All Ophtho Flashcards
What are the functions of the uvea?
(Aqueous humor dynamics, remove waste, absorb light, control light, and is the blood aqueous barrier)
What anatomical structures make up the uvea which is the vascular tunic of the eye?
(The iris, the ciliary body, and the choroid)
What anatomical structure is affected in anterior versus posterior uveitis?
(Anterior → iris and ciliary body; posterior → choroid)
What are some of the ocular signs of uveitis?
(Episcleral injection, ciliary flush, corneal edema, miosis, synechiae, aqueous flare, hyphema, hypopyon, keratic precipitates, and rubiosis irides)
What is the term for 360 degree vascularization of the cornea that you will not typically see with surface diseases so it indicates something wrong inside the eye?
(Ciliary flush)
What results in miosis in cases of uveitis?
(Painful spasming of the ciliary body musculature)
What is synechiae and which type is more common in uveitis cases?
(Adherence of the iris to the cornea (anterior) or lens (posterior) led by inflammatory cells, fibrin, and fibroblasts; posterior is more common in uveitis cases)
What is the presentation of aqueous flare and why does it occur?
(It will present as a hazy anterior chamber and it is a result of proteins leaking through the disrupted BAB into the aqueous humor)
If you are presented with a dog with keratic precipitates but they are otherwise completely normal both ocularly and systemically, what does that indicate?
(They had a prior occurrence of inflammation that has resolved on its own)
What is rubiosis irides?
(Injection of the iridal blood vessels)
Do you expect the IOP to be high or low in an animal with other signs of uveitis and why?
(Low → ciliary body is not producing enough AH and BAB is allowing fluid to escape faster than it is being replaced)
What are some potential complications of uveitis?
(Synechiae, iris bombe, corneal edema and degeneration (permanent), cataracts, lens instability, vitreous degeneration, retinal detachment, secondary glaucoma, and phthisis bulbi)
What are possible causes for uveitis?
(Primary ocular dz (have another ? on this so not going to list them here), idiopathic, trauma, and ocular manifestation of systemic dzs)
What are primary ocular diseases that can lead to uveitis?
(Cataracts, lens rupture, corneal ulcers, and intraocular masses)
What are the two types of lens induced uveitis (a common cause of uveitis in dogs) and what diseases lead to them?
(Phacolytic uveitis → soluble lens protein leaks through an intact lens, cataracts can cause this; phacoclastic uveitis → sudden exposure of intact lens protein d/t lens capsule tear, diabetes and trauma can cause this)
What are the most common primary and metastatic neoplasms that cause uveitis in dogs?
(Primary → melanoma; metastatic → lymphoma)
What are the common causes of uveitis in dogs?
(Infectious, lens induced uveitis, reflex uveitis, neoplasia, breed specific/immune mediated, and metabolic)
What are the common causes of uveitis in cats?
(Infectious, metabolic, and neoplastic)
What should your initial serology testing plan include for dogs with uveitis?
(Fungal, tick titers, and toxoplasmosis)
What should your initial serology testing plan include for cats with uveitis?
(Fungal, FeLV, FIV, FIP, and toxoplasmosis)
What presentation of uveitis warrants an ocular ultrasound?
(If you cannot see past the iris and lens)
When might you pursue thoracic radiographs and/or an ultrasound in a patient with uveitis?
(When you suspect fungal or neoplasia)
What should the goals be of your supportive care for a patient with uveitis?
(Control pain, prevent sequela, and stabilize/restore BAB)
What does topical atropine do to the eye that is useful in treatment of uveitis?
(Induces mydriasis → prevents synechiae, cycloplegic → analgesia, and stabilizes BAB)
When is topical atropine contraindicated?
(If there is lens instability, if there is glaucoma, and if a patient has dry eye)
You are presented with a dog with a cloudy eye, you believe you have localized it to the cornea and are between a corneal ulcer or endothelial dysfunction based on its appearance (fairly homogenous cloudiness), what diagnostic test can help you distinguish between those two options?
(Fluorescein stain)
You are presented with a dog with a cloudy eye that you believe you have localized to the cornea and it has a relatively homogenous, diffuse presentation with some faint stippling (you might say it looks like ground glass), the dog is non-painful and fluorescein stain negative, what is your top differential?
(Endothelial dystrophy/degeneration)
What are your differentials for a homogenous, focal cloudiness of the cornea?
(Corneal scar/fibrosis, corneal ulcer or an anterior lens luxation causing focal edema)
What are some causes for chronic abrasions of the eye resulting in corneal scars/fibrosis?
(Entropion, distichia, ectopic cilia)
What are some causes for chronic exposure of the eye resulting in corneal scars/fibrosis?
(Lagophthalmos and KCS)
What are the two causes for lipid keratopathy?
(Lipid dystrophy and lipid degeneration)
What can cause lipid degeneration that can then result in lipid keratopathy?
(Prior keratitis, infiltrative corneal dz, topical corticosteroid use, and systemic metabolic dzs such as cushings, diabetes, hyperthyroidism, and primary hyperlipidemia)
What is the typical presentation of a dog affected by lipid dystrophy?
(A young dog with bilaterally cloudy, non-painful eyes; lesion of the eye will appear particulate with numerous coalescing small particles → may appear glittery/sparkly/refractile)
If you note a sparkly lesion on the periphery of the cornea in an older dog who also has PU/PD and weight loss with an increased appetite, what is your top differential?
(Diabetes → lipid at the periphery of the cornea is often related to metabolic dz)
Compare and contrast the appearance of corneal lipid and corneal mineralization.
(Similar → numerous coalescing particles; differences → corneal mineralization is spiculated and not shiny whereas corneal lipid is not spiculated and shiny)
If a patient of yours has a cloudy cornea and they are painful, that narrows down your list of causes; describe what their cloudiness should look like on closer inspection and list the causes of that cloudiness.
(Edema > homogenous, faintly stippled (if more chronic), focal (ulcer) to diffuse (uveitis/glaucoma); caused by an ulcer, anterior uveitis, or glaucoma)
What clinical sign associated with uveitis can cause a cloudy eye, which you can diagnose by looking for the Tyndall effect with a slit lamp?
(Aqueous flare)
What is the main way to distinguish between aqueous and lipemic flare?
(Pain, unless the lipemic flare is caused by uveitis it will be painless, if it is caused by uveitis then it doesn’t really matter if its lipemic or aqueous, tx the uveitis)
What is an easy diagnostic test you can run when you have a cloudy eye that you suspect is either aqueous or lipemic flare but you’re just not quite sure?
(Spin down a hematocrit tube → milky serum = lipemia, not milky serum = aqueous flare d/t uveitis)
What are two causes of a cloudy lens?
(Nuclear sclerosis and cataracts)
What is the main way to determine if a cloudy lens is d/t nuclear sclerosis versus a cataract?
(If the light can get through the cloudiness when using a distant direct ophthalmoscopy technique = nuclear sclerosis, if light cannot get through = cataract)
What is asteroid hyalosis?
(A normal aging change (though can also be seen with intraocular masses) → calcium and phosphorus particulates in the vitreous fluid which is also starting to liquify)
(T/F) In a case of conjunctival hyperemia, the location of the most severe hyperemia often suggests the location of disease.
(T)