Leber's optic neuropathy. New observations.

Leber's disease is a hereditary optic neuropathy characterized by a triad of ocular fundus changes, including circumpapillary telangiectatic microangiopathy, pseudoedema of the nerve fiber layer around the disc, and absence of peripapillary staining on fluorescein angiography. We report two families in which the first afflicted member had insufficient fundus changes to enable a diagnosis of Leber's disease. However, the presence of telangiectatic microangiopathy in either a symptomatic or asymptomatic family member established the diagnosis of Leber's optic nerve disease under these circumstances. These observations suggest that circumpapillary telangiectatic microangiopathy is a genetic marker and may not always be a pathogenetic predeterminant of Leber's optic neuropathy. In view of our findings, we propose the term "typical Leber's disease" for patients demonstrating the characteristic fundus triad and the term "atypical Leber's disease" for patients who lack diagnostic fundus changes but who have a family member with classic telangiectatic microangiopathy.