Modification of the Kestenbaum operation for correction of nystagmic torticollis and improvement of visual acuity with the use of convergence.

In five patients with congenital nystagmus and compensatory head turn we performed a modified Kestenbaum operation intended to correct the compensatory head turn and to improve visual acuity. All patients had nystagmus without strabismus and fully developed binocular function. The nystagmus decreased but did not cease completely during the lateral gaze, and the patients adopted compensatory head turn positions to improve their visual acuity. The near acuity was better than the distance and the head turn decreased on near fixation. In such cases the original Kestenbaum procedure transfers the neutral zone to the primary position and corrects the head turn, but does not improve the visual acuity because a considerable amount of nystagmus is still present. Our aim was to perform an asymmetric Kestenbaum operation with a greater amount of surgery to the eye that turns out and a lesser amount to the eye that turns in, thus creating a postoperative divergence of the eyes. The result of compensating for this divergence (through stimulation of the fusional reserve) blocks the residual nystagmus of the neutral zone and, consequently, improves visual acuity. The results obtained from performing this modified Kestenbaum operation in five patients were very satisfactory. The compensatory head turn was corrected in all patients and remained so during the follow-up period. In four cases, the postoperative visual acuity in the neutral zone was better than before. There was no improvement in one case.