Large horizontal rectus recession for the treatment of nystagmus: Long-term follow-up

Purpose: Two years ago we presented short-term (∼2 mos) oculographic follow-up for 8 patients who had undergone arge horizontal rectus muscle recessions for the treatment of nystagmus. The time when the eyes were fixating within ±0.5° of the target improved in 8/8 patients; the average slow phase velocity during this period improved in 6/8. Modest improvements in acuity were also noted in 6/8 patients. It has been suggested that adaptive changes in muscle could conceivably have negated these changes. The present study addresses this issue. Methods: Six patients with congenital nystagmus were examined preoperatively and from 8 to 39 mos. (mean, 16.7 mos) post-op IR oculographic recordings of primary position fixation were analyzed by an automated computer program for the features noted above. Results: One patient restudied at 39 mos. post-op had virtually no detectable nystagmus in primary position. Of the others, 4/5 showed statistically significant improvements in time on target; 4/5 had significantly reduced slow phase velocity during this time (p<.04, t-test, both measures). Improved acuity was also maintained in 5/6 patients. Conclusions: The improvements noted in the short-term after large 4-muscle recession are not eliminated in the long term by adaptive remodeling of the extraocular muscles. Changes in both vision and nystagmus are maintained.