam 1 Flashcards
Function of Eyelid
o Protect the globe
o Remove foreign debris
o Spread tear film
o Direct tears towards lacrimal puncta
o Contains glands to provide nutrition to cornea
Muscles of the Eyelid
Orbicularis oculi
Closes palpebral aperture
Levator palpebrae superioris
Elevates the upper eyelid
Blood Vessels & Ligaments of the Eyelids
Eyelid Blood Vessels
o Superficial Temporal artery
o Malar artery
o Angularis Oculi Vein (branch of facial)
Eyelid Ligaments
o Medial & lateral canthal ligament (lateral poorly defined)
Trichiasis; What, Treatment
o Hair emerging from a normal location but growing in an abnormal direction
Treatment
surgical correction may be warranted
Medial canthoplasty
Crytothermia
Electroepilation
Neonatal Opthalmia; Basics, Treatment
o Infection occurs behind the eyelids prior to natural opening of the eyelids
o prominent distension of eyelids, +/- purulent discharge
o Bacterial or viral in kittens
o bacterial in puppies
Treatment:
Gently open eyelids at medial canthus
Flush gently with sterile eyewash
BNP in dogs
terramycin or erythromycin in cats
Dermoid
o Skin and hair that develops in an abnormal location
o Referral Procedure
o Requires reconstruction of eyelid and keratectomy if cornea involved
Distichiasis; Basics, Clinical Signs
o Hair emerging at lid margin from the Meibomian Gland duct openings
o Typically emerge within first 2 years of life
o Irritating to the corneal surface
o Soft coated breeds often not an issue
Clinical Signs
Tearing
Blepharospasm
corneal ulcer formation or delayed healing of corneal ulcers
Distichiasis; Treatment
Single
* Electroepilation/ electrolysis
* Referral procedure
* Damage eyelid margin
* Must have proper equipment and magnification
Numerous
* Cryothermia
* Excessive freeze can cause necrosis of eyelid margin
* May require second treatment
Ectopic Cilia; Basics, Treatment
o Hair emerging through the palpebral conjunctiva from the meibomian glands
o Directed towards the cornea
o PAINFUL
o Usually leads to corneal ulcer formation
Treatment:
En Bloc Micro-surgical excision of cilia and hair follicles
Performed under surgical operating microscope
Electrolysis
NO steroids
Macroblepharon
o Excessive eyelid for the size of the globe
o Very common in St. Bernards, Newfoundlands, Great Danes
o Surgical correction may or may not be warranted
Spastic Entropion; Basics, Treatment
o Entropion secondary to pain
o globe is retracted and allows the eyelid margin to roll inward towards the cornea
Treatment
Apply topical anesthetic (proparacaine) and the entropion corrects itself
identify reason for pain
Puppy Entropion; Basics, Treatment
o Puppies, Foals with Maladjustment Syndrome, Lambs
Treatment
4-0 non-absorbable suture
Vertical Mattress
Close to eyelid margin
Suture away from the eyelid
Leave sutures in place for 3 weeks or until fall out
Need E-collar
Modified Hotz Celsus Entropion Correction; what is it for, how to
o For congenital entropion
How to
o Incision made approx 2-3 mm from and parallel to the eyelid margin
o Extend incision 1 mm beyond afffected area
o 6-0 silk
o remove sutures in 10 days
Ectropion – lower eyelid “droop; Clinical Signs, Treatment
Clinical Signs
Conjunctival hyperemia
Inflammation and irritation
Ocular discharge
Corneal damage
Treatment
Lid shortening
Lateral canthal ligament support
Blepharitis; Clinical Signs, Causes, Diagnosis, Treatments
Clinical Signs
Eyelid swelling, excoritaions, crusty exudate, hyperemia
Patients tend to be very pruritic and painful
Causes
Allergies (food/atopy/ staph)
Immune mediated disease
Dermatophyte infection
Parasites
Insect or spider bite
Neoplasia
Diagnosis
skin scrape
Impression smear: cytology
Fungal culture
Bacterial culture and sensitivity
Biopsy and histopathology
Response to therapy
Treatments
Treat underlying issue
Canine Vs Feline Eyelid Tumors
Canine Eyelid Tumors
o Usually benign
o Often irritating to cornea
Feline Eyelid Tumors
o Relatively uncommon compared to dogs
o Tend be be more aggressive
o Squamous Cell Carcinoma most common then mast cell tumor
Eyelid Neoplasia Treatment
o Clean Margins Required
o Can remove up to 1/3 eyelid length in dog,
o 1⁄4 in the cat
o Requires precise eyelid margin apposition
o Close SQ layer
o Close margin with figure of 8 suture pattern
Function of Lacrimal System
o Provides moisture to the ocular surface
o Maintains health of the cornea
