Resistance of iris vascular structure to obesity: an anterior segment optical coherence tomography angiography study.

PURPOSE: To quantitatively evaluate iris and limbal vascular density using anterior segment optical coherence tomography angiography (AS-OCTA) in pediatric and adult participants across different body mass index (BMI) categories and to investigate the potential effects of obesity on anterior segment microcirculation.

METHODS

This prospective cross-sectional study included 300 participants: 200 adults (≥ 19 years) and 100 children (4-17 years). Adult participants were classified according to the World Health Organization BMI criteria, whereas pediatric participants were categorized using age- and sex-specific BMI-for-age percentiles. Iris and limbal vascular density were measured using AS-OCTA in the superotemporal, superonasal, inferonasal, and inferotemporal quadrants. Adult and pediatric groups were analyzed separately.

RESULTS

No significant differences in iris or limbal vascular density were observed among BMI categories in adults (all P > 0.05). Likewise, iris vascular density did not differ significantly among BMI-for-age categories in children. However, limbal vascular density differed significantly in the superotemporal (P = 0.014) and inferotemporal (P = 0.040) quadrants in the pediatric group. Post hoc analysis demonstrated a significant difference only between the normal-weight and obese groups in the superotemporal quadrant, whereas no significant pairwise differences were identified in the inferotemporal quadrant.

CONCLUSIONS

Obesity was not associated with widespread alterations in anterior segment vascular density in adults, whereas localized limbal vascular differences were observed in children. These findings suggest that obesity-related anterior segment microvascular changes may be region-specific and age-dependent. Larger longitudinal studies are needed to clarify the clinical significance of these findings and to determine the potential role of AS-OCTA in the assessment of obesity-related ocular microvascular alterations.