Association of iron status with visual field loss in US females: data from national health and nutrition examination survey (NHANES) 2005-2008.

BACKGROUND

The relationship between iron status and visual field loss (VFL) remains unclear. This study aimed to explore the potential association between iron deficiency (ID) and the prevalence of VFL among females aged 40-49 in the United States.

METHODS

Data were extracted from the National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and 2008. Participants provided detailed information on iron status and visual field measurements. Several statistical approaches, including survey-weighted logistic regression, restricted cubic spline (RCS) analysis, subgroup analysis, and sensitivity analysis, were employed to explore the association between iron status and VFL.

RESULTS

After adjusting for potential confounding factors, a negative association was observed between transferrin saturation (TS) and the prevalence of VFL (odds ratio [OR] = 0.313, 95% confidence interval [CI] = 0.158-0.619, P = 0.010). Similarly, RCS analysis demonstrated a significant negative correlation between TS and VFL prevalence (P for overall = 0.017). ID, as defined by either the ferritin model (OR = 4.350, 95% CI = 1.702-11.114, P = 0.015) or the mean corpuscular volume (MCV) model (OR = 3.301, 95% CI = 1.066-10.219, P = 0.037), was associated with an increased risk of VFL.

CONCLUSIONS

This study revealed a negative association between TS and the prevalence of VFL among females aged 40-49 in the United States. Furthermore, ID, defined by both ferritin and MCV models, is linked to an elevated risk of VFL. Nevertheless, due to the limitations inherent in cross-sectional design, establishing a causal relationship between iron status and VFL remains challenging.