The relationships among cycloplegic refraction, keratometry, and axial length in children with refractive accommodative esotropia

PurposeTo explore the relationships among cycloplegic refraction, keratometry, and axial length in children with refractive accommodative esotropia and to evaluate the feasibility of axial length estimation from the other 2 parameters.MethodsThis is a prospective case series of children ages 4-12 years who were diagnosed with refractive accommodative esotropia, cooperative for keratometry and optical biometry by the IOLMaster, and without amblyopia in the right eye. The right eyes of the first group of patients were used to generate a linear regression formula from cycloplegic refraction, keratometry, and axial length. This formula was used in the second group of patients to estimate axial length from cycloplegic refraction and keratometry.ResultsA total of 100 children were enrolled. Cycloplegic refraction ranged from +2.25 D to +8.25 D, keratometry ranged from 38.34 D to 48.37 D, and measured axial length ranged from 19.34 mm to 23.66 mm. Estimated and measured axial lengths were strongly correlated (Pearson coefficient = 0.9; 95% CI, 0.83-0.94) with the former values having a greater mean by the paired t test (2-sided P < 0.0001; difference between means, 0.27 mm). Estimated and measured values differed by <0.5 mm for most eyes (33/50, 66%) and were within 1 mm for all eyes.ConclusionsIn children with refractive accommodative esotropia, there exists a constant mathematical relationship among cycloplegic refraction, keratometry, and axial length. This relationship allows reasonable estimation of axial length from the other 2 parameters.