Age-related macular degeneration is one of the leading causes of blindness in the elderly, affecting more than 2 million people in the United States and leading to progressive loss of central vision. Genome wide studies have identified almost three dozen genes that play a role in the disease, but exactly where in the eye they inflict damage was not well known.

Researchers  report in the  journal Nature Communications that glial cells (or support cells), and vasculature cells tasked with providing blood to the retina as well as cone cells contribute to degeneration of the macula, in the central part of the retina.

"This study helps pinpoint cell types that can be investigated closely to develop new types of therapeutics," said co-senior author.

There are a limited number of effective long-term treatments available for the two forms of macular degeneration. The wet form is caused by growth of abnormal blood vessels underneath the macula, which can be mitigated by regular injections in the eye. Other than eye vitamin supplements, there is no treatment for the dry form of the disease, which is marked by accumulations of yellow deposits called drusen in the macula. While current treatments provide some benefits, over time there can be a continued, progressive loss of vision in both forms of the disease.

While genes associated with the risk of developing macular degeneration had been identified, the team used new single-cell sequencing to generate the first comprehensive human retinal atlas and employed data analysis technology to localize their effects to specific cell types associated with the disease.

The authors identify all major retinal cell types, and their corresponding gene expression signatures. Heterogeneity is observed within macroglia, suggesting that human retinal glia are more diverse than previously thought.

Finally, GWAS-based enrichment analysis identifies glia, vascular cells, and cone photoreceptors to be associated with the risk of AMD and thus providing possible targets for novel therapies to improve and restore vision.

https://news.yale.edu/2019/10/24/yale-researchers-find-cells-linked-leading-cause-blindness-elderly

https://www.nature.com/articles/s41467-019-12780-8

http://sciencemission.com/site/index.php?page=news&type=view&id=publications%2Fsingle-cell-transcriptom_4&filter=22