Retinochoroidal structural and microvascular changes assessed by optical coherence tomography angiography in obese children: Association with insulin resistance indices-a pilot study.

Abstract

Background: Childhood obesity is associated with metabolic dysfunction and may be accompanied by early microvascular alterations. The retinal and choroidal circulation can be assessed non-invasively using optical coherence tomography angiography (OCTA).

Objective: To explore retinochoroidal structural and microvascular changes in children with obesity and assess their association with insulin resistance indices, including Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and triglyceride glucose (TyG) index.

Methods: This exploratory pilot cross-sectional comparative study included 20 obese children (BMI >95th percentile) and 20 healthy normal-weight children (BMI >5th and <85th percentile for age and sex) as controls. OCTA 6 × 6 mm scans were used to assess central macular thickness, choroidal thickness, foveal avascular zone, choriocapillaris flow area, and superficial/deep retinal vessel densities (SVD/DVD) in parafoveal and perifoveal sectors. Anthropometric measurements, lipid profile, HOMA-IR, and TyG index were assessed and correlated with OCTA parameters.

Results: Obese children had significantly lower visual acuity and thinner choroidal thickness compared with normal-weight controls. OCTA showed significant reductions in SVD and DVD across multiple parafoveal and perifoveal sectors, with more consistent involvement of DVD. Waist-to-height ratio, HOMA-IR, and TyG index showed significant negative correlations with several OCTA parameters, particularly DVD. Effect size analysis showed large differences in TyG index, whole DVD, and parafoveal DVD between obese and normal-weight children.

Conclusion: Childhood obesity was associated with subclinical retinochoroidal structural and microvascular differences, particularly involving the deep capillary plexus. These exploratory findings suggest that OCTA may provide useful non-invasive information about obesity-related ocular changes in children, especially in relation to central adiposity and insulin resistance. Larger longitudinal studies are needed to confirm these findings and clarify their clinical relevance.