19. Ophthalmology Flashcards
Contact lens-associated infectious keratitis is a medical emergency that causes a painful, red eye and opacification and ulceration of the cornea. Most cases are due to what organisms?
Gram-negative (PSEUDOMONAS and serratia)
Can also be due to Gram positive orgs and some fungi and amoebas. Most require topical broad-spectrum abx
Differentiate preseptal cellulitis from orbital cellulitis
Preseptal - infx of eyelid anterior to orbital septum
Orbital - more serious. infx posterior to orbital septum –> diplopia, pain with EOM, and ophthalmoplegia (eye mm paralysis). Can cause blindness
Leukocoria (white reflex instead of normal red reflex) is a sign of what until proven otherwise?
retinoblastoma
What is the most common predisposing factor for orbital cellulitis (proptosis, ophthalmoplegia, diplopia)?
Bacterial sinusitis
Presbyopia (farsightedness) is a common age-related decrease in what that leads to difficulty with near vision?
Lens elasticity
Note: middle-aged individual who has to hold books at arms length to read is classic
Patient wakes up with red eye and is entirely asymptomatic. Dx? management?
Subconjunctival hemorrhage
Observation - benign
Dendriform corneal ulcers and a vesicular rash in the trigeminal distribution of the cutaneous branch of the first division of the trigeminal nerve in an immunosuppressed patient
Herpes zoster ophthalmicus. Caused by VZV. Conjunctivitis and dendriform corneal ulcers characterize the eye involvement
Painless loss of monocular vision in a patient with hx of carotid artery disease is most likely caused by what? Fundoscopy shows ischemic retinal whitening and cherry red spots. Tx?
Embolism –> central retinal artery occlusion
Abruption of blood flow through central retinal artery –> ischemia of inner retina (ophthalmic a is first intracranial branch of the internal carotid)
Tx: Emergency! immediate intervention is ocular massage and high flow o2
Acute angle closure glaucoma can be precipitated by decongestant use (anti-cholinergic). Inc intraocular pressure can damage the optic n and lead to vision loss. What can be helpful to dx if the gold standard (gonioscopy) is not available immediately?
Tonometry - measures intraocular pressure
What Presents with inflammatory changes in the medial canthal region of the eye with S aureus and b-hemolytic Strep as the usual infecting organisms?
Dacryocystitis
Abscess located over the upper or lower eyelid usually caused by S aureus. Appears as a localized red, tender swelling over the eyelid
Hordeolum
Lid discomfort due to chronic, granulomatous inflammation of the meibomian gland. Hard, painless lid nodule
Chalazion
