Epidemiology of Coloboma: Prevalence and Patterns in Texas, 1999-2014

Coloboma is a rare congenital malformation in which part of the tissue that makes up the eye is missing and may cause visual impairment or blindness. Little is known about the epidemiology of this condition. Therefore, we obtained data from the Texas Birth Defects Registry on children identified with coloboma for the period 1999-2014.

Using information on all live births from the same period, prevalence ratios (PRs) for selected demographic and clinical factors were used to estimate associations using Poisson regression among cases with coloboma. Coloboma cases were divided into subgroups to explore patterns of co-occurring defects and syndromes. All variables significant in unadjusted models (p < 0.05) were included in multivariable models to evaluate adjusted PRs (aPRs).

We identified 1587 cases with coloboma, of whom 934 (58.8%) were nonsyndromic, and 474 (29.9%) were isolated. When considering all identified cases, factors associated with significant differences in prevalence included plurality (multiple vs. singleton aPR = 1.4, 95% CI: 1.1-1.8); maternal education (college or greater vs. less than high school aPR = 0.7, 95% CI: 0.6-0.9); maternal race/ethnicity (Hispanic vs. non-Hispanic White aPR = 0.9, 95% CI: 0.8-1.0); and maternal diabetes (yes vs. no aPR = 1.3, 95% CI: 1.0-1.6). There was a notable increase in the birth prevalence of coloboma during the study period (p-for-trend < 0.001). Effect estimates were similar across the different subgroups.

In our large population, we identified several factors associated with the prevalence of coloboma. These findings may help define subgroups of women more likely to have children affected by coloboma, which could inform improved screening efforts.