Dr Arnold Knapp presented a case in which blindness followed an operation for empyema of the frontal sinus. The patient, 50 years old, had had 5 attacks of manifest empyema of the right frontal sinus following influenza in 5 months. The anterior extremity of the middle turbinal was removed and 2 days later the sinus was operated on according to the Kuhnt method; the entire anterior and inferior was removed. The disc went on to atrophy and the patient remained blind.
Reference: Knapp A. Arch Ophthalmol. 1901;30: 308-309.