Infantile esotropia

Presentation

The condition was historically termed congenital strabismus, but that label was considered inadequate because it grouped esotropias with differing causes, features, and prognoses. In 1988, Gunter K. Von Noorden described essential infantile esotropia as early acquired, not congenital, though congenital factors may favour its development between three and six months. He identified onset from birth to six months, a large stable deviation exceeding 30 dioptres, no central nervous system abnormalities, defective abduction with excessive adduction, oblique muscle dysfunction, dissociated vertical deviation, initial alternation with crossed fixation, and limited binocular potential.

Earlier, Cianca (1962) named Cianca's Syndrome and noted manifest latent nystagmus, while Lang (1968) called it Congenital Esotropia Syndrome and observed abnormal head postures. Helveston (1993) expanded the description to include esotropia between 10 and 90 dioptres, possible fixation preference with amblyopia, neurologically normal status, hyperopic correction not eliminating the squint, frequent nystagmus (latent or manifest latent), and possible associated conditions such as oblique muscle dysfunction, vertical incomitance, dissociated vertical deviation, asymmetric optokinetic nystagmus, and torticollis.

Presence is confirmed by six months, and best treatment yields subnormal binocular vision. The terms congenital esotropia, infantile esotropia, idiopathic infantile esotropia, and essential infantile esotropia are often used interchangeably.

Cause

The cause remains undetermined. A recent study by Major et al. reports that prematurity, family history or secondary ocular history, perinatal or gestational complications, systemic disorders, use of supplemental oxygen as a neonate, use of systemic medications, and male sex are significant risk factors. Further evidence suggests that neonates who suffer injuries perturbing binocular inputs into the primary visual cortex (V1) have a far higher risk of developing strabismus.

Treatment

A Cochrane review of 2023 notes that controversies remain regarding type of surgery, non-surgical intervention, and age of intervention, and that more good studies are needed. Treatment aims include eliminating amblyopia, achieving cosmetically acceptable alignment, long-term stability, and binocular cooperation. Early ophthalmologic referral is essential. A full eye examination identifies associated pathology, and glasses are prescribed to optimise acuity, though infantile esotropia is not typically linked to refractive error.

About 15% of patients have accommodative esotropia; for them, antiaccommodative therapy with spectacles is indicated before surgery, as it fully corrects the deviation in many cases and significantly reduces it in others. Amblyopia is treated by occlusion (patching or atropine drops) of the non-squinting eye to achieve full alternation. Management thereafter is surgical. Botulinum toxin therapy has also been used.

Craniosacral therapy may accompany ophthalmologic treatment to relieve tension. Controversy exists over surgical selection and planning—some favour a prescribed approach with multiple episodes, others aim for full alignment in one procedure with the number of muscles determined by squint size—and over timing and outcome.