Ophtalmology Flashcards
A 15-year-old girl is brought to the office with:
Acute onset of left eye pain while inserting her contact lens
Complaint of blurred vision, tearing, and sensitivity to light
Uptake of fluorescein dye is seen during slitlamp exam.
What is the probable cause of this patient’s eye discomfort?
Corneal abrasion
Explanation
Symptoms of corneal abrasions include pain, tearing, photophobia, and blurred vision. Infants may present with inconsolable crying. Diagnosis is made with a slitlamp or Wood lamp after the application of fluorescein dye. Treat with a topical antibiotic ointment and oral analgesics. Although not routinely indicated, topical anesthetics may be used acutely to remove contact lens and for examination, but do not send them home with the patient. Eye patching is no longer considered effective. Recheck the patient within 24–48 hours to ensure resolution.
What condition involves the misalignment of one or both eyes?
Strabismus
Explanation
The misalignment can be in 1 of 4 directions:
in (esotropia)
out (exotropia)
up (hypertropia)
down (hypotropia)
Pseudostrabismus, on the other hand, has the appearance of misalignment; however, it is caused by a wide nasal bridge and/or epicanthal folds that obscure the nasal sclera. Corneal light reflex and cover/uncover tests are normal in pseudostrabismus. The tests are abnormal in strabismus.
Which type of involuntary rapid eye movement is normal in infants looking at objects moving across their visual fields?
Nystagmus (optokinetic)
Explanation
Nystagmus is a form of involuntary rapid eye movement (usually side-to-side). As we track objects across the visual field, eye movement is usually smooth (smooth pursuit). Infants often demonstrate optokinetic nystagmus (nystagmus induced by looking at objects moving across the visual field), attempting to provide stability of visual images while tracking. This is considered a normal part of visual development.
What diagnostic study is necessary for a firm diagnosis of orbital cellulitis?
CT scan of orbits
Explanation
Swelling of the eye and surrounding tissue is often extensive; the patient may not be able to open their eye for an examination of ocular movement. An orbital CT scan is usually required to confirm the diagnosis of orbital cellulitis. These children generally appear ill and should be admitted for IV antibiotics. If organisms are recovered, S. aureus or streptococci are usually identified, though orbital cellulitis is generally caused by multiple organisms.
A 10-year-old boy presents after being hit in the eye with a baseball. He is sleepy, nauseated, and complains of eye pain. You see a layer of blood obscuring the lower third of the iris. The pupil looks normal.
What is the most likely diagnosis?
Answer
Hyphema
Explanation
A hyphema is the presence of blood in the anterior chamber of the eye. It usually occurs after trauma. Occasionally, it can be spontaneous. In this scenario, also check for blowout fracture (e.g., diplopia, limited upward gaze) and a ruptured globe. Protect the eye with a rigid shield, control pain and nausea, and consult an ophthalmologist. Complications include glaucoma and rebleeding.
What is the most common cause of visual loss in children (and adults < 45 years of age)?
Answer
Amblyopia
Explanation
Amblyopia can result from childhood refractive disorders, strabismus, cataracts, corneal opacities, or an unequal refractive error between the eyes (anisometropia). Amblyopia is generally not correctable with glasses or contacts, but patching the better-seeing eye is recommended. The earlier treatment is started, the better the outcome.
Are full-term, normal-weight newborns farsighted or nearsighted, or do they have normal vision?
Answer
Farsighted (hyperopic)
Explanation
The normal eye at birth is farsighted (hyperopic) due to its size and shape. As the visual system matures, the eye elongates and becomes less farsighted. Although most full-term infants are mildly hyperopic at birth, premature and low-birth-weight infants tend to be less hyperopic or even myopic (nearsighted), often with some degree of astigmatism. ~ 45% of premature infants are myopic compared to 20% of full-term infants.
A playful 16-month-old boy presents with:
A recent history of an insect bite by his right eye
Swelling, redness, and warmth noted to his right eyelid and surrounding skin
No pain, chemosis, or proptosis
What is the cause of this child’s eye findings?
Preseptal cellulitis
Explanation
Rare complications of sinusitis, insect bites, and eye trauma are preseptal cellulitis and orbital cellulitis. Both include erythema, warmth, swelling, and tenderness to the eyelid and surrounding skin. Preseptal cellulitis is typically mild. Orbital cellulitis is much more severe and includes fever, eye pain with eye movement, vision loss, diplopia, proptosis, ophthalmoplegia, and chemosis. Besides a CBC and blood culture, obtain a CT scan of the sinuses/orbits if there is any possibility of orbital cellulitis.
