Ocular Trauma Flashcards
what are the most common causes for eyelid lacerations?
foreign body and dog bite
how should you treat eyelid lacerations?
FB = consider a CT scan
dog bite = tetanus prophylaxis
both will need stitching/surgical intervention
what are the common types of chemical burns?
alkali burns (more damage than acidic) - usually at work or at home
what determines the severity of the chemical burn injury?
duration of exposure, type of chemical and deviation of chemical’s pH from physiological pH (5.5-7.5)
what type of damage do acids cause in the eye?
cause denaturation and coagulation of proteins - resulting in clouding of the ocular surface
what type of damage do alkali substances cause in the eye?
cause saponificaiton (combination of fatty acids and proteins) resulting in liquefacative necrosis
what is the first question you ask a patient who has suffered a chemical burn?
has copious irrigation been performed? (need to make sure pH is closer to physiological before you stop = 15-30min)
what does conjunctival blanching indicate in chemical burns?
the level of blanching is a good indicator of the prognosis - the more blanching the worse the injury
what treatment do you give for a grade 1 chemical injury - no corneal opacity, no limbal ischemia and excellent prognosis?
antibiotics, topical steroids QID 1 week, preservative free AT’s, and cycloplegic to increase comfort
what treatment regimen do you give patients who have suffered grade 2, 3, or 4 chemical injuries?
topical steroid q1h x 10d then taper, cycloplegic, oral pain meds, topical broad spectrum antibiotic, oral doxycycline to reduce risk of corneal melting and topical/oral vitamin C (increase collagen healing)
what is a grade 2 chemical injury?
corneal haziness but visible iris details, ischemia < 1/3 of limbus and good prognosis
what is a grade 3 chemical injury?
significant cornea haziness to obscure iris detail, ischemia 1/3 to 1/2 limbus and guarded prognosis
what is a grade 4 chemical injury?
cornea is opaque - no view of iris or pupil, ischemia > 1/2 limbus, ischemic necrosis of proximal conjunctiva and sclera dismal prognosis
what are some chemical burn sequelae?
scarring, symblepharon formation, cicatricial ectropion/entropion, destruction of goblet cells (dry eyes), limbal stem cell deficiency, and elevated IOP (injury to TM)
what are the symptoms and signs of a corneal abrasion?
symptoms = sharp pain, photophobia, FB, tearing
signs = epithelial defect that stains with NaFl
what is the treatment for a corneal abrasion?
broad spectrum antibiotic QID, cycloplegic, bandage CL, T-patch/pressure patch, and topical NSAID
what is a sequelae of a corneal abrasion?
recurrent corneal errosion
when should you not use a pressure patch or a bandage CL?
if the patient is a CL wearer = cornea is already weaker
what is the purpose of cycloplegic drops in a corneal abrasion?
relieve pain by immobilizing the iris, prevent PAS, and stabilize blood-aqueous barrier to help further prevent protein leakage
what are the cycloplegic agents used for corneal abrasions?
cyclopentolate = TID for mild-moderate uveitits homatropine = BID for midl-moderate uveitis Atropine = BID-TID only for severe uveitis
what tests should you perform if a patient has a corneal foreign body?
VA prior to any procedures, locate/assess depth of FB, assess size of residual epithelium abrasion and perform DFE to rule out intraocular FB
which layers of the cornea can you still remove a FB from?
if anterior to Bowman’s layer - remove FB and any residual rust ring
what are the signs of a conjunctival laceration?
mild pain, FB sensation, hx of ocular trauma, NaFl staining of conjunctiva and torn up/rolled up conjunctiva
what is the treatment for a conjunctival laceration?
antibiotic ung QID, most heal on their own without surgical repair, follow-up 3-5 days and can pressure patch for large lacerations
what causes an iris sphincter tear?
usually due to blunt trauma
what are the signs and symptoms of an iris sphincter tear?
pupillary boarder has irregular shape, pupil of affected eye may be larger and less reactive to light - must differentiate from neurological etiology