2 Flashcards
What is the diagnosis? What breed is likely to develop this?
Uveal cyst, black labradors.
What is the diagnosis?
Naevi
Describe the appearance of anterior uveal melanoma. How is it treated?
Heavily pigmented mass in iris/ciliary body. Iris may be thickened. Treatment = enucleation
What is the most common intraocular neoplasm?
Anterior uveal melanoma
Diagnosis? How is it treated?
Ciliary body adenoma. Enucleation
What are the clinical signs of anterior uveitis?
- pain
- red eye
- visual disturbance
- corneal oedema
- breakdown of blood/aqueous barrier causing aqueous flare
- reduced intraocular pressure
- miosis
- iris swelling
What is aqueous flare?
Breakdown of blood/aqueous barrier allows protein + inflam cells into aqueous. Causes light scattering in anterior chamber which is observed as diffuse scattering of light between the light on the cornea and iris.
What is uveodermatological syndrome?
Blinding uveitis in arctic breeds (refer!)
How would you treat anterior uveitis?
Aim: control intraocular inflam to prevent full-blown uveitis (potentially blinding)
- Treat underlying cause if poss
- Reduce intraoc inflam + restore blood-aq barrier with topical/systemic NSAIDS/corticosteroids. Intact cornea = topical corticosteroids, ulcerated cornea = topical NSAIDs. Severe inflam = systemic corticosteroids, if unsafe to use systemic steroids = systemic NSAIDs.
- Use mydriatics eg. atropine, to induce relative mydriasis to prevent posterior synechiae forming.
- Monitor intra oc pressure to prevent seondary glaucoma
Describe the cause/s of glaucoma
=outflow of aqueous compromised by obstruction or functional failure of drainage angle
PRIMARY = bilat, abnorm drainage angle, predisposed breeds
SECONDARY = due to lens luxation, uveitis, neoplasia, H+, retinal detachment, pigmentary glaucoma
What are the clinical signs of acute and chronic glaucoma?
ACUTE: pain, visual loss, episcleral congestion, increased intraoc pressure. If >40mm HG: corneal oedema, mod dilated + poorly responsive pupil
CHRONIC: buphthalmos, corneal vascularisation + pigmentation, lens lux/sublux, tears in Descemets membrane, retinal degen + optic disc cupping, maybe pain
You identify what looks like a cataract in an older dog. However on opthalmoscopy it doesn’t appear as an opacity. Diagnosis?
Nuclear sclerosis. (Norm aging change)
What are the clinical signs of lens luxation?
Iridodenesis (wobble oscillation of iris with eye movements)
Flat iris
Strands of vitreous protruding from around pupil
Aphakic crescent (crescent shaped gap between lens equator + iris when pupil dilated)
Corneal opacity if anterior luxation that rubs corneal endothelium
What are the complications of posterior + anterior lens luxation?
Posterior- similar to sublux as drainage angle not blocked.
Anterior- acute glaucoma, corneal opacity, painful red eye
What are the treatment options for posterior/anterior luxation + subluxation of the lens?
POSTERIOR: wait until it moves forward then remove
ANTERIOR: refer for removal as emergency!
SUBLUX: lendectomy or prostaglandin analogues to keep it behind constricted pupil and reduce IOP
Describe the different types of lens cataracts
Incipient: small (<15% lens), no effect on vision, not progressive
Immature: more extensive, no fundic reflex
Mature: total opacity + no fundic reflex -> blindness
Hypermature: contracted, irregular lens w/ deep anterior chamber
Morgagnian: type of hypermature cataract w/ sig. resorption of lens
Intumescent: rapidly developing eg. in diabetes mellitus
List the clin signs of orbital disease
Orbital swelling
Globe deviation
Eno/exophthalmos
Difficulty in digital retropulsion of globe
3rd eyelid protrusion
Pain on opening mouth
Conjunctival hyperaemia
Lagophthamos -> exposure keratitis
What are 2 causes of orbital disease?
Retrobulbar abscess/cellulitis + retrobulbar neoplasia
Draw a diagram of the fundus
Refer to notes
Diagnosis?
Collie eye anomaly: choroid hypoplasia lat to optic disc- white region of sclera w/ abnormal choroidal vessels on top.
Diagnosis?
Generalised progressive retinal atrophy: mottled non-tapetal fundus, tapetum hyperreflectivity, retinal vasc attenuation
What are the clinical signs of inflammatory retinopathies?
- grey/white opacities due to inflam cells
- hyporeflectivity due to thickened region
- H+
- retinal detachment
- hazy vitreous
- can lead to atrophy of affected retina causing focal areas of tapetal hyperreflectivity
Describe the charcteristic appearance of optic nerve hypoplasia
Small, dark/grey optic disc (due to lack of myelinated fibres) w/ otherwise normal fundus. Can impair vision
What is an optic nerve coloboma?
Non-progressive focal loss of tissue in optic nerve, appears as pit/shallow depression.
What does optic neuritis look like? How is it treated?
Enlarged optic disc w/ congestion. Large dose of immunosuppressive systemic steroids.
What is papilloedema and what does it look like?
Pressure on optic nerve from within orbit eg. retrobulbar neoplasm. Causes oedamotous swelling of optic nerve.
Pathology + clinical signs of collie eye anomaly.
PATHOLOGY = impaired mesodermal differentiation -> choroid defects
CLIN SIGNS = choroid hypoplasia lat to optic disc (white sclera w/ abnormal choroid vessels), 30% also have potic disc coloboma
Describe the aetiology + signalment of generlaised progressive retinal atrophy.
=group of photoreceptor diseases
PHOTORECEPTOR DYSPLASIA: irish setters, dachsunds
PHOTORECEPTOR DEGENERATION: lab, cocker spaniel, golden retriever
What are the clinical signs of Generalised progressive retinal atrophy?
- night blindness leading to full blindness
- retinal vascular attenuation
- tapetal hyperreflectivity
- ‘pavementing’- patchy losses of pigment in nontapetal fundus
An older dog presents to you with sudden vision loss but a normal fundus on examination. What is top of your differentials?
Sudden acquired retinal degeneration
