This study presents a machine learning model that predicts cycloplegic refraction in adults with myopia using standard non-cycloplegic eye measurements, aiming to reduce the need for cycloplegic drops while still identifying patients who require them.

Myopia is a highly prevalent, irreversible refractive disorder with substantial impact on quality of life. Cycloplegic refraction is the gold standard for assessing refractive error in adults considering optical or surgical correction, but it is time-consuming, slow to recover from, and frequently associated with ocular discomfort. Non-cycloplegic refraction is therefore used routinely in clinical practice, despite known differences from cycloplegic values in a subset of adult myopes.

Critically, this discrepancy varies substantially between individuals and cannot be anticipated from non-cycloplegic measurements alone. Clinicians have no reliable way to identify, prior to dilation, which patients are likely to be overcorrected if cycloplegia is omitted, potentially leading to overcorrected prescriptions, asthenopia, and myopic progression.

Machine learning approaches that capture non-linear relationships between clinical predictors and refractive outcomes have shown promise in children, but comparable models for adults remain largely unexplored, and most rely on axial length, which is unavailable in routine optometric settings. Refractive surgery centers offer a uniquely suitable data source, as every candidate undergoes standardized paired non-cycloplegic and cycloplegic refraction with detailed anterior segment biometry during routine preoperative evaluation. This study leverages such data to develop and validate models estimating cycloplegic refractive error from non-cycloplegic parameters, providing a decision-support tool that reduces unnecessary cycloplegia while flagging patients for whom dilated refraction remains indicated.

Inclusion Criteria:

1. Age 18 to 60 years, of either sex;
2. Spherical equivalent between -0.50 diopters and -10.00 diopters, with myopia in one or both eyes, and with cylinder of 4.00 diopters or less;
3. Best-corrected visual acuity of 20/25 or better in each eye;
4. Clear cornea, no keratoconus, corneal scarring, or other pathologies; clear lens;
5. Intraocular pressure of 21 mmHg or less, with no history of glaucoma;
6. No history of ocular surgery, especially corneal refractive surgery or cataract surgery;
7. Time interval between non-cycloplegic refraction and cycloplegic refraction of 7 days or less, with complete data.

Exclusion Criteria:

1. Incomplete clinical data to support the diagnosis;
2. Ocular conditions such as subclinical keratoconus, keratoconus, or moderate-to-severe corneal haze or leukoma;
3. Allergy or contraindication to cycloplegic agents;
4. Refusal to participate in the study.

Each subject underwent a comprehensive preoperative examination, including cycloplegic and non-cycloplegic refractions, Pentacam, etc.