Causes of low vision in children: A systematic review.

OBJECTIVE: To identify the ocular pathologies that are reported as causes of low vision in children. MATERIAL AND METHODS: The systematic search was carried out in Medline (PubMed), Embase and Lilacs. Observational studies with populations between 0-18 years of age, reporting visual acuity data between 20/60-20/400 and reporting the frequency of ocular pathologies were selected. Studies in which the diagnosis of the condition had not been verified by a professional, or which covered only cases of blindness, uncorrected refractive errors, or amblyopia, were excluded. The methodological quality of the articles was evaluated using the Joanna Briggs Institute instrument for prevalence studies. RESULTS: 27 studies conducted in Asia (13 publications), Africa (6 studies), Oceania (4 studies), Europe and South America (2 studies each) were included. The most reported causes of low vision were: cataract, with prevalence between 0.8% and 27.2%; albinism with from 1.1% to 47%; nystagmus, with prevalence between 1.3% and 22%; retinal dystrophies between 3.5% and 50%; retinopathy of prematurity (ROP) with prevalence between 1.1% and 65.8%, optic atrophy between 0.2% and 17.6%, and glaucoma from 2.4% to 18.1%. CONCLUSIONS: Cataract, albinism and nystagmus are the ocular pathologies most mentioned by studies as a cause of low vision in children, as well as retinal diseases such as ROP and optic nerve diseases such as atrophy. However, there are numerous eye conditions that can result in low vision in the pediatric population.

Risk of cataract in smokers: A meta-analysis of observational studies. / Riesgo de catarata en fumadores: metaanálisis de estudios observacionales.

OBJECTIVE: The aim of the study was to compare the risk of cataract in smokers and ex-smokers. METHODS: A systematic search of observational studies was carried out in Medline, Embase, and Lilacs databases. Studies that have evaluated the association between cigarette smoking and any type of clinically diagnosed cataract were selected. The association estimators were extracted, adjusted at least by age, and were combined using random-effects models, by subtype of study (cohort, case control and cross sectional), subtype of cataract (nuclear, cortical, and posterior subcapsular), and exposure (current smoker or ex-smoker). Statistical heterogeneity, meta-regression analysis and publication bias were assessed. RESULTS: A total of 13 cohort studies, 12 case-control studies, and 18 cross-sectional studies were selected. A risk of cataract was found in current smokers: cohort (OR: 1.41; 95%CI: 1.24-1.60), cases and controls (OR: 1.45; 95%CI: 1.08-1.96), and cross-sectional studies (OR: 1.21; 95%CI: 1.09-1.34); risk of nuclear cataract: cohort (OR: 1.71; 95%CI: 1.47-1.98), case-control (OR: 1.79; 95%CI: 1.43-2.25), and cross sectional studies (OR: 1.45; 95%CI: 1.27-1.65). There was no risk of cortical or posterior subcapsular cataract in ex-smokers. CONCLUSIONS: There is a risk of cataract in smokers, particularly nuclear type. With cross-sectional studies, similar results are obtained with cohorts and cases and controls.