o Provides nutrition, moisture, protection
o Tear film is a major refractive surface
o Important for corneal healing
o Flush debri
o Lubrication
Three Layers of Tear Film
Outer Layer
Produced by Meibomian gland
Oily layer
Middle Layer
Lacrimal galnds
Aqueous
Inner Layer
Goblet cells
Mucin
Glands that Produce Tears
o Lacrimal produces 65% of tears
o Gland of third eyelid produces 35%
Schirmer Tear Test
o Measures basal and reflex secretion rate
o Normal for dogs = 15-25 mm/min
o Less than 15 mm/min = keratoconjunctivitis sicca (KCS)
o Often clinical if <10mm/min
o Cats can be variable
Keratoconjunctivitis Sicca (KCS); Causes & Treatment
Immune mediated
* Lacrimal Stimulant
* Optimmune
* Tacrolimus
Secondary bacterial
* Topical antibiotic
Neurogenic
* 2% Pilocarpine orally
* One drop per 10 lbs of body weight BID
* Monitor for SE
Low Estrogen
* DES orally
Parotid Duct Transposition
Highly successful at adding moisture to the corneal surface
Can cause mineral build-up and damage the cornea
Requires chronic treatment
Use EDTA to try to bind mineral
May use Powdered buttermilk
Poor Tear Film Diagnosis
- Fluorescein stain adherence to entire cornea
- Rose Bengal stains cells when deficiency in pre-corneal tear film
Nasolacrimal Duct Obstruction DIagnosis
Flush & radiograph to look for narrowing or obstruction
Dacryop; What, Treatment
Looks like mass at medial canthus but is cyst of N-L system
Treatment
* Surgical removal of dacryop
* Very delicate surgery
* Preserve function of lacrimal duct
Prolapse Third Eyelid Gland; What, Treatment
- DO NOT REMOVE GLAND
- Surgical treatment to replace gland back into normal position
- 65-90% success rate
- Morgan Pocket Technique commonly used in general practice
- Check tear flow prior to and after surgery
Limbus
Corneal/scleral junction
Conjunctivitis; Clinical Signs, Diagnosis
Clinical Signs
Ocular discharge- serous, mucoid, mucopurulent, purulent, eosinophilic
Blepharospasm
Conjunctival Hyperemia- mild to severe
Chemosis- mild to severe
Episcleral injection (perpendicular to the limbus) - do not move w/ conjunctival tissue and do not blanch out with epinephrine (severe)
Diagnosis
Schirmer tear test FIRST
Evaluate eyelids for conformational abnormalities
Fluorscein stain (Jone’s test - stain out of nose)
Conjunctivitis; Most Common Causes Dogs, Cats, Horses, Rabbits
Dogs
* KCS
* Allergies
Cats
* Hepes FHV-1
* Chlamydia
Horses
* Trauma
* Corneal ulcer
* Uveitis
Rabbit
* Dental dz
Treatment for Allergic Conjunctivitis
If the patient shows signs of allergies you must treat these before the ocular treatment will be successful
BNP-HC
* for dogs or horses (not cats)
* broad spectrum ab & weak steroid
NPDex
* broad spectrum antibiotic and strong steroid
* use very cautiously
* Avoid in cats
* Don’t use if corneal lesion in any species
NSAIDS
* Diclofenac
* ketorolac
Antihistamines
* ketotifen
Follicular Conjunctivitis; What is it, Clinical Signs, Treatment
o Seen in dogs under 24 months age
o Immune stimulation (Possible allergies)
Clinical Signs
Mild discomfort
Ocular discharge
Responds to topical antibiotic/steroid
Recurs when treatment stops
Cobblestone appearance behind 3rd eyelid
Treatment
Start with BNP-HC or NSAID
May need NPDex if not responsive
Cyclosporin or ketotifen
Z/D diet
Ophthalmia neonatorum; What is it, Causes, Treatment
o Conjunctivitis prior to
Physiologic eyelid opening (10-14 days old)
Causes
Puppies- often staph, strep, E coli
Cats- usual FHV1, may be bacterial
Treatment:
Gently tease open the eyelids at the medial canthus enough to allow drainage
Gentle saline flushing
Adminstration of antibiotic such as terramycin or erythromycin
Layers of the Cornea
Epithelium
o 4-9 layers of epithelial cells
o protective layer coated by tear film to keep it moist and refractile
o attached to stroma by basal epithelial cells
o lipophilic = does not take up fluorescein stain
Stroma
o Bulk of corneal thickness
o Gives shape and tectonic strength to cornea
o Composed of bundles of collagen fibers
o Superficial stroma is densely Innervated (non-myelinated)
Descemet’s Membrane
o Basement membrane of corneal endothelium
o Deep to stroma
o Very fragile and easily ruptures when exposed
Endothelium
o Innermost layer of cornea
o Single cell layer
o Na-K- ATPase Pump to keep cornea dehydrated
o Endothelial cells do not regenerate (decrease with age)
How is the Cornea Transparent?
