Structural Eye Disorders and Glaucoma B&B Flashcards
how does scleritis present?
dark red eyes, severe boring pain with eye movement (extra-ocular muscles insert on sclera) - potentially blinding
half of cases associated with systemic disease, esp. rheumatoid arthritis!
scleritis and episcleritis are both commonly associated with what systemic disease?
rheumatoid arthritis - disease of connective tissues, sclera is connective tissue of the eye!
how does episcleritis present?
[episcleritis is thin layer above sclera]
tear, localized redness, mild/no pain, self-limited
acute inflammation, usually idiopathic but often associated with rheumatoid arthritis
which patients are particularly at risk for keratitis?
corneal inflammation with bacterial/viral/fungal cause
contact lens wearers at risk! sight-threatening disorder if cornea becomes damaged
presents with pain, photophobia, red eye, foreign body sensation
corneal abrasions are common among contact lens wearers and can become infected with ______, and thus are treated with _______
pseudomonas - treat with ciprofloxacin (fluoroquinolone) eye drops
how does ocular disease caused by HSV-1 present?
HSV-1 causes herpes labialis (cold sores) and keratoconjunctivitis: infection of cornea and conjunctiva with pain/redness/discharge
most ocular disease is caused by recurrent HSV (reactivating after establishment of viral latency)
what are the most common viral (3) and bacterial (6) causes of conjunctivitis?
viral causes (80%): adenovirus (majority!), measles, HSV-1
bacterial: S. aureus, H. influenza, S. pneumoniae, Moraxella catarrhalis, Neisseria gonorrhea, Chlamydia,
how does the most common cause of conjunctivitis present?
80% of conjunctivitis is viral, and 60-90% of those are caused by adenovirus (naked, DNA, very stable on surfaces)
causes a watery discharge (not purulent like bacterial conjunctivitis!)
adenovirus also causes pharyngitis and pneumonia
what is the classic triad of measles infection (rubeola)?
enveloped, (-)RNA paramyxovirus
causes Cough, Coryza, Conjunctivitis + Koplik spots (mouth) and maculopapular rash
what are the typical causes of bacterial conjunctivitis in adults vs children? (3 each) what about in neonates (2)?
adults:
1. staph. aureus
2. strep. pneumoniae
3. H. influenzae
children:
1. H. influenzae
2. strep. pneumoniae
3. Moraxella catarrhalis
neonatal: Neisseria gonorrhea or chlamydia
what is given as prophylaxis for neonatal conjunctivitis?
aka ophthalmia neonatorum, caused by Neisseria gonorrhea or Chlamydia infection from passage through birth canal
untreated —> visual impairment
prophylaxis: erythromycin ophthalmic ointment
Reiter’s syndrome
triad of symptoms presenting with reactive arthritis (autoimmune arthritis following infection by intestinal bacteria or chlamydia trachomatis)
- arthritis (duh)
- conjunctivitis (red eye, discharge)
- urethritis (dysuria, frequency)
what 3 structures are considered part of the uvea?
- iris
- ciliary body
- choroid (vascular layer)
anterior uveitis =
intermediate uveitis =
posterior uveitis =
recall uvea = iris + ciliary body + choroid
anterior uveitis = iritis/iridocyclitis (pain, redness)
intermediate uveitis = vitreous humor inflammation
posterior uveitis = chorioretinal inflammation (floaters, decreased vision, no pain)
what are the possible etiologies of uveitis?
- infectious - agents that infect CNS (HSV, CMV, toxoplasmosis, syphilis)
- associated with systemic inflammatory disease (choroid = vascular layer of eyeball)
recall uvea = iris + ciliary body + choroid
hypopyon
inflammatory infiltrate in anterior chamber of eye
seen in endophthalmitis (inflammation of aqueous/vitreous humor), keratitis, uveitis
describe the life cycle of aqueous humor
- produced by ciliary muscle epithelium (stimulated by beta2 receptors)
- drained out of anterior chamber by trabecular network
- drained out of eye via Canal of Schlemm
how do the parasympathetic and sympathetic nervous systems regulate intraocular pressure, respectively?
PSN (via muscarinic receptors): constricts ciliary muscle allow aqueous humor to drain and lower intraocular pressure
SNS (via beta2 receptors): stimulates ciliary muscle epithelium to produce aqueous humor and increase intraocular pressure
what is the pattern of vision loss with glaucoma?
peripheral vision lost first, then central
open angle vs closed angle glaucoma (cause and presentation)
open angle (more common): overproduction or decreased drainage of aqueous humor —> chronic, no symptoms until loss of eyesight begins (peripheral first)
closed angle: angle for drainage suddenly closes —> abrupt onset of painful/red eye, blurred vision with halos, “rock hard” eye, ophthalmologic emergency!
what factors/drugs can trigger closed angle glaucoma?
closed angle: angle for drainage suddenly closes —> abrupt onset of painful/red eye, blurred vision with halos, “rock hard” eye, ophthalmologic emergency!
symptoms triggered when pupil dilates - such as entering a dark room or drugs with dilating effects (scopolamine, atropine)
how does glaucoma appear in fundoscopy?
“disc cupping” - optic disc appears large and bright like the sun
how are the following drugs used for chronic management of open glaucoma?
a. M3 agonists
b. alpha2 agonists
c. beta blockers
d. prostaglandin analogues
e. carbonic anhydride inhibitors
a. M3 agonists: contracts ciliary muscle (more drainage)
b. alpha2 agonists AND c. beta blockers: blocks ciliary epithelium from releasing aqueous humor
d. prostaglandin analogues: vasodilate Canals of Schlemm
e. carbonic anhydride inhibitors (oral acetazolamide): decrease aqueous humor synthesis
how do carbachol and pilocarpine treat open angle glaucoma?
parasympathomimetics (muscarinic agonists)
cause contraction of ciliary muscle —> opens trabecular meshwork for more aqueous humor drainage
how do apraclonidine and brimonidine treat open angle glaucoma?
alpha2 agonists —> decrease aqueous release from ciliary body epithelium
note can have ocular side effects - blurred vision, ocular hyperemia, foreign body sensation, itchy eyes
how are bimatoprost/latanoprost/tafluprost/travoprost used in the management of open angle glaucoma?
all PROSTaglandin analogues (“-prost”)
vasodilate Canals of Schlemm —> more drainage/outflow
note, will darken iris
how does latanoprost treat glaucoma?
Prostaglandin analog (prodrug for PGF2a) - increases uveoscleral outflow in treatment of glaucoma
latanoPROST[aglandin]
how does brinzolamide treat glaucoma?
Carbonic anhydrase inhibitor - decreases aqueous humor production
how does apraclonidine treat glaucoma?
Alpha-2 agonists - Decreases aqueous humor production, increase uveoscleral outflow
for what eye disorder is bevacizumab used?
Age-related macular degeneration - blocks neovascularization mediated by VEGF
what is the biggest modifiable risk factor for both wet and dry age-related macular degeneration (ARMD)?
smoking
wet vs dry age-related macular degeneration (ARMD)
wet/exudative/neovascular: minority, severe vision loss, choroidal neovascularization may cause subretinal hemorrhage, treated with anti-VEGF
dry/nonexudative: majority (80%), slowly progression pigment changes, peripheral vision lost first, geographic atrophy at end stage (dense scotoma/blind spots in areas of atrophy)
papilledema vs papillitis
papilledema = bilateral optic disc edema due to elevated intracranial pressure
(intracranial mass, pseudotumor cerebri, cerebral venous thrombosis, Chiari, aqueductal stenosis)
papillitis = unilateral or bilateral, due to optic nerve inflammation
(optic neuritis, HTN, diabetic, ischemic)
