Imagine if a simple beam of light could one day treat conditions like nearsightedness or age-related macular degeneration (AMD). Researchers at the ÐÔ°®ÎåÉ«Ìì, Reno School of Medicine (UNR Med) and the University of Washington, Seattle, have uncovered — an insight that could revolutionize vision care.
The Gonzales Lab at UNR Med, led by Albert Gonzales, Ph.D., assistant professor of physiology and cell biology, spearheaded this study, shedding new light on how our eyes work and opening the door to non-invasive treatments for common eye diseases.
The role of light in eye physiology
When light enters the eye, it activates the retina’s photoreceptor cells — cones and rods — that enable vision. Behind the retina lies the choroid, a dense network of blood vessels key for delivering oxygen and nutrients to these photoreceptors while removing metabolic waste. However, the choroid’s high blood flow can hinder this exchange. The researchers compared this to trying to hand a note to someone sprinting at full speed versus walking: “Slower movement facilitates smoother exchange. Similarly, reducing blood flow improves this process.”
Discovery of opsins in the choroid
Led by former postdoctoral fellow Ahmed Eltanahy, M.D., (now at Seattle Children’s Hospital), and current postdoctoral scholar Alex Aupetit, D.Sc., the Gonzales Lab collaborated with Ethan Buhr, Ph.D., and Russell Van Gelder, M.D., Ph.D., from the University of Washington, Seattle, to explore how the choroid regulates blood flow. Their research revealed that light-sensitive proteins known as opsins—similar to those in photoreceptors—are also present in the choroid’s blood vessels. Using advanced imaging techniques, the team demonstrated that violet light (405 nm) activates these opsins, causing the arterioles to constrict. This constriction regulates blood flow and controls fluid movement in the eye.
“Our inspiration stemmed from a serendipitous observation,” Gonzales said. “While conducting experiments, Dr. Eltanahy noticed that specific vascular cells in the choroid responded when exposed to specific wavelengths of light. This unexpected discovery led my team to explore the link between light activation and vascular function more deeply.”
By testing various wavelengths, the team identified violet light as the most effective in activating opsins. “Opsins act as detectors within a specific wavelength range,” Aupetit explained. “By identifying the specific opsin type present in the choroid, we confirmed the optimal activation wavelength.”
Alex Aupetit, D.Sc., imaging isolated cells on Revolution Hybrid Microscope by Discover Echo designed for life science research.Implications for eye health
The implications of these findings are significant. Proper regulation of blood flow in the choroid is crucial for maintaining the shape of the eye and the metabolic balance required by energy-demanding photoreceptors.
“Our research demonstrated that light-sensitive choroidal vasculature helps modulate blood flow, facilitating efficient nutrient delivery and waste removal - this process is vital for maintaining retinal health,” Aupetit said.
The team is now exploring the therapeutic potential of these mechanisms. “Targeted blue light therapy and the modulation of choroid blood flow could offer non-invasive treatments for conditions like myopia and AMD,” Aupetit noted.
In myopia, changes in the shape of the choroid and the eye cause the focal point to form in front of the retina, but blue light-induced changes in fluid movement may help reshape the eye and reposition the retina for clearer vision. For AMD, where waste accumulation leads to vision loss, light therapy might enhance waste clearance and slow disease progression. However, the researchers also caution against overstimulation.
“Excessive exposure to violet light could lead to detrimental effects, such as arterial remodeling that might reduce vascular responsiveness,” Aupetit warned.
A platform for growth, exploration and collaboration
The study’s success hinged on advanced imaging techniques and whole-eye preparation developed by Dr. Eltanahy, which allowed the team to capture subtle yet significant changes in cellular activity.
“Without these tools, visualizing light-induced vascular responses with high resolution would have been challenging,” Aupetit said. He also highlighted the collaborative nature of the research. “Our expertise in advanced imaging and vascular physiology was central to the discovery process, and the University of Washington’s contributions were instrumental in confirming the opsin types involved.”
This project served as a valuable learning platform for emerging researchers. “It offered hands-on experience in experimental design, data analysis, and advanced imaging technologies, contributing significantly to the professional development of our postdocs,” Gonzales said.
The broader impact of fundamental research
Reflecting on the study’s broader impact, Gonzales emphasized the importance of fundamental scientific exploration. “Our findings reveal a fascinating connection between light and vascular health in the eye, emphasizing the potential for non-invasive therapies for vision-related conditions. This research underscores the importance of fundamental scientific exploration, as even serendipitous discoveries can lead to groundbreaking insights that may one day transform patient care.”
