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). 


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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. 

Reference

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