Optical treatment of amblyopia in astigmatic children: the sensitive period for successful treatment.
OBJECTIVE
To compare the effectiveness of eyeglass treatment of astigmatism-related amblyopia in children younger than 8 years (range, 4.75-7.99 years) versus children 8 years of age and older (range, 8.00-13.53 years) over short (6-week) and long (1-year) treatment intervals.


METHODS
Prospective, interventional, comparative case-control study.


METHODS
Four hundred forty-six nonastigmatic (right and left eye, <0.75 diopters [D]) and 310 astigmatic (RE, > or =1.00 D) Native American (Tohono O'odham) children in kindergarten or grades 1 through 6.


METHODS
Eyeglass correction of refractive error, prescribed for full-time wear, in astigmatic children.


METHODS
Amount of change in mean right-eye best-corrected letter visual acuity for treated astigmatic children versus untreated, age-matched nonastigmatic children after short (6-week) and long (1-year) treatment intervals.


RESULTS
Astigmatic children had significantly reduced mean best-corrected visual acuity at baseline compared to nonastigmatic children. Astigmats showed significantly greater improvement in mean best-corrected visual acuity (0.08 logarithm of the minimum angle of resolution [logMAR] unit; approximately 1 line), than the nonastigmatic children (0.01 logMAR unit) over the 6-week treatment interval. No additional treatment effect was observed between 6 weeks and 1 year. Treatment effectiveness was not dependent on age group (<8 years vs. > or =8 years) and was not influenced by previous eyeglass treatment. Despite significant improvement, mean best-corrected visual acuity in astigmatic children remained significantly poorer than in nonastigmatic children after 1 year of eyeglass treatment, even when analyses were limited to results from highly compliant children.


CONCLUSIONS
Sustained eyeglass correction results in significant improvement in best-corrected visual acuity in astigmatic children, including those previously believed to be beyond the sensitive period for successful treatment.
Department of Ophthalmology and Vision Science, University of Arizona, Tucson, Arizona 85711, USA. emharvey@u.arizona.edu
Erin M
EM
Harvey
Velma
V
Dobson
Candice E
CE
Clifford-Donaldson
Joseph M
JM
Miller
D000293:Adolescent; D000550:Amblyopia / Q000208:ethnology / Q000503:physiopathology / Q000628:therapy*; D001251:Astigmatism / Q000208:ethnology / Q000503:physiopathology / Q000628:therapy*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005139:Eyeglasses; D005260:Female; D006801:Humans; D007198:Indians, North American / Q000208:ethnology; D008297:Male; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D015348:Vision, Binocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology