An inexpensive and non-invasive eye test could potentially detect Parkinson’s disease before any symptoms develop, a recent study found.

The researchers were able to use a novel imaging technique that observes changes in the retina, which are the first sign of the disease. Symptoms such as muscle stiffness, slowness, and tremors only become apparent after 70% of the brain’s dopamine-producing cells have been destroyed, according to the study published by Acta Neuropathologica Communications.

This new technique would lead to earlier diagnoses of the disease and could monitor treatment response as well, according to the study.

“This is potentially a revolutionary breakthrough in the early diagnosis and treatment of 1 of the world's most debilitating diseases,” said lead researcher Francesca Cordeiro, PhD. “These tests mean we might be able to intervene much earlier and more effectively treat people with this devastating condition.”

For the test itself, standard ophthalmic instruments were used. After observing retinal changes in the rat models, researchers treated them with a new version of Rosiglitazone, an anti-diabetic drug that protects nerve cells, according to the study.

Researchers discovered decreased retina cell death and a protective effect on the brain. They believe their findings could be a potential treatment for Parkinson’s disease.

The technique has been tested in humans with glaucoma, and clinical trials for Alzheimer’s disease will start soon.

“These discoveries have the potential to limit and perhaps eliminate the suffering of thousands of patients if we are able to diagnose early and to treat with this new formulation," said first author Dr Eduardo Normando. “The evidence we have strongly suggests that we might be able to intervene much earlier and more effectively in treating people with this devastating condition, using this non-invasive and affordable imaging technique.”