Diseases of the Eye

Question 0

age related macular degeneration features

Answer 0

characteristics: loss of central vision (bc macula is affected); blurred vision, distortion, scotoma are common

complete loss of vision almost never occurs!

peripheral vision preserved

Question 1

Most common cause of vision loss in ppl over 65y

Answer 1

age-related macular degeneration

Question 2

Most common causes of visual impairment/loss in developed countries

Answer 2

• diabetic retinopathy (most common cause in adults < 65 yrs)
• age related macular degeneration (armd) (most common cause adults > 65 yrs)
• cataracts
• glaucoma

Question 3

Risk factors age related macular degeneration

Answer 3

advanced age= #1!; female gender, caucausian race, smoking, htn, fam hx

Question 4

Categories of armd

Answer 4

1. exudative (wet): sudden visual loss due to leakage of serous fluid and blood as a result of abnormal vessel formation (neovascularization) under the retina
2. nonexudative (dry): atrophy and degeneration of central retina; yellowish-white deposits called drusen form under the pigment epithelium and can be seen with opthalmoscope

Question 5

therapies of armd

Answer 5

1. exudative/wet: intraocular injections (anti-VEGF inhibitors) have supplanted photocoagulation and other therapies
2. nonexudative/dry: over the counter formulations of vitamins

Question 6

Age-related macular degeneration (quick hits)

Answer 6

• “wet” form of ARMD can develop at any time, so patients with “dry” ARMD must be monitored closely
• supplements of certain vitamins containing antioxidants thought to be beneficial but preventative or therapeutic effect not proven
• ranibizumab (and several other related drugs) given as intraocular injection have been shown to be effective in reducing rate of visual loss in “wet” ARMD

Question 7

Most common cause of nonreversible blindness in African-Americans

Answer 7

Glaucoma

Question 8

Glaucoma

Answer 8

one of most important causes of blindness worldwide!

typically characterized by: increased intraocular pressure, damage to optic nerve, irreversible vision loss

pathogensis of optic nerve damage not fully understood, but may be due to:
- ischemia
…
loss of ganglion cells over time –> atrophy of optic disc (and enlargement of optic cup, called “cupping”)

Question 9

Types of glaucoma

Answer 9

1. open-angle glaucoma: 90% of all cases
   - impaired outflow of aqueous humor from the eye
   - absence of symptoms early in course can –> delay in dx and “silent” progression
2. closed-angle glaucoma
   - acute angle closure glaucoma: characterized by very rapid increase in intraocular pressure due to occlusion of narrow angle and obstruction of outflow of aqueous humor
   - -> this is an opthalmologic emergency that can lead to irreversible vision loss within hours if untreated!
   - may be precipitated by dilation of iris in a patient w preexisting anatomically narrow anterior chamber angle

Question 10

Risk factors for glaucoma

Answer 10

1. older age (> 50 yrs)
2. african american race (increased incidence of open angle glaucoma)
3. asian or eskimo ancestry (increased incidence of acute angle closure glaucoma)
4. family hx glaucoma
5. hx of significant eye trauma or intraocular inflammation
6. steroid medications

Question 11

Other sx in pts with acute angle closure glaucoma

Answer 11

severe abdominal pain and nausea, occasionally are misdx as having acute surgical abdomen (eg, appendicitis)

Question 12

Clinical features glaucoma

Answer 12

1. open angle glaucoma
   - painless, increased intraocular pressure (may be only sign), characteristic changes in optic nerve
   - progressive and insidious visual field loss (usually sparing central vision until end-stage dz)
2. closed angle glaucoma
   - red, painful eye
   - sudden decrease in visual acuity (blurred vision), seeing “halos,” markedly elevated intraocular pressure
   - nausea and vomiting (common), headache
   - involved pupil is dilated and nonreactive (in mid-dilation)

