Purpose: To assess the stability of visual and refractive outcomes that was compared between three and 12 months after MyoRing implantation in moderate and severe keratoconus Methods: This study included 54 eyes of 50 patients (27 males and 23 females) with stage II and III keratoconus who underwent MyoRing (Dioptex GmbH) implantation. Clinical outcomes including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, spherical equivalent (SE) and mean keratometry (k)- readings were compared preoperatively and postoperatively (follow-up times were at 1, 3, 6 and 12 months postoperation). Results: The mean age was 28.48±6.3. The mean UDVA (logMAR) and the mean CDVA (logMAR) improved significantly from 1.20±0.24 to 0.20±0.09 and from 0.58±0.22 to 0.14±0.06, respectively (p<0.001). Both SE and the maximum keratometry (k)-reading decreased significantly by six diopters (p<0.001). There was no significant difference in visual and refractive outcomes between three and 12 months postoperatively. Twelve months after MyoRig implantation the predictability was 47 eyes (87%) within ±1.00 D and 31 eyes (57%) within ±0.50 D of emmetropia. Conclusion: MyoRing implantation in keratoconic patients improves SE, UDVA and CDVA significantly. Additionally, the improvement in UDVA was remarkable (approximately 10 lines). The procedure was safe and effective in treatment of patients with moderate and severe keratoconus. The visual and refractive outcomes remained stable between three and 12 months postoperatively
