The ophthalmic trials of G. H. A. Hansen.

G. H. A. Hansen (1841-1912) is widely known as the discoverer of the infectious cause of leprosy. It is less well known that his career was threatened by an episode involving experimentation on the eye. As a staff physician at the leprosy hospitals of Bergen, Norway, early in his career, Hansen learned about ocular involvement in leprosy and co-authored Leprous Diseases and the Eye. In 1873 he observed bacilli in leprous nodules, but proof of an infectious origin was difficult to obtain because the agent could not be cultured and no one had demonstrated direct transmission. Hansen tried several unsuccessful experiments, and in 1879 he passed a cataract knife that had incised an active leprous nodule into a woman's conjunctiva. No nodule developed, but the woman complained of pain and said she was never asked for permission. Hansen was brought to trial where eminent physicians testified on his behalf-but Hansen himself readily admitted that no permission had been sought for fear the woman would say no. He was convicted, and relieved of his post as staff physician, but he was allowed to retain an appointment as Chief Medical Officer of Health for Leprosy, in which capacity he worked for the rest of his life.