Predictability, stability and safety of MyoRing implantation in keratoconic eyes

during one year follow-up

Sahar