In Reply

We thank Dr Wedig for his positive comments (1). The swinging flashlight test is extremely important and helps avoid drastic misdiagnoses. Leber’s hereditary optic neuropathy (LHON) is fortunately rare, but it is indeed an important differential diagnosis. LHON is almost always confused with optic neuritis, as long as only one eye is affected and no other cases have been diagnosed in the same family. It requires a certain amount of experience to identify the typical peripapillary changes. The fact that some cases of LHON are accompanied by similar foci of demyelination as is multiple sclerosis makes things even more difficult. We also recommend treatment with idebenone. A problem of the study cited by Dr Müller-York is the fact that recruitment was possible even 5 years after disease onset. Under these circumstances it is amazing that a positive result was achieved at all. A practical problem might lie in the fact that time passes until a genetic diagnosis is made, because it seems sensible to start treatment as early on as possible. The high costs of the treatment should be borne in mind.