o Lack of Blood vessels, Pigment, Myelin, Lymphatics
o State of relative dehydration
o Collagen organization
What does it mea if the cornea is red or white?
Red in the Cornea
o After 1 week, if a corneal defect has not healed, vessels will advance from the limbus to help heal the defect
o Vessels advance about 1mm per day
OR
o Stromal hemorrhage
White in Cornea
o Edema
o cellular infiltrate (ex abscess)
o lipid or calcium deposition
Corneal Dehydration
o Epithelium provides barrier against tears entering stroma from surface
o Endothelium has pump to pump aqueous out of cornea & back into anterior chamber
o Loss of either = corneal edema & loss of clarity
Normal Corneal Thickness
o 500-600 microns in dogs & cats
o 1mm in horse
Most Likely Dz Corneal Edema + miotic or dilated pupil
Miotic
Uveitis
Dilated
Glaucoma
Endothelial Pump Failure; Basics, Clinical Signs
o Loss of Na pump in area of failure -> corneal edema
o Lost cells do not regenerate
o DO NOT treat w/ steroids
Clinical Signs
Diffuse edema-bluish color, mottled appearance
May develop bullae that rupture (water blisters)
Corneal Ulcer; Common Causes, Diagnosis
Common Causes
Trauma
Herpes
Chlorhexidine, alcohol, etc
KCS
Diagnosis
Schirmer tear test FIRST
Fluorescein stain
Assess depth of ulcer
Look for cause of ulcer
Is it infected (cytology) or melting?
Superficial Corneal Ulcer; Basics, Treatment
loss of full thickness epithelial cells
exposure of superficial stroma
no loss of stroma
Stroma is hydrophilic and takes up fluorescein stain
Cobalt filter enhances (excites) fluorescein
Distinct edge to ulcer
PAINFUL
Treatment
* Topical antibiotic: BNP, erythromycin or terramycin (dogs & horses)
* Terramycin or erythromycin (cats)
* Avoid ofloxacin unless needed in infected cases
* Topical atropine for pain (sparingly w/ KCS, NO w/ glaucoma)
* Tramadol (dogs
* Buprenorphine (cats, small dogs)
* Flunixin (horses)
* Avoid NSAIDS
* NO STEROIDS
What to do if Superficial Ulcer Hasn’t Healed after 7 Days
- Change diagnosis not antibiotic
- Repeat STT
- Look for missed cause
- Look for epithelial edges
Spontaneous Chronic Corneal Epithelial Defect; What is it, Treatment
Boxer or any breed over 5-6 years of age
Loose epithelial edges– Epithelium does not adhere to stroma
No stromal loss
Treatment
* Debridement to healthy attached epithelium with cotton tipped swab
* Contact lens if possible
* Pain management
* E-collar
* Doxycycline orally
* Topical antibiotic
* Atropine
* After above, do not touch for a week
Recheck Spontaneous Chronic Corneal Epithelial Defect
1-Healed
o negative stain
o keep E-collar on for 1 more week
o stop meds
2-
o Takes up stain but ulcer size smaller with
no loose edges
o treat 1 more week and recheck
3
o Has not healed or improved, or has loose edges
o Look again for underlying cause
o if not found then Please refer it or at least consult w/ an ophthalmologist
o These patients are very painful and vision and globe loss are at risk
Grid Keratotomy
o VERY painful
o unless a contact lens can be fitted, it is not recommended
o Often leads to melting and Catastrophic cornea
o Never grid stromal ulcers, infected ulcers, cats, or horses
Stromal Ulcer; Basics, Treatment
o Any ulcer depth into stroma
o not to Descemet’s membrane
Treatment
NEVER STEROIDS (=melting)
Anti-collagenase hourly
Topical antibiotics if infected (Neomycin, Polymixin, Terramycin, Ofloxacin)
Oral doxycycline or clavamox if perforated
Debride unhealthy cornea
Conjunctival graft for blood supply
Descmetocele; Diagnosis, Treatment, DO NOTs
Diagnosis
Ulcer so deep fluoresceine stain is not taken up
Aqueous may leak out
Iris can prolapse through hole
Treatment
Emergency referral
Ofloxacin
Serum
EDTA
Doxycycline
Pain management
E collar
DO NOT
Use steroids
Attempt to debride
Blue Eye; Causes, Diagnosis
Cause
Anything that causes failure of endothelial pump or corneal edema
Diagnosis
Check vision!
