Abstract
Abstract: :
Purpose: To evaluate levodopa in respect to older childhood amblyopia in combination with part-time occlusion and full refractive correction. Methods: Twenty-nine amblyopic (anisometropic, strabismic or combined) children ages 7 to 18 years participated in a double-masked, placebo controlled study between 1998 and 2001. Full corrections for refractive errors were worn for the duration of the study. All children underwent five hours per day occlusion of the dominant eye for at least six weeks. After vision stabilized (improving less than one line), participants were randomly assigned either .75mg/kg levodopa/carbidopa (17 children) or placebo (9 children) 3X/day for five weeks with continued patching five hours per day. Visual acuity tests included Snellen, Landolt Cs (3 charts with constant intersymbol distances of 35, 17.2 and 2.6 min of arc), Contrast Sensitivity (5 spatial frequencies 0.56, 1.48, 2.96, 6.11 and 11.48 c/deg) and stereo acuity. Visual acuities were measured pre and post patching, and 2.5 and 5 weeks during drug administration, with follow-up at six weeks, six months and one year after drug administration. Results: Fifty-nine percent (17/29) children improved an average of 2.5 lines following a minimum of six weeks part-time occlusion with optical correction. Two patients improved within a one line difference after patching therefore did not meet the greater than two line difference for study inclusion. Participation was terminated for one child due to significant side effects of levodopa. Fifty-nine percent (10/17) of children receiving levodopa improved an average of almost two Snellen lines while 56% (5/9) of children receiving placebo improved less than one line following a minimum of 11 weeks patching. All of the children receiving levodopa except one improved in at least two of the Landolt C charts. Sixty-five percent (11/17) maintained improvement in visual acuity at intersymbol distances of 35 and 17 min of arc one year after levodopa and patching. Conclusion: Patching in older children, when accompanied with full optical correction, improves vision; and systemic levodopa further enhances the visual acuity improvement. CR: none Support: none
Keywords: 313 amblyopia • 490 neurotransmitters/neurotransmitter systems • 620 visual acuity