ophthalmology II Flashcards
(38 cards)
What is near-sightedness due to
Near-sightedness occurs when the optical power of the eye is too large and causes light to focus in front of the retina
what is far sightedness due to
Far-sightedness occurs when the optical power of the eye is too small and causes light to focus behind the retina
what is astigmatism
Astigmatism describes the shape of the cornea and causes light to focus in front or behind the retina.
presbyopia
another form of refractive error however it results when the eye progressively losses its ability to focus on near objects. It is a symptom caused by natural aging as the lens becomes less flexible. Usually first occurs around 40-50 yrs. The ability to focus on near objects continues to decline throughout our lives
how is visual acuity tested
Standard Snellen Eye chart. Stand 20 ft away and measure one eye at a time, with glasses (or pinhole)
How are visual fields measured
Have patient look at your nose and cover one eye. Hold fingers in periphery at ask how many fingers present. Then repeat for other eye.
how is ocular motility measured
follow finger left, right, up and down
how are pupils tested
Are they round, reactive to light, equal,
how is external eye exam performed
use pen light to observe eyelids, conjunctiva, cornea and anterior chamber
What is the fundoscopic exam
using hand held ophthalmoscope, check red reflex, optic nerve and retina
causes of unilateral red eye
Viral or Bacterial Conjunctivitis, Iritis, Corneal Abrasion, Corneal Ulcer, Herpes Simplex, Herpes Zoster Ophthalmicus, Subconjunctival Hemorrhage
causes of bilateral red eye
dry eyes or allergic conjunctivitis
most common viral cause of conjunctivitis
adenovirus- or after respiratory tract infection
most common cause of bacterial conjunctivitis
staph aureus and strep peumoniae.
compare presentation of bacterial vs viral conjunctivitis
bacterial has more inflammation of conjunctiva. Viral appears more red. Bacterial will have thick, purulent discharge and eyelid can appear more swollen and almost closed
treatment of bacterial conjunctivits
eyedrops- Preferably 3rd or 4th generation fluoroquinolone (Ciloxan, Ocuflox, Zymaxid or Vigamox), Sulfacetamide or Tobramycin. Gentamicin drops can be toxic and cause irritation with prolonged use.
symptoms of iritis
ocular or periorbital eye pain, photophobia, blurred or cloudy vision, redness (near limbus), irregular shaped pupil
Iritis treatment
Topical Steroid Eye Drops (Pred-Forte), Dilating Eye Drops (help prevent synechiae within the eye and with pain), Occasionally Topical Glaucoma Drops
Causes of recurrent iritis
Ankylosing Spondylitis, Rheumatoid Arthritis, Behcet’s Disease, Crohn’s Disease, Ulcerative Colitis Lupus, Sarcoidosis, Syphilis, TB
Corneal abrasion - symptoms and diagnosis
severe eye pain or foreign body sensation with acute onset, tearing, blurred vision and redness. Can use fluorescein stain with blue light to see epithelial defect
corneal abrasions- treatment
milde: artificial tears and topical antibiotic. Large: antibiotic ointment and patching of eye, or contact lens. NO topical anesthetic eye drops b/c they delay healing
corneal ulcer- what is it, what causes it
Corneal ulcer is an infection of the corneal stroma.
Causes include bacterial (Staph aureus, Pseudomonas), fungal (Fusarium) and protozoa (Acanthamoeba). Caused by trauma with vegetative matter (fungal), contact lens wear (bacterial or protozoa) and risk 10 x higher for extended wear, dry eye, facial nerve paralysis.Corneal ulcer is an infection of the corneal stroma.
Causes include bacterial (Staph aureus, Pseudomonas), fungal (Fusarium) and protozoa (Acanthamoeba). Caused by trauma with vegetative matter (fungal), contact lens wear (bacterial or protozoa) and risk 10 x higher for extended wear, dry eye, facial nerve paralysis.
Corneal ulcer- symptoms
Acute onset with severe pain, redness, decrease in vision, eyelid swelling. White infiltrate in cornea, thinning of cornea at infiltrate, hypopyon inside anterior chamber.
corneal ulcer treatment
small: hourly trtmt with 4th generation fluoroquinolone. Large: require culture to determine the organism. Done with a calgi swab and placed on blood agar, Chocolate and Sabouraud’s plates. Also require fortified antibiotics including vancomycin and tobramycin. Slow healing and can leave scar with vision loss. Corneal transplant if risk of perforation
small: hourly trtmt with 4th generation fluoroquinolone. Large: require culture to determine the organism. Done with a calgi swab and placed on blood agar, Chocolate and Sabouraud’s plates. Also require fortified antibiotics including vancomycin and tobramycin. Slow healing and can leave scar with vision loss. Corneal transplant if risk of perforation