The largest study of vision disorders has found that older children are at an increased risk to both strabismus (cross-eyed or wall-eyed) and amblyopia (referred to as lazy eye) than younger kids.
The researchers at the Keck School of Medicine of the University of Southern California (USC) involved more than 6,000 Los Angeles-area children composed equally of African-American and Hispanic youngsters, aged between six months to six years.
The first phase of the Multi -Ethnic Pediatric Eye Disease Study (MEPEDS). showed that the overall prevalence of strabismus as 2.5 percent while the finding remained constant regardless of gender or ethnicity.
The study identified that the prevalence of the disease increased with age. The overall prevalence of amblyopia, was 2.6 percent in both ethnic groups. This also increased with age.
The authors established that although this graph stabilized by three years of age, strabismus had no difference when amblyopia results were stratified by gender. "This is the first evaluation of strabismus and amblyopia in these two ethnic groups," said principal investigator Rohit Varma, MD, professor of ophthalmology and preventive medicine at the Keck School of Medicine, and director of the Ocular Epidemiology Center at USC's Doheny Eye Institute.
"What was most surprising about our findings, was that the vast majority of children who we diagnosed with either strabismus or amblyopia had been previously undiagnosed and hadn't received any care. "Both of these disorders can be detected by age three, so this points to a crucial need for early screening and intervention programs that could prevent lifelong visual impairments," he added.
"These study results fill an important gap in our knowledge base regarding the magnitude of strabismus and amblyopia in infants and young children, as well as our understanding of age-related differences in these children," said Susan Cotter, OD, the study's co-principal investigator and a research professor of ophthalmology at the Keck School.
The study is currently available in the online edition of the journal Ophthalmology.