Term
| What is iris atrophy? What does it look like? |
|
Definition
-normal aging change in geriatric dogs (especially mini and toy poodles) and cats
-appears as an irregular thining of the iris at the pupil or can be as advanced as holes in the iris |
|
|
Term
| Does iris atrophy cause an afferent or efferent PLR deficit? |
|
Definition
|
|
Term
| Where do iris cysts originate? |
|
Definition
| -origniate at the pupil margin from the posterior pigmented epithelium of hte iris |
|
|
Term
| Are iris cysts non-pathologic or pathologic? Any exceptions? |
|
Definition
-non-pathologic
-exceptions: Golden Retrievers they are assoc with pigmentary uveitis |
|
|
Term
| What are the locations within the anterior chamber that iris cysts tend to occur? |
|
Definition
-attached at the pupil margin
-floating in the ventral anterior chamber
-ruptured cysts appear on the ventral corneal endothelium |
|
|
Term
| How do we differentiate iris cysts from melanoma? |
|
Definition
| -cysts are smooth, round, and you can see the tapetal reflection through it |
|
|
Term
| What color are iris cysts? |
|
Definition
| -always a dark chocolate brown |
|
|
Term
| What is the etiology behind persistent pupillary membranes? |
|
Definition
|
|
Term
| What are persistant pupillary membranes? |
|
Definition
| -remnants of blood vessels spanning thepupil in embryonic development => as eye develops there is not complete atrophy of the membrane tissue |
|
|
Term
| What is the most common type of persisitan pupillary membrane? ARe they clinically significant? What about any other kinds? |
|
Definition
-Iris to iris: not clinically significant
-Iris to lens or iris to cornea: uncommon but can be clinically significant if it results ina large lens or corneal opacity atthe point of attachment |
|
|
Term
| Are iris melanomas usually benign or malignant in the dog? What about in the cat? |
|
Definition
-Dog: benign but locally invasive with a low metastatic potential
-Cat: higher metastatic potential |
|
|
Term
| HOw do we treat canine iris melanoma? |
|
Definition
-If small: laser ablation
-If large: enucleartion once secondary glaucoma develops and the eye is blind and painful |
|
|
Term
| Are iris lymphomas usually benign or malignant? Clinical signs? |
|
Definition
-always considered metastatic at stage V
-diffuse iris infiltration and hyphema |
|
|
Term
| What are the purposes of the blood-ocular barriers? |
|
Definition
| -protect intraocular structures from infectious agents, toxins, drugs, and neoplastic cells |
|
|
Term
| What is the blood-aqueous barrier? |
|
Definition
| -ciliary body epithelium (iris capillary endothelium) |
|
|
Term
| What is the blood-retinal barrier? |
|
Definition
| -retinal pigmented epithelium (Retinal capillary endothelium) |
|
|
Term
|
Definition
| -inflammation of the uvea with the breakdown of the blood-ocular barriers |
|
|
Term
| Describe the physiology of uveitis. |
|
Definition
-disruption of BOB tight junctions and dilated, leaky blood vessels allow cells and protein to lead into tissue
-prostaglandin-mediated
-Miosis: prostaglandin effect on iris sphincter
-Pain: prostaglandin effect on ciliary muscle |
|
|
Term
| What are the non-specific clinical signs for uveitis? |
|
Definition
-blepharospasm: pain from ciliary muscle spasm
-inflamed conjunctiva
-engorged sleral vessels
-discharge: tearing or mucoid
-corneal edema: inflammatory cells in the aqueous affect endothelial cell function
-Vision loss: when uveitis is svere from cloudy aqueous, scarred or closed pupil, cataract, retinal detachment |
|
|
Term
| What are the specific clinical signs for uveitis? |
|
Definition
-keratic precipitates: WBCs in aqueous precipitate on corneal endothelium
-aqueous flare: loss of BAB tight junctions and leak iris blood vessels allow cells and protein into the aqueous
-Hypopyon: leak blood vessels allow WBCs into the anterior chamber
-Hyphema: due to leaky blood vessels
-Fibrin: forms from inc protein in the aqueous
-Miosis: prostaglandin effect
-iris effects: color change, swelling
-synechia
-iris bombe
-choroidal exudates and retanl detachment
-retinal and choroidal hemorrhages |
|
|
Term
| How does the iris change to indicate uveitis specifically? |
|
Definition
-color change: results from engoged iris blood vessels
-Swelling/thickening: results from inc iris vessel permeability allowing edema and/or neoplastic infiltrate into the iris stroma |
|
|
Term
| What is posterior synechia? How is it a clinical signs specific for uveitis? |
|
Definition
| -fibrn and exudates in the aqueous act like a glue which creates adhesions b/n the iris and lens |
|
|
Term
| What is iris bombe? What is it specific for? |
|
Definition
-360 deg posterior synechia obstructing aqueous flow through the pupil and causing the peripheral iris to bulge forward
-uveitis |
|
|
Term
| What causes choroidal exudates and retinal detachment in uveitis cases? |
|
Definition
| -leake choroidal blood vessels and disruption of the RPE tight junctions allow fluid and/or cells into the space b/n the RPE and neurosensory retina resultin in retinal detachment (trasudative/exudative/hemorrhagic), granuloma, neoplastic cell infiltrates, or any combo |
