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Ocular Disease part 2 > Lids/conjunctiva/cornea > Flashcards

Flashcards in Lids/conjunctiva/cornea Deck (98)
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what are phlyctenules (or phlyctens)?

focal, translucent lymphocytic nodules generally located at limbus and usually accompanied by inflammation


what is the hallmark sign of a phlyctenule?

elevated, finger-like projection across the limbal juncture onto peripheral cornea with overlying pannus (superficial vessels)


what is the pathophysiology for phlyctenular keratoconjunctivitis?

staphylococcus - secondary to lid disease = industrialized countries

tuberculosis or GI parasites = developing countries


what type of hypersensitivity are phylctenules?

type 4 = delayed cell-mediated hypersensitivity reaction to staphylococcal antigens or other exogenous sources


what are the 3 pieces of treatment for phylctenular keratoconjunctivitis?

topical steroid pulse (prednisolone acetate 1% or phosphate, loteprednol/lotemax 0.5%) = q2h - 3 to 4 days and taper quickly for 3 days

topical antibiotic (Besivance, vigamox, zymar) = q2-4h or q4-8h

OTC vasoconstrictor

*can also use an antibiotic/steroid combo


what do you prescribe for resistant staph-caused cases of phylectenular keratoconjunctivitis?

tetracycline 250mg PO QID until asymptomatic for 2-3 weeks


what types of lab testing would you order for phylenctenular keratoconjunctivitis?

TB testing (immigrant = SE Asia or central america, substance abusers)

GI parasites = serologic testing/Amebicide therapy


what is the treatment for mild phlyctenules?

they often self-limit and only need OTC vasoconstrictor drops QID


how would you know if phlyctenules were caused by staph or TB/GI parasites?

phlyctenules caused by staph respond poorly to steroids alone without treating the source of staph (lid disease)


what are some examples of combo antibiotic/steroid drops for phylectenular keratoconjunctivitis?

maxitrol (dexamtheasone 0.1%/neomycin/polymyxin B)

Pred-G (gentamicin/pred acetate 1%)

Tobradex or Tobradex ST (tobramycin/dexamethasone 0.10% or 0.05%)


what are some signs associated with sterile marginal corneal infiltrates (corneal ulcer)?

midperipheral island(s) of infiltrate, clear zone between infiltrate and limbus, often 4:00 - 8:00 and can present as a sterile marginal ulcer


what causes sterile marginal corneal infiltrates?

corneal hypersensitivity to sterile lid exotoxins (staphylococcal exotoxins)


what is the treatment for sterile marginal infiltrates if the cornea is intact (no staining) and generally healthy?

vigorous treatment of lid disease = hygiene and antibiotics (AzaSite)

low concentration of steroid drop to quiet inflammation = prednisolone acetate 0.12%, FML 0.1%, loteprednol (all TID to QID 5-7 days)


what is the treatment for sterile marginal infiltrates if the cornea is intact (no staining) but has diffuse SPK?

conservative approach with prophylaxis antibiotic 7-10 days (fluoroquinolone or aminoglycoside with polysporin ung or AzaSite)

lid hygiene

low concentration steroid TID to QID

possible culture if condition doesn't improve

artificial tears


what is the treatment for sterile marginal infiltrates if the cornea is compromised (with staining) with diffuse SPK?

antibiotic gtt/ung to protect cornea

culture and sensitivity may be important for CL wearers

lid therapy for blepharitis and artificial tears

low concentration steroid drops for inflammation QID


what is the treatment for sterile marginal infiltrates that are probably sterile with a corneal ulcer?

lid therapy for blepharitis and artificial tears for cornea

combination steroid-antibiotic QID (maxitrol, trobradex, Pred-G)

**sterile ulcer represents greater inflammation and requires a stronger steroid


what is a sterile marginal infiltrate that has an indolent ulcer?

a shallow, superficial ulcer unaccompanied by vascularization and infiltration, causing little reaction, few symptoms, and little tendency to spread or heal


what are the symptoms associated with infectious bacterial keratitis (corneal ulcer)?

R = red eye (intensely) S = sensitive to light V = vision change (reduced, disrupted) P = pain (acute, unilateral with tearing)


what are some signs associated with infectious bacterial keratitis?

focal stromal infiltration surrounding excavation (ulcer), AC cells and flare, conjunctival injection, purulent discharge, mucoid plugs, eyelid edema, and folds in Descemet's membrane


what causes infectious bacterial keratitis?

staphylococcus aureus or in CL/cosmetics = pseudomonas aeruginosa


what is the chain of events that leads to bacterial keratitis?

1. pathogenic bacteria colonize cornea and become antigenic - release enzymes/toxins (antigen-antibody immune reaction and inflammatory reaction) 2. PMNs phagocytize/digest bacteria - create infiltrate 3. collagen stroma undergoes degradation/necrosis/thinning = scaring of cornea, perforation or endophthalmitis


the majority of bacterial primary care ulcers are small, peripheral and minimal AC reaction/discharge - what are they successfully treated with in outpatient?

3rd and 4th generation fluoroquinolones off/on label


what are some 4th generation fluoroquinolones used for used for bacterial keratitis off-label?

moxifloxicin (Vigamox) and gatifloxacin (Zymar)


what is a chlorofluoroquinolone used for bacterial keratitis off-label?

besifloxacin (besivance) with Durasite vehicle (increases ocular residence time) ** has non systemic counterpart - less chance of developing resistance


what are 3 fluoroquinolones used on-label for bacterial keratitis?

AzaSite (with Durasite)

Ciloxan (ciprofloxacin) for patients 12 or older

Ocuflox (ofloxacin) for patients 1 or older


how do you treat secondary iritis in patients that have bacterial keratitis?

cyclopentolate, homatropine, or atropine (dose is higher than with abrasions) - no steroids


when can you prescribe/use steroids in infectious bacterial keratitis?

after ulcer is sterile and before cornea epithelializes to speed healing and decrease inflammation and scarring


what are 4 situations when you should never use steroids alone?

epithelial (non-stromal) HSK, active bacterial or fungal infections, large corneal epithelial defects and if unsure of diagnosis


what is an exception to the rule for never using steroids alone for bacterial infections?

you can use a steroid alone IF there is clinically significant secondary inflammation (as damaging to cornea as infective organism)


what does the timing need to be in order for steroids to be beneficial in infectious bacterial keratitis?

the ulcer needs to be made sterile by the antibiotic - then it must be used while the ulcer bed is still open