Designation Criteria and Nationwide Epidemiological Survey of Leber Hereditary Optic Neuropathy in Japan

In conjunction with a working group for retina-choroidal and optic atrophy funded by the Ministry of Health, Labor, and Welfare (MHLW), the Japanese Neuro-ophthalmology Society has recently defined the Designation Criteria for Leber hereditary optic neuropathy (LHON) and has conducted a nationwide epidemiological survey on LHON to justify its eligibility as a specified intractable disease defined by MHLW. According to the characteristic major symptoms and ancillary prognostic test results, the criteria classify patients with LHON into definite, probable, and possible cases, as well as asymptomatic carriers. Questionnaires were sent to 1\_h,\/397 facilities, which were certified by either the Japanese Ophthalmological Society or the Japanese Neuro-ophthalmology Society, to determine the number and sex of patients with definite and probable LHON who had one of three mitochondrial DNA mutations at nucleotide positions 3460, 11778, or 14484 and had newly developed symptoms during the year 2014. One hundred seventeen patients were estimated to have newly developed LHON (95% confidence interval, 81 to 153). Over 86% and 90% of these patients possessed the 11778 mutation and were male, respectively, and both percentages were higher than those reported previously in foreign countries. The median age at onset was over 30 years, which was older than previously reported. The establishment of the Designation Criteria and identification of the number of patients not only fulfill the eligibility of LHON as a specified intractable disease but also attract general ophthalmologists' interest towards LHON. Moreover, it motivates researchers and pharmaceutical companies to develop new treatment modalities for LHON.