Profiling of visual acuity and genotype correlations in RP2 patients: a cross-sectional comparative meta-analysis between carrier females and affected males.

BACKGROUND: X-linked retinitis pigmentosa (XLRP) is the most severe form of retinitis pigmentosa (RP) and accounts for 15-20% of all RP cases. In this study, we investigated the progression of visual acuity loss across age groups in female carriers and compared it to affected males. METHODS: A PubMed literature search was conducted, and RP2 cases were included based on specific inclusion criteria. Visual acuity (VA), refractive error spherical equivalent (SE), and retinal findings were recorded. Cross-sectional analyses investigated the relationship between VA and age in carrier females and affected males. Genotype-phenotype VA correlations were studied using t-tests. RESULTS: 35 carrier females and 28 affected males with confirmed RP2 mutations were collected from 13 studies. The mean age and logMAR VA of carrier females were 44.2 ± 17.4 years, and 0.5 ± 0.5, respectively. 78.8% of carrier females showed abnormal XLRP-related fundus findings and had significantly reduced VA compared to those with normal fundi (0.6 ± 0.5 vs. 0.1 ± 0.1; p = 0.03). Compared to affected males, no statistical correlation was found between logMAR VA and advancing age in carrier females (p = 0.75). Statistically significant linear correlations were found between logMAR VA and SE in each of carrier females (p = 0.01). There were no observed differences in logMAR VA based on mutation type (p = 0.97) or mutation location (p = 0.83). Anisometropia was observed in 38% of carrier females and 68% of affected males; these prevalence numbers are statistically significant between the two groups (1.7 ± 0.3 vs. 3.9 ± 10.9 dioptres; p = 0.03). CONCLUSIONS: RP2 carrier females generally maintain good VA throughout their lifetime, as opposed to affected males, whose vision progressively declines. Our study provides important VA prognostic data that is crucial for patient counseling.

Association Between Exclusive Breastfeeding and Infant Health Outcomes in Pakistan.

PURPOSE: The infant mortality rate in Pakistan is one of the highest in the world with most cases attributed to diarrheal or respiratory diseases. Exclusive breastfeeding for the first 6 months of life is recommended by the World Health Organization to achieve optimal growth and health, however, in Pakistan the rate of exclusive breastfeeding by mothers is <40%. The aim of this study was to investigate the relationship of exclusive breastfeeding, diarrhea, acute respiratory infections and fever among infants under the age of 6 months. DESIGN AND METHODS: The cross-sectional study analyzed secondary data from the 2017-18 Pakistan Demographic and Health-Survey. The sampling frame for the current study consisted of last-born children who were under the age of 6 months. The study sample consisted of 1033 infants under the age of 6 months. RESULTS: The prevalence of exclusive breastfeeding was 53.6%. Compared to infants who were not breastfed exclusively, infants who were had lower odds of diarrhea, acute respiratory infection, and fever. The observed association was independent of potential confounders. CONCLUSIONS: Exclusive breastfeeding reduces the odds of childhood illnesses. Plausible explanations for the observed association may be related to human milk's contents including necessary nutrients to fulfill an infant's needs within first months of life. Additionally, continued exposure to breastfeeding also reduces exposure to other contaminated foods to ensure adequate nutrition for the infant. PRACTICE IMPLICATIONS: The findings have important implications for educating families and healthcare providers about the benefits of exclusive breastfeeding for optimal child health outcomes.