Lids/conjunctiva/cornea Flashcards
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?
- 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
what signs do you look for in bacterial keratitis before you taper off drops?
infiltrate shrinks (less stain), epithelium fills in (no plug or stain), patient feels better, and any AC reaction is reduced/eliminated
when do you take a culture with infectious bacterial keratitis?
before antibiotic drops are applied - most yield negative results from scrapping **do not wait to begin treatment = use broad spectrum therapy
what is fortified antibiotic treatment for infectious bacterial keratitis?
cephalosporin (Gm +) alternated with aminoglycosides (Gm - ) compounded by a pharmacist *Fortified Ancef + fortified Tobramycin
when should you see a patient for follow-up with infectious bacterial keratitis?
in the first 24 hours (admit patient to hospital if you are uncertain of their compliance to treatment)
what causes primary herpes simplex?
acquired from environment
how do patients with primary herpes simplex often present?
unilateral vesicular blepharoconjunctivitis, pruritic (itching) of the lids/skin, follicular conjunctivitis, membrane formation and +PAN
what is the treatment for primary herpes simplex skin lesions?
warm saline soaks, drying agents (Burow’s solution or 70% alcohol), topical antibiotic gtt/ung no steroid needed = HSK skin lesions do not scar
what is the treatment for primary herpes simplex lid lesions?
Vira-A not effective topical acyclovir (Zovirax cream)
what is the treatment for primary herpes simplex blepharitis?
if conjunctivitis only (no keratitis) = no antivirals
broad spectrum antibiotic (polytrim, vigamox, zymar, besivance)
lubricants/cool compresses
OTC vasoconstrictors QID
NO STEROIDS