Full-ring Intrastromal Corneal Implantation for Correcting High Myopia in Patients with Severe Keratoconus

The aim of this study was to evaluate the effect of the mechanical implantation of a MyoRing in patients with severe keratoconus and high myopia. The study involved 32 eyes of 32 patients (14 men and 18 women; mean age: 29.6 ± 6.7; age range: 20 - 44). The patients underwent MyoRing implantation with mechanical dissection using a Pocket Maker microkeratome, and outcomes were assessedat3 months after surgery. The main outcome measures were uncorrected and corrected distance visual acuity (UDVA and CDVA, both in Logarithm of the Minimum Angle of Resolution [logMAR] units), manifest refraction, and keratometry readings. There was a significant improvement in the UDVA, from 1.14 ± 0.32 to 0.35 ± 0.24 (P ˂ 0.001), and in the CDVA, from 0.47 ± 0.20 to 0.22 ± 0.15 (P ˂ 0.001). There was also a significant improvement in the spherical equivalent refractive error (-10.51 ± 2.81 D to -1.32 ± 2.29 D) (P ˂ 0.001). There was a significant decrease of manifest refraction in the mean sphere and cylinder of 7.70 and 2.6 D, respectively (P < 0.001). Furthermore, with regard to corneal topography, there was a significant reduction of 3.55 D (P ˂ 0.001) in the mean keratometry reading. The results show that the mechanical implantation of a MyoRing is effective for the correction of myopia in patients with keratoconus and high myopia.