Poor nutrition can lead to sight loss in later life, according to study

An unhealthy diet including high fat and cholesterol-enriched food can contribute to developing
eye diseases which lead to a loss of vision, University of Southampton research has revealed.
The study, led by Dr. Arjuna Ratnayaka, has shown how retinal pigment epithelial (RPE) cells in
the eye become damaged due to poor nutrition, but also revealed a potential new treatment
route through which these cells could be rescued before diseases such as age-related macular
degeneration (AMD) develop.

How an unhealthy diet could increase the likelihood of eye disease is still poorly understood,
therefore scientists analysed how disease-causing pathways triggered by poor nutrition could
impact RPE cells.

The study determined how healthy RPE cells breakdown by-products generated by daily
activities of photoreceptors through the cells’ waste disposal system (which terminates in small
vesicles called lysosomes).

Scientists found healthy RPE cells had a considerable degree of flexibility to cope with changing
conditions in the aging eye, whereas a high fat diet can disrupt this breakdown process in RPE
cells, thus causing long term damage and subsequently sight-loss.

Dr. Ratnayaka, Lecturer in Vision Sciences at the University, said: “Although the effects of poor
nutrition in eye health has been studied in large populations, how this actually brings about
disease-causing changes in retinal cells is less well understood.

“We also found that some lysosomes appeared to remain undamaged even in such stressed
RPE, suggesting an altogether new way in which damaged cells could be rescued to prevent
eventual sight-loss.

“As our results showed how the waste disposal system of the RPE becomes damaged by
unhealthy diet-driven disease pathways, our next step is to find out whether this type of
damage can be reversed through better nutrition and if stressed or damaged RPE cells
can possibly be rescued. Potential new therapies developed along these lines could offer
new treatments for some AMD patients.”