A rogue misfolded prion protein that destroys the brain was discovered in the eyes of 11 infected patients, a new study reveals.
Researchers hope that the discovery could lead to early diagnosis of Creutzfeldt-Jakob disease or CJD, the most common prion disease.
The findings were discussed in the journal mBio.
Prion Proteins Found In Patients' Eyes
Researchers from the National Institute of Health along with the scientists from the University of California, San Diego and the University of California, San Franciso examined the eyes of deceased patients who were diagnosed with CJD. Using the RT-QuIC, a method also use in diagnosing prion disease, they checked for the presence of misfolded prion proteins from eye tissue of 11 patients.
They found that the retina has the highest level of prions in all 11 patients. Moreover, the researchers also found traces of prions throughout the cornea, lens, and muscles in and around the eye. This is the first study to detect prions in these parts of the eye.
Fear Of Prion Disease Infection
The findings also raised concerns over the possibility of patients being infected with prion disease. The illness shows up spontaneously most of the time when a prion protein suddenly changes into a misfolded form, affecting other proteins around it.
For some, it is genetic. However, it can also be infectious. Prion disease can be passed from person to person or animal to person.
The concern over the new findings comes from the possibility that eye exam equipment, which is designed for repeated use, has been contaminated. About 40 percent of people who have sporadic CJD develop eye problems and, therefore, go through regular eye exams.
In addition, people who have prion disease but have not been diagnosed might be spreading CJD to another person through cadaveric corneal transplants. The study revealed that there are already two to three possible cases of disease transmission.
CJD is fatal. The disease can also be difficult to diagnose because its symptoms are similar to those of other, more common diseases.
The researchers said that they will continue evaluating ways to use accessible eye components and fluids to diagnose CJD. They also hope that the method used in the study could be applied to other neurodegenerative diseases
"If the RT-QuIC method can be used to amplify other aggregated proteins, this might lead to advances in diagnosis for Alzheimer's, Parkinson's and related diseases," stated Michael Geschwind, co-author of the study.