Cutoff Values of Noncycloplegic Spherical Equivalent Refraction for Myopia Detection in Southwestern Chinese Children

Cycloplegic refraction, the gold standard for detecting myopia, is not available to everyone, even in hospital-based scenarios. Nevertheless, the conclusions of previous studies investing in noncycloplegic indicators for myopia detection were inconsistent. We aimed to explore noncycloplegic indicators for detecting myopia in children from southwestern China.

This retrospective cross-sectional study collected data from 562 children aged 6-14 who visited the optometry clinic at Chongqing Shapingba District People's Hospital in southwestern China between October 2023 and September 2024. The key noncycloplegic indicators, such as gender, age, uncorrected visual acuity (UCVA), intraocular pressure (IOP), average corneal curvature (ACC), noncycloplegic spherical equivalent refraction (NCSER), axial length (AL), AL to average corneal radius of curvature (AL/ACRC), height and weight, were estimated via logistic regression and receiver operating characteristic (ROC) curves to evaluate the efficacy of various indicators for detecting myopia (defined as cycloplegic spherical equivalent refraction ≤ -0.50 D).

A total of 562 subjects were included, with 72.2% diagnosed with myopia via cycloplegic refraction. Univariate logistic regression identified age, UCVA, NCSER, AL, and AL/ACRC ∗ 100 as predictors of myopia (CSER ≤ -0.50 D). The multiple logistic regression analysis revealed that UCVA, NCSER, and AL/ACRC ∗ 100 were significant indicators for myopia (CSER < -0.50 D). Although the area under the ROC curve (AUC) of the combined use of UCVA, NCSER, and AL/ACRC (AUC = 0.982) was the largest among the indicators under exploration, there was no significant difference from that of NCSER alone (AUC = 0.975) (p = 0.120). The cutoffs for NCSER were -0.815 D in the 6-8 year age range, -0.804 D in the 9-11 year age range, and -0.687 D in the 12-14 year age range.

Our study of children (6-14 years) in southwestern China established NCSER as the most robust noncycloplegic indicator for myopia. Consequently, applying age-specific NCSER thresholds may provide a practical clinical tool to guide decisions on both the necessity for cycloplegic refraction and the early implementation of myopia prevention strategies without initially requiring cycloplegia.