Ophthalmology Flashcards
What is the eye disorder in each of the following: Marfan syndrome, CHARGE, Congenital CMV, JIA?
- Marfan → ectopic lentis
- CHARGE → coloboma
- Congenital CMV → chorioretinitis
- JIA → anterior uveitis
What are 3 causes of leukocoria?
- Retinoblastoma
- Cataract
- Vitreous hemorrhage (AHT)
- Coloboma
- Coat’s disease (subretinal lipid)
- Persistent fetal vasculature
- Ocular toxocariasis (after exposure to cat or dog feces)
- Retinal detachment
What are tests that can be done to assess for amblyopia or strabismus?
-
Hirschberg light reflex
- Look at the light reflex on the corneas
- If the eyes are straight, light reflexes should fall in the same place in each eye
-
Cover test
- Require a child’s attention/cooperation, good eye movement capability, reasonably good vision in each eye
- Comprised of 1) cover-uncover test 2) alternate cover test
-
By age:
- HOTV chart (four-letter shapes), tumbling E chart or Lea symbols (shapes) from 36mo of age
- Logarithm of the minimum angle of resolution, Lea Hyvärin (LogMAR LH) chart (standardized validated identifiable shapes) from 42 months of age.
- LogMAR Snellen chart (letters of the alphabet or numbers) after six years of age.
- The Allen chart (pictograms), previously widely used, is now thought to be too culturally specific to be helpful
What is the management of a hyphema?
- Urgent ophtho consult
- Minimize vision-threatening sequelae (rebleeding, glaucoma, corneal blood staining).
- Bedrest, head of bed to 30degrees, monitor intraocular pressure
- Limit activity for at least 1 week
- Eye shield without patch over affected eye until hyphema resolved or at least 1 week
- Cycloplegic agent to immobilize the iris
- Topical/systemic steroids to minimize intraocular inflammation
- Avoid all NSAIDs
- Topical/systemic pressure lowering agents if pressure is raised
When is the highest risk of re-bleeding in hyphema cases?
4-5 days after injury
What are possible complications of hyphemas?
- Glaucoma
- Permanent vision loss
What is the management for a corneal abrasion?
- Topical antibiotics (ointment)
- Cycloplegic if having photophobia
- NSAIDs for pain
- Remove FB if present
What is the management of orbital cellulitis?
- IV antibiotics → Ceftriaxone (if CNS symptoms) or Cefuroxime IV, total 14-21 day course with step-down
- HR: Cefuroxime IV 150 mg/kg/d divided q8h for 2-7 days followed by Amoxicillin clavulanic acid PO tid (amoxicillin component 45-60mg/kg/d, max 4 g/d) for a total IV +PO antibiotic treatment time of 14 days
- Note: usually don’t need to for cover S. aureus and anaerobes unless chronic sinusitis
- Treat underlying condition - nasal steroid spray/decongestant
- Urgent referral to ophthalmology → follow-up at least Q24h in sever cases
- CT/MRI imaging of orbits/sinuses to detect complications
- Possible surgical drainage of abscess → wide variation in threshold for surgery, consider if:
- VIsion threatened
- Superior → subperiosteal abscess (risk of frontal sinus spread to brain)
- Severe disease (drainage may shorten LOS and ABx duration)
What are the visual field findings for the following:
- Suprasellar/pituitary mass
- Optic tract lesion
- Parietal lobe lesion
- Temporal lobe lesion
- Occipital cortex lesion
-
Suprasellar/pituitary mass compresses chiasm
- Classic visual field defect = bitemporal hemianopia
-
Optic tract lesion
- Visual field defect = homonymous hemianopia
-
Parietal lobe lesion
- Visual field defect = inferior quadrantanopia
-
Temporal lobe lesion
- Visual field defect = superior quadrantanopia
-
Occipital cortex lesion
- Visual field defect = homonymous hemianopia with sparing of fovea
What are red flags at > 3-4mo for poor vision?
- Visually disinterested +/- stares at bright lights
- Forcefully rubs/pokes eyes
- Strabismus
- Nystagmus/searching eye movements
- Disconjugate eye movements
- Skew deviation
- Sunsetting
A child with a right cranial nerve seven palsy (CN VII) may suffer from:
- Inability to open the affected eye
- Inability to close the affected eye
- Poor corneal sensation
- Corneal ulcer and poor visual acuity
- B and D
5 – CN III is the columns that hold the eye open, CN VII is the hook that closes the lids, for CN V1 remember that that Five is for Feelings (sensation). Inadequate eyelid closure, reduced blinking, or reduced sensation may lead to corneal epithelial defects/ulcer and associated visual loss.
