Eye Emergencies Flashcards
What is a pinhole device used for?
Opaque disc with one/more small holes through it - used to test for visual acuity.
What is the opthalmascope used for?
Monitor pupil reactions.
What does the fraction indicate on a Snellen chart?
Numerator - top number equates to the distance (m). Denominator - position on the chart of the smallest line read by the ‘patient.’ e.g. 6/60 means the subject can only see the top letter when viewed at 6m.
Define the marcus gunn response.
When each pupil responds differently when the light is shone into them. Indicates dysfunction in the optic nerve/retina. Pupil dilates when light shone.
State where an extraocular foreign body would be found.
Cornea and subtarsal (inner eyelid surface).
State a symptom of an extraocular foreign body.
Pain. Foreign body sensation. Reddening of conjunctiva. Reduced visual acuity.
State a treatment for extraocular foreign body.
1) Topical anaesthetic e.g. tetracaine, benoxinate, proxymetacaine 2) Remove embedded corneal FB with needle attached to cotton-tipped applicator (CTA)
State 2 signs of an intraocular foreign body.
Pain. Eye pain - following explosion. Markers - peaked pupil (pupil comes out), aqueous leak on fluorescein staining (used with blue light). Iridiodialysis - separation/tearing away of iris from ciliary body.
State a cause of corneal abrasion.
Poke in the eye.
State a symptom of corneal abrasion.
Erythema (inflamed blood capillaries) with edema of eyelids. Severe pain. Pain on light (photophobia). Reduced visual acuity.
State a treatment of corneal abrasion.
Chloramphenicol ointment (dilates iris). Pain relief.
State how you would treat a chemical ocular injury.
Extraction of fluid then check pH (flush until normal pH 6.5-8.5). Chloramphenicol ointment (antibiotic used to treat bacterial infections). Opioid analgesia.
Define a dendritic ulcer.
A form of keratitis (inflammation of the cornea), caused by recurrent herpes simple virus (HSV) infection.
State symptoms of keratitis.
Pain. Impaired eyesight. Photophobia (light intolerance). Red eye.
Define the pathophysiology of keratitis.
Inflammation of the anterior chamber of the eye (find leukocytic exudate).
State a treatment of keratitis.
Antibacterial solutions e.g. levofloxacin, gatifloxacin, moxifloxacin, ofloxacin. Aciclovir (main treatment for HSV).
State a complication of keratitis.
Corneal leukoma e.g. scar tissue formation with prescence of corneal vascularisation. Irregular astigmatism e.g. uneven healing of stroma (thickest layer of the cornea). Corneal perforation may result in endopthalmitis (inflammation of intraocular cavities).
State the difference between corneal abrasion and corneal ulcer.
Corneal abrasion - fluorescein stain +ve, transparent look, normal contour of cornea, epithelium only.
Corneal ulcer - fluorescein stain +ve, opaque, uneven colour, stroma involvement.
State another name for conjunctivitis.
Pink eye.
State a common bacteria associated with keratitis.
Streptococcus. Pseudomonas. Enterobacteriacae (including Klebsiella, Enterobacter, Serratia and Proteus). Staphylococcus species.
Define conjunctivits.
Inflammation of the outermost layer of white part of eye.
State a symptom of conjunctivitis.
Pain. Burning. Scratchiness. Itchiness.