Background/Aims: Bupivacaine injected into animal muscles induces a cycle of myotoxicity, degeneration, regeneration, and hypertrophy of muscle fibers without adverse effect on other tissues. We intend to harness this induced hypertrophy to treat strabismus.
Methods: Bupivacaine, 4.5 ml of a 0.75% solution was injected into the right lateral rectus muscle (RLR) of a patient who complained of diplopia and who showed 14-prism diopters (pd) of esotropia.
Results: RLR paresis persisted for seven days. Then, the RLR regained its abducting ability, and progressive improvement of alignment to 4 pd esophoria occurred over the next 33 days, with elimination of the diplopia. Alignment remained the same at 54 days after injection. MRI examination showed a focal increase in size of the injected RLR of 58% in the posterior area, with less change in anterior portions of the RLR.
Conclusion: Injection of bupivacaine to induce hypertrophy of the injected muscle and thus alter eye alignment was effective in our patient. This approach promises to become a useful addition to the treatment of strabismus.
- eye muscles