DC Child Accident & Safety Blog

A better, earlier way to diagnose amblyopia — commonly called “lazy eye” — has been reported by ophthalmologists at Children's Hospital Boston. A screening procedure that takes only seconds with a handheld scanning device may enable pediatricians to identify the disorder that causes a loss of vision in a structurally normal eye. The ophthalmologists tested 202 children with the Pediatric Vision Scanner, some as young as 2.

Lazy eye usually results from a misalignment of the eyes or from one eye having a weaker focusing power. In either case, one eye is underused, and vision deteriorates as the brain loses its ability to interpret visual information from that eye. Lazy eye affects 3% to 5% of children and is the leading cause of vision loss in childhood.

The younger the patient, the more responsive to treatment. But the disorder is difficult to detect in young children because they cannot reliably communicate what they’re seeing, and they can’t read eye charts.

"The eyes of a child with amblyopia can look perfectly fine, even while one eye is slowly losing vision," said David Hunter, chief of ophthalmology at Children's Hospital Boston and an author of the study published in the journal Investigative Ophthalmology and Visual Science. "Once a child reaches school age, treatment is less likely to restore useful vision.”

Doctors can reverse lazy eye by patching the stronger eye or blurring it with eye drops, forcing the child to use the weaker eye. Hunter hopes pediatricians will use the scanner to screen toddlers and preschoolers for amblyopia during annual well-child visits, and that health insurers will cover the cost. Some states mandate eye exams just before kids begin school, but that’s too late to treat amblyopia most effectively, according to Hunter.