Levodopa-carbidopa and childhood retinal disease.
OBJECTIVE
Our purpose was to determine the influence of levodopa-carbidopa on visual function in children with retinal disease.


METHODS
Two studies were undertaken, a single-dose study and a longitudinal dosing study. A double-masked, placebo controlled single-dose study was undertaken of levodopa-carbidopa (2.08 mg/kg of body weight levodopa with 25% carbidopa) on monocular visual acuity in 14 children with retinal disease. Subjects received two capsules approximately 2.5 hours apart, and monocular visual acuity was measured 2 hours after each capsule ingestion. The second study was a double-masked, placebo-controlled 12-week longitudinal dosing (0.62 mg/kg of body weight) crossover study in which subjects received levodopa-carbidopa for 6 weeks and placebo for 6 weeks.


RESULTS
The single-dose study revealed a small but statistically significant improvement in monocular visual acuity after levodopa-carbidopa ingestion. The longitudinal study revealed a small but statistically significant improvement in binocular visual acuity after levodopa ingestion. In both studies placebo had no significant effect on visual acuity. Six subjects participated in both studies and demonstrated a significant correlation (r = 0.76, p < 0.05) between change in visual acuity in the single-dose study and the longitudinal dosing study.


CONCLUSIONS
The results are consistent with the hypothesis that dopamine influences the receptive field characteristics of retinal cells. The results also suggest that there may be low retinal dopamine levels in some types of retinal disease, which may be amenable to treatment.
Leguire
L E
LE
Department of Ophthalmology, Children's Hospital, and the College of Medicine, Ohio State University, Columbus 43205-2696, USA.
Jende
D L
DL
Nairus
T M
TM
Walson
P D
PD
Rogers
G L
GL
Bremer
D L
DL
McGregor
M L
ML
D000293:Adolescent; D002230:Carbidopa / Q000008:administration & dosage / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D018592:Cross-Over Studies; D015259:Dopamine Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004338:Drug Combinations; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D007980:Levodopa / Q000008:administration & dosage / Q000627:therapeutic use*; D008137:Longitudinal Studies; D012164:Retinal Diseases / Q000188:drug therapy* / Q000235:genetics; D014792:Visual Acuity / Q000187:drug effects
D015259:Dopamine Agents; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D007980:Levodopa; D002230:Carbidopa