Ophthalmology I-II Flashcards
Macula
most critical part of retina, responsible for about 90% of vision.
Refractive errors
- 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
Test for visual acuity
Snellen eye chart
-distance at 20 feet
Confrontational visual fields.
Ocular motiity
look for restrictions as moving finger left right up down
Red reflex
During fundoscopic exam: light reflecting off of retina
Red Eye
Unilateral:
- viral or bacterial conjunctivitis
- iritis
- corneal abrasion
- corneal ulcer
- herpes simples
- herpes zoster ophthalmicus
- subconjunctival hemorrhage
Bilateral:
- dry eyes
- allergic conjunctivits
conjunctivitis
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
Iritis
-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
Corneal abrasion
- 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
Corneal ulcer
- 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
Corneal foreign body
- 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)
Dry Eye
- 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
Allergic Conjunctivitis
- 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
Herpes simplex (cause of red eye)
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
Herpes Zoster
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.
