Leber's optic neuropathy I. Clinical studies.

A detailed ophthalmological study on 72 individuals at risk to develop Leber's Optic Neuropathy (L.O.N) has revealed that early signs may be present. These included usually non-specific signs such as tortuosity of the peripapillary capillaries as best seen on fluorescein angiography; hyperaemia and a hazy boundary of the disc; relative paracentral and central scotomata; abnormal VERs; and increases in the error score with the Farnsworth 100-Hue test. The only possibly specific sign may be tortuosity of the capillaries. This conclusion was reached by comparing the findings in individuals at risk with the results of examination of five patients seen during the acute phase of L.O.N. One of the persons at risk, who had many early signs, developed L.O.N. 6 months after being studied. In 7 of 13 carriers abnormalities were observed that resembled those seen in certain individuals at risk.