A new paper finds that widely available retinal imaging techniques may help reveal more about brain disease and monitor treatment efficacy, including a currently untreatable form of childhood-onset dementia, Sanfilippo syndrome.

Sanfilippo syndrome is one of a group of about 70 inherited conditions which collectively affect 1 in 2800 children in Australia, and is more common than cystic fibrosis and better known diseases. Around the world 700,000 children and young people are living with childhood dementia. The researchers studied Sanfilippo syndrome in mouse models, discovering for the first time that advancement of retinal disease parallels that occurring in the brain. 

"This means the retina may provide an easily accessible neural tissue via which brain disease development and its amelioration with treatment can be monitored," says Associate Professor Kim Hemsley who leads the Childhood Dementia Research Group at the Flinders Health and Medical Research Institute (FHMRI) at Flinders University.

Credit: Childhood Dementia Initiative

Disorders that cause childhood dementia are neurodegenerative (debilitating and progressive) and impair mental function, according to the Childhood Dementia Initiative. The results showed that disease lesions appear in the retina very early in the disease course, in fact much earlier than previously thought. The progression of lesions in the retina - which is part of the central nervous system - may be a 'window to the brain.'

"Our findings suggest that retinal imaging may provide a strategy for monitoring therapeutic efficacy, given that some treatments currently being trialled in children with Sanfilippo syndrome are able to access both brain and retina," Hemsley says. 

Therapeutic strategies currently being evaluated in human clinical trials include IV delivery of an AAV9-based gene therapy, and a non-invasive, quantitative measure of neurodegeneration would support development of effective treatments, she says.