After being struck by a baseball to the right maxilla, a 6-year-old girl with eyelid swelling has pain, nausea and vomiting when she tries to look up. The most appropriate management is
- Urgent MRI brain
- Orbital floor fracture repair if symptoms persist >2 weeks
- Emergent CT orbits followed by surgery to free an entrapped inferior rectus muscle
- Consult ophthalmology to rule out papilledema and consult neurosurgery
- MRI brain within 2 weeks
3 - “White-eyed blowout” fracture (inferior rectus muscle entrapment) requires emergency management
A 2-year-old boy presents to the emergency department with the right eyelid inflammation. MRI demonstrates ethmoidal sinusitis with an obvious subperiosteal abcess of the medial orbital wall. The most important next step is
- Urgent drainage of the abcess
- Metronidazole IV
- Moxifloxacin PO and nasal decongestants
- Cefuroxime IV
- Saline nasal rinses
4/D – admission with IV antibiotic therapy and close follow up is recommended. Coverage for anaerobes is generally not required, but may be considered in the setting of chronic sinusitis.
A child with new onset eyelid ptosis, pupil dilation, exotropia and hypotropia most likely has
- CN III palsy
- CN VI palsy
- Cerebral aneurysm
- Horner syndrome
- Papilledema
Answer: A / 1
A 3-year-old child with recurrent chalazia and photophobia has a white ‘dot’ on the right cornea for the past few weeks. The most appropriate management is
- Incision and drainage of the chalazia
- Patch to treat the corneal abrasion
- Warm compresses and eyelid care
- Tetracycline PO
- Urgent ophthalmology consultation
5 / E – A white spot on the cornea is never normal. Cornea abrasions do not cloud the cornea, they cannot be easily seen without fluorescein staining.
An effective topical antibiotic for community bacterial conjunctivitis is
- a. Fusidic acid bid
b. Moxifloxacin tid
c. Polymyxin B sulfate/gramicidin qid
d. Gatifloxacin tid
e. Any topical antibiotic is effective for this self-limited condition
E – Relative to systemic antibiotics, topical antibiotics on the ocular surface provide extremely high antibiotic concentrations to the conjunctiva. This negates the need for culture and sensitivity testing for uncomplicated cases of community-acquired conjunctivitis: essentially all antibiotics (if used as prescribed) are effective in this scenario.
A 5 year old is struck in the eye by a foam projectile from a toy “Nerf” gun. On examination, the visual acuity is 20/80. The conjunctiva appears injected. The affected pupil is large and slightly oval. A red reflex is present. Which of the following diagnoses is MOST likely?
- Vitreous hemorrhage
- Microhyphema
- Traumatic optic neuropathy
- CN III palsy
- Ruptured globe
2 / B – Microhyphema.
- Hyphema is a common complication of blunt injury to the eye. The lack of any visible blood in the anterior chamber does not rule out a microhyphema (versus a ‘macro’, or ‘gross’ hyphema). A slit lamp exam is required to microscopically identify red blood cells in the anterior chamber.
- Significant blunt ocular trauma is often associated with a traumatic mydriasis with a slightly irregular pupil, indicating a significant injury to the iris sphincter muscle.
- This should be distinguished from a “peaked” (tear drop shaped) pupil that would suggest a corneoscleral laceration.
- CN III palsy involves more than pupil dilation and would not occur with this mechanism of injury.
- Traumatic optic neuropathy is characterized by an afferent pupil defect and is typically associated with profound vision loss at time of diagnosis. It is unlikely with this mechanism of injury in the absence of other eye findings.
- The presence of a red reflex suggests that there is no significant vitreous hemorrhage.
In your brightly-illuminated exam room, a 3-month-old boy’s right pupil is slightly smaller than the left. Which of the following findings would suggest Horner syndrome of the right eye?
- A severe right upper eyelid ptosis.
- The right iris appears lighter in colour than the left.
- A mild right proptosis.
- Optic disc edema in the right eye.
- Limited abduction in the right eye.
