Term
| What is the purpose of the orbit? |
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Definition
| -protective function for the eye |
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Term
| What structures are contained within the orbit? |
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Definition
-fat
-blood vessels
-orbital lacrimal glands
-nerves
-extraocular mm |
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Term
| What are the extraocular mm? |
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Definition
-dorsal rectus (3)
-ventral rectus (3)
-lateral rectus (6)
-superior oblique ($)
-inferior oblique (3)
-retractor bulbi mm (6) |
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Term
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Definition
| -eye ball sits deep in the orbit |
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Term
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Definition
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Term
| What are the clinical signs of enophthalmia? |
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Definition
-dec palpebral fissue size
-recessed globe position
-prolapsed nictitans |
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Term
| What are the three major causes of enophthalmia? |
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Definition
-Voluntary globe retration: pain or protective response
-HOrner's Syndrome: lack of sympathetic tone
-Dec masticatory muscle mass: post-inflammatory atrophy, neurogenic (5) atrophy |
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Term
| What are the clinical signs of exophthalmia? |
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Definition
-inc palpebral fissue size
-protroding globe position
-prolapse nictitans |
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Term
| What are the major causes of exophthalmia? |
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Definition
-Abscess (retrobulbar): tooth root abscess, foreign body penetration throug the mouth
-Myoitis of masticatory mm or extraoculr mm
-Neoplasia: extension from nasal sinuses, metastatic (especially lymphoma), primary |
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Term
| What parts of an ocular exam do we add for diagnosing orbital disease? |
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Definition
-retropulsion of the globe
-oral exam
-vision |
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Term
| How do we know if it is an abscess causing exophthalmia on an exam? |
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Definition
-pain opening mouth
-lack of blindness |
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Term
| What diagnostic tests do we use for the orbit? |
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Definition
-ocular US
-CT or MRI
-dental or skull rads
-FNAs |
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Term
| How do we treat retrobulbar abscesses? |
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Definition
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Term
| HOw do we confirm a diagnosis of masticatory myositis? |
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Definition
| -serum titers for Ab against specific masticatory muscle myofibers |
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Term
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Definition
| -the globe is anterior to the eyelids with the eyelids usually folded under behind the equator of the globe |
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Term
| What are the causes of proptosis? |
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Definition
-Trauma: hit by car, dog fight
-Over-restraint of a brachycephalic dog |
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Term
| What is the prognosis of proptosis? |
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Definition
-much worse for cats and dolichocephalic or mesocephalic dogs vs brachycephalic dogs due to the amount of force required to proptose the globe
-traumatic etiologies much worse that over-restraint
-immediate replacement carries the best prognosis |
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Term
| What is the first thing to do during treatment of proptosis? |
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Definition
-systemic assessment of the patient when trauma is the cause
-key the eye lubricated with sterile saline rinse and KY jelly or ophthalmic antibiotic ointment of artificial tear ointment |
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Term
| When would we turn to enucleation in the case of a proptosis? |
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Definition
-if cornea is desiccated or severely ulcerated
-if the globe is ruptured
-if the optic nerve is severed
-if the globe is only attached by a few extraocular muscles |
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Term
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Definition
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Term
| The phrase "save the eye" also means "save the vision". |
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Definition
| -NO, saving the eye does not mean saving the vision |
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Term
| If there is a chance to save the eye in the case of a proptosis, what do we do surgically? |
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Definition
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Term
| OUtline a temporary tarsorrhaphy. |
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Definition
-clip and sterile prep around the eye, rinse the cornea well removing any adhered debris
=give dexamethasone-SP and cefazolin IV at induction
-lateral canthotomy if needed using scissors
-gently unfold the eyelid margins and pre-place the tarsorrhaphy sutures using stents and correct technique
-use a lubricated scalpel blade handle to push the globe in as you pull up on the sutures and tie the mattress sutures |
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Term
| Describe the post-operative treatment of a proptosis. |
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Definition
-oral antibiotic: Cephalexin, Clavamox
-oral prednisone (better than NSAID) anti-inflammatory dose: dec retrobulbar tissue swelling, help with optic nerve trauma
-tramadol for pain
-leave sutures in for a minimum of 2 weeks |
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Term
| What are some post-proptosis sequelae? |
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Definition
-lateral strabismus due to tearing of the medial rectus muscle: will be permanent
-blind due to optic nerve damage
-prognosis for vision ALWAYS GUARDED for a traumatic proptosis |
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Term
Definition: Microphtalmia
-in which animals is it common? |
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Definition
-congenitaly small eye often associated with other ocular congenital anomalies; with or without blindness
-common in coat color dilutions |
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Term
| Definition: Phthisis bulbi |
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Definition
-small-shrunken globe (blind) due to profound damage to the ciliary body and minimal aqueous production
-severe hypotony |
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Term
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Definition
| -decreased intraocular pressure |
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Term
| What are the causes of phthisis bulbi? |
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Definition
-post severe intraocular inflammation
-chronic glaucoma (less common) => presumed ischemic damage to the ciliary body |
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Term
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Definition
| -removal of the globe, eyelids, and nictitans |
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Term
| What are the indications for an enucleation? |
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Definition
-blind and painful eye
-permanently blind eye due to trauma in a cat
-invasive neoplasia of the globe or eyelids
- |
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Term
| Definition: Exednteration |
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Definition
| -removal of the globe, eyelids, nictitans, and all orbital contents |
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Term
| What are the indications for a exenteration? |
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Definition
-orbital neoplasia
-ocular neoplasia that has invadd outside the globe |
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