Check STT for KCS
Check IOP for glaucoma or uveitis
FL stain for ulcers
Recent vaccination (Adenovirus 1)
German Shepherd Pannus; Basics, Treatment
o Sub-epithelial inflammatory cell infiltrate, proliferation of blood vessels, corneal edema and pigmentation
o Non-ulcerative (generally)
o Immune mediated
o Exacerbated by UV light
o Bilateral, usually starts laterally
o Progressive if not controlled
o Affects several breeds
o DO NOT BREED
Treatment
Life-long
Topical steroids (aggressive) pred acetate 1% or NPDex
Tapered to maintain control
CYCLOSPORINE 0.2%
‘Doggles’ or RexSpecs / Avoid UV light
Oral doxycycline may be helpful Initially in severe cases
German Shepherd Pannus; Clinical Signs
Early
* blood vessels
* cellular infiltrate and pigment
* negative fluorescein stain
Active
* Corneal vasculization
* Edema
* Inflammatory cells & pigment
* 3rd eyelid plasmoma
Controlled
* Pigment persists
* regression of blood vessels, edema and cellular infiltrate
Pigmentary Keratitis; Signalment, Causes, Treatment
o Common in brachycephalic breeds (PUGS)
Causes
Result of chronic irritation to the cornea
Exophthalmos
Lagophthalmos
Exposure keratitis
distichia, ectopics
Medial entropion with trichiasis
KCS or poor tear film health
Treatment
Cyclosporine or tacrilimuhelps with tear production, tear film quality and reduction of corneal pigmentation
Eliminate cause
Interven before pigment causes vision loss
NO STEROIDS
Corneal Subepithelial Dystrophy; Basics, Treatment
o Hereditary, non-painful, typically non-progressive
o Cholesterol-lipid deposits
Treatment
Feed LOW FAT DIET (< 10% total fat)
Check thyroid
Uveal Cysts; Basics, Iris Cysts, Corpora Niga Cysts
o perfectly round, transilluminates
o May be attached to iris or lens or be free floating
Iris Cysts
Transilluminate
Incidental findings in cats, horses and most dogs
Not incidental in golden retrievers, great danes, Bulldogs
Corpora Nigra Cysts
Might affect vision
If treatment needed, diode laser ablation of aspiration
Pigmentary Uveitis of Golden Retrievers; Features, Early Clinical Signs, Treatment
Features
Numerous cysts fill the eye
Pigment dispersion
Entropion uvea
Posterior synechia
Cataracts
Glaucoma
Blind
Early Clinical Signs
Iris pigmentation & cysts
Minimal to no inflammation or pain
Treatment
Refer early
Topical NSAID once daily
Monitor IOPs every 3 months
When IOP > 20 mmHg start dorzolamide/timolol
ENUCLEATE blind/painful eyes
Iris Sphincter Degeneration
o Normal iris shape/architecture is lost
o Can be seen just at sphincter muscle or out in stroma
o Also called iris atrophy
o Differential for visual but dilated eye
Uveitis; Clinical Signs
Clinical Signs
Miosis (sometimes mydriasis in cats)
Enophthalmos
Blepharospasm
Epiphora
Conjunctival hyperemia
Photophobia
Hypotony
Keratitic Precipitates
FLARE
Decreased IOP
Flare; Basics & Types
Definition of uveitis
proteins within the anterior chamber
Need a dark room and very thin beam of light to see it!
