Parents and clinicians may sometimes catch the white glare in a child’s eye that signals potentially devastating eye problems, but a new app aims to make the process even easier and more accurate.
Bryan F. Shaw, PhD
There’s an app for anything these days, even for rare childhood eye disorders. The app, designed in part by a researcher whose own son was affected by retinoblastoma and lost an eye before he was a year old, aims to help parents recognize problems early and get help. Bryan F. Shaw, PhD, associate professor of chemistry and biochemistry at Baylor University in Waco, Texas, co-authored the paper, published in Science Advances, says the app is a White Eye Detector app aimed at helping to identify leukocoria, which can be a symptom of common eye disorders as well as rare disorders like retinoblastoma, Coats’ disease, or pediatric cataract.
“The White Eye Detector app, or “CRADLE” as it is sometimes called, does not do anything that a parent is not already supposed to be doing-be on the watch for recurrent photographic leukocoria,” Shaw says. “The app just helps parents detect leukocoria in photographs. Sometimes, leukocoria is difficult to spot in a photograph, even if you are looking for it.”
For Shaw, it was only after his son was diagnosed with retinoblastoma by a physician that he went back to look at photographs to see if he could catch the pale reflection that often signals early problem. Sure enough, he saw it in a photo taken shortly after his son was born. Built for parents, Shaw says the free app can also be used by clinicians.
“We built the White Eye Detector/CRADLE app for parents, but clinicians are welcomed to use it, and several are using CRADLE. By taking photographs of their children, with a flash, parents unknowingly examine their child's retina and lens much more often than a pediatrician will examine the child,” Shaw says. “Parents take pictures at myriad optic axes, focal lengths, and in different lighting conditions. This diversity maximizes the chances that photographic leukocoria will occur, regardless of the location of the lesion or abnormality.”
Shaw says he has heard success stories about the app from clinicians who have adopted it, and it helps providers in areas with limited resources to provide additional screening.
“The app can also operate in video mode, which allows you to search live video frames for leukocoria while shining your phone's LED,” he says. “This seems to be the mode that clinicians prefer. CRADLE turns the smartphone into an improvised ophthalmoscope for red reflex testing.”
Although the app isn’t perfect and can’t detect every leukocoric picture, the study reveals that it had 75% accuracy in detecting pathologic leukocoria in children younger than 6 months, and 90% accuracy for children younger than 2 years. False positive rates generated by the app were low, according to the report. Another consideration, he adds, is that the app cannot always distinguish physiologic leukocoria from pathologic leukocoria in a photograph. It’s also important to use the flash when taking photos in order to detect leukocoria, Shaw says.
The app is particularly useful because it gives parents-the primary detectors of these problems, another tool to use Shaw says.
“Peer reviewed studies have demonstrated that parents are more effective than primary care physicians at detecting leukocoria in children with retinoblastoma,” Shaw says.
Researchers at Memorial Sloan Kettering showed that parents or family members and friends detect the initial symptoms of retinoblastoma in about 80% of cases; primary physicians detect symptoms in about 8% of cases; and ophthalmologists catch the remaining 12%, Shaw adds.
“Therefore, the red reflex test, employed by a primary care physician has a false negative rate of about 90%,” he says. “In terms of detecting leukocoria associated with retinoblastoma, it is tough for an app like CRADLE to do any worse than a primary care physician. Parents, on the other hand, are hard to beat.”
Shaw says the app can also detect more subtle cases that parents might miss in regular photos.
“The app can detect traces of leukocoria that might be difficult for a parent to notice in a picture. Sometimes, leukocoria is faint, appearing as a gray pupil. Other times, a child might be exhibiting leukocoria in a photograph with a wide field of view,” Shaw says. “Here, the pupil might not easily seen on a small screen. CRADLE can detect leukocoria in such an image, where a pupil is composed of as few as 18 pixels.”
The hope, Shaw says, is not only that the app will help parents catch these problems early, but that pediatricians renew their efforts to educate parents to be on the watch for leukocoria.