Younger age associated with greater treatment response in children with amblyopia

"Evidence that amblyopia treatment is effective in some older children raises the longstanding question of whether or not there is a relationship between age and magnitude of treatment response," write Jonathan M. Holmes, B.M., B.Ch., of the Mayo Clinic, Rochester, Minn. and the Jaeb Center for Health Research, Tampa, and colleagues as background information in the article.

Dr. Holmes and colleagues conducted a meta-analysis of four previous randomized multicenter clinical trials for treatment of amblyopia, conducted by the Pediatric Eye Disease Investigator Group (PEDIG). The meta-analysis included data from 996 children who were 3 years to less than 13 years of age.

Based on analysis of visual acuity change versus age by amblyopia severity at the time of enrollment in the study, the authors found a decrease in treatment response with increasing age that was most evident for children with more severe amblyopia. After adjusting for covariates, children who were 7 years to less than 13 years of age had less improvement than children who were 3 years to less than 7 years of age for both moderate and severe amblyopia.

The authors found no difference in treatment response between children 3 years to less than 5 years of age and children 5 years to less than 7 years of age for moderate amblyopia; however, they found a suggestion of greater treatment responsiveness in children in the younger age group (3 years to less than 5 years of age) for severe amblyopia.

The authors note that despite the reduced treatment response of older children compared to younger children seen in the analysis, "there was still an improvement in the mean visual acuity with treatment, and some individuals responded dramatically."

"In conclusion, while there is improvement in visual acuity across all age ranges (from 3 to <13 years of age), children 7 to less than 13 years of age are least responsive to amblyopia treatment," the authors write. "Despite reduced mean [average] treatment response in children 7 to less than 13 years of age, some children in this age group showed marked improvement with treatment."

Research Letter: Evaluating Residual Amblyopia

An intensive final treatment push (using patching and atropine) does not appear to produce improved visual acuity in children with mild residual amblyopia compared to gradually discontinuing treatment, according to a research letter in the July issue of Archives of Ophthalmology.

The Pediatric Eye Disease Investigator Group (PEDIG) conducted a randomized trial to determine whether an intensive final treatment push with combined patching and atropine sulfate would improve visual acuity in children (ages 3 to 10 years) with residual amblyopia (remaining visual acuity deficit after initial treatment for amblyopia). Between October 2007 and March 2009, 27 children were randomized to the intensive treatment group (six hours of eye-patching daily combined with daily atropine) and 28 were randomized to the weaning treatment group (reduction of current treatment for four weeks with two hours of eye-patching daily or once-weekly atropine followed by eyeglasses alone if needed).

At the ten-week primary outcome examination, visual acuity in the amblyopic eye had improved in 11 percent (n=3) of children in the intensive group and 22 percent (n=6) of children in the weaning treatment group. After adjustment for sex, cause of amblyopia, refractive error in the amblyopic eye and visual acuity testing method, results were similar between the two groups.

"For children with amblyopia who have already stopped improving with six hours of prescribed daily patching or with daily atropine, we found that an intensive final push of combined treatment with patching and atropine did not produce a better visual acuity outcome after ten weeks compared with a control group in whom treatment was gradually discontinued," the authors conclude.