Types
* Proteinaceous (classic flare)
* Lipemic (fat cells)
* Hyphema (red blood cells)
* Fibrinous or hypopyon (white blood cells +/- fibrin)
Traumatic Uveitis; Treatment
- NO steroids
- Oral NSAIDs much safer than topical NSAIDs
- Atropine (if IOP is ok) can stabilize blood/eye barrier
- Topical antibiotics
- +/- topical NSAIDs
Lens Induced Uveitis
Juvenile & diabetic Cataracts (severe uveitis)
Other cataracts
Luxated or subluxated lenses
Ruptured lenses
Corneal Ulcers and Reflex Uveitis ; Basics & Effects per Species
Corneal ulceration can result in reflex uveitis
Treating the ulcer should resolve the uveitis
Adding in oral NSAIDs can help
Species
* Severe in horses & rabbits
* Moderate in dogs
* Mild in cats
Intraocular Tumors
Uveal melanoma
* Most uveal melanoma tumors (90%) in the dog are benign
* Very destructive to the eye (high IOP, hyphema) -Enucleation with histopathology is recommended
Ciliary body adenoma/adenocarcinoma
* Focal red “fluffy” mass
* Locally destructive to the eye, enucleation is considered curative
Metastaic tumors
* Uncommon but possible
* Always discuss pre-op imaging
* If eye is removed, send for histo
Hyphema; Causes, Treatment
Causes
Retinal detachment
Inflammation
Tumors
trauma
Coagulopathy
Hypertension
Metastatic neoplasia
Treatment
Check blood pressure!
Lab work!
Physical exam!
Address underlying cause
Amlodipine for BP
Topical pred acetate or Dex If FL stain neg
+/- Atropine
No NSAIDs (Will worsen bleed)
Lipemic Uveitis; Signalment, Causes, Treatment
o Mini Schnauzers and Yorkies predisposed
Causes
Systemic hypertriglyceridemia
+/- Diabetes
+/- Cushings
+/- Hypothyroidism
Treatment
Basic uveitis treatment
low fat diet,
IM work up
Infectious Causes of Uveitis in Rabbits
o Pasturella
o Staph
o E Cuniculi
Immune Mediated Uveitis
o Must rule out other causes
o Typically lymphocytic/plasmacytic; but can be histiocytic
o LIFELONG medications are needed
o Must get patients into remission and then taper medications
o Referral often indicated
Uveodermatologic Syndrome
o A form of immune mediated uveitis, but specifically attacks melanocytes
o Akitas, Aussies, Dachshunds, Alaskan breeds
o 80% of cases start in the eyes, then go to skin
o GUARDED prognosis,
o progression to glaucoma, loss of vision and skin issues is very common
o Diagnosis on histopathology (iris, skin biopsies)
Treatment for Uveitis
Prednisolone acetate 1%
for DOGS
Penetrates cornea well,
DO NOT USE with CORNEAL DISEASE (ulcers, dystrophy, etc)
Diclofenac
Topical NSAID,
penetrates cornea well
Not quite as potent as pred acetate; but safer for cornea
Use this in cats!
Oral doxycycline (all tick borne dz)
Oral anti-inflammatories
Carprofen usually safest UNLESS kidney/liver issues OR retinal detachment
Prednisone- usually start at 1 mg/kg/day (typically safe with infectious diseases)
Atropine if no glaucoma, ocular hypertension or KCS
Clindamycin
toxoplasmosis or severe oral disease
Clavamox
uveitis related to oral disease or systemic UTI, sepsis, etc
topical antbiotic if worried about corneal dz
fluoroquinolones, cefazolin, chloramphenicol
Complications of Prednisolone Acetate
Dogs
Corneal dystrophy
Cats
Herpatic corneal ulcers
Horses
Fungal corneal ulcers
Exotics
Systemic absorption
Panophthalmitis; Basics, Treatment
o All ocular tissues are affected (uvea AND orbit, cornea, etc.)
o high normal intraocular pressure
o Often seen with dog bite wounds (bit in the eye)
Treatment
MUST confirm if globe is intact – referral for ocular ultrasound
IF globe has scleral wall rupture = enucleation
IF globe is intact = medical therapy (but poor prognosis for vision)
5 Retinal Types
Holangiotic: Canine
Vessels arcuate over optic nerve
Nerve has MYELIN (variations in shape)
Retina is related to coat color!
