Acute Optic Neuritis (AON) is an acute, rare inflammatory disease of the optic nerve.
The classic triad of inflammatory optic neuritis consists of loss of vision, periocular
pain and dyschromatopsia, and is unilateral in 70% of adults (Pau et al. Eye 2011).
Inflammation of the optic nerve induces significant demyelination and axonal damage,
leading to permanent visual dysfunction. Acute ON is closely related to Multiple
Sclerosis as it is the initial presentation in approximately 20% of cases.
Standard of Care
Patients that suffer an AON episode are currently treated with IV corticosteroids
for 3-5 days. This treatment may hasten recovery due to its strong anti-inflammatory
effects, but it has no effect on visual outcome, which depends on axonal damage
produced in the optic nerve during the inflammation.
AON uses to happen in young people (20-40 years old). The incidence of new cases of
AON has been historically estimated at 5/100,000 cases although recent epidemiological
data suggests it may have increased (Martínez-Lapiscina et al. J Neurol. 2014).
Neuromyelitis Optica (NMO, also known as Devic’s disease) is a rare, chronic-relapsing
inflammatory and demyelinating disease characterized mainly by recurrent and simultaneous
attacks of optic neuritis and transverse myelitis. NMO is a severe and life-threatening
disease as a high proportion of patients will become legally blind in one or both eyes
and/or suffer from paralysis within 5 years of diagnosis. Eventually, death may occur
due to severe myelitis leading to respiratory failure.
Standard of Care
NMO patients’ treatment is ineffective and includes IV corticosteroids for 3-5 days for
acute relapses as well as immunosuppressive treatment to prevent relapses (e.g.
azathioprine, mycophenolate or off-label rituximab and chemotherapy is often used). There
are no approved efficacious therapies for preventing relapses nor for treating the
disability associated with relapses.
The condition has an estimated prevalence of 1-5/100,000 and the Guthy Jackson Charitable
Foundation estimates there are around 10,000 patients in the US suffering from this severe