3 - Optho Flashcards
Foreign bodies may present as
Bump on the cornea
How do you treat foreign body
Remove after administering topical anesthesia
What do you remove a foreign body with on the eye
Hydropulsion or very fine forceps
Keratoconjuctivitis sicca
Disease resulting in keratitis and conjunctivitis caused by a lack of aqueous tear production
Are seen with stain Superficial ulcers
May not be visible
Signs of superficial ulcers
Blepharospams, epiphora, discharge, pain, conjectural hypermedia
Superficial ulcer
You just lost the epithelium
How are superficial ulcers treated
Triple antibiotics and atropine
Who shows more pain in superficial ulcers
Long nosed dogs
Stromal ulcer
Any ulcer that extends into the stroma
Stromal ulcers result in
Divor that makes the corneal contour uneven
Many stromal ulcers are
Infected
Stroma ulcer have what type of appearance
Gelatinous appearance MMPs
Treatment of stromal ulcer is dependent on
Presence or absence of infection, melting, and predisposing cause
Descemetocele
Very deep ulcer that extends all the way through the stroma to descements membrane
What will take up stain with decemtocele
Walls will take up stain, not the floor of ulcers
What should be done with descemetocele
Surgery!
Perforation / iris prolapse occurs with
Trauma or worsening of a deep ulcer to the point of a hole developing in the cornea
Within minutes of perforation / iris prolapse, the hole becomes
Plugged with fibrin or iris
What will fluorescenin stain show with perforation / iris prolapse
Aqueous leakage
What should u look for with perforation / iris prolapse
Collapsed anterior chamber, fibrin plug, MBIO tic pupil, hypopyon
What should be done with perforation / iris prolapse e
Cultured and have surgery
Facet
Divot in the corneal stroma that has intact overlying epithelium
With a facet, it takes some time for the keratoconjuctivitis to
Secrete enough collagen to fill in stromal defect
If re - epithelializaiton occurs prior to to complement filling then
A facet will be present
Melting ulcer etiology
Stromal ulcer complicated by the release of proteases and collagenase that cause rapid progressive stromal dissolution
Collagenase that cause rapid progressive stromal dissolution I are also called
Matrix mellatoproteinases
Matrix metalloproteinases are family of enzymes that have what type of activity
Proteolytic activity
Collagenase is also an
MMP
If MMP activity is present in a case of corneal ulceration, what will happen
Stroma will rapidly degrade and appear soft and malacic
What is used to counteract melting from MMP
Topical serum
Where do MMP come from
Cornea, invading leukocytes, microorganism
MMP are normal present in the
Cornea
MMP serve the function of what in the cornea
Cleaning up necrotic debris in cases of stromal ulceration
The overactive expression of corneal MMP seem more common in
Eyes of Brachycephalics
Another cause of stimulation of MMP
Topical corticosteroids
Steroids are strictly contraindicated in
Corneal ulceration
PMN is
Leukocytes
Pros of PMN
Necessary to keep infection at bay
Cons of PMN
Liberate large quantities of proteolytic enzymes including MMP
How do steroids affect PMN
Inhibit the influx of PMN
What pathogens are the best MMP secretors
Pseudomonas and B hemolytic Streptococcus
3 etiologies of ulcers with stromal loss
Bacterial infection, fungal infection , chronic unrelenting imitation
Ulcer with stromal los are most infected with
Pseudomonas, streptococcus’s or staph
Ulcers with stromal los caused by fungal infections are usually what color
Brown
What is teh medical treatment of deep ulcers
Topical AB every 2 hours, serum every 2 hours , atropine, e collar
What is the topical antibiotics used in standard medical treatment
TObramycin and Cefazolin
When do you use serum for medical treatment
If melting or infected
After 24 hour treatment of deep ulcer what do you do if there is improvement
Antibiotics and serum are dropped to every 4 hours
Conjunctival pedicle graft
Strip of bulbar conjunctivitis is sutured over the corneal ulcer
The conjunctival pedicle graft gives the compromised cornea
Structural support
Why is the blood supply important in conjunctival pedicle graft
The serum contain a couple of compounds that inhibit MMP activity
What is in the serum that inhibit MMP activity
A2 macrogolbulin and a 1 anti trypsin
Products that are collagen sheets that are available for conjuctivial pedicle graft
BioSy and A-Cell
Biosys is made from
Porcine small intestinal submucosa
A cell is made from
Urinary bladder
Indolent ulcers
Chronic superficial non healing ulcer with loose edge of epithelium
Physio of indolent ulcer
Lack of functional basal epithelial hemidesmosomes
What are some hypothesis on why indolent ulcers occur
Primary corneal dystrophy, over active level of protease in teh tear film which degrade the fibroneciton network onto the basal epithelial cells migrate, and presence of a cellular zone in the anterior stroma
Overactive level of protease in teh tear film cause what
Degrade the fibronectin network onto which the basal epithelial cells migrate
The presence of an acellular zone in the anterior stroma will prevent
Attachment of overlying epithelium
The fluorscein stain in indolent ulcer often migrate
Under the loose edge of the epithelium
Indolent ulcer are ALWAYS
Superficial
Treatment of indolecent ulcer
Debride, grid keratotomy, antibiotics
What antibiotics do u use for indolecent ulcer
Oxytetractyline
Recheck after tx of indolecent ulcer
2 weeks and repeat debridement
Additional therapies of indolecent ulcer
Contact lens, remend, topical morphine sulfate eye drops, cyanoacrylate, e collar, lamellar keratotomy
What will contact lens do for indolecent ulcer
Protect any new formed epithelium from being wiped away
What therapy is reserved for indolecent ulcer that haven’t healed after 6 - 8 weeks
Lamellar keratectomy or conjuctivial pedicle graft
Corneal lacerations are caused by
Trauma
If corneal laceration is less than 1/2 thickness can treat
Medically
If corneal laceration is > 2/3 thickness need to
Primary closure
Pigmentary keratitis
Non specific change that develops with long sanding Trauma/ irrigation to the cornea
Pigmentary keratitis manifests as
Corneal pigmentation
Pannus is aka
Chronic superficial keratitis
Panus
often bilateral immune mediated vascularized pigment lesion of the cornea
Pannus begins as
Red vascularized conjunctival lesion
Pannus initially invade the
Temporal or inferior temporal limbus
Pannus can turn into
Fleshy lesion causing blindness
Etiology of Pannus
Immune mediated, genetic, UV radiation
What breed is predisposed to Panus
German Sheperds
Pannus is usually controllable but not
Curable
Begin treatment of Pannus with
Dxamethasone or prednisone TID - QID
How long might it take for Panus to respond to treatment
3 - 4 weeks
What can be used for maintenance of Pannus
Cyclosporine or tacrolimus
How do you monitory if Pannus lesion is quiescent or active
Vasculariaztion
What can be used as TX in severe Pannus
Strontium radiation
Scars - fibrosis
Result from abnormal alignment of corneal stromal lamellar
Scars - fibrosis usually secondary to
Ulceration or other chronic disease
Appearance of scars - fibrosis
Grey irregular opacity +/- vessels and pigment
How do you DX scars - fibrosis
Fluorescein negative, white or pigmented opacity
Corneal dystrophy
Primary, axial llcaoted, bilateral, inherited disorder of teh cornea that is not accompanied by corneal inflammation or systemic disease
Corneal dystrophy typically results from
Deposition of lipid in the cornea
