Ophthalmology Flashcards
What is normal IOP pressure?
10-21 mm Hg
Ocular hypertension 22-25 mmHg
Concern for glaucoma >30 mmHg
*most people >40 mmHg have some degree of eye pain
How to organize an approach to the red eye?
Extra vs. intra-ocular
Painless vs. painful
What are extra-ocular causes of red eye?
blepharitis chalazion, hordeolum dacrocystitis periorbital cellulitis orbital cellulitis
What are intra-ocular causes of red eye?
conjunctivitis - viral, bacterial, fungal, irritant corneal abrasions corneal ulcers/erosions keratitis - infectious, chemical, inflammatory iritis/uveitis, radiation episcleritis scleritis subconjunctival hemorrhage hyphema endophthalmitis acute angle closure glaucoma
Where is aqueous humour produced
ciliary body
What is the path of aqueous humour in the eye
ciliary body - posterior chamber - pupillary aperture - anterior chamber - canal of schlemm - absorbed into episcleral vein
What are 6 causes of floaters
o Retinal break or detachment o Posterior vitreous detachment o Vitreous haemorrhage o Vitreous debris o Posterior uveitis o Corneal opacity / FB
What are causes of flashes
o Retinal break or detachment o Retinitis o Posterior vitreous detachment o Migraine o CNS disorder → occipital lobe pathology
What type of bacterial conjunctivitis requires IV antibiotics instead of topical?
Gonoccocal conjunctivitis
What are 5 historical points to ask on review of systems?
floaters/flashers vision loss blurry vision redness pain headache tearing itching scalp tenderness
What are 10 points on ocular physican exam to include?
visual acuity pupillary response RAPD extra-ocular movements other cranial nerves color/red desaturation ocular pressure lid/lacrimation/external exam lymphadenopathy *pre-auricular conjunctiva/sclera cornea anterior chamber iris lens vitreous fundus
What are 10 points on ocular physican exam to include?
visual acuity pupillary response RAPD extra-ocular movements other cranial nerves color/red desaturation ocular pressure lid/lacrimation/external exam lymphadenopathy *pre-auricular conjunctiva/sclera cornea anterior chamber iris lens vitreous fundus
What 2 muscles innervate the eyelids? What nerves innervate these muscles?
orbicularis oculi - CN VII
levator palpebra - CN III
What are the 3 chambers of the eye?
anterior chamber - cornea to iris
posterior chamber - iris to lens
vitreous chamber - lens to retina
What are the 5 layers of the cornea? (superficial to deep)
- epithelium
- bowman’s layer
- stroma
- descemet’s membrane
- endothelium
What innervates the sensation in the cornea?
CN V - trigeminal nerve
What are 5 ocular causes of red eye that need urgent ophthalmology referral?
acute angle closure glaucoma infectious keratitis hyphema hypopion iritis/uveitis corneal ulcer
What are 5 ocular causes of red eye that need urgent ophthalmology referral?
acute angle closure glaucoma infectious keratitis hyphema hypopion iritis/uveitis corneal ulcer
What is the physiology behind hyperopia? myopia?
hyperopia: visual axis length too short
myopia: visual axis length too long
What are 2 classes of mydriatic drugs?
- Anticholinergic (dilation by paralyzing iris sphincter)
- tropicamide, cyclopentolate, homatropine
* also cycloplegic, paralyze ciliary body, will affect accommodation - Adrenergic (dilation by stimulating pupillary dilator)
- phenylephrine
* not a cycloplegic
What are 2 classes of mydriatic drugs?
- Anticholinergic (dilation by paralyzing iris sphincter)
- tropicamide, cyclopentolate, homatropine
* also cycloplegic, paralyze ciliary body, will affect accommodation - Adrenergic (dilation by stimulating pupillary dilator)
- phenylephrine
* not a cycloplegic
What are 4 types of glaucoma topical medications?
- Beta blockers
- timolol, levobunolol - Cholinergic agonists
- pilocarpine - Alpha 2 agonists
- brimonidine, apraclonidine - adrenergic stimulating
- epinephrine - carbonic anhydrase inhibitors
- acetazolamide, brinzaolamide, etc.
What is the mechanism of action of the different anti-glaucoma medications? (lower IOP)
- Beta blockers
reduce formation of aqueous humour by ciliary body - Cholinergic agonists
increase aqueous outflow through trabecular network - alpha 2 agonists
decrease aqueous production, increased uveoscleral (non trabecular meshwork) aqueous outflow - carbonic anhydrase inhibitors
aqueous humor suppression
What are 3 common causes of bacterial conjunctivitis?
non typeable H. influenza
S. aureus
S. pneumonia