Holangiotic: Feline
Large tapetum
Nerve is NOT myelinated
Vessels do not cross nerve head
Parangiotic: Equine
Retinal capillaries surround optic nerve head
Limited blood supply -> necrotic w/in 45-60 mins
LOTS of variation based on coat color
Optic nerve is elliptical
Merangiotic
Rabbits
Must get below them to see
Anangiotic
Birds & other exotics
NO vessels
Anatomy of a Basic Mammalian Retina
10 total layers
o Inner layer
Made of ganglion cells (form ONH)
Outer layer
photoreceptors
rods – night vision & motion
cones – day vision & acuity
MOST outer layer
Retinal Pigment Epithelium
The RPE is either pigmented or non-pigmented
This layer does NOT detach in a retinal detachment
Lots of genetic (HUMAN & ANIMAL) diseases affect this layer
Collie Eye
o Merle ocular dysgenesis
o Seen in herding dogs
o Choroidal hypoplasia
o Optic nerve colobomas
o Retinal detachments
o Hemorrhage
Optic Nerve Hypoplasia
o Unilateral blindness
o Genetic
o Do not breed
Progressive Retinal Atrophy; Basics & Clinical Issues
o Hereditary
o Night blindness progressing to total blindness
o Bilaterally symmetrical
Clinical Issues
Dilated pupils
Vascular attenuation
hyperreflective tapetum
Secondary cataracts that are not surgical
Sudden Acquired Retinal Degeneration Syndrome (SARDS); Signalment, Clinical Signs, Diagnosis, Treatment
Signalment
Middle aged dogs
Females overrepresented
Clinical Signs
ACUTE loss of vision (days to weeks)
Dilated pupils (sluggish but PLR +)
Weight gain,
PU/PD,
polyphagia
Lab work resembles adrenal disease
Diagnosis
ERG is flat
Treatment
None
Deal w/ blindness
Optic Neuritis; Basics, Clinical Signs, Treatment
o Inflammation of optic nerve
o Hyperemia
o blindness
Clinical Signs
Acute loss of vision
dilated pupils (slow or no response)
Optic nerve changes
Treatment
Emergency
Prednisone
oral antibiotics
+/- oral antifungals
Retinal Detachment; Rhegmatogenous
- Giant retinal tear
- Surgery for treatment
Retinal Detachment Non-Rhegmatogenous, Basics, Diagnosis, Treatment
- Fluid accumulates beneath the retina (often from choroid) and “pushes” retina off of the RPE
Diagnosis
o Refer
OR
o CBC/Chemistry/UA
o BLOOD PRESSURE (Doppler preferred)
o Thoracic radiographs
o Abdominal ultrasound
o Infectious disease testing
o Ocular ultrasound (difficult)
Treatment
o Treat underlying cause
o Control BP
o Oral doxycycline for tick borne dz
o Steroids if you don’t have diagnosis but CAREFULLY
o Retina can re-attach & vision can restore
Acute Blindness in cats
o USUALLY hypertensive retinopathy
o Due to CKD, hyperthyroid, cardiovascular dz
o Treat underlying dz
o Amlodipine & increase every wk until BP controlled
Chorioretinitis; Diagnosis, Treatment
Diagnosis
CBC/Chemistry/UA
Thoracic radiographs & abdominal ultrasound
Infectious disease testing
Treatment
treat underlying cause!
doxycycline,
Oral steroids (anti-inflammatory doses and with caution!)
Toxic Retinal Injury
Ivermectin toxicity
* Acute blindness +/- other neuro signs
* Central blindness may be reversed
* May or may not have retinal lesions
Enrofloxacin (Baytril)
Acute loss of vision in cats
Older cats
Renal/hepatic impairment
IV admin
Chlamydia in Cats; Clinical SIgns, Diagnosis, Treatment
o C. felis
Clinical Signs
Highly contagious
Mild-severe unilateral-bilateral conjunctivitis
NO corneal involvement
Diagnosis
Epithelial cell, intracytoplasmic inclusion bodies seen on cytology
Treatment
topical Terramycin or erythromycin
systemic doxycycline
Bartonella in Cats; Clinical SIgns, Diagnosis, Treatment
Clinical Signs
Conjunctivitis
Uveitis
`no corneal involvement
Diagnosis
Serology
Treatment
Doxycycline 3-6wks
Calici Virus in Cats; Clinical Signs, Treatment
Clinical Signs
Conjunctivitis w/ concurrent URI
Ulcers on tongue
NO corneal involvement
Treatment
Symptomatic for respiratory dz
Topical terramycin or erythromycin for conjunctivitis
