May 25, 2015

Discovery Opens New Strategy for Preventing Vision Loss

Many of the Foundation’s sight-saving research projects are focused on photoreceptors. This is because photoreceptors are critically important for vision – they are needed to sense light. Many blinding eye diseases involve the gradual loss of photoreceptors. In fact, in some of these diseases it appears that ONLY photoreceptors are lost. Actually, this is one of the reasons that scientists are so optimistic about developing therapies for retinal degenerative diseases– to restore vision, they only need to fix one kind of cell.

The more we learn, however, the more complicated the picture becomes. Although many diseases, such as retinitis pigmentosa (RP), start with the degeneration of a specific kind of photoreceptor (in the case of RP, it is the rod photoreceptors that are lost first), we now know that the loss of photoreceptors impacts the health of other eye cells. This is why Dr. Pamela Lagali is devoted to studying the eye’s interneurons (the cells that connect to photoreceptors).

At the Ottawa Hospital Research Institute, Dr. Lagali spends her days studying retinal interneurons. She found her way into the laboratory of Dr. David Picketts after reading about his research on the Foundation Fighting Blindness website. As a graduate student, Dr. Lagali became fascinated with vision: “Since I embarked on my studies of the eye and retinal diseases more than 15 years ago, I have been intrigued with understanding the complexities and beauty of this remarkable organ.” Dr. Lagali believes that “Vision is our most highly valued physical sense and its loss is among our greatest fears.”She explains that “the increasing prevalence of vision disorders, including within my own family, motivates me further to try and contribute to our understanding of how the eye works and how we can overcome diseases that threaten its precious function.”

Today, Dr. Lagali is committed to understanding why interneurons die so that she can develop strategies to prevent their death. Her most recent discovery revealed a critically important role for retinal bipolar cells (a kind of interneuron). Her careful experiments demonstrated that these cells are needed to maintain the health of other retinal interneurons (specifically, the amacrine and horizontal cells). By focusing on the health of retinal interneurons, the team hopes to discover new strategies to prevent vision loss. This matters because healthy interneurons are needed to transmit visual signals to the brain.

Restoring sight will require more than replacing damaged photoreceptors; in many cases, it will require fixing other parts of the visual pathway. Thanks to our donors, Dr. Lagali is making sure that we keep this entire pathway in sight.