The demographics and distribution of idiopathic optic neuritis (ON) reflect those of multiple sclerosis (MS). The annual incidence varies between 1 and 5 per 100,000. In Olmstead County, Minnesota, USA, the incidence of ON is 5.1 per 100,000. In Stockholm, Sweden, where the incidence of MS is high, the annual incidence of ON is 2.3 per 100,000 for females and 0.6 per 100,000 for males. The majority of patients with acute ON are aged 20 to 50 years.[4]Jin YP, de Pedro-Cuesta J, Soderstrom M, et al. Incidence of optic neuritis in Stockholm, Sweden 1990-1995: I. Age, sex, birth and ethnic-group related patterns. J Neurol Sci. 1998 Jul 15;159(1):107-14.
http://www.ncbi.nlm.nih.gov/pubmed/9700712?tool=bestpractice.com
Females are more commonly affected than males.[5]Gu W, Tagg NT, Panchal NL, et al. Incidence of optic neuritis and the associated risk of multiple sclerosis for service members of U.S. Armed Forces. Mil Med. 2023 Mar 20;188(3-4):e697-702.
https://academic.oup.com/milmed/article/188/3-4/e697/6356083?login=false
http://www.ncbi.nlm.nih.gov/pubmed/34417807?tool=bestpractice.com
In the Optic Neuritis Treatment Trial (ONTT), 77% of patients were females, 85% were white, and mean age was approximately 33 years.[2]Optic Neuritis Study Group. The clinical profile of optic neuritis: experience of the Optic Neuritis Treatment Trial. Arch Ophthalmol. 1991 Dec;109(12):1673-8.
http://www.ncbi.nlm.nih.gov/pubmed/1841573?tool=bestpractice.com
As for MS, the geographic distribution follows a striking latitude gradient, with higher frequency the closer the location is to the poles. Within the same geographical distribution, white people are at higher risk than other ethnic groups such as black people. The latter group, although less susceptible, tends to have more severe disease.[6]Phillips PH, Newman NJ, Lynn MJ. Optic neuritis in African Americans. Arch Neurol. 1998 Feb;55(2):186-92.
https://archneur.ama-assn.org/cgi/content/full/55/2/186
http://www.ncbi.nlm.nih.gov/pubmed/9482360?tool=bestpractice.com
Recent epidemiologic studies point to a more diverse etiology of ON. Although the leading cause is idiopathic ON/ON associated with MS, there is a higher than previously reported prevalence of ON associated with other inflammatory diseases and infections, including sarcoidosis, Behcet disease, giant cell arteritis, Lyme disease, etc.[3]Petzold A, Fraser CL, Abegg M, et al. Diagnosis and classification of optic neuritis. Lancet Neurol. 2022 Dec;21(12):1120-34.
http://www.ncbi.nlm.nih.gov/pubmed/36179757?tool=bestpractice.com
[7]Braithwaite T, Subramanian A, Petzold A, et al. Trends in optic neuritis incidence and prevalence in the UK and association with systemic and neurologic disease. JAMA Neurol. 2020 Dec 1;77(12):1514-23.
https://www.doi.org/10.1001/jamaneurol.2020.3502
http://www.ncbi.nlm.nih.gov/pubmed/33017023?tool=bestpractice.com