Operation on the vertical muscles in cases of nystagmus.

ALTHOUGH it has been recognized for a considerable time that operation on a strabismus co-existing with nystagmus may have a beneficial effect on the nystagmus, it does not appear to have been until 1953 that work was published relating to operation on cases of nystagmus with the direct intention of improving this condition. Then, from three different continents within a short time, separate recommendations were made that, in cases of lateral jerky nystagmus worse in one direction than the other, operation on the medial and lateral recti should be considered. Anderson (1953) suggested a recession of the medial rectus of one eye and the lateral rectus of the other eye in cases of eccentric nystagmus where there was a marked difference in nystagmus to either side. This weakening of the rotators was to be done on the side on which the nystagmus is less evident. Kestenbaum (1953, 1954) recommended surgical rotation of the eyes in the direction of the rapid phase of a nystagmus by resection and recession or controlled tenotomy of the corresponding muscles. Goto (1954) recommended advancement of the appropriate muscles but no corresponding recession. These procedures must now be considered as useful additions to the treatment of nystagmus and, in a small number of recent cases, I have found them to be of benefit. In 1953, a case was referred to me in which there was a marked nystagmus in all directions of gaze except downwards, and this seemed to have some points of similarity with the type of case mentioned above. Although operation on similar lines would involve, at the least, recession of the four depressors it seemed justified by the severity of the disability produced by the condition. The results seemed to merit repetition in a similar case seen 3 years later and these two cases are the subject of the present communication.