According to a study led by the Universidad Complutense de Madrid (UCM), amyotrophic lateral sclerosis (ALS), which is characterized by damage to nerve cells in the brain and spinal cord, also affects retinal tissue.
The study was published in Nervous system regeneration study, shows that ALS patients may suffer from changes in the microglial cells responsible for protecting and defending nerve cells, as well as the loss of ganglion cells, or retinal neurons.
These changes observed in this disease can serve as biomarkers in the diagnosis and follow-up of ALS patients and in reviewing the effectiveness of different treatments through a simple, non-invasive and less expensive way of monitoring. “
Pilar Rojas, Research Fellow, Ramón Castroviejo Institute for Eye Research (IIORC), UCM
In addition to describing retinal changes, the work also shows that these changes develop over the course of the disease. Microglial changes from the M2 state or phenotype (anti-inflammatory) in the earlier stages to M1 (proinflammatory) in the final stages.
“This has been observed in the spinal cord of these patients, but not in the retina, which is a step forward as this may be less invasive in patient follow-up,” says Rosa de Hoz of IIORC.
First observation in humans, confirmation in mice
The study was conducted at IIORC in collaboration with UCM’s Department of Biochemistry, Madrid’s Gregorio Marañón General University Hospital, the Carlos III Institute of Health’s Ophthalmology Network OFTARED, and the Ministry of Science and Innovation’s RetiBrain Network. and universities.
In conducting the study, the researchers recorded retinal changes with optical coherence tomography (OCT) – a non-invasive test that analyzes the retina and optic nerve and is able to detect small changes that are often invisible to the human eye. “says another author, Ana Isabel Ramírez.
Once observed in vivo in humans, they confirmed this in an animal model by microscopic analysis by immunohistochemical techniques in mice with the superoxide dismutase-1 mutation – one of the most common in humans with ALS.
“Our group has extensively studied retinal changes in various neurodegenerative diseases, such as Alzheimer’s disease. However, few studies have described what happens in the retina and more specifically in ALS microglial cells,” concludes José Manuel Ramírez, professor of ophthalmology at UCM and director of IIORC.
Complutense University of Madrid
Ramirez, A., et al. (2021) Amyotrophic lateral sclerosis, a neurodegenerative motor neuronal disease involving the retina. Nervous system regeneration study. doi.org/10.4103/1673-5374.324841.