Ophthalmology Flashcards
What are the vision screening principles? (I-ARM)
- Inspection - Evaluation for pupil and eyelid symmetry, face or head tilt, conjunctival redness, and squinting
- Acuity assessment
- Neonates and infants: evaluation of eye fixation and pupillary responses
- Children: use of eye charts or cards
- Red reflex assessment - single best screening examination for infants and children
- Motility assessment of each eye and assessment of alignment (Hirschberg test)
Why is visual accuity poor at birth?
When does it improve?
Immaturity of the visual centers in the brain responsible for vision processing
Rapidly improves during the first 3-4 months of life
What is the meaning of the following findings on red reflex examination?
- Dark, dull, or white reflex:
- Dark, dull reflex:
- Yellow or white reflex:
- Unequal red reflex:
- Brighter red reflex in a deviated eye:
- Dull reflex:
- Dark, dull, or white reflex: Cataract
- Dark, dull reflex: Vitreous hemorrhage
- Yellow or white reflex: Retinoblastoma
- Unequal red reflex: Anisometropia
- Brighter red reflex in a deviated eye: Strabismus
- Dull reflex: Glaucoma
Normal visual development is dependent on…(2)
- Proper eye alignment
- Equal visual stimulation of each retina
Visual development is most critical during the first __-__ months of life
3-4
What is binocular fusion? What is required for binocular vision to develop?
The integration of retinal images from both eyes into a single, three dimensional perception
Binocular cortical connections are present at birth but apropriate visual input from each eye is necessary to refine and maintain these neural connections
What is the most common cause of decreased vision during childhood?
Amblyopia
What can lead to impairment in stereopsis (depth perception)?
- Improper eye alignment
- Any pathologic condition that unilaterally blurs the retinal image (congenital cataracts)
What is amblyopia?
Poor vision caused by abnormal visual stimulation that results in abnormal visual development
What is the most comomn cause of red watery eyes in the first 24 hours of life?
Chemical conjunctivitis (lasts less than 24 hours)
What factors can lead to more severe vision loss with amblyopia?
When are children most susceptible to amblyopia?
The earlier the onset, the longer the duration of the abnormal stimulus, and the more blurry the image, the more severe the vision loss
The first 3-4 months of life
What is the best screening test for amblyopia in infants and preverbal children?
In older children?
- Infants: bilateral red reflex test
- older children: Formal acuity testing
What are the management steps in treating amblyopia?
- Ensure that there is a clear retinal image by correcting any refractive errors with eyeglases or surgically removing opacities
- Patching the normal eye forces the use of the amblyopic eye
- The earlier the intervention, the better the prognosis
What are some causes of neonatal conjunctivitis (during 1st month of life)?
- Infection acquired from the vaginal canal or from hand-to-eye contamination (Neisseria gonorrhoeae, Chlamydia trachomatis, herpes simplex)
- Chemical conjunctivitis results from drops or ointment that are typically instilled into a newborn’s eyes as prophylaxis against Neisseria gonorrhoeae (1% silver nitrate)
How do you distinguish conjunctivitis due to Neisseria vs. Chlamydia vs. herpes simplex?
- N. Gonorrhoeae: 2-4 days of life; purulent discharge, eyelid swelling and can lead to corneal ulcer
- C. Trachomatis: 4-10 days of life; serous or purulent discharge, variable lid swelling
- Herpes simplex: 6 days - 2 weeks of life; usually unilateral serous discharge
How is conjunctivitis treated when due to…
- N. Gonorrhoeae
- C. Trachomatis
- Herpes Simplex
- N. Gonorrhoeae: IV cefotaxime and topical erythromycin; treat parents
- C. Trachomatis: Oral erythromycin; treat parents
- Herpes simplex: IV acyclovir and topical trifluorothymidine
Define the following differential diagnoses for conjunctivitis
- Congenital glaucoma:
- Dacrocystitis:
- Endophthalmitis:
- Congenital glaucoma: Glaucoma characterized by clear tears, enlarged cornea, and corneal edema
- Dacrocystitis: Infection of nasolacrimal sac
- Endophthalmitis: Infection within the eye - rare and often results in blindness
What are the most common causes of red eyes in older infants and children?