Mycoplasma Felis; Basics, Clinical Signs, Treatment
Normal bacterial inhabitant of conjunctiva that may see on conjunctival cytology
Clinical Signs
Possible cause of conjunctivitis
No corneal involvement
Treatment
* Topical terramycin
FHV-1; Clinical SIgns, Diagnosis, Treatment
o Most common cause of conjunctivitis
Clinical Signs
URI followed by ocular issues
Brown waxy exudate
Serous or purulent discharge
May have keratitis
Diagnosis
Rule out other causes of conjunctivitis
Treatment
Intranasal FVRC vaccine can prevent ocular involvement
Lysine interferes w/ viral replication
Topical terramycin or erythromycin for secondary bacteria
Oral doxycycline for co-infection w/ Calici
Avoid stress
Feline Herpes Keratits; Clinical Signs, Diagnosis, Treatment
Clinical Signs
Initial infections with respiratory signs
Corneal ulcers
nasal ulcers
oral ulcers
Any age onset
Diagnosis
Dendritic or punctate ulcers in central cornea
Can progress to geographic ulcers & perforation
Treatment
Lysine
Terramycin or erythromycin
Doxycycline
Oral famciclovir
Intranasal FVRC Vx
Feline Eosinophilic Keratitis; Diagnosis, Treatment
o Due to chronic FHV-1
Diagnosis
Raised white plaques
Cytology w/ at least 1 eosinophil
Neutrophils
+/- corneal ulcer
Treatment
Difficult
Cyclosporin or tacrolimus
Mast cell blocker
Terramycin
Topical megestrol
Corneal Sequestrum; Basics & Treatment
o Dead corneal tissue
o Black/dark brown “seed-like” appearance
Treatment
Keratectomy & conjunctival graft (preferred)
Long-term antivirals (painful)
Feline Uveitis; Agents, Diagnosis, Secondary Effects, Treatment
Agents
FelV
FIV
FIP (young cats)
FHV-1
Toxo
Bartonella
Mycosis
Diagnosis
Ocular exam
CBC/Chem
FeLV / FIV / FIP serology
Toxo Titers IgG & IgM Bartonella
Fungal screen if suspicious
If all else (-), maybe herpes maybe bartonella maybe immune mediated
Secondary Effects
Cataract
Lens luxation
Glaucoma
Treatment
Topical NSAID (or pred if sure there is no ulcer)
Systemic pred w/ caution
Atropine ointment
Systemic antibiotic if needed
Feline Glaucoma; Secondary to? Treatment
Usually secondary to:
uveitis,
lens lux,
neoplasia,
trauma,
senile change
aqueous misdirection
Treatment
Dorzolamide/timolol
Removal of lens for aqueous misdirection
Feline Retinal Degeneration
o Enrofloxacin
o Taurine deficiency
o Hereditary PRA
o Trauma
Feline Hypertensive Retinopathy; Clinical Signs, Treatment
Clinical Signs
Acute blindness
Retinal detachment,
serous or hemorrhagic
BP>190mmHg usually
Treatment
Drop BP with amlodipine
Identify and treat primary cause
Lens; Functions & Anatomy
Function
o Focuses light on retina
o Allows for acute vision
o Animals have reduced accommodation of lens
Anatomy
o Located w/in a lens capsule (anterior much thicker than posterior)
o Lens proteins secured form body by capsule
o Suspended by zonular ligaments from ciliary epithelium
o 65% water & 34% protein (high protein than any tissue in body)
Normal Aging of the Lens
o Continues to grow ->
o compacting of the lens nucleus ->
o Biochemical changes to the lens proteins ->
o increase in reflection of light to the nucleus ->
o Hazy lens ->
o light being scattered not blocked ->
o nuclear sclerosis ->
o Able to see thru lens but vision impaired in low light
o NOT cataract
Lens Luxation; Clinical Signs, Treatment
Clinical Signs
Causes damage to corneal endothelial cells
Chronic uveitis
Pain
Increased risk of glaucoma
Treatment
Removal of lens
Open sky procedure
Cataract Formation; Pathophysiology & Diabetic Pathophysiology
Pathophysiology
clarity is dependent upon minimal intercellular water and tight packing of lens fibers
change = cloudiness
Diabetic Pathophysiology
* Increase in glucose in AH is also manifested in the lens ->
* Overloads glycolysis and hexokinase pathway ->
* Shunted towards sorbitol pathway ->
* Enzyme aldose reductase ->
* Polyols form & stay in lens ->
