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Opthamology > Exam 1 > Flashcards

Exam 1 Flashcards

1
Q

Function of Eyelid

A

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

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2
Q

Muscles of the Eyelid

A

Orbicularis oculi
 Closes palpebral aperture

Levator palpebrae superioris
 Elevates the upper eyelid

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3
Q

Blood Vessels & Ligaments of the Eyelids

A

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)

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4
Q

Trichiasis; What, Treatment

A

o Hair emerging from a normal location but growing in an abnormal direction

Treatment
 surgical correction may be warranted
 Medial canthoplasty
 Crytothermia
 Electroepilation

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5
Q

Neonatal Opthalmia; Basics, Treatment

A

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

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6
Q

Dermoid

A

o Skin and hair that develops in an abnormal location
o Referral Procedure
o Requires reconstruction of eyelid and keratectomy if cornea involved

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7
Q

Distichiasis; Basics, Clinical Signs

A

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

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8
Q

Distichiasis; Treatment

A

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

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9
Q

Ectopic Cilia; Basics, Treatment

A

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

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10
Q

Macroblepharon

A

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

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11
Q

Spastic Entropion; Basics, Treatment

A

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

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12
Q

Puppy Entropion; Basics, Treatment

A

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

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13
Q

Modified Hotz Celsus Entropion Correction; what is it for, how to

A

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

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14
Q

Ectropion – lower eyelid “droop; Clinical Signs, Treatment

A

Clinical Signs
 Conjunctival hyperemia
 Inflammation and irritation
 Ocular discharge
 Corneal damage

Treatment
 Lid shortening
 Lateral canthal ligament support

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15
Q

Blepharitis; Clinical Signs, Causes, Diagnosis, Treatments

A

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

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16
Q

Canine Vs Feline Eyelid Tumors

A

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

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17
Q

Eyelid Neoplasia Treatment

A

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

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18
Q

Function of Lacrimal System

A

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

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19
Q

Three Layers of Tear Film

A

Outer Layer
 Produced by Meibomian gland
 Oily layer

Middle Layer
 Lacrimal galnds
 Aqueous

Inner Layer
 Goblet cells
 Mucin

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20
Q

Glands that Produce Tears

A

o Lacrimal produces 65% of tears
o Gland of third eyelid produces 35%

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21
Q

Schirmer Tear Test

A

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

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22
Q

Keratoconjunctivitis Sicca (KCS); Causes & Treatment

A

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

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23
Q

Parotid Duct Transposition

A

 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

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24
Q

Poor Tear Film Diagnosis

A
  • Fluorescein stain adherence to entire cornea
  • Rose Bengal stains cells when deficiency in pre-corneal tear film
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25
Q

Nasolacrimal Duct Obstruction DIagnosis

A

Flush & radiograph to look for narrowing or obstruction

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26
Q

Dacryop; What, Treatment

A

 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

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27
Q

Prolapse Third Eyelid Gland; What, Treatment

A
  • 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
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28
Q

Limbus

A

Corneal/scleral junction

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29
Q

Conjunctivitis; Clinical Signs, Diagnosis

A

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)

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30
Q

Conjunctivitis; Most Common Causes Dogs, Cats, Horses, Rabbits

A

Dogs
* KCS
* Allergies

Cats
* Hepes FHV-1
* Chlamydia

Horses
* Trauma
* Corneal ulcer
* Uveitis

Rabbit
* Dental dz

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31
Q

Treatment for Allergic Conjunctivitis

A

 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

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32
Q

Follicular Conjunctivitis; What is it, Clinical Signs, Treatment

A

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

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33
Q

Ophthalmia neonatorum; What is it, Causes, Treatment

A

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

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34
Q

Layers of the Cornea

A

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)

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35
Q

How is the Cornea Transparent?

A

o Lack of Blood vessels, Pigment, Myelin, Lymphatics
o State of relative dehydration
o Collagen organization

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36
Q

What does it mea if the cornea is red or white?

A

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

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37
Q

Corneal Dehydration

A

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

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38
Q

Normal Corneal Thickness

A

o 500-600 microns in dogs & cats
o 1mm in horse

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39
Q

Most Likely Dz Corneal Edema + miotic or dilated pupil

A

Miotic
 Uveitis

Dilated
 Glaucoma

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40
Q

Endothelial Pump Failure; Basics, Clinical Signs

A

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)

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41
Q

Corneal Ulcer; Common Causes, Diagnosis

A

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?

