Visual outcomes after femtosecond-assisted intracorneal MyoRing implantation: 18 months of follow-up.

PURPOSE: To determine the long-term results of femtosecond-assisted MyoRing implantation for the treatment of keratoconus.

METHODS

In this prospective, non-randomized, interventional clinical study, 47 eyes of 46 patients with keratoconus grade 1 to 3 entered the study. For all patients, a MyoRing (Dioptex, GmbH, Austria) was implanted using a femtosecond laser (Femto LDV, Ziemer, Germany).

RESULTS

At 18 months, mean uncorrected and best corrected visual acuity was 0.41 ± 0.19 logMAR, (P = 0.004) and 0.62 ± 0.22 logMAR (P < 0.001), and mean manifest refraction spherical equivalent was -0.38 ± 2.62D (P < 0.001). The central 3-mm maximum and mean keratometry decreased by 5.20 ± 3.06D and 4.77 ± 2.47D, respectively (both P < 0.001), and the 8-mm maximum keratometry decreased by 1.16 ± 5.50D (P = 0.185). Central and minimal corneal thickness showed an insignificant increase. Both corneal hysteresis and corneal resistance factor showed an insignificant decrease of about 0.13 mmHg. Endothelial cell count decreased by 215.43 ± 300.55 cell/mm(2) (P < 0.001). Twenty-six subjects (55.3 %) had halo vision at night and 24 subjects (51.1 %) had glare at night.

CONCLUSIONS

Femtosecond-assisted intracorneal MyoRing implantation can be an appropriate treatment option in keratoconus patients with central corneal protrusion, but the incidence of optical disturbances can be relatively high.