Comparison Of The Visian Implantable Collamer Lens And Smile For Moderate Myopia: Refractive Outcome, Higher Order Aberration And Biomechanical Change

To evaluate the visual outcomes, high-order aberrations and corneal biomechanical properties of the implantable collamer lens (V4c ICL) in moderate myopia and compare the results with small incision lenticule extraction (SMILE). 

Prospective comparative study

Measures were postoperative changes from the preoperative manifest refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, corneal higher order aberrations (HOAs) and endothelial cell count. The corneal biomechanics parameters were quantitatively assessed with the Corvis-ST preoperatively, 3 months, 6 months and 12 months postoperatively.

45 eyes received ICL and 45 eyes received SMILE. The mean spherical equivalent was -5.54 diopters (D) ± 0.77 (SD) preoperatively, and -0.16 ± 1.08 D  postoperatively (P < 0.01). The mean efficacy index was not statistically different between the ICL (1.32 ± 0.12) and the SMILE (1.09 ± 0.23) (P > 0.05). ICL induced significantly fewer HOA and corneal stiffness parameter changes (ΔSP-A1) than SMILE (Total HOA: ICL 0.365 ± 0.112μm, SMILE 0.686 ± 0.168 μm, P < 0.01; ΔSP-A1: ICL 3.18±1.56 mmHg/mm, SMILE 40.23±10.68 mmHg/mm, P < 0.001). The surgical induced HOA was significantly correlated with ΔSP-A1 in either ICL or SMILE procedure [ ICL: r = 0.29, P<0.01; SMILE: r = 0.64, P < 0.01].

 ICL implantation for moderate myopia yielded fewer higher order aberrations and less corneal biomechanical changes than SMILE. Regarding the corneal morphology alteration may affect high-order aberrations, biomechanical effects should be considered in the design and analysis of refractive surgery.