Purpose: To investigate a recurring syndrome of postoperative hypotropia after cataract surgery performed under local anesthesia.
Setting: Hawaiian Eye Center, Wahiawa, Hawaii, USA.
Methods: Thirty-one left eyes in 2143 cataract surgeries developed postoperative hypotropia. Phacoemulsification and intraocular lens implantation were performed by one surgeon; the anesthetic (containing bupivacaine) was administered by one anesthesiologist who had treated 4200 patients without incident. We conducted epidemiologic, outcomes, and prevention studies to identify the etiology, evaluate hypotropia treatment, and test specific anesthetic techniques, respectively.
Results: Changes in preoperative and intraoperative management and surgical methods were unsuccessful in preventing the hypotropia. In 55% of the cases, strabismus surgery was required and in 13%, prism glasses. Early recession of the inferior rectus and conjunctiva was successful. After repeated observations of the anesthetic technique, it was noted that the right-handed anesthesiologist misdirected the retrobulbar needle into the left orbit. This resulted in a change in the anesthetic technique, and there has been no incidence of postoperative hypotropia in 3000 surgeries.
Conclusion: We believe this syndrome resulted from mytoxicity or perimuscular inflammation, producing contracture hypotropia and restricted elevation of the globe. We propose the term postbupivacaine hypotropia for this chiefly left-sided syndrome.