- Viral
- Bacterial
- Allergic conjunctivitis
- Blepharitis (eyelid inflammation)
What diagnoses should be considered if history includes unilateral conjunctivitis?
- Foreign body
- Corneal ulcer
- Herpes simplex keratitis
What are the steps in evaluaiton of red eye in children?
- History
- Occular examination (I-ARM)
- Fluorescein staining of corneal epithelium to evaluate for abrasion of the corneal tissue
- Positive staining associated with trauma, ulcer, or hepes simplex keratitis
If there are eosinophils on conjunctival scraping or severe itching of the eye, the cause of conjunctivitis is most likely…
Allergy
What are the differences between features of bacterial and viral conjunctivitis?
Bacterial: Purulent, no preauricular lymphadenopathy and bacteria and PMNs on gram stain
Viral: Watery, preauricular lymphadenopathy common, no bacteria on gram stain
Both have minimal itching
What are the most comomn causes of bacterial conjunctivitis?
- nontypeable Haemophilus influenzae
- Streptococcus pneumoniae
- Moraxella catarrhalis
- Staphylococcus aureus
What are some clinical features of bacterial conjunctivitis?
Purulent discharge, conjunctival erythema, lid swelling; bilateral involvement is common
What is the management for bacterial conjunctvitis?
Topical antibiotics are effective and include sulfacetamide, polymyxin B and trimethoprim sulfate, gentamicin, tobramyicin, and erythromycin
What indications are there for referral to an opthalmologist with a child who has bacterial conjunctivitis?
Severe eye involvement, conjunctivitis associated with contact lenses, suspected corneal ulcer, or lack of improvement with topical antibiotics
Describe pharyngoconjunctival fever
An upper respiratory infection that includes pharyngitis and fever and bilateral conjunctivitis
What are the clinical features of viral conjunctivitis?
Severe watery conjunctival discharge, hyperemic conjunctiva, preauricular lymphadenopathy, and foreign body sensation cause by corneal involvement
Viral conjunctivitis is highly contagious and lasts for…
2-3 weeks
What is the management of viral conjunctivitis?
Cool compresses and topical nonsteroidal anti-inflammatory drug drops; abx if bacterial superinfection occurs
What virus leads to epidemic keratoconjunctivitis? (similar to pharyngoconjunctival fever but confined to the eyes)
Adenovirus
What are the clinical features of Epidemic keratoconjunctivitis?
- Petechial conjnctival hemorrhage
- Pseudomembrane along conjunctiva
- Photophobia from corneal inflammation (in 1/3 of patients)
- Lack of fever or pharyngitis
- Highly contagious
What is the management of epidemic keratoconjunctivitis? When should the child be referred to an opthalmologist?
Treatment is supportive, including cool compresses and topical NSAID drops
Children with corneal involvement should be referred to an opthalmologist
Which type of herpes causes ocular herpes simplex infection?
HSV-1 (initial exposure)
What are the clinical features of ocular herpes simplex virus?
Skin eruption with multiple vesicular lesions
Corneal ulcer (rare)
What is the management of ocular herpes simplex?
- Systemic or topical acyclovir may speed recovery if administered within 1-2 days of onset
- Topical antibiotics applied to the skin may prevent secondary bacterial infection
What type of hypersensitivity reaction leads to allergic conjunctivitis?
Type 1 hypersensitivity reaction
How is allergic conjunctivitis managed?
- Removal of environmental allergen
- Topical mast cell stabilizing drops, such as cromolyn
- Topical antihistamines
What is Hemorrhagic conjunctivitis?
What causes it?
Hemorrhagic conjunctivitis is a dramatic presentation of pediatric red eye in which the child presents with both conjunctivitis and subconjunctival hemorrhage
Causes include infection with Haemophilus influenzae, adenovirus, and picornavirus
What causes blepharitis?
