Snapshot A 4-month-old boy is brought to the pediatrician by his parents after noticing he had a "lazy" eye. Birth history is unremarkable and there is no family history of such ocular findings. On physical exam, the corneal light reflex is notable for mild deflection of the light on the right eye. On cover testing there is refixation of the uncovered eye. The patient is subsequently referred to a pediatric ophthalmologist for specialized care. (Strabismus) Strabismus Clinical definition describes congenital or acquired misalignment of the eyes that can be horizontal vertical torsional Epidemiology incidence 2-4% of the population risk factors family history low birth weight vision deprivation e.g., congenital cataracts, corneal scars, retinoblastoma, and severe ptosis Presentation physical exam eye misalignment can see asymmetric corneal light reflex refixation of the uncovered eye with the cover test relatively intense red reflection on the deviated eye on Bruckner testing Differential pseudostrabismus Studies this is a clinical diagnosis based on a number of physical exam maneuvers such as corneal light reflex cover test cover and uncover test Bruckner test testing is based on clinical suspicion for underlying etiology e.g., ordering neuroimaging for children with neurologic disorders Treatment treatment is dependent on underlying cause e.g., strabismus caused by refractive error can be treated with refractive error correction occlusive therapy Complications amblyopia diplopia psychosocial and vocational impairment Amblyopia Clinical definition reduced visual acuity due to abnormal visual development in infancy or childhood this is considered a critical period of visual development Epidemiology incidence 1-5% worldwide risk factors strabismus refractive error vision deprivation e.g., congenital cataracts, corneal scars, retinoblastoma, and severe ptosis prognosis most patients can be successfuly treated if detected early Presentation symptoms visual deficit physical exam strabismus refer to the strabismus (above) section for a description of the physical exam maneuvers Differential retinoblastoma Studies a clinical diagnosis Treatment correct underlying cause strabismus eye realignment via glasses or surgery in severe cases refractive error refractive correction with glasses visual deprivation remove insult e.g., surgery to remove cataract patching or optic penalization patching occluding the "better" eye to encourage use of the amblyopic eye optic penalization atropine, a cycloplegic, is added to the "better" eye both are equally effective Complications permanent vision loss of the affected eye