Neural plasticity following surgical correction of strabismus in monkeys

摘要: The preferred treatment for correcting strabismus in humans involves the surgical manipulation of extraocular muscles (EOM). Although widely practiced, this has varying levels success and permanence, possibly due to adaptive responses within brain or at muscle. We investigated neural plasticity following surgery by recording from cells oculomotor abducens nuclei before after two monkeys with exotropia (divergent strabismus) underwent a correction that involved weakening lateral rectus (LR) strengthening medial (MR) muscle one eye. Eye movement neuronal data were collected period 6-10 months during monocular viewing smooth-pursuit task. These fit first-order equation resulting coefficients used estimate population drive (ND) each EOM deviated eyes. Surgery resulted an ~70% reduction angle both animals reverted towards pre-surgical misalignment about 6 treatment. In first month surgery, ND treated MR reduced animal LR increased other animal, indicating active effectiveness these changes resolved months, we also found evidence inappropriate peripheral adaptation limited over long term. Outcome could be improved identifying ways enhance "positive" limit "negative" adaptation.