Staphylococcus aureus infection
How is blepharitis treated?
Treatment includes eyelid hygiene, in which the eyelids are scrubbed twice daily with baby shampoo
Topical erythromycin ointment is also applied
What is nasolacrimal duct obstruction (NLD)?
Failure of complete canalization of the lacrimal system that results in obstruction to tear outflow
Where does obstruction occur in nasolacrimal duct obstruction?
Obstruction typically occurs distally at Hasner’s valve
What are the clinical features of NLD?
- Watery eye
- Matted eyelashes
- Mucus in the medial canthal area
- Bilateral involvement (1/3 of patients)
What is usually the only management needed for NLD?
What are secondary management options?
- Observation only is needed for most children
- Nasolacrimal massage may help open the distal obstruction
- Topical antibiotics are administered if infection is present
Describe NLD probing
A small steel wire is passed through the nasolacrimal system through Hasner’s valve into the nose - cures NLD obstruction in most cases
Typically performed between 6 and 12 months of age
What is amniotocele and what causes it?
Amniotecele is swelling of the nasolacrimal sac caused by accumulatin of fluid as a result of NLD obstruction
What are the clinical features of amniotocele?
Bluish swelling in the medial canthal area - represents fluid in the distended nasolacrimal sac
Infection may occur, manifesting as warmth, erythema, tenderness, and increased induration
What is the management for amniotocele?
- Local massage (if no infection)
- Intravenous antibiotics
- Urgent NLD probing (if infection)
Retinal hemorrhages are highly suggestive of…
Child abuse
What are some nonabuse causes of retinal hemorrhages?
Birth trauma, leukemia, increased ICP, malignant htn, bacterial endocarditis, ITP, and rarely cardiopulmonary resuscitation
How long does corneal abrasion take to heal?
24-48 hours
What are clinical features of corneal abrasion?
- Severe pain, tearing and photophobia
- Foreign body sensation
How is corneal abraison diagnosed?
Corneal abrasion is identified on fluorescein staining of the cornea
What are the managment options for corneal abrasion? When is an opthalmologist consulted?
- Placement of a protective shield or patch for 24-48 hours in severe cases
- Instillation of a topical antibiotic prevents bacterial superinfection
- Opthalmologic consultation to evaluate for a bacterial corneal ulcer if abrasion is associated with contac lens
What is hyphema?
Blood in the anterior chamber
What causes hyphema?
- Blunt trauma is the most frequent cause (tearing of iris vasculature)
- Iris neovascularization (diabetes, tumors, vascular diseases)
- Iris tumors (juvenile xanthogranuloma)
What are the clinical features of hyphema?
What are the complications?
- Impaired vision (blood aqueous fluid level may be seen)
- Complications
- Rebleeding 3-5 days after initial injury
- Glaucoma
- Staining of the cornea with blood
- Optic nerve damage (in kids with sickle cell)
What is the management for hyphema?
Opthalmologic consultation and bed rest for at least 5 days
What is the usual cause of orbital floor fracture?
Blunt trauma
In an orbital floor fracture, the _____ _____ and the ______ ______ ______ can become entrapped within the fracture
Orbital fat; Inferior rectus muscle
What are some possible negative outcomes of entrapment of tissues due to orbital floor fracture?
- Diplopia as a result of restricted vertical eye movement
- Strabismus
- Enophthalmos (backwards displacement of the globe into the orbit)
Numbness of the cheek and upper teeth below an orbital fracture may occur as a result of _______ ______ injury
infraorbital nerve
What is the management of an orbital floor fracture?
- Empiric oral antibiotics (prevent infectious contamination from the maxillary sinus)
- Surgical repair is indicated if diplopia persists 2-4 weeks after injury or if enophthalmos is significant
What is normal intraocular pressure in infants?
How high is the ocular pressure in infants with congenital glaucoma?
Normal pressure: 10-15 mm Hg
Congenital glaucoma: exceeding 30 mm Hg
What is the difference between congenital glaucoma and adult glaucoma?