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42
Q

Superficial Corneal Ulcer; Basics, Treatment

A

 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

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43
Q

What to do if Superficial Ulcer Hasn’t Healed after 7 Days

A
  • Change diagnosis not antibiotic
  • Repeat STT
  • Look for missed cause
  • Look for epithelial edges
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44
Q

Spontaneous Chronic Corneal Epithelial Defect; What is it, Treatment

A

 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

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45
Q

Recheck Spontaneous Chronic Corneal Epithelial Defect

A

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

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46
Q

Grid Keratotomy

A

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

47
Q

Stromal Ulcer; Basics, Treatment

A

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

48
Q

Descmetocele; Diagnosis, Treatment, DO NOTs

A

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

49
Q

Blue Eye; Causes, Diagnosis

A

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)

50
Q

German Shepherd Pannus; Basics, Treatment

A

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

51
Q

German Shepherd Pannus; Clinical Signs

A

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

52
Q

Pigmentary Keratitis; Signalment, Causes, Treatment

A

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

53
Q

Corneal Subepithelial Dystrophy; Basics, Treatment

A

o Hereditary, non-painful, typically non-progressive
o Cholesterol-lipid deposits

Treatment
 Feed LOW FAT DIET (< 10% total fat)
 Check thyroid

54
Q

Uveal Cysts; Basics, Iris Cysts, Corpora Niga Cysts

A

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

55
Q

Pigmentary Uveitis of Golden Retrievers; Features, Early Clinical Signs, Treatment

A

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

56
Q

Iris Sphincter Degeneration

A

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

57
Q

Uveitis; Clinical Signs

A

Clinical Signs
 Miosis (sometimes mydriasis in cats)
 Enophthalmos
 Blepharospasm
 Epiphora
 Conjunctival hyperemia
 Photophobia
 Hypotony
 Keratitic Precipitates
 FLARE
 Decreased IOP

58
Q

Flare; Basics & Types

A

 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)

59
Q

Traumatic Uveitis; Treatment

A
  • NO steroids
  • Oral NSAIDs much safer than topical NSAIDs
  • Atropine (if IOP is ok) can stabilize blood/eye barrier
  • Topical antibiotics
  • +/- topical NSAIDs
60
Q

Lens Induced Uveitis

A

 Juvenile & diabetic Cataracts (severe uveitis)
 Other cataracts
 Luxated or subluxated lenses
 Ruptured lenses

61
Q

Corneal Ulcers and Reflex Uveitis ; Basics & Effects per Species

A

 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

62
Q

Intraocular Tumors

A

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

63
Q

Hyphema; Causes, Treatment

A

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)

64
Q

Lipemic Uveitis; Signalment, Causes, Treatment

A

o Mini Schnauzers and Yorkies predisposed

Causes
 Systemic hypertriglyceridemia
 +/- Diabetes
 +/- Cushings
 +/- Hypothyroidism

Treatment
 Basic uveitis treatment
 low fat diet,
 IM work up

65
Q

Infectious Causes of Uveitis in Rabbits

A

o Pasturella
o Staph
o E Cuniculi

66
Q

Immune Mediated Uveitis

A

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

67
Q

Uveodermatologic Syndrome

A

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)

68
Q

Treatment for Uveitis

A

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

69
Q

Complications of Prednisolone Acetate

A

Dogs
 Corneal dystrophy

Cats
 Herpatic corneal ulcers

Horses
 Fungal corneal ulcers

Exotics
 Systemic absorption

70
Q

Panophthalmitis; Basics, Treatment

A

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)

71
Q

5 Retinal Types

A

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

72
Q

Anatomy of a Basic Mammalian Retina

A

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

73
Q

Collie Eye

A

o Merle ocular dysgenesis
o Seen in herding dogs
o Choroidal hypoplasia
o Optic nerve colobomas
o Retinal detachments
o Hemorrhage

74
Q

Optic Nerve Hypoplasia

A

o Unilateral blindness
o Genetic
o Do not breed

75
Q

Progressive Retinal Atrophy; Basics & Clinical Issues

A

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

76
Q

Sudden Acquired Retinal Degeneration Syndrome (SARDS); Signalment, Clinical Signs, Diagnosis, Treatment

A

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

77
Q

Optic Neuritis; Basics, Clinical Signs, Treatment

A

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

78
Q

Retinal Detachment; Rhegmatogenous

A
  • Giant retinal tear
  • Surgery for treatment
79
Q

Retinal Detachment Non-Rhegmatogenous, Basics, Diagnosis, Treatment

A
  • 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

80
Q

Acute Blindness in cats

A

o USUALLY hypertensive retinopathy
o Due to CKD, hyperthyroid, cardiovascular dz
o Treat underlying dz
o Amlodipine & increase every wk until BP controlled

81
Q

Chorioretinitis; Diagnosis, Treatment

A

Diagnosis
 CBC/Chemistry/UA
 Thoracic radiographs & abdominal ultrasound
 Infectious disease testing

Treatment
 treat underlying cause!
 doxycycline,
 Oral steroids (anti-inflammatory doses and with caution!)

