Significance of congenital cyclo-vertical motor defects of the eyes.

THE fact that vertical disturbances are sometimes present in cases of horizontal strabismus has been early recognized and described. Strabismus surso-adductorius, a condition in which a marked upshoot of the eyes is seen in adduction, was first observed by von Graefe (1855) and accounted for in different ways by him and by others, who considered it as occasioned by an abnormal vestibular stimulation (Ohm, 1916, 1918), by anomalies of the scleral insertion of the internal rectus (Cords, 1922) or by an overaction of the inferior oblique (Graefe, 1875), either primitive (Bielschowsky, 1935) or secondary to an ipsilateral superior oblique or to a contralateral superior rectus insufficiency (Urrets-Zavalia, 1948a). Cases in which a downshoot of the adducted eye occurs, were also, although more rarely, noted by Ohm (1928), who attributed them also to labyrinthine disturbances. These findings were contemplated as exceptional (de Lapersonne, 1905), or at least as relatively uncommon; Ohm (1928), for instance, detected elevation in adduction in only 10 per cent. and depression in adduction in 1 per cent. of all his cases of congenital strabismus. Vertical defects, however, are much commoner than was previously suspected; yet only recently has sufficient attention been given to the fact that they are the underlying cause of a great number of cases of exotropia or esotropia which were thought to be purely concomitant (Chavasse, 1939; White and Brown, 1939; Malbran, 1940; Wagman, 1945; Anderson, 1947; Epstein, 1947; Urrets-Zavalia, 1948a, 1948b, 1948c, 1950a, 1950b, 1950c, 1950d, 1952; Spaeth, 1948). More than 6 years ago, we pointed out the fact that when such is the case, the observation of the position of the eyes in direct elevation and depression is extremely important, since these may give rise to a relative divergence or convergence of the visual axes of a prominent diagnostic value. We stated at the time that although these cases are truly concomitant inasmuch as the lateral component of the deviation does not alter in direct dextroversion and laevoversion, they are utterly incomitant in that the magnitude of that component varies within wide limits in pure elevation and depression (UrretsZavalia, 1948c).