Small Animal Sx- Optho- Cornea

wilsbach's version from 2015-12-02 05:14

how cornea of a joke can I put here

Question Answer
what are the 4 layers of the cornea?epithelium, stroma (majority of the mass), decement's membrane, endothelium
functions of the cornea?(1) component of fibrous tunic (2) main ocular surface barrier (entry of pathogens, penetration of therapeutic agents must be considered)
what makes the cornea so clear??(1) absence of BVs (2) DETURGESCENCE (mechanism where cornea stays relatively dehydrated via endothelium has active pumps- helps keep out excessive water) (3) regular arrangement of collagen lamellae in stroma (4) absence of pigment (5) relatively acellular
in the cornea, any dec in clarity means...pathology!
MODB: order?? why?bc some tests can mess up other tests. So order is menace response, direct and consensual pupillary light reflex, palpebral reflex, Schirmer tear test, fluorescein stain, and tonometry
what will mess up schirmer tear test?like, any topical
7 deadly corneal colors: what do they mean?? Red, blue, white (wispy/sparkly), yellow, greasy tan, brown, blackRed: BVs. Blue: corneal edema. White wispy: fibrosis. White sparkly: deposits. Yellow: cellular infiltrates. Greasy tan: keratic precipitates. Brown: pigment. Black: sequestrum, FB
RED cornea means blood vessels. What DO and what DONT blood vessels tell you?DONT tell you WHAT the dz is, just that there is chronic irritation. DO tell you WHERE it is
superficial vs deep blood vessels-- WHERE is the dz, what do the BVs look like SUP: corneal epithelial dz, fine branching "trees" of BVs. DEEP: stromal (deep corneal) or intraocular dz- non-branching "hedge" like BVs
what is BV growth like in relation to injury? (said in class)3d lag time before they start to grow, and then about 1mm a day
If the cornea is blue, you pissed off WHAT structure that makes the water in the cornea go away?endothelium
3 things that piss off corneal endothelium- what does this result in?Uveitis, glaucoma, stromal abscess (yellowish spot)...results in a blue cornea bc endothelium is what pumps out water (deturgescence)
****conjunctival vs scleral hyperemia chart you gotta know
SUPERFICIAL VESSELS (trees) usually happen due to what two problems?(1) insufficient corneal protection- such as lagopthalmos (cant close eye all the way), macropalpebral fissure, CN V or VII paralysis, sctropion, KCS (2) excessive corneal irritation- entropion, distichiasis, ectopic cilia, trichiasis, foreign body, lid tumor, blepharitis
DEEP VESSELS (hedges) usually happen bc of what problems?deep keratitis, scleritis, uveitis, glaucoma, anterior lens luxation
BLUE= EDEMA. What if the blue is Diffuse, fluorescein negative, and marked--> nonpainful, uninflamed, normal IOP, flare absent? (causes, do what?)endothelial degeneration OR endothelial dystrophy (monitor for corneal bullae and 2* ulceration)
BLUE= EDEMA. What if the blue is Diffuse, fluorescein negative, and marked--> painful, inflamed, abnormal IOP, flare present? (causes, do what?)Glaucoma, uveitis, lens luxation (do intraocular exam and dx testing)
BLUE= EDEMA. What is the blue is focal, fluorescein positive, and milder/focal? (causes, what do?)CORNEAL ULCERATION!
Three things you should think of if diffuse corneal edema?uveitis, glaucoma, ANT lens luxation
whats keratomalacia?melting cornea
Wispy grey/white colored cornea means? what has happened? how does it react to fluorescein?This is SCAR TISSUE which is flu. negative. It is non-painful and is disorganized stromal collagen which may remodel very slowly. Usually needs no tx
sparkly white colored cornea is what? (3 things it can be, give examples)means LIPID/MINERAL deposits. (1) Deposits: cholesterol (lipid) or calcium (mineral) (2) PRIMARY DYSTROPHY: "corneal dystrophy"-- bilateral (not always symmetrical) young dogs (inherited) (3) SECONDARY DYSTROPHY: often asymmetric, systemic condition, corneal injury, uni or bilateral
primary versus secondary corneal dystrophy (and what does it look like color-wise)SPARKLY WHITE! PRIMARY DYSTROPHY: "corneal dystrophy"-- bilateral (not always symmetrical) young dogs (inherited). SECONDARY DYSTROPHY: often asymmetric, systemic condition, corneal injury, uni or bilateral
once again: 3 things sparkly white cornea can be(1) corneal lipid degen (2) corneal lipid dystrophy (3) corneal lipid limbal infiltrates
corneal lipid degeneration- what is going on in this dz? 1* or 2* dz? symmetric or asymmetric, uni or bilateral?lipid and mineral corneal stromal infiltrates that are accompanied by vascularization, scarring, and pigmentation. Usually develops secondary to chronic corneal ulceration or nonulcerative keratitis. typically ASYMMETRIC and can be uni OR bilateral
what is going on in corneal lipid dystrophy? (a)symmetric? bi or unilateral? 1* or 2*WHITE RING ON CORNEA!!! it is a primary symmetric bilateral non-inflammatory inherited corneal opacity that is associated with a lipid infiltrate in the corneal stroma. might affect the epithelium (recurrent erosions may ensue), stroma, or endothelium (chronic corneal edema). specfic for many breeds of dogs
what is going on in corneal limbal lipid infiltrates?usually bilateral limbal-assocaited lipid infiltrates 2* to lipid-laiden serum in the limbus. occasionally extends around entire limbus (arcus),-- systemic hyperlipidosis (look for metabolic abnormalities: hypothyroidism, pancreatitis, DM, hyperadrenocortisism, 1* hyperlipidimia)