The Neuro-Ophthalmopathy of Leonhard Euler (1707-1783)

I note that the famed Swiss mathematician Leonhard Euler (1707-1783) suffered from a hereditary ophthalmopathy (Figure 1) whose characteristics may also correspond to Leber Hereditary Optic Neuropathy (LHON). During his life, Euler suffered from:(i)A longstanding familial eye condition so that his ancestral surname was sometimes referred as Euler-Schölpi translated as ‘Euler-squint-eyed’ or ‘Euler-crooked-eyes’.(ii)He had sequential visual loss, first aged 31 in his right eye and then his left eye aged 59 years. Frederick the Great of Prussia called him ‘cyclops’ and just before the loss of vision in his left eye, it was diagnosed as a cataract. (iii)He had 13 children but only 5 survived into infancy, however there is no reported evidence of ophthalmopathy in his sons. As a result, although he is noted to have had an inherited ophthalmopathy, this evidence may suggest a maternal and therefore possibly mitochondrial component. Together these facts of inherited eye condition with sequential visual loss in adulthood suggest that the most likely differential could be Leber's hereditary optic neuropathy (LHON). Although the 28-year difference in sequential eye loss between the right and left eye is high, there have been reports of long periods between visual loss in each eye associated with this disease. Additionally, it is reported that Euler eventually died aged 76 from brain hemorrhage. This diagnosis may have been due to cerebrovascular disease associated with Euler’s age, but may also represent the increased mortality and increased incidence of stroke (with a relative risk of 2.38 compared to unaffected family members) in LHON patients. Other differential diagnoses for hereditary sequential vision loss in the eyes includes Stargardt's Disease, retinitis pigmentosa, glaucoma and optic atrophy. It is interesting to note that one of the greatest mathematicians of all time suffered from an inherited mitochondrial neuropathy over a century before Theodor Leber (1840–1917) first described this condition in 1871, and reinforces Euler’s brilliance in continually demonstrating mathematical genius despite suffering from neuro-ophthalmological disease.