Ophthalmology I-II Flashcards Preview

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Flashcards in Ophthalmology I-II Deck (20)
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1
Q

Macula

A

most critical part of retina, responsible for about 90% of vision.

2
Q

Refractive errors

A
  • near sighted, far sighted, astigmatism, presbyopia
  • near sightedness occurs when the optical power of the eye is too large and causes light to focus in front of the retina.
  • Far-sightedness (length of eye smaller) occurs when the optical power of the eye is too small and causes light to focus behind the retina.
  • Astigmatism: should have spherical cornea but here it is shaped like a football (light focuses in front and behind retina)–>blurry
  • Presbyopia:loses ability to focus on near objects. natural aging, lens becomes less flexible
3
Q

Test for visual acuity

A

Snellen eye chart
-distance at 20 feet

Confrontational visual fields.

4
Q

Ocular motiity

A

look for restrictions as moving finger left right up down

5
Q

Red reflex

A

During fundoscopic exam: light reflecting off of retina

6
Q

Red Eye

A

Unilateral:

  • viral or bacterial conjunctivitis
  • iritis
  • corneal abrasion
  • corneal ulcer
  • herpes simples
  • herpes zoster ophthalmicus
  • subconjunctival hemorrhage

Bilateral:

  • dry eyes
  • allergic conjunctivits
7
Q

conjunctivitis

A

inflamm of conjunctiva
viral or bac
few days in duration
complain of eye pain discharge, blurred vision, eyelids “glued shut in morning”

“pink eye”

Viral:
more common
after URI often
adenovirus most common org
moderate inflamm of conjunctiva (pink)
watery discharge
May have a pre-auricular lymph node enlargement
Treatment:
self limiting
hand hygiene
cool compresses, artificial tears
topical steroids if severe
Bacteria
strep, staph
purulent discharge
eye more inflamed
yellowish discharge
eyelids more swollen
Treatment: culture not routine, abx eyedrops, fluoroqinolones, sulfactemid, tobramycin
8
Q

Iritis

A

-inflamm of iris
-common in 20-40 year olds
Sx: ocular or periorbital pain, photophobia, blurred or cloudy vision
-redness near limbus
-may have irregular shaped pupil (inflamm in anterior chamber, adhesion of iris to lens can alter shape)
-Treatment:
topical steroid eye drops
dilating eye drops (help prevent synechiae within the eye and with pain)
occasionally topical glaucoma drops (decrease IOP)

Causes: idiopathic
second episode: systemic?
bloodwork: ankylosing spondylitis, RA, crohn’s, sarcoids, syphilis, TB, ulcerative colitis, lupus

9
Q

Corneal abrasion

A
  • scratch of cornea
  • painful
  • tearing, blurry vision, red, feeling of foreign body.

Dx: fluorescein stain (scratch or epithelial defect)

Treatment:
mild corneal abrasions treated with artifical tears, topical abx
-large: require abx ointment, patching of eye, or contact lens
-No topical anesthetic eye drops bc they delay healing
-risk of future abrasions

10
Q

Corneal ulcer

A
  • infection of corneal stroma
  • causes: bacterial (staph, pseudomonas), fungal (fusarium), protozoa (acanthemoeba)
  • Caused by trauma with vegetative matter (fungal), contact lens wear (bac/protozoa), and risk 10x higher for extended wear (sleep in contacts), dry eye, facial nerve paralysis
  • acute onset with severe pain, redness, decrease in vision, eyelid swelling

-White infiltrate in cornea (infec could spread)
-may see thinning of cornea where infiltrate is present
-May see a hypopyon inside anterior chamber
Treatment:
-hourly abx (small ulcers–fluoroquinolone.
-larger ulcers require culture to determine the organism, may require fortified abx including vancomycin and tobramycin
-slow healing
-can leave corneal scar with permanent vision loss
-can perform corneal transplant if not healing, or if becoming too thin and risking perforation

11
Q

Corneal foreign body

A
  • foreign material on corneal surface
  • metal, glass or organic material common
  • considered minor trauma
  • grinding metal, ceiling work, auto, hammering, windy days
  • suspicious for penetrating injury
  • may migrate (check under eyelids)

Treatment:
-remove (may not cause long term problems)

12
Q

Dry Eye

A
  • disorder of the tear film
  • Bilateral cause
  • common
  • redness, tearing, blurred vision, foreign body sensation
  • worsens toward end of day and activities that require attn (reading, computer work)
  • environmental influences (low humidity, etc)

Causes:

