Ciliary muscle morphology and accommodative function in children with accommodative esotropia: A prospective cross-sectional study

Purpose To evaluate ciliary muscle (CM) morphology and accommodative function in children with accommodative esotropia (AE) versus healthy controls, and determine subtype-specific differences independent of refractive and biometric confounders. Methods Prospective cross-sectional study of 74 eyes from 37 children with AE (non-refractive, refractive, and partially accommodative subtypes) and 70 eyes from 35 controls. Cycloplegic refraction, axial length (AL), swept-source OCT (CM thickness at 1, 2, and 3 mm posterior to scleral spur [CMT1–3], maximum thickness, cross-sectional area, linear/curved length [CMLarc]), and accommodative function using the Tonoref III, measuring minimum accommodative value (Min AV), maximum accommodative value (Max AV), and total accommodative amplitude (TAA) were assessed. Generalized estimating equation models adjusted for spherical equivalent and AL. Results After adjustment, AE patients showed higher Min AV (3.04 vs. 0.09 D, p = 0.001) and longer CMLarc (5489.10 vs. 5367.19 µm, p = 0.029). TAA and Max AV did not differ. Subtype analysis revealed: partially accommodative AE had higher Min AV ( p = 0.007) and greater CMT1 ( p = 0.041); non-refractive AE showed lower pupil diameter during accommodation ( p = 0.008), longer CMLarc ( p = 0.013), and shorter scleral spur–maximum thickness distance ( p = 0.037); refractive AE had longer CMLarc ( p = 0.040). Higher Min AV correlated with longer CMLarc ( r = -0.255), thinner CMT3 ( r = -0.224), and smaller cross-sectional area ( r = -0.236). Conclusion Children with AE demonstrate subtype-specific alterations in CM morphology and accommodative function independent of refractive error and AL, offering new insights into AE pathophysiology.