* create osmotic gradient and pull water into the lens ->
* Lens fibers swell and rupture ->
* vacuoles form ->
* cataract
Diabetic Cataracts; Basics, Complications
o Glucose regulation does not eliminate risk of cataract formation
o Vision can be lost in days or weeks
o Large fluctuations in glucose can speed cataract development and increase risk of uveitis
o Certain breeds at greater risk
Complications
Blindness
Lens induced uveitis/synechia formation
Glaucoma
Lens Capsule rupture
Diabetic Retinopathy
Diabetic Cataracts; Treatment
Medical
* Topical/systemic anti-inflammatories, Diclofenac
* Kinostat (aldose reductase inhibitor) for prevention
Surgical
* Phacoemulsifiction (ideal)
* Lens removal
Lens Induced /phagolytic Uveitis
“leakage” of lens proteins across lens capsule ->
Lens proteins recognized as foreign ->
Stimulates inflammation ->
Acute: decrease in IOP
Chronic: elevated IOP/ glaucoma & PIFM formation
Risk of synechia formation
Risk of glaucoma
Can be an ocular emergency
Ongoing concern as long as lens is cataractous
Treat prophylactically once cataract appears
Lens Capsule Rupture
Rapid cataract formation ->
rapid swelling of lens ->
lens capsule rupture
Phacoemulsification; Basics, Pre-exam, Complications
o Restores vision
o Pain free
o Topical NSAIDs 2x weekly for life
Pre-exam
Ophthalmic exam
ERG
ultrasound
Complications
Glaucoma
Retinal Detachment
Capsular Scars
Lens Regrowth
Mature Cataract or No?
If you can see any tapetum, it isn’t mature
Glaucoma; Pathophysiology
o Obstruction of aqueous outflow ->
o Increased IOP ->
o Loss of ganglion cells, axoplasmic flow, optic nerve atrophy = glaucoma ->
o Vision loss
IOP & Vision Loss
o Normal IOP in dogs = 12-22mmHg
o IOP > 30 mmHg -> loss of 10% of optic nerve axons
o IOP > 40 mmHg results in loss of 100%
o Complete loss with non repairable damage can occur within 24-48 hrs
Primary Glaucoma; Basics, Diagnosis
o Problem with development of drainage angle within the eye
o Suspected Hereditary component in some breeds
o When one eye develops glaucoma, the second eye will typically go blind ~ 6mo
o Problem is often not detected until both eyes are affected
Diagnosis
gonioscopy
Secondary Glaucoma Due to Uveitis
o Pre iridial fibrovascular membrane (PIFM) formation
o Blocks drainage angle
o Results in elevated IOP
o Chronic can result in phthisis bulbi
Feline Ocular Melanoma Treatment
o Diode laser or iridectomy if small
o Enucleation & histo if diffuse
Aqueous Misdirection Syndrome; Pathophysiology, Clinical Signs, Treatment
Pathophysiology
Misdirection of the aqueous into the vitreal body ->
increased vitreal pressure ->
anterior displacement of the lens ->
Shallow anterior chamber
Clinical Signs:
Mydriasis
Vision loss
Glaucoma
Treatment:
Lensectomy
Medical management
Acute Vs Chronic Glaucoma Clinical Signs
Acute
Ocular pain
Scleral Injection
Corneal Edema
Considered Ocular Emergency
Chronic
Striae
Buphthalmia
Exposure keratitis
Secondary corneal ulcers
Phthisis bulbi
Dilated pupil absent PLR
No menace or dazzle
Pain
Not an emergency
Short-term Glaucoma Treatment
IOP 27-40mmHg
Dorzolamide, Brinzolamide, or Methazolamide
Timolol (beta blocker)
Cosopt (Dorzolamide + timolol)
Re-measure IOP in 1 hr
IOP 40-55mmHg
Cosopt topically
Mannitol 5-7ml/lb IV over 30 mins
Re-measure IOP in 1hr
IOP 55-80mmHg
Cosopt
Mannitol
Latanoprost (do not use in uveitis cases)
Referral
Long-term Glaucoma Treatment for visual & blind/painful eyes
Visual Eyes
o Medical therapy often ineffective
o Trans Scleral Cyclophotocoagulation/Endolaser
o Diode Laser Micropulse Therapy (trial phase)
o Aqueous humor shunts (Ahmed valve)
Blind, Painful Eye
o Enucleation
o Evisceration w/ intrascleral prosthesis (not for intraocular tumor, corneal disease, or cats)
o Chemical cycloablation (not for cats, may cause tumors)
o Diode Laser Treatment