Adult glaucoma - increased intraocular pressure that damages the optic nerve but does not change the size of the eye
Congenital glaucoma - not only restricts optic nerve injury but also expands the size of the eye because the eye wall is much more elastic during infancy
What anatomic abnormality leads to congenital glaucoma?
Outflow of aqueous humor is reduced because of maldevelopment of the trabecular meshwork
What is the inheritance of congenital glaucoma?
Autosomal dominant
What are the clinical features of congenital glaucoma? How often is it bilateral?
Tearing, photophobia, enlarged cornea, corneal clouding, and a dull red reflex
Bilateral involvement is present in 70% of patients
What is the management of congenital glaucoma?
Surgery to open outflow channels is almost always required
Topical or systemic medications such as ß-adrenergic and carbonic anhydrase inhibitors
What is retinopathy of prematurity (ROP)?
Proliferation of vessels seen in premature infants exposed to oxygen
What are some risk factors for ROP (besides high concentration oxygen exposure)?
- Low birth weight
- Young gestational age
- Blood transfusions
- Hyalin membrane disease
- Intracranial hemorrhage
What are some possible late complications of ROP?
Myopia, astigmatism, amblyopia, strabismus, and blindness
Opthalmologic examinations are performed every _-_ weeks in patients with ROP to monitor for progression
1-2 weeks
What is the management for severe ROP?
Retinal cryopathy and laser therapy
What are the two most important factors for prevention of ROP?
- Minimizing the amount of oxygen delivered
- Effective treatment of hyaline membrane disease
What is leukoria?
A white pupil - refers to an opacity at or behind the pupil that can be caused by a cataract, an opacity within the vitreous, or by retinal disease (retinoblastoma)
What are some general causes of congenital cataracts?
- Genetic syndromes
- Nonsyndromic genetic inheritance
- Metabolic derangements
- Intrauterine infections
- Trauma
What is the management of congenital cataracts?
Treatment includes evaluation for underlying disease and early surgery to prevent amblyopia
Surgery for congenital cataracts perfromed after _______ of age is associated with poor visual outcome
2-3 months
What is retinoblastoma?
A malignant tumor of the sensory retina
What is the average age at presentation for retinoblastoma?
13-18 months
What genetic abnormality is associated with retinoblastoma?
Mutation or deletion of a growth suppressor gene on both alleles on the long arm of chromosome 13 (requires 2 hits)
How is retinoblastoma inherited?
Autosomal recessive
What are the two most common presenting signs of retinoblastoma?
Leukocoria and strabismus
What is the hallmark finding for retinoblastoma on imaging?
Calcification within the tumor
How is retinoblastoma diagnosed?
Visual inspection with an opthalmoscope
How do you manage retinoblastoma when the tumor is…
- Large:
- Small:
- Very small and peripheral:
- Large: generally treated by removal of the entire eye
- Small: External beam radiation; however, radiation may induce formation of secondary tumors
- Very small and peripheral: Cryotherapy or laser photocoagulation
The cure rate for retinoblastoma is ___% if the tumor does not extend beyond the sclera or into the orbit
90%
What is strabismus?
Misalignment of the eyes
Describre the following terms (strabismus):
- Esotropia
- Exotropia
- Vertical
- Pseudostrabismus
- Esotropia: eye turned nasally
- Exotropia: eye turned laterally
- Vertical: eye turned up or down
- Pseudostrabismus: prominence of the epicanthal folds that results in the false appearance of strabismus even though the eyes are actually appropriately aligned
If strabismus occurs before 5-7 years of age, how is vision affected?
The child suppresses the image in the deviated eye. If this suppression is prolonged, amblyopia may result
How is vision affected if strabismus occurs later than 5-7 years of age?
The mature visual system is unable to suppress the image in the deviated eye, and diplopia results
How is strabismus managed?
How is it managed if it is associated with farsightedness?
- Occular patching to prevent amblyopia is important
- Surgery is often required to correct any misalignment that does not respond to patching or glasses
- Strabismus associated with farsightedness is intially treated with corrective lenses
