RT Journal A1 HOWE L T1 TEnotomy or advancement JF Journal of the American Medical Association JO Journal of the American Medical Association YR 1909 FD July 17 VO LIII IS 3 SP 186 OP 191 DO 10.1001/jama.1909.92550030007002e UL http://dx.doi.org/10.1001/jama.1909.92550030007002e AB When Dieffenbach and his contemporaries began to operate for heterotropia they always divided the tendon of the muscle, or even the muscle itself toward which the eye turned. Naturally many of these eyes soon turned quite as far out of place in the opposite direction. Then operations for advancement were attempted, although at first only in a crude form. During the three-quarters of a century since that time ophthalmologists have differed in their opinions as to when to make tenotomy and when advancement. We have the important fact that thousand of eyes have been satisfactorily straightened by tenotomy, and, on the other hand, we know the unsatisfactory results of this operation which come to even the best operators, and the theoretical reason for advancement—that it is always better to strengthen one muscle than to weaken its opponent. An examination of the literature seems to indicate