A smaller Ambrósio’s relational thickness to the horizontal profile (ARTh) value after orthokeratology (OK) lens wear indicates a better refractive state, slower axial elongation (AE), and may predict treatment outcomes, according to a study published in BMC Ophthalmology.

Researchers enrolled 47 teenagers in the study, consisting of patients who wore OK lenses for more than 1 year (n=23) and age-matched control individuals who wore single-vision spectacles (n=24). The team assessed corneal biomechanical properties through ultra-high-speed Scheimpflug imaging and examined associations between these properties and OK treatment outcomes.

Investigators found less axial elongation (AE) in the OK group (P =.021) compared with control individuals. The OK group experienced a statistically significant decrease in the A1 deformation amplitude (P =.02), whole eye movement maximum (P =.026), and ARTh (P <.001). The team noted statistically significant increases in pachyslope and Corvis biomechanical index (both P <.001). 

Continue Reading

Smaller ARTh and a larger highest concavity deflection area resulted in a better refractive state, and the inhibitory effect of AE was better for older patients with smaller ARTh, according to the report. 

“OK treatment can decrease the AE by approximately 50% within 1 year,” according to the researchers. The team notes the differences in biomechanical parameters between the 2 groups and states, “ARTh after OK treatment was associated with a better refractive state and slower AE, suggesting that ARTh has the potential to be used as an indicator of OK lens treatment outcomes.”

The study was limited by its cross-sectional design. 


Li X, Xu J, Hong J, Yao J. The relationship between corneal biomechanical parameters and treatment outcomes of orthokeratology lenses. BMC Ophthalmol. Published online June 11, 2022. doi:10.1186/s12886-022-02480-1