When botulinum
therapy was used for
esotropia with abnormal
retinal correspondence, the
esotropia improved effectively and
binocular function recovered. Transient overcorrected deviation appeared in 92% of different cases of
retinal correspondence. Patients without
binocular function and abnormal
retinal correspondence of various types were the subjects of this study. There were 18 congenital esotropes and 12 acquired esotropes. Before treatment, there was normal
retinal correspondence > abnormal
retinal correspondence (NRC >
ARC) in 5 cases, abnormal
retinal correspondence > abnormal
retinal correspondence (
ARC > NRC) in 8 cases, abnormal
retinal correspondence (
ARC) in 16 cases, and lack of
retinal correspondence (LRC) in 1 case and the
binocular function was incomplete in all cases.
Botulinum toxin (0.25-0.5 U) injected into the medial rectus muscles showed hypertonic action. The dose was adjusted according to the deviation angle. We found some changes in
retinal correspondence caused by the botulinum
therapy in 24 of the 30 patients (80%). Of these there was NRC in 6, NRC >
ARC in 11, and
ARC > NRC in 7.
Secondary esotropia was found in 92% of the 24 cases. We believe that improvement of
retinal correspondence is due to suppression of anomalous
retinal areas with the change of the overcorrected deviation after the usual visual direction disappears. Our results suggest that normal
retinal correspondence has a relatively wide range of correspondence area.