Abstract
Purpose :
Inferior Oblique Over Action (IOOA) is commonly associated with congenital esotropia. However, the association of new-onset IOOA with acquired esotropia has not been studied. To explore this further, we analyzed the correlation between lateral rectus recession (LRrc) surgery and the incidence of IOOA.
Methods :
A retrospective chart review from January 2010 to December 2011 studied children over two and below 18 years who had lateral rectus recession for exotropia with subsequent post-operative esotropia. Exclusion criteria included patients who had an initial history of esotropia overcorrected by surgery resulting in a consecutive exotropia, patients for whom operative notes were unavailable and magnitude of lateral rectus recession was unknown. Sixty-five patients (116 eyes) met inclusion criteria. Baseline measurements of age, sex, presence of central nervous system pathology, number of surgeries, laterality, and magnitude of recession were tested for association with IOOA. Primary outcome was the relationship between baseline measures and incidence of IOOA.
Results :
Included were 116 eyes and 65 patients total. IOOA was observed in 9 eyes of 6 patients (7.8 and 9.2% respectively) and demographics were similar for those with and without IOOA (p>0.05). No statistically significant relationship was found between the incidence of IOOA and laterality (p=0.13), number of surgeries (p=0.20), age at most recent surgical lateral rectus recession (p=0.49), presence of central nervous system pathology (p=0.99), or sex (p=0.54). A statistically significant association was found between magnitude of LRrc and the incidence of post-operative IOOA (p=0.005). The mean distance of recession was 7.3 ± 0.1 mm (mean ± SEM) for eyes that did not develop IOOA and 8.4 ± 0.4 mm for eyes that did develop IOOA. The odds ratio for the development of IOOA given a one millimeter increase in recession was 1.76 (CI 1.19 - 2.60, p=0.005). This indicates that the odds of IOOA increase 76% for each additional millimeter of recession.
Conclusions :
Magnitude of surgical LRrc is positively associated with the incidence of post-operative IOOA in a dose-dependent fashion in children with consecutive esotropia. This finding may help elucidate the etiology of IOOA.
This is a 2021 ARVO Annual Meeting abstract.