The Genes That Drive Eye Size

The length of a normal eye is about 16 mm at birth, growing over the first two years to about 23 mm. In some babies, eye growth stops too soon, and in others, eyes grow too large.

Nanophthalmos is an inherited disorder in which the eye is structurally normal, but stops growing at 16-20 mm. Exceedingly rare, it results in extreme farsightedness (hyperopia), angle-closure glaucoma, and other vision problems. Conversely, myopia is a more common condition, characterized by lengthening of the eye (as large as 30-32mm in some extreme cases). Myopia results in nearsightedness, and in some instances, structural problems.

To support his work understanding the genetic factors that contribute to eye size disorders, Lev Prasov, M.D., Ph.D., has received a grant from the E. Matilda Ziegler Foundation for the Blind. The foundation supports innovative vision research by outstanding early-career investigators.

Dr. Prasov’s current project builds on his previous studies of families with instances of nanophthalmos caused by a variant of the gene MYRF. It aims to describe how the MYRF transcription factor impacts the development of retinal pigment epithelium (RPE) and its interactions with other eye cells. This work is in collaboration with Kellogg medical retina specialist Jason Miller, M.D., Ph.D.

“We know that as the eye grows, RPE cells are critical in eye size determination,” explains Dr. Prasov. “But it’s unclear why defects in the RPE cause eye size disorders.”

A better understanding of the cell-to-cell interactions and genetic pathways that govern eye size could eventually lead to new methods of treating eye size disorders.

“Ultimately, we may be able to design interventions that manipulate those pathways,” he says, “stimulating eye growth in patients with nanophthalmos, and slowing eye growth in patients developing myopia.”

Header image caption: Lev Prasov, MD, PhD