Amblyopia's influence on sense of self

A new study offers more evidence that treating amblyopia early can impact patients' vision and quality of life.

The study, published online in the Nov. 15 JAMA Ophthalmology, considered the self-images of children with amblyopia. Previous studies have shown patients with the condition typically have reading and eye-hand coordination deficits, say researchers affiliated with the Retina Foundation of the Southwest (Dallas, Texas); the department of ophthalmology; University of Texas Southwestern Medical Center (Dallas); ABC Eyes (Dallas) and the school of optometry and vision science, Queensland University of Technology (Brisbane, Queensland, Australia).

The study's purpose, according to researchers, was "to determine whether amblyopia is associated with lowered self-perception of competence, appearance, condition, and global self-worth and whether the self-perception is associated with their performance of reading and eye-hand tasks."

Eighty-one children, ages 8 through 13, participated in the study including 50 with amblyopia, 13 without the diagnosis (neither history nor treatment for amblyopia) and 18 in a control group. Among the assessment tools used were the Self-perception Profile for Children and the Movement Assessment Battery for Children 2 (motor skills and coordination). All students received comprehensive eye examinations.

The results?

"These findings suggest that lower self-perception is associated with slower reading speed and worse motor skills and may highlight the wide-ranging effects of altered visual development for children with amblyopia in their everyday lives," the researchers conclude.

Amblyopia (also known as lazy eye) is one of the most common eye conditions among children, affecting an estimated 2 or 3 individuals out of 100, according to the Centers for Disease Control and Prevention.

In its Evidence-Based Clinical Practice Guideline: Comprehensive Pediatric Eye and Vision Examination, the AOA recommends:

• Infants receive a comprehensive, baseline eye exam between the ages of 6 and 12 months, immediately after the critical period when the eye undergoes rapid and profound changes and is therefore most vulnerable to interference with normal development.
• Preschoolers receive at least one in-person, comprehensive eye exam between the ages of 3 and 5 to prevent or diagnose any condition that may have long-term effect.
• School-age children (6 to 18 years) should receive a comprehensive exam prior to entering the first grade and annually thereafter.
• Treatment for lazy eye may include a combination of prescription lenses, prisms, vision therapy and eye patching. In vision therapy, patients learn how to use the two eyes together, which helps prevent some forms of lazy eye from reoccurring.

Early diagnosis and intervention increases the chance for recovery—the reason why the AOA recommends that children have a comprehensive optometric examination by 6 months of age and again at age 3.

The earlier the better

Glen Steele, O.D., is a member of the AOA's InfantSEE^® and Children's Vision Committee and professor of pediatric optometry at Southern College of Optometry in Memphis, Tennessee. His practice emphasis is on vision care of infants and young children.

"This study clearly shows that amblyopia has a more far-reaching effect on human development than a 'simple' assessment of visual acuity," Dr. Steele says. "According to the study, children with amblyopia have issues in development that make it more difficult to read as quickly as their peers and more difficult to effectively engage in motor skills such as sport activities. This negatively affects self-perception during critical stages of development.The results are not surprising and are welcomed by those who manage patients with amblyopia," he adds. "It has long been known that processes leading to amblyopia affect more than just the eye with amblyopia."

For instance, Dr. Steele says, VEP (visual evoked potential) recordings in the amblyopic eye are generally reduced indicating a reduced signal from that eye when compared to the non-amblyopic eye. However, when the VEP recordings in the non-amblyopic eye are compared to control group responses, the non-amblyopic eye also shows a reduction in VEP, he says.

"What that means is that the VEP shows an overall reduction in visual function, not just in the amblyopic eye," Dr. Steele says. "Vision is so critical in overall human development. When visual responses are slowed, overall development is slowed, too."

What can doctors of optometry do? Prevention by the earliest possible identification and intervention, Dr. Steele says. Early intervention minimizes the impact of reduced function and allows children to participate in activities with their peers in a manner typical for their age, he adds.

When these times are missed, he says, care management involves working as efficiently as possible to restore visual loss but more mportantly, improving overall function that has been impacted by the conditions that led to amblyopia in the first place.

"This is very strong support for the concept of early identification and intervention," Dr. Steele says. "When factors that are related to amblyopia are identified and intervention initiated in the earliest stages, overall outcomes have the potential to be better.

"The issues surrounding amblyopia begin much earlier than the time of diagnosis," he says. "The AOA recommends that the first examination should be between six and 12 months of age, a time frame when intervention can have significant impact on overall development. There are even greater complications when the amblyogenic factors are unilateral. When intervention is initiated at the earliest time, the impact of amblyogenic factors is minimized."