Abstract
Purpose:
Prenatal exposure to recreational drugs such as alcohol, nicotine, marijuana and methamphetamine influences cognitive and physical development. The aim of this study was to assess the effect of prenatal drug exposure on global motion perception, a function of the dorsal visual stream, which is thought to be particularly vulnerable to abnormal development.
Methods:
One hundred and thirty 54-month-old children (71 male) who were enrolled in the IDEAL (Infant Development, Environment and Lifestyle study) cohort took part in this study. Global motion perception was assessed psychophysically using random dot kinematograms (100 dots, dot speed 6°/sec) whereby motion coherence thresholds (MCT) were measured using a 2-down 1-up staircase approach. Stereoacuity was assessed using the VAO stereotest and unaided visual acuity was measured with the crowded Keeler LogMAR chart. Children were also screened for ocular motility and ocular health problems.
Results:
75.4% of the children had prenatal exposure to nicotine, 55.4% to alcohol, 46.2% to methamphetamine, 43.8% to marijuana and 79.2% of children were exposed to multiple drugs. The effect of nicotine exposure on MCTs differed significantly between males and females (F = 4.9, p = 0.03) whereby nicotine exposure impaired MCTs to a greater extent for males than females. In addition there was a significant interaction between marijuana and alcohol exposure (F = 4.7, p = 0.03) whereby exposure to marijuana in the absence of alcohol tended to improve MCTs. No effects of methamphetamine exposure on MCTs were observed and no effects of drug exposure on stereopsis or visual acuity were found. MCTs were significantly correlated with stereopsis (rho= 0.4, p<0.001) but not visual acuity (rho= 0.092, p=0.300).
Conclusions:
Prenatal exposure to recreational drugs may influence the development of global motion perception, however factors such as gender and multiple drug exposure appear to moderate this effect.
Keywords: 601 motion-2D •
503 drug toxicity/drug effects •
756 visual development