Residual Strabismus in Children Following Improvement of Cranial Nerve Palsies Affecting Ocular Ductions

Abstract

Background Children with brain neoplasms often develop cranial nerve palsies (CNP) affecting ocular ductions. Duction deficits may improve or resolve with treatment of their intracranial disease. However, these children may be left with residual strabismus. Methods We identified 104 children with third, fourth, and/or sixth cranial nerve palsies who were treated for central nervous system (CNS) neoplasms. A retrospective chart review was conducted to determine the presence or absence of residual strabismus following resolution of duction deficits. Results Of the 104 children with CNP secondary to an intracranial neoplasm, forty-five had improvement or resolution of their duction deficit with treatment of their CNS lesion. Of these forty-five children, one had a third cranial nerve palsy, six had fouth cranial nerve palsies (one was bilateral), thirty-seven had sixth cranial nerve palsies (thirteen were bilateral), and one had two different cranial nerve palsies in the same eye (fourth and sixth). Of the eighteen children with improved (but not resolved) duction deficits, only three (17%) experienced resolution of their strabismus. Of the twenty-seven children with resolved duction deficits, nine (33%) experienced resolution of their strabismus. For the children with residual strabismus, the average angle of strabismus before duction deficits improved or resolved was 33.2Δ; while for those children without residual strabismus, it was 20Δ. Conclusions Our findings indicated that the majority of children with improved or resolved duction deficits from CNP after treatment for CNS neoplasms are left with residual strabismus. Therefore, we suggest children with CNP secondary to CNS neoplasms need ophthalmic care after duction deficits resolve, as they are likely to have residual strabismus.