[Biomechanical control of myopia: potential of bidirectional corneal applanation with high-speed video recording].

The introduction of bidirectional corneal applanation technologies into clinical practice made possible the in vivo assessment of biomechanical properties of the fibrous tunic in myopic eyes.

Purpose: This study analyzes the potential of bidirectional corneal applanation with high-speed video recording for biomechanical control of myopia, focusing on the biomechanical parameters of the sclera and cornea.

Material and methods: The study included 129 patients (168 eyes) with myopia ranging from -0.75 to -13.25 D in spherical equivalent. The axial length (AL) and central corneal thickness (CCT) ranged from 22.64 to 29.05 mm and from 492 to 644 µm, respectively. AL was measured using laser biometry, CCT with a rotating Scheimpflug camera, and the biomechanical properties of the fibrous tunic were assessed using bidirectional corneal pneumatic applanation with high-speed video recording using the Corvis ST device.

Results: A weak positive correlation was found between AL and CCT, while no significant correlation was observed between CCT and the stress-strain index (SSI). However, there was a significant negative correlation between SSI and AL. Additionally, a clear and statistically significant trend of decreasing SSI with increasing AL was identified.

Conclusion: The stress-strain index (SSI), determined using bidirectional corneal pneumatic applanation with high-speed video recording, could potentially be considered a clinical indicator characterizing the scleral component of the ocular fibrous tunic in the biomechanical control of myopia.