Why do the eyes cross? A review and discussion of the nature and origin of essential infantile esotropia, microstrabismus, accommodative esotropia, and acute comitant esotropia.
OBJECTIVE
To try to explain the long-term stability of bilateral medial rectus botulinum toxin (botox) chemo-denervation in essential infantile esotropia; to evaluate divergent fusion amplitude in accommodative esotropia and acute comitant esotropia of emmetropes; to look for accommodation anomalies in high AC/A ratio accommodative esotropia and acute comitant esotropia of myopes; and to discuss characteristics of microstrabismus.


METHODS
Retrospective analysis of 61 essential infantile esotropia patients with early treatment with one botox injection in both medial rectus; measurement of divergent fusion amplitude in accommodative esotropia and acute comitant esotropia; measurement of Near point of accommodation in high AC/A ratio accommodative esotropia and acute comitant esotropia of myopes.


RESULTS
Stable results were found in 85.24% of essential infantile esotropia treated patients; reduced divergent fusion amplitude was detected in accommodative esotropia and acute comitant esotropia; hypo-accommodation was found in some patients with high AC/A ratio accommodative esotropia and a convergence spasm in acute comitant esotropia of myopes.


CONCLUSIONS
Very early botox treatment probably eradicates the effect of an excessive convergence tonus in essential infantile esotropia. A prevention of accommodative esotropia with full retinoscopic correction is only mandatory with a significantly reduced amplitude of fusional divergence. A deficit in accommodation should be looked for in high AC/A ratio accommodative esotropia, before bifocal lenses prescription. Early diagnosed acute comitant esotropia of myopic patients can be treated as a convergence spasm. Only surgery treats acute comitant esotropia, in patients with emmetropia or moderate hypermetropia.
Professor of Ophthalmology, University of Bologna, Bologna, Italy; Chief of Ophthalmology, St. Orsola-Malpighi Teaching Hospital, Bologna, Italy.
Emilio C
EC
Campos
D000065:Accommodation, Ocular / Q000502:physiology*; D000208:Acute Disease; D018450:Disease Progression; D004948:Esotropia / Q000209:etiology* / Q000503:physiopathology; D005133:Eye Movements / Q000502:physiology*; D006801:Humans; D007223:Infant; D011379:Prognosis; D012720:Severity of Illness Index; D013285:Strabismus / Q000209:etiology / Q000503:physiopathology