VISION ASSESSMENT OR SCREENING - Vision assessment should be performed at every well child exam during first few years to prevent permanent vision loss - During infancy: by observation fixation and tracking
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- Older infants and children: cover-uncover test for strabismus - Age 3 onwards: monocular visual acuity using Snellen’s chart or tumbling E chart. Visual acuity worse that 20/40 at 3-5 years or worse than 20/30 at >6 years ophthalmologic evaluation for refractive errors - Abnormal red reflexes, misalignment, pupillary asymmetry of >1mm, corneal asymmetry, ptosis or other lesions obstructing the visual axis, and nystagmus are additional indications for referral.
Can be intermittent or constant - Ocular malalignment due to nasal deviation (esotropia) or rarely temporal deviation (exotropia) - (watch video of cover test on youtube) - Intermittent strabismus can be expected in infants age <4 months due to immaturity of the extraocular muscles (ocular instability of infancy) reassurance and abservation - Esotropia beyond early infancy must be treated to prevent amblyopia (vision loss from disuse of deviated eye). The first 5 years of life are extremely critical to the development of visual acuity as it is the time for visual cortex maturation. During this stage, any anomaly (eg, strabismus, refractive error, cataract) can compromise vision. PSEUDOSTRABISMUS - Provide reassurance
Major cause of blindness worldwide - Caused by Chlamydia trachomatis A-C - Active phase: follicular conjunctivitis and pannus (neovascularization) formation in cornea. Concurrent infection occurs in nasopharynx nasal discharge - Dx: Giemsa stained examination of conjunctival scrapings - Rx: topical tetracycline or oral azithromycin—start immediately - Repeated infections corneal scarring
OPTIC GLIOMA IN NEUROFIBRAMATOSIS TYPE 1 - Occurs in 15% pts with NF, type 1 (axillary freckling and café-au-lait spots) - Occurs mostly in children <6yrs - H/o slowly progressive u/l visual loss and dyschromatopsia - Exophthalmos sometimes present - Optic disk may be normal, swollen, pale or atrophic Retinal hamartoma typical of tuberous sclerosis
RETINOBLASTOMA - Every case of leukocoria is considered retinoblastoma until proven otherwise refer to ophthalmologist - Most common intraocular tumor of childhood - Inactivation of tumor suppressor Rb gene familial or sporadic - Highly malignant delay in treatment mets to liver and brain death - Other manifestations: strabismus, ↓ vision, ocular inflammation, eye pain, glaucoma, and orbital cellulitis - Dx: highly suspected on US or CT findings of mass with calcifications