To assess the influence of small-incision lenticule extraction (SMILE) for high myopia on the visual image quality assessed by the logarithm of the Visual Strehl Ratio (logVSX), and put this into a clinical context by pairwise comparing the logVSX of postoperative eyes with those of myopic controls wearing spectacles and/or contact lenses.
University Hospital DESIGN:: Prospective & cross-sectional clinical study METHODS:: Patients with a myopic spherical equivalent of at least 6 diopters treated with SMILE aimed at emmetropia and correspondingly myopic controls corrected with spectacles and/or contact lenses were included. The logVSX calculation was divided into habitual logVSX based on the wavefront aberration measurement directly, and optimal logVSX calculated in a theoretical through-focus experiment to obtain the best-achievable logVSX.
117 eyes of 61 patients and 64 eyes of 34 myopic controls were included. SMILE did not affect the habitual logVSX, but worsened the optimal logVSX (P<0.001). The postoperative habitual logVSX was significantly worse compared to contact lenses (P=0.002). The postoperative optimal logVSX was significantly worse compared to both spectacles (P<0.01) and contact lenses (P=0.003). There was no difference in habitual or optimal logVSX between spectacles and contact lenses.
SMILE for high myopia does not affect the habitual logVSX but decreases the optimal logVSX slightly. The postoperative habitual logVSX is worse than for contact lenses but not spectacles, and the postoperative optimal logVSX is worse than for both contact lenses and spectacles. There is no difference in either habitual or optimal logVSX between spectacles and contact lenses.