Nongenetic risk factors for infantile cataracts: Systematic review of observational studies

Abstract

Introduction While infantile cataracts are a major cause of childhood blindness, risk factors remain unknown for approximately two‐thirds of cases. Methods We systematically searched electronic databases PubMed, Ovid MEDLINE, Web of Science, and Scopus, from inception through March 2018, to identify relevant cohort, case–control, cross‐sectional studies, case reports, and case series. We also manually screened bibliographies and consulted with experts in the field to identify additional publications. We reviewed cross‐sectional studies, case reports, and case series and provided a narrative summary of the reported potential risk factors. We evaluated methodological qualities of cohort and case–control studies, extracted relevant data, and described statistically significant associations with infant, maternal, and paternal characteristics. Quality assessment and data extraction were conducted by two reviewers independently. All discrepancies were discussed with the senior author and resolved by consensus. Results Overall, 110 publications were included in the review, 33 of which were cohort and case–control studies. Most of these studies (n = 32) used population‐based data and had either excellent (n = 31) or good (n = 2) methodological quality. Nine studies reported statistically significant associations with infant characteristics (preterm birth, low birth weight), maternal occupations and diseases during pregnancy (untreated hypertension, infections), and paternal sociodemographics (younger age, employment in sawmill industry during pregnancy). Conclusions This systematic literature review provided a comprehensive summary of the known nongenetic risk factors for infantile cataracts, identified gaps in the literature, and provided directions for future research. Studies identifying modifiable risk factors are warranted to design interventions aimed at primary prevention of infantile cataracts.

Descriptive and risk factor analysis of infantile cataracts: National Birth Defects Prevention Study, 2000–2011

“…These estimates, however, were calculated using data from older birth cohorts (1968–1998), and the birth prevalence may have changed over this time period. Common nongenetic risk factors for infantile cataracts reported in previous studies include maternal first trimester infections with rubella, herpes simplex viruses, cytomegalovirus, genitourinary tract infections, and influenza/common cold/respiratory illnesses accompanied with fever (reviewed in Nalbandyan et al, 2021). The risk factors for infantile cataracts were also examined within the National Birth Defects Prevention Study (NBDPS), the largest population‐based case‐control study in the United States investigating risk factors for major birth defects.…”

“…However, due to a limited sample size, they were unable to explore a broader range of exposures collected within the NBDPS, as well as examine exposures by varying pregnancy time windows that may be critical for lens development (first trimester) or lens maturation (second and third trimesters) (Sadler & Langman, 2012), and conduct a subanalysis within a potentially more homogeneous group of isolated cases. Currently, the risk factors remain unknown for approximately two-thirds of infantile cataract cases and the gaps in the literature include further understanding of etiological differences by cataracts laterality and birth defect classification (isolated vs. nonisolated cases), and the teratogenic effects of environmental exposures at different timings of pregnancy (Nalbandyan et al, 2021). Thus, studies providing additional insights into the prevalence and etiology of infantile cataracts are warranted.…”