All eye doctor Natalia Uribe needed was five seconds.
But her patient, Julia Bailey, was two days shy of her first birthday and had an infinitesimal attention span.
Uribe wiggled a toy duck in front of Judith's eyes with one hand and held a vision prism with the other. Judith squirmed, giggled and finally focused on the toy, giving Uribe her fleeting opportunity to determine if the infant favored one eye over the other.
"Sometimes it's just two seconds and that's all you can get with children so young," Uribe said.
Julia and Elizabeth Bailey, her 4-year-old sister, were brought into a special new clinic Thursday in downtown Riverside as participants in a trailblazing children's eye study conducted by USC's Doheny Eye Institute. When released, the study, sponsored by the National Institutes of Health, will be one of the most comprehensive assessments of the health of young children's eyes and vision to date.
"It's the largest study of its kind looking at preschool children for eye diseases," said Dr. Rohit Varma, director of clinical trials for the institute and the study's principal investigator. "There's not just a need for this type of eye care, but a need for everyone to be educated."
Clinicians are searching for abnormalities in the young eyes -- near and farsightedness; strabismus, or crossed eyes; and amblyopia, or lazy eye -- that otherwise would go undiagnosed in young children. After diagnosing the children, the institute will break down the data to find if certain eye diseases are more prevalent in different ethnicities, ages and geographies.
Already, in the Inglewood area, the institute has examined 6,000 children ages 6 months to 6 years for the Multi-Ethnic Pediatric Eye Disease Study. The results from that three-year study are expected to be released soon in medical journals.
The Riverside research is the study's second leg. The institute expects to examine 3,000 children there over the next two years. It will conclude by examining the same number in Monterey Park.
A mobile unit for home examinations is also used to perform examinations on children whose parents do not have transportation to the Riverside clinic.
To find such a large sample pool, the institute uses census tract data to identify the most populated areas and conducts door-to-door surveys until it gathers enough participants.
Most parents are willing to have their children participate, because the study is free and they see it as a long-term benefit, said Amanda Reiner, the project's manager. If a serious eye problem is detected, the parents are referred to a local optometrist.
The grant used to perform the study allots funds for the examination only, not for any care.
"These areas will offer us a good representative sample of children throughout the United States," Reiner said. "It's three different populations, but combined, the demographic makeup mirrors that of the United States as a whole."
In order to keep the sample pool a reflection of the area's population, the institute does not insist upon health insurance documents.
"We analyze the data, and after that the personal information is stripped," Reiner said. "We are just looking at the numbers."
It is tough, as Uribe can attest, to examine such young children.
Many parents are unaware that children can be tested before they can read an eye chart.
"It's amazing that they can do it in children so young," said Judith Bailey, the mother of Julia and Elizabeth, who agreed to participate after receiving a flier at her home. "I didn't think they could really tell what was going on."
Children as young as 30 months are given HOTV tests, in which one of those four letters is placed on a screen. The four letters are also on a sheet of paper in front of the child, who points out which of the four he or she is currently seeing.
But for infants as young as Julia, it's a game of hit and miss. During her examination, she showed no interest in a spinning Buzz Lightyear toy held up 10 feet away from her.
Instead, she focused on Uribe holding a light near her eye.
Then just as fast as a snap of the fingers, Uribe got Julia to focus on Buzz.
"Sometimes they have a short span," the doctor said. "It's tough to work in that time frame, but if we can get to all we can now, we can make sure the eyes develop 100%."