  • not making enough tears: sytemic (RA, lupus, Graves’s), meds (anti-histamines, pain meds, antidep)
  • also if tears evaporate too fast:
    (attn: computer, reading; environ: ceiling fans, AC)

Tests:

  • Schirmer’s test (paper strips, how far tears travel)
  • Fluoroscein stain (stippling pattern on cornea)

Treatments:

  • artificial tears
  • vitamins: omega 3, flax seed
  • med eye drops to help produce tears
  • modification of oral meds, treat underlying condition
  • punctal plugs
13
Q

Allergic Conjunctivitis

A
  • allergen irritates conjunctiva, often bilateral and seasonal
  • sx: itching, eyelid swelling, redness, water discharge
  • more common w/ hx of allergies, hay fever, asthma, eczema
  • Common allergens: pollen, animal saliva, air pollution, dust mites, smoke, eye drops

Dx: symptoms (Esp itchy eyes)

Treatment: 
OTC
topical antihist
topical mast cell stabilizer/antihist
topical steroids
14
Q

Herpes simplex (cause of red eye)

A

HSV1
corneal epithelium
“herpetic keratitis”
one of most frequent causes of permanent vision loss
–unilateral eye redness (can be bilat)
-pain, photophobia, decreased vision, tearing
-Fluorescein on ocular surface shows dendritic epithelial ulcer in branching pattern w/ terminal bulbs

Treatment:

  • most resolve spont (meds shorten duration)
  • topical trifluridine Q2H
  • Oral acyclovir
  • Once healed, can get corneal scar, which can cause blurred vision
  • ->contact lens;corneal tranplant
15
Q

Herpes Zoster

A

Herpes zoster ophtalmicus is a reactivation of VZV

  • represents about 10-25% of all cases of Herpes zoster, up to 65% develop ocular manifestations
  • derm involvement of V1 distribution
  • Sx include prodromal period of fatige, low grade fever, unilateral rash on forhead, upper eyelid, nose
  • Ocular involvement more likely if there is lesions affecting the tip of the nose (Hutchinson sign) –both inn by nasociliary nerve.
  • sx include unilateral eye pain, redness, decreased vision, photophobia
  • Fluorescein can show mutliple swollen lesions with staining around them.

Treatment:
antivirals (systemic)

May devel neurotrophic cornea and pts are at risk for chronic dry eye and infections requiring chronic artificial tear supplements.

16
Q

Pterygium

A
  • “wing”
  • benign fibrovascular tumor, UV induced
  • often becomes inflamed
Treatment:
artificial tears
sunglasses
vasoconstrictors (short term)
conjunctival autograft with Tissel glue
17
Q

Subconjunctival hemorrhage

A
  • ruptured blood vessel under the conjunctiva
  • can be in absence of trauma
  • Usually asx

sneezing, coughing, eye rubbing, trauma, no treatment necessary

18
Q

Angle closure glaucoma

A

RFs: ethnicity (asian), age (6th-7th decade), hyperopia

  • sx: unilateral severe eye pain, nausea, redness, vlurred vision, halos around lights
  • Exam may show sluggish, mid-dilated pupil, conjunctival injection, hazy cornea and shallow anterior chamber. When palpating – feels hard.
  • aq fluid in anterior chamber, produced by ciliary body. flows thru pupil through anterior chamber then leaves eye thru trabecular meshwork. Acute attack: Iris becomes adherent to lens , fluid has nowhere to go, pushes iris forward and closes off meshwork

Treatment:
-laser (hole in iris, so aqueous can get to anterior chamber and opens up trabecular meshwork, fluid leaves eye)

19
Q

Open angle glaucoma

A
  • progressive
  • impacts optic nerve, associated with increased IOP
  • RFs: age, ethnicity, myopia, FH
  • Pts usually don’t experience sx as it slowly causes damage to peripheral vision
  • elevated IOP stresses optic nerve, leading to nerve cell damage and enlargment of optic nerve (want cup less than 50% diameter)
20
Q

Cataracts

A

-common
-clouding of eye’s lens. (lens help focus light)
-can cause progressive decline in vision as it obstructs light from entering eye.
-looking thru “dirty glass”
-usually develops with age as lens prot break down
other causes in younger pts:
-diabetes
-steroids
-trauma
-radiation

May need surgical intervention.
phacoemulsification involves lens removal using an ultrasound probe
-cataract replaced w/ artificial lens and is necessary for functional vision post-op.
–>monofocal lenses common, also bifocal for distance and reading