Question 13

Diagnosis of glaucoma

Answer 13

tonometry: measures iop
opthalmoscopy: evaluate optic nerve for damage
gonioscopy: visualize anterior chamber helps determine cause of glaucoma
visual field testing: perform in all pts in whom glaucoma suspected and regularly in everyone w glaucoma to monitor dz

Question 14

Goal of glaucoma treatment

Answer 14

control intraocular pressure, thereby prevent further damage to optic nerve and visual field defects

Question 15

Treatment of glaucoma

Answer 15

1. chronic open angle glaucoma (in escalating order)
   - topical meds: most 1st w beta blocker topically, alpha agonist, carbonic anhydrase inhibitor, and/or prostaglandin analogue singly or in combo to reach target pressure
   - laser or sx treatment for refractory
2. acute angle closure glaucoma
   - opthalmic emergency refer to optho immediately; emergently lower iop; medical trtmt includes pilocarpine drops, IV acetazolamide, and oral glycerin
   - laser or sx iridectomy = definitive treatment

Question 16

Cataracts

Answer 16

opacifications of natural lens of eye: half of ppl over age 75 have cataracts
- loss of visual acuity that progresses slowly over many years; pts may complain of glare and difficulty driving at night

risk factors: old age, cigarette smoking, glucocorticoids, prolonged UV radiation exposure, trauma, diabetes, Wilson’s disease, Down syndrome, and certain metabolic dzs

definitive treatment: sx; effective in restoring vision; indicated if visual loss significant to patient, interferes w activities;
extraction of cataract + implantation of artificial intraocular lens

Question 17

Red eye (most common cause)

Answer 17

many causes benign, but evaluation searching for need to refer to optho

most common cause: conjunctivitis

Question 18

Conditions causing/associated with red eye that require ophtho referral

Answer 18

• eye pain that does not respond to therapy
• flashers, floaters, sudden decrease in visual acuity
• hx of recent eye sx (esp if infection suspected)
• corneal opacification, corneal ulcer, or corneal foreign body that cant be removed
• hx of penetrating trauma or significant blunt trauma
• hx of chemical exposure (esp alkali agents)
• orbital cellulitis
• -> always check visual acuity, pupil size, reactivity; evert lids to look for foreign body

Question 19

“Second sight”

Answer 19

• some pts with cataracts become increasingly near-sighted and may no longer require reading glasses (–> referred to as “second sight”)
• phenomenon due to increased refractive power of lens of eye caused by cataract!

Question 20

Steroid eye drops

Answer 20

in general should be given by opthalmologist

Question 21

Differential diagnosis red eye

Answer 21

1. conjunctivitis
2. subconjunctival hemorrhage
   - caused by rupture of small conjunctival vessels; induced by valsalva maneuver trauma; less commonly coagulopathies or htn
   - -> focal unilateral blotchy redness of conjunctiva (looks worse than it is)
   - usually self-limiting, resolves in few weeks
3. keratoconjunctivitis sicca (dry eye)
   - long ddx (meds such as anticholinergics or antihistamines), autoimmune dzs (Sjogrens), CN V or VII lesions
   - eye may appearl normal or may be mildly injected
   - pts may complain of foreign body sensation
   - treat w artificial tears during day, maybe lubricating ointment at night
4. acute angle closure glaucoma
   - consult ophto immediately
5. blepharitis
   - inflammation of eyelid, often assoc w infection w staph species;
   - usually dx by careful exam of eyelid margins (red, often swollen w crusting that sticks to lashes)
   - treat w lid scrubs and warm compresses; give topical abx for severe cases
6. episcleritis
   - inflammation of vessels lining episclera (lining beneath conjunctiva)
   - thought to be autoimmune process (may be seen w connective tissue dzs)
   - causes redness, irritation, dull ache, possible watery discharge
   - sclera may appear blotchy w areas of redness over episcleral vessels
   - usually self limited; nsaids may provide symptomatic relief
   - refer pt for eval by ophto
7. scleritis
   - inflammation of sclera assoc w systemic immunologic dz (eg rheumatoid arthritis)
   - causes sig eye pain (severe, deep pain); on exam: ocular redness + pain on palpation of eyeball; can cause visual impairment
   - refer pt for prompt eval by optho
   - treatment: topical and sometimes systemic corticosteroids
8. acute anterior uveitis (aka iritis or iridocyclitis)
   - inflamation of iris and ciliary body; more common in young and middle aged
   - assoc w connective tissue dzs (eg, sarcoidosis, ankylosing spondylitis, reiter’s syndrome/reactive arthritis, ibd)
   - clinical findings: circumcorneal injection (redness most prominent around cornea), blurred vision, pain and photophobia, constricted pupil compared to contralateral eye
   - refer pt for prompt eval by optho
9. herpes simplex keratitis
   - caused by HSV1; may present similarly to viral conjuctivitis, except usually unilateral!
   - presents with ocular irritation and photohobia; pain may be absent
   - look for classic dendritic ulcer on the cornea; can result in irreversible vision loss if untreated
   - warrants semiurgent ophto referral
   - treat w topical antiviral eye drops; consider oral acyclovir for severe or refractory dz

