Corneal Ulceration and Perforation Flashcards
Will fluoroscein bind to Descemet’s membrane?
NOPE – it means that it’s progressed to a desmetocoele
When is Schirmer Tear Test highly indicated?
- mucopurulent discharge (probably KCS)
- dull or lackluster appearance to corneal surface
- chronic or non-healing ulcers or recurrent ulcers with an undefined underlying cause
Perform PRIOR to anesthetics as they reduce tear film production. (why we lube them when we anesthetize)
Corneal cytology is useful for ________
- bacterial or fungal infections
- deepening or expanding corneal ulcers
- apparently minor ulcers with disproportionately severe intraocular inflammation
- ulcers accompanied by severe mucopurulent discharge
What is the order of diagnostic tests?
- STT
- Culture
- Cytology
- Stain
Goals of corneal therapy
- Prevent/treat Infection (topical abx)
- Prevent/treat Stromal collagenolysis (anti-proteolytics)
- Promote corneal healing
- Maintain patient COMFORT
Factors that delay corneal healing
- Presence of secondary corneal infection
- Continued corneal abrasion (from distichia, ectopic cilia, entropion, foreign body, etc.)
- Inadequate tear production
- Corneal exposure due to inability to completely blink over eye
Topical Abx
- Aminoglycosides (Neomycin, Gentamicin, Tobramycin)
- Chloramphenicol (broad -static mycop and chlamyd)
- Fluoroquinolones (broad -cidal mycop and chlamyd)
- Tetracyclines (broad -static mycop and chlamyd)
- Cefazolin (G+ 1st gen ceph.)
Anti-proteolytics
- Autogenous serum: may also speed epithelialization
- Acetylcysteine: inhibits metalloproteinase by binding zinc irreversibly
- Tetracycline: inhibit proteolytic activity (Ca, Zn, and enzyme binding)
Mydriatics/cycloplegics
Atropine - pain relief be stopping spasm
may cause reversible but severe DECREASE in TEAR production
Anti-inflammatories
Systemic NSAIDs - aspirin, carprofen, etc
- indicated for PAIN and management of reflex anterior uveitis associated with corneal ulcers
Topical NSAIDs - caution in cases of ulcerative keratitis; they do INHIBIT HEALING and implicated in corneal melting
Topical Corticosteroids should NEVER be used for corneal ULCERS
Topical opiates
Topical 1% morphine may provide some relief from corneal discomfort without impairing corneal healing
TX Acute Superficial Ulcers
take up stain but cannot visualize loss of stroma
localized corneal edema
TX prophylactic topical ABX and Atropine based on amount of reflex uveitis
Re-check in 2-3 days and should be healing and every 2-4 days after that.
If not healed within 7-10 days, suspect an unidentified underlying cause or indolent ulcer (i.e. Boxer ulcer).
TX Chronic Superficial Ulcers
Surgical Tx is indicated, minor and under topical anesthesia.
- Superficial striate keratotomy/grid keratotomy
- Superficial punctate keratotomy
- Diamond burr keratotomy
- 3rd eyelid flap in conjunction w/ 1 of the above
Recheck every 7 days. If not healed w/in 2 weeks another procedure is indicated.
TX of Mid-stromal ulcers
DX: Culture and Cytology
TX: - Topical Abx q4-6hr
- Protease inhibitors q4-6hr and systemic doxy
- Topical Atropine for pain to maintain pupil dilation
Recheck every 24-48 hrs and Continue Topical ABX until Fluoroscein Negative**
TX Deep Stromal Ulcers
TX: Topical abx q2-4 hrs; consider big guns (fluoroquinolone or combo cefazolin/gentamicin)
- Protease inhibitors q2-4hr and systemic doxy
- Topical atropine to maintain pupil dilation
Animals with deep stromal ulcers should be hospitalized for the intensive treatment indicated.
Progression beyond 50% stromal depth is an indication that surgical intervention in the form of a conjunctival flap should be considered.
