Retinal toxicity associated with occupational exposure to the fish anesthetic MS-222.

PURPOSE: To report a case of retinopathy associated with chronic occupational exposure to ethyl-m-aminobenzoic acid methanesulfonate (MS-222), a retinotoxic fish anesthetic.

METHOD: Case report with electroretinograms to document changes in visual electrophysiology.

RESULTS

An ichthyologist with a long history of skin exposure to MS-222 was initially examined for decreased vision, photophobia, and photopsia. His electroretinogram abnormalities were similar to those seen in animal models of acute MS-222 toxicity. After terminating MS-222 contact for 7 months, his vision returned to normal, and his electroretinogram improved.

CONCLUSION

Individuals with occupational exposure to MS-222 should exercise caution to avoid systemic absorption of this retinotoxic compound.