Clinical Features and Evaluation
The eyes may have equal vision, in which case alternate fixation or cross-fixation will be present. Cross-fixation, the use of the adducted eye for fixation of objects in the contralateral visual field, is associated with large-angle esotropias (Fig 8-2). Amblyopia is, however, commonly associated with infantile esotropia, and when it is present, a fixation preference can be observed.
Figure 8-2 Infant boy with left esotropia. Cross-fixation of the right eye from the adducted position.
(Courtesy of Katherine A. Lee, MD, PhD.)
Versions and ductions are often normal initially. The deviation is comitant and characteristically larger than 30Δ. Overelevation in adduction and dissociated strabismus complex develop in more than 50% of patients, usually after 1–2 years of age. There may be an apparent abduction deficit because of cross-fixation; children with equal vision in both eyes have no need to abduct either eye on side gaze. If amblyopia is present, the better-seeing eye will fixate in all fields of gaze, making the amblyopic eye appear to have an abduction deficit. The infant’s ability to abduct each eye can be demonstrated with the doll’s head maneuver or by observation after patching either of the patient’s eyes. The clinician can also hold the infant and spin in a circle, which stimulates the vestibular-ocular reflex and helps demonstrate full abduction.
Asymmetry of monocular horizontal smooth pursuit is normal in infants up to age 6 months, with the nasal-to-temporal direction less well developed than the temporal-to-nasal. Patients with infantile esotropia, however, have persistent smooth-pursuit asymmetry throughout their lives. Fusion maldevelopment nystagmus syndrome (also known as latent and manifest latent nystagmus) is also a commonly associated motility anomaly. Cycloplegic refraction characteristically reveals low hyperopia (+1.00 to +2.00 diopters [D]). Hyperopia greater than 2.00 D should prompt consideration of spectacle correction; reduction of the strabismic angle with glasses indicates the presence of an accommodative component.
A severe form of infantile esotropia, referred to as Ciancia syndrome, consists of large-angle esotropia (>50Δ), abducting nystagmus, and mild abduction deficits. Children with this syndrome uniformly use cross-fixation.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.