82
Q

Toxic Retinal Injury

A

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

83
Q

Chlamydia in Cats; Clinical SIgns, Diagnosis, Treatment

A

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

84
Q

Bartonella in Cats; Clinical SIgns, Diagnosis, Treatment

A

Clinical Signs
 Conjunctivitis
 Uveitis
 `no corneal involvement

Diagnosis
 Serology

Treatment
 Doxycycline 3-6wks

85
Q

Calici Virus in Cats; Clinical Signs, Treatment

A

Clinical Signs
 Conjunctivitis w/ concurrent URI
 Ulcers on tongue
 NO corneal involvement

Treatment
 Symptomatic for respiratory dz
 Topical terramycin or erythromycin for conjunctivitis

86
Q

Mycoplasma Felis; Basics, Clinical Signs, Treatment

A

 Normal bacterial inhabitant of conjunctiva that may see on conjunctival cytology

Clinical Signs
 Possible cause of conjunctivitis
 No corneal involvement

Treatment
* Topical terramycin

87
Q

FHV-1; Clinical SIgns, Diagnosis, Treatment

A

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

88
Q

Feline Herpes Keratits; Clinical Signs, Diagnosis, Treatment

A

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

89
Q

Feline Eosinophilic Keratitis; Diagnosis, Treatment

A

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

90
Q

Corneal Sequestrum; Basics & Treatment

A

o Dead corneal tissue
o Black/dark brown “seed-like” appearance

Treatment
 Keratectomy & conjunctival graft (preferred)
 Long-term antivirals (painful)

91
Q

Feline Uveitis; Agents, Diagnosis, Secondary Effects, Treatment

A

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

92
Q

Feline Glaucoma; Secondary to? Treatment

A

Usually secondary to:
 uveitis,
 lens lux,
 neoplasia,
 trauma,
 senile change
 aqueous misdirection

Treatment
 Dorzolamide/timolol
 Removal of lens for aqueous misdirection

93
Q

Feline Retinal Degeneration

A

o Enrofloxacin
o Taurine deficiency
o Hereditary PRA
o Trauma

94
Q

Feline Hypertensive Retinopathy; Clinical Signs, Treatment

A

Clinical Signs
 Acute blindness
 Retinal detachment,
 serous or hemorrhagic
 BP>190mmHg usually

Treatment
 Drop BP with amlodipine
 Identify and treat primary cause

95
Q

Lens; Functions & Anatomy

A

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)

96
Q

Normal Aging of the Lens

A

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

97
Q

Lens Luxation; Clinical Signs, Treatment

A

Clinical Signs
 Causes damage to corneal endothelial cells
 Chronic uveitis
 Pain
 Increased risk of glaucoma

Treatment
 Removal of lens
 Open sky procedure

98
Q

Cataract Formation; Pathophysiology & Diabetic Pathophysiology

A

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

99
Q

Diabetic Cataracts; Basics, Complications

A

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

100
Q

Diabetic Cataracts; Treatment

A

Medical
* Topical/systemic anti-inflammatories, Diclofenac
* Kinostat (aldose reductase inhibitor) for prevention

Surgical
* Phacoemulsifiction (ideal)
* Lens removal

101
Q

Lens Induced /phagolytic Uveitis

A

 “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

102
Q

Lens Capsule Rupture

A

 Rapid cataract formation ->
 rapid swelling of lens ->
 lens capsule rupture

103
Q

Phacoemulsification; Basics, Pre-exam, Complications

A

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

104
Q

Mature Cataract or No?

A

If you can see any tapetum, it isn’t mature

105
Q

Glaucoma; Pathophysiology

A

o Obstruction of aqueous outflow ->
o Increased IOP ->
o Loss of ganglion cells, axoplasmic flow, optic nerve atrophy = glaucoma ->
o Vision loss

106
Q

IOP & Vision Loss

A

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

107
Q

Primary Glaucoma; Basics, Diagnosis

A

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

108
Q

Secondary Glaucoma Due to Uveitis

A

o Pre iridial fibrovascular membrane (PIFM) formation
o Blocks drainage angle
o Results in elevated IOP
o Chronic can result in phthisis bulbi

109
Q

Feline Ocular Melanoma Treatment

A

o Diode laser or iridectomy if small
o Enucleation & histo if diffuse

110
Q

Aqueous Misdirection Syndrome; Pathophysiology, Clinical Signs, Treatment

A

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

111
Q

Acute Vs Chronic Glaucoma Clinical Signs

A

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

112
Q

Short-term Glaucoma Treatment

A

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

113
Q

Long-term Glaucoma Treatment for visual & blind/painful eyes

A

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

Opthamology (3 decks)

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