BackgroundOptic neuritis (ON) is one of the common manifestations both in neuromyelitis-optica spectrum disorders (NMOSD) and in multiple sclerosis (MS).ObjectivesThe objective of this paper is to compare clinical presentations, laboratories and imaging findings in ON associated with MS and NMOSD.MethodsA retrospective chart review was performed in patients presenting with ON in 59 NMOSD patients with 72 eyes’ involvement and 163 ON attacks, and 20 MS patients with 23 eyes’ involvement and 36 ON attacks.ResultsON-NMOSD patients had recurrent ON more often and tended to have simultaneous bilateral ON involvement at their first ON attack. Individuals with ON-NMOSD revealed worse visual acuity at first ON attacks and also had poorer long-term visual outcome than those with ON-MS, with nearly half of ON-NMOSD patients still having LogMAR visual acuity ≥1 at their last follow-up (p = 0.035). Significant thinner average retinal nerve fiber layer thickness was found in the ON-NMOSD group. We found no significant differences in segmentation location of the optic nerve lesions and the length of involvement between the two groups.ConclusionsIt was difficult to completely differentiate ON-NMOSD from ON-MS. ON-NMOSD patients, however, tended to have simultaneous bilateral ON involvement and poorer long-term visual outcome than individuals with ON-MS.

The preliminary results of this study showed that the H2 formula performed well even without the LT value. It was comparable to the Haigis and Hoffer Q formulas.

We performed an observational prospective analysis to study the clinical characteristics as well as a molecular genetic analysis of 17 members of a Thai family who had visual loss and/or muscle weakness. Their blood mitochondrial DNA were examined for the presence of the G11778A Leber's hereditary optic neuropathy (LHON) mutation. Facioscapulohumeral muscular dystrophy (FSHD) DNA analysis was performed in four members who had visual loss. Of 17 family members, the eight members who had the 11778 LHON mutation were all from branch 'a'. Three of these eight members had FSHD with a 17-27-kb deletion of a tandem repeat in the 4q35 subtelomere, and two had been clinically diagnosed as FSHD. Four of six examined members in branch 'b' showed muscular dystrophy clinically diagnosed as FSHD. No correlation of blood DNA analysis between LHON and FSHD in affected members was found. We describe the first family with FSHD and G11778A LHON in which a mutation in mitochondrial DNA at nucleotide position 11778 of branch 'a' was found to be the origin of the mutation.