• Northwestern University
    Comprehensive Ophthalmology, Retina/Vitreous

    Northwestern University scientists have identified a new retinal ganglion cell (RGC) type in mice that may cause myopia.

    "This discovery could lead to a new therapeutic target to control myopia," said Greg Schwartz, PhD, lead investigator and assistant professor of ophthalmology at Northwestern University Feinberg School of Medicine.

    Schwartz named the cell ON delayed due to its slow responses to lights becoming brighter. This dysfunction may be linked to the amount of time a child spends indoors and away from natural light.

    Scientists have long known the retina contains a signal to focus the image in the eye, and this signal is important for properly regulating eye growth during childhood.

    "But for years no one knew what cell carried the signal," Schwartz said. "We potentially found the key missing link, which is the cell that actually does that task and the neural circuit that enables this important visual function."

    In his study published online in Current Biology last month, Schwartz and colleagues used microscopic glass electrodes to record electrical signals from cells in a mouse retina while presenting patterns of light on a digital projector.

    Responding with an unusually long latency to light stimulation, ON Delayed RGCs respond earlier as the visual stimulus increased in size. They also showed that these cells can be excited by light falling far beyond their dendrites.

    The next goal for Schwartz is to find a gene specific to this cell so that it can be manipulated to induce or cure myopia.