2 / B – Horner syndrome is characterized by a pupil that fails to dilate (miosis), along with mild ipsilateral ptosis (loss of Muller muscle function) and anhydrosis of the ipsilateral face. In its congenital form, interruption of the sympathetic tracts also results in asymmetric iris colour, usually in the form of inadequate pigmentation of the ipsilateral iris (iris heterochromia).
A 2-year-old girl has a new onset swollen, erythematous left knee. You consider a diagnosis of juvenile idiopathic arthritis (JIA). Which of the following will be most helpful in confirming this diagnosis?
a. Bilateral episcleral injection near the limbus (“ciliary flush”) b. Bilateral photophobia
c. Prominent blepharitis in both eyes
d. Mild enlargement of the globes
e. White blood cells in the anterior chamber of both eyes
E – Slit lamp examination by a trained examiner is the ONLY way to detect the chronic “silent” uveitis that gradually leads to irreversible vision loss in patients with JIA.
Which diagnosis could be suspected in a 5-month-old with exotropia and an abnormal red reflex?
- Bilateral retinoblastoma
- Monocular congenital cataract
- Myopia resulting from congenital glaucoma
- Infantile exotropia
- All of the above
E – Any media opacity within the eye can block light from entering and leaving the eye (including corneal lesion, hyphema, cataract, vitreous hemorrhage, retinoblastoma). Refractive error and strabismus do not produce an absent red reflex, but can produce asymmetric red reflexes.
A 2-month-old has “big, beautiful eyes”. It is hard to get her to open her eyes. You note tearing in the right eye. Red reflexes are present. What is the most likely diagnosis?
- Neurofibromatosis type 1
- Congenital glaucoma
- Nasolacrimal duct obstruction
- Persistent fetal vasculature
- Stickler’s syndrome (COL2A1 mutation)
2
An obese 16-year-old girl with headaches and blurry vision presents with new onset diplopia. She takes isotretinoin for acne. You detect an esotropia on cover testing. The diagnosis is:
- Right lateral rectus muscle dysfunction
- Right cranial nerve VI palsy
- Raised intracranial pressure
- Isotretinoin-induced intracranial hypertension
- All of the above
E – Raised intracranial pressure induces CN VI palsy, preventing the lateral rectus from abducting the eye(s) fully. In its most subtle form, this manifests as an esotropia that can only be detected with cover test while the patient fixates in side gaze on a distance target. Idiopathic and medication-induced intracranial hypertension is a common diagnosis that demands timely diagnosis to prevent permanent visual loss.
What is the most likely visual field defect arising from a large pituitary macroadenoma?
- Monocular visual loss
- Bitemporal hemianopsia
- Homonymous hemianopsia
- Superior quadrantanopsia
- Bilateral macular scotomata
2 / B - Lesions anterior to the optic chiasm produce monocular, ipsilateral visual field loss. Posterior to the optic chiasm, lesions produce bilateral homonymous field defects in the visual field opposite to the lesion. Chiasmal lesions classically impinge on the fibres from the nasal retina of both eyes, producing bitemporal visual field loss.
- Which scenario best describes amblyopia?
- Visual acuity improves to normal IMMEDIATELY when a myopic 6-year-old puts on her spectacles for the first time
- A 3-year-old with a congenital cortical arteriovenous malformation has a complete right homonymous hemianopia
- An 8-year-old has an obvious exotropia for 30 minutes before bedtime every night
- A baby’s congenital cataract is successfully in early infancy. After surgery, she wears a contact lens but still has poor visual acuity in the affected eye.
- A 5-year-old with optic nerve glioma has an afferent pupillary defect
- D – Amblyopia is a failure of normal visual development… the brain has not learned to see normally. Clinically, the visual acuity remains subnormal even when all causes of decreased acuity have been corrected. Instantaneous improvement in visual acuity with spectacle wear indicates refractive error, whereas a gradual improvement with weeks or months of continuous spectacle wear indicates amblyopia.
- Most cortical brain lesions spare visual acuity, but even if acuity were affected, this would represent a structural cause of vision loss rather than simply amblyopia. Intermittent strabismus that is only present for a small portion of waking hours tend not to develop amblyopia, as they are functioning binocularly most of the time.
- Even with “perfect” surgical treatment and aggressive visual rehabilitation, outcomes for congenital cataracts remain suboptimal, as deprivational congenital amblyopia has such a strong effect on visual development.
- An optic nerve lesion with an afferent pupillary defect is a structural cause of visual acuity loss, one does not need to postulate amblyopia as a cause for the poor vision.