Question 22

Viral conjunctivitis

Answer 22

highly contagious!!!

patients should avoid any direct or indirect eye contact w others; encourage strict personal hygiene and frequent handwashing; clean all surfaces and equipment in contact w patient as soon as patient leaves office

Question 23

When a patient presents w red and itchy eyes, tearing, and nasal congestion…

Answer 23

think allergic conjunctivitis!

aka most common cause of red eye

Question 24

Wearing contact lenses overnight

Answer 24

dramatically increases a person’s risk for developing corneal infection and ulceration

Question 25

Conjunctivitis

Answer 25

• most common cause of red eye
• generally refers to inflammation of transparent membrane lining inside of eyelides (palpebral conjunctiva) and the globe (bulbar conjunctiva)

Question 26

Do not send a patient home who has a rapid onset of copious, purulent exudate!

Answer 26

• consistent with hyperacute bacterial conjunctivitis, caused by neisseria gonorrhea
• typical patient is sexually active young adult
• sx: progress rapidly to severe redness, swelling, pain
• warrants immediate attention from opthalmologist
• if untreated, can lead to corneal scarring and blindness!

Question 27

Causes conjunctivitis

Answer 27

1. viral (most common form)
   –> adenovirus most common organism
   (ask about recent hx of uri); hyperemia of one or both eyes, watery discharge; palpable preauricular lymph node may be present
   - usually self limited
   - if membranous conjunctivitis: requires topical steroids and stripping of membrane
2. bacterial: most commonly caused by s.pneumoniae but also can be caused by gram neg orgs; rapid onset irritation, hyperemia, tearing; mucopurulent exuate w crusting
   * treat empirically w broad spectrum abx
   - acute: broad spectrum (erythromycin, ciprofloxacin, sulfacetamide)
   - hyperacute: treat gonococcal conjunctivitis w one time dose ceftriaxone 1g IM + topical therapy
3. chlamydial conjunctivitis
   trachoma: most common cause of blindness worldwide due to chronic scarring
   treat (adults and adolescents): oral tetracycline, doxycycline, erythromycin for 2 wks
   treat sex partners for std
4. allergic conjunctivitis
   - v common in pts w atopic dz, usually seasonal
   treat: remove allergen, cold compress, topical antihistamines or mast cell stabilizers; systemic anithistamines maybe; topical nsaids maybe as adjunct to treatment

Question 28

Amaurosis fugax

Answer 28

• presents: sudden, transient monocular loss of vision
• due to embolization of cholesterol plaque from carotid arterial system w retinal ischemia
• when reperfusion established (spontaneously), vision returns
• -> order carotid ultrasound and cardiac workup (lipid profile ekg)