The short- and long-term effects on the visual system of children following exposure to maternal substance misuse in pregnancy.

Purpose: To document the prevalence of ophthalmic morbidities in babies born to mothers who misused substances in pregnancy and to assess whether it changes over 5 years.

Design: Retrospective comparative case series.

Methods: The series included: (1) a retrospective review of 301 children born between 2000 and 2004 to mothers misusing substances during pregnancy; (2) assessment at 5-year follow-up of this cohort; and (3) comparison with 7887 age-matched controls drawn from the preschool screening cohort in the north of Scotland in the same time period. Odds ratios (OR) and 95% confidence intervals (CI) were calculated. Following data collection in both patient and control groups, the following were calculated: (1) rate of referral to the ophthalmology department; (2) prevalence of nystagmus and strabismus at presentation in the study group and at 5 years of age in both patient and control group; (3) prevalence of reduced visual acuity and lack of stereopsis.

Results: Ophthalmology referrals, strabismus, and nystagmus were found to be statistically significantly higher in the study group compared with the control group. In the study group, at baseline referral, 46 of 301 (15.3%) had strabismus (2.8% in control group) and 11 of 301 (3.7%) nystagmus (0.004% in control group). At 5-year follow-up, the prevalence of strabismus was 14.0% (OR 5.70, 95% CI: 4.01-8.12) and that of nystagmus was 3.3% (OR 90.34, 95% CI 24.73-330.02). A total of 42.4% of these children at age 5 had no demonstrable binocular vision and 28.2% had visual acuity of 0.3 (logMAR) or worse in 1 or both eyes. Clinic attendance at last follow-up was poor (61.9%).

Conclusions: Exposure to maternal drug misuse in utero is associated with a statistically significantly higher prevalence of strabismus and nystagmus. These abnormalities tend to persist at 5 years of age and are associated with long-term visual morbidity, such as lack of binocularity and poor visual acuity. Our study highlights the need for ophthalmologic surveillance of this population and supports attendance, as nonattendance may be linked to more problems with substance misuse in parents and greater pathology in the child.