In Reply.
—The letter from Drs Lang and Heinrich raises an interesting question regarding results of the Prism Adaptation Study. Their observations are based in part on summary statistics from our article that are not ideally suited for answering their question. Table 1 sheds light on the question of successful outcome vs age at onset of strabismus.Table 1 shows the percentages of cases of orthotropia and motor success as defined by the study design (ie, absolute deviation of 0 to 8 Δ 6 months after surgery as measured by an examiner blinded to group assignment; see also the results of Repka and Wentworth1). Table 1 shows that (a) for the study's original definition of motor success (absolute deviation of 0 to 8 Δ), there definitely is not a clear trend of increasing success with increasing age at onset of strabismus; (b) there is some evidence for such a