Power Profiles of an Extended Depth of Focus Contact Lens for Myopia Management

To characterise the optical power profiles of an extended depth of focus (EDOF) contact lens (MYLO, Mark'ennovy) for myopia management across its full range of labelled powers and fitting parameters.

Power profiles of 91 MYLO lenses were measured using the NIMOevo® instrument. Lenses ranged in labelled power from -1.00 to -10.00 D, total diameters (TD) from 13.50 to 15.50 mm and back optic zone radii (BOZR) from 7.1 to 9.8 mm. Central thickness (CT) was assessed using spectral-domain optical coherence tomography. Lens power profiles were fitted with piecewise cubic splines, and peaks and troughs were identified using both semi- and fully-automated inflection-point detection. Zernike polynomial fitting, applied at enhanced resolution, was used to derive power within the central 0.50 mm radius.

All lenses demonstrated a damped sine-wave power profile, featuring three consistent peaks and troughs superimposed on a general trend toward peripheral minus power. The location and relative magnitude of these features remained highly consistent across all combinations of lens power, TD and BOZR. Central zone analysis revealed a mean relative hyperopic defocus of 1.24 ± 0.79 D within the central 0.25 mm radius, followed by a myopic shift of 0.41 ± 0.38 D in the 0.25-0.50 mm annulus, resulting in a near-emmetropic outcome (0.08 ± 0.38 D) across the full central 0.00-0.50 mm region. CT was not correlated with labelled power.

The MYLO lens demonstrated a stable and predictable optical profile across a broad range of fitting parameters, indicating that changes in lens power or parameters do not impact its optical performance. The study highlights the need for refined standards in the evaluation of power profiles of EDOF contact lenses.