Retina and Optic Nerve Flashcards
Normal Variation
- Dogs
- Cats
Retinal Dysplasia
- who
- other causes?
• Usually inherited
– Can be associated with multiple ocular anomalies
• Other causes:
– Maternal viral infections
• Canine herpes and parvo viruses, feline panleukopenia
– Vitamin A deficiency
– X-ray irradiation
– Drug toxicities
– Intrauterine trauma
findings with retinal dystrophy
Retinal Dysplasia in Labrador Retrievers
Hereditary oculoskeletal dysplasia
Collie Eye Anomaly (CEA)
Inherited Retinopathies
- May initially affect rods, cones, or RPE
- Very long list of affected breeds
- Majority are autosomal recessive
retina and optic nerve (meekins)
Progressive Retinal Atrophy
• Clinical signs:
– Bilateral – progressive loss of vision–blindness
– Decreased night vision (nyctalopia) usually first sign
– Progressive decrease in PLR
– Larger than normal resting pupil size
• Owner will sometimes report increase in “eye shine”
– Cataract formation in very late stages
retina and optic nerve (meekins)
Sudden Acquired Retinal Degeneration Syndrome (SARDS)
- what
• SARDS-_acute_ photoreceptor death
• Usually middle aged to older dogs; female overrepresented
• All breeds affected
• Associated clinical signs
– May have ‘Cushing’s-like’ signs for weeks or months prior to vision loss
retina and optic nerve (meekins)
Sudden Acquired Retinal Degeneration Syndrome
• Clinical signs:
– Acute vision loss
– Variable PLR
• Chromatic PLR
• Red light –
• Blue light +
– Fundic exam
• NORMAL initially
• Chronic cases
– Retinal degeneration
retina and optic nerve (meekins)
Sudden Acquired Retinal Degeneration Syndrome
- Diagnosis:
- Treatment:
- Diagnosis:
- Electroretinogram (ERG)
- May have elevated ALP, or other Cushing’s-like changes on blood work; less commonly diagnosed with Cushing’s via traditional screening tests
- No proven treatment-permanent blindness
- Emphasize quality of life as blind pet
retina and optic nerve (meekins)
Retinal Detachments
small vs large
retina and optic nerve (meekins)
Rhegmatogenous retinal detachment
-
Retinal tear present which allows liquefied vitreous to enter subretinal
space - Primary ocular disorder (previous cataract surgery, inherited vitreal
degeneration, etc.)
retina and optic nerve (meekins)
Non-rhegmatogenous retinal detachment
- Remains attached at ora ciliaris retinae & optic disc
- Serous sub-retinal fluid-bullous retinal detachment
- Exudative retinal detachments-inflammatory or exudative sub-retinal fluid
- Systemic disease
retina and optic nerve (meekins)
Differentials for Non-rhegmatogeous RD
• Depends on type of sub-retinal fluid/material
• Exudate (cloudy or discolored, yellow)
– Same as chorioretinitis (i.e., posterior uveitis) → suspect systemic infection
• Transudate (clear)
– A.k.a. bullous
– *Hypertension
– Hypoproteinemia
– Idiopathic (steroid responsive?)
• Dog specific
retina and optic nerve (meekins)
Retinal Detachments
- always do ______ with non-rhegmatogenous patients
- Always perform a systemic work-up in animals with non-rhegmatogenous retinal detachments
– CBC/chemistry panel/urinalysis
– Blood pressure
– Chest radiographs
– Titers/antigen tests if any suspicion of infectious cause
retina and optic nerve (meekins)
Surgical Repair of Retinal Detachments
• Only appropriate for rhegmatogenous detachments
• Laser retinopexy
– 2 rows of burns around detachment to create adhesions
– Prophylactic vs. barrier
• Retinal reattachment
Retinal Hemorrhages: location
retina and optic nerve (meekins)
Optic Neuritis
retina and optic nerve (meekins)
DDX Optic Neuritis
