Biometric factors and orthokeratology lens parameters can influence the treatment zone diameter on corneal topography in Corneal Refractive Therapy lens wearers

Abstract

Purpose: To investigate the relationship between patients' baseline biometric factors or lens parameters and the diameter of the treatment zone in young myopic children undergoing Corneal Refractive Therapy.

Methods: The data of patients undergoing Corneal Refractive Therapy lens treatment within two years were retrospectively reviewed. Baseline clinical data, including sex, age, refractive power, corneal topography readings, ocular optical biometric measurements, and Corneal Refractive Therapy lens parameters, were subjected to Pearson, Spearman, and partial correlation analyses to identify the potential factors that may influence treatment zone diameter on corneal topography. Logistic and linear regression analyses were used to predict the treatment zone size.

Results: The Right eyes of 309 patients were included in this study. The spherical refraction, flat keratometric reading, Reverse Zone Depth 2, Landing Zone Angle 1, and lens diameter were independent factors of treatment zone diameter. In the multivariate analyses, Landing Zone Angle 1 was positively correlated, while Reverse Zone Depth 2 and lens diameter were negatively correlated with the size of the treatment area. The accuracy of logistic regression in predicting the treatment zone size was 71.5%.

Conclusion: Adjustments to Corneal Refractive Therapy lens parameters may influence the treatment zone diameter on corneal topography. A higher Reverse Zone Depth 2, smaller Landing Zone Angle 1, and larger lens diameter can lead to a smaller treatment zone for Corneal Refractive Therapy lens treatment.

Keywords: Corneal Refractive Therapy; Myopia; Orthokeratology.