Photoreceptors are specialized cells in the retina that are responsible for converting light into signals that the brain can understand as images. Wouldn’t it be great if there was a way to actually see photoreceptors?
Researchers at Duke University have developed a device that can produce an image of photoreceptors in adults and infants. This device is a hand-held adaptive optics scanning laser ophthalmoscopy that incorporates both a novel adaptive optics algorithm and custom optics. Sounds great, doesn’t it? Still, what exactly does it do?
Let’s go back a little to how images of photoreceptors were captured in the past. Before this device was developed, photoreceptors were studied using an adaptive optics scanning laser ophthalmoscope (AOSLO). These devices are not portable, they are expensive, and overall they are very complex medical instruments. A patient who is having imaging done with an AOSLO needs to sit upright and fixate on something for several minutes. The practical challenges of sitting for this test make it difficult to get photoreceptor images from adults who have Alzheimer’s or mobility issues, not to mention squirmy infants. The lead author of the study, Theodore DuBose, a PhD student at Duke, created an AOSLO that weighs less than 200g /7 ounces and measures 4 inches by 2 inches by 5.5 inches/10cm x 5cm x 14cm, which is a little bit bigger than a tablet computer. This portability allows doctors to take this device directly to the patient and get images more quickly.
During its clinical trial, the device was tested on 12 adults and two children. Researchers were able to get detailed images of photoreceptors close to the center of the retina where vision is most acute. In addition, they were able to get some of the first adaptive optics enhanced images of cones in infants. This is particularly important for premature babies since they are at greater risk of developing retinopathy, which can lead to blindness if it isn’t caught and treated quickly.This tool can also be used to track brain development in children, since the retina develops along with the central nervous system. Another great use for this device is to check for brain trauma in athletes, such as football or soccer players, who experienced a head injury during a game.
This technology will help to improve diagnoses for those with a variety of vision conditions. Expect to hear more about this device in the coming months.
To allow for the reproducibility of this research, the optical and mechanical designs, as well as the optics algorithm are available via this link: http://people.duke.edu/~sf59/HAOSLO.htm