|
|
Term
| How does uveitis lead to retinal and choroidal hemorrhages? |
|
Definition
| -inflammation or direct vessel damage resutls in horrhage from retinal vessles (small) or choroidal vessels (large and associated with retinal detachment) |
|
|
Term
| What are the consequences of uveitis-caused protein, fibrin, hypopyon, and hyphema? |
|
Definition
-cause iris to stick to the lens: posterior synechia that becomes iris bombe
-cause obstruction of the iridocorneal angle dec aqueous outflow from the eye: secondary glaucoma
-cause fibrosis across the pupil
-cause anterior lens capsule opacification: cataract |
|
|
Term
| What are the consequences of choroidal exudates and retinal detachment caused by uveitis? |
|
Definition
| -death of photoreceptors in the affected area due to separation from their nutrition source (choroid) |
|
|
Term
| How do we diagnose uveitis? |
|
Definition
-clinical signs: COMPLETE PHYSICAL EXAM
-Tonometry: IOP=dec, secondary glaucoma can be a serious complication
-Fluorescein stain: to rule out corneal ulcer etiology and tells us if it is safe to use a topical steroid |
|
|
Term
| What are the primary ocular etiolgies of uveitis? |
|
Definition
-Cornea: ulcer, laceration, stromal abcess
-Lens: cataract or lens rupture
-Trauma
-Primar intraocular neoplasia
-Immune-mediated
-Idiotpathic: Goden Retriever Pigmentary Uveitis |
|
|
Term
| How can cornea etiologies such as ulcers, lacerations, or stromal abcesses lead to uveitis? |
|
Definition
| -corneal injury triggers release of anterior uveal prostaglandins |
|
|
Term
| How can lens etiologies such as cataracts ro lens rupture lead to uveitis? |
|
Definition
| -lens proteins leak through the capsule and are very antigenic to the anterior uvea |
|
|
Term
| How can trauma to the eye lead to uveitis? |
|
Definition
| -results in immediate release of prostaglandins from the anterior uvea? |
|
|
Term
| How can primary intraocular neoplasia lead to uveitis? |
|
Definition
| -causes direct damage to uveal blood vessels and infiltrates normal uveal tissue |
|
|
Term
| What causes Uveodermatoligic Syndrome? AKA what? |
|
Definition
-imminue-mediated with melanocytes as the target
-vogt-Koyanagi-Harada Syndrome (VKH) |
|
|
Term
| What is the typical signalment of VKH? |
|
Definition
|
|
Term
| What are the ophtalmic clinical signs of VKH? Dermatologic signs? |
|
Definition
-SEVERE bilateral uveitis (anterior and posterior) with retinal detachment
-depigmentaiton and ulceration
-can cause uveitis |
|
|
Term
|
Definition
-NEGATIVE for infectious disease
-histopath on skin biopsy or enucleated globe is diagnostic |
|
|
Term
|
Definition
-lifelong systemic immunosuppressive therapy
-topical prednisolone and atropine |
|
|
Term
| What is the typical signalment of Golden Retriever Pigmentar Uveitis? |
|
Definition
-adult Goldens
-cau cause uveitis |
|
|
Term
| What are the clinical signs of Golden Retriever Pigmentary Uveitis? |
|
Definition
-bilateral iris and ciliary body cysts
-posterior synechia
-flare
-fibrin
-secondary flaucoma |
|
|
Term
| How do we diagnsoe Golden Retriever PIgmentary Uveitis? |
|
Definition
-clinical signs
-signalment
-systemically normal |
|
|
Term
| How do we treat Golden Retriever Pigmentary Uveitis? |
|
Definition
-REFER!!! Difficult to manage and often lose vision
-topical steroids, NSAIDs
-+/- systemic immunosuppressive therapy |
|
|
Term
| How does uveitis occur secondary to systemic disease? |
|
Definition
-direct tisue invasion by pathogen => vasculitis => degn of BOB
-pathogen stims release of inflammatory mediators => vasculitis => degen BOB
-direct vascular damage by pathogen => vasculitis => breakdown of BOB |
|
|
Term
| What are the possible systemic etiologies of uveitis? |
|
Definition
-any pathogen that has access to vascualr system or damages blood vessels
-ex: Rickettsial, Lepto, Bartonella, CDV, FIP, Mycotic, Toxo, Neoplasia, Hpertension, Prototheca (algea), HW, Roundworms |
|
|
Term
| What are the general principles of uveitis? |
|
Definition
-MUST suprpess inflammation
-MUST prevent synechia
-MUST eliminate underlying cause
-systemic route of medication MUST be used for posterior uveitis |
|
|
Term
| What is the treatment protocol for anterior uveitis inflammation suppression? Contraindications for each? |
|
Definition
-topical corticosteroids: CI = corneal ulcer, FHV, stromal abscess in horse
-topical NSAID: CI = hyphema, glaucoma, stromal ulcer
-systemic NSAIDs |
|
|
Term
| What is the treatment protocol for posterior uveitis inflammation suppression? |
|
Definition
-Oral corticosteoirds: give for immune-mediated or inflammatory dose for infectious
-oral immunosuprpessives: only for immune-mediated |
|
|
Term
| What is the treatment protocols for anterior uveitis for prevention of synechia? Any contraindications? |
|
Definition
-topical atropine: CI = glaucoma, lens instability
-systemic NSAID |
|
|
Term
| Why do we use atropine to prevent synechia with anterior uveitis? |
|
Definition
| -paralyzies ciliary muscle and thus helps stabilize blood-aqueous barrier |
|
|
Term
| What is our major concern with treating uveitis? |
|
Definition
| -treat the underlying cause AND the uveitis |
|
|
