The meta-analysis of earlier studies published this week in the Archives of Opthalmology, one of the JAMA/Archives journals has revealed that the treatment for amblyopia, also known as lazy eye, was associated with good response among younger children between 3 to less than 7 years of age compared to older children.
Jonathan M. Holmes, B.M., B.Ch., of the Mayo Clinic, Rochester, Minn. and the Jaeb Center for Health Research, Tampa, and colleagues carried out a meta-analysis of four earlier randomized multicenter clinical trials that included data from 996 children between 3 to 13 years of age who had undergone amblyopia treatment. These studies were conducted by the Pediatric Eye Disease Investigator Group (PEDIG).
In the background information regarding the study, the authors write:
“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.”
For both moderate and severe amblyopia, after adjusting for covariates, children between 3 to less than 7 years of age demonstrated more improvement in the disorder compared to children between 7 to less than 13 years of age. The analysis of visual acuity change versus age by amblyopia severity during enrollment in the study showed a decrease in response to treatment with increasing age which was most obvious for children with more severe amblyopia.
For moderate amblyopia, the authors establish no difference in treatment response of children between 3 to less than 5 years of age and children between 5 to less than 7 years of age. For severe amblyopia, researchers found clues of greater treatment responsiveness in children in the younger age group i.e. between 3 to less than 5 years of age.
Although during analysis it was observed that there was a decrease in the response to treatment of older children compared to younger children. The authors wrote:
“There was still an improvement in the mean visual acuity with treatment, and few 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," "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."
With reference to a research letter published in the same issue, in children with mild residual amblyopia (remaining visual acuity deficit after initial treatment for amblyopia), an intensive final treatment push using patching and atropine does not appear to improve visual acuity compared to steadily discontinuing the treatment.
A randomized trial aimed at finding out whether an intensive final treatment push using patching and atropine sulfate would improve visual acuity in residual amblyopia children of 3 to 10 years of age was conducted by The Pediatric Eye Disease Investigator Group (PEDIG). Between October 2007 and March 2009, 27 children were randomized to the intensive treatment group and 28 were randomized to the weaning treatment group. In the intensive treatment group, the children were administered an eye patching therapy daily for six hours combined with daily atropine. In the weaning treatment group, the reduction of current treatment for four weeks was carried out with daily eye-patching for two hours or once-weekly atropine followed by eyeglasses alone if needed.
An improvement in visual acuity in the amblyopic eye was seen in 11 percent (n=3) of children in the intensive group and 22 percent (n=6) of children in the weaning treatment group at the end of ten-week primary outcome assessment. Results were similar between the randomized groups after adjusting for gender, cause of amblyopia, refractive error in the amblyopic eye and visual acuity testing method.
The authors concluded:
“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.”
Jonathan M. Holmes, BM, BCh; Elizabeth L. Lazar, MS, MPH; B. Michele Melia, ScM; William F. Astle, MD; Linda R. Dagi, MD; Sean P. Donahue, MD, PhD; Marcela G. Frazier, OD, MPH; Richard W. Hertle, MD; Michael X. Repka, MD, MBA; Graham E. Quinn, MD, MSCE; Katherine K. Weise, OD, MBA
Arch Ophthalmol. Published online July 11, 2011. doi:10.1001/archophthalmol.2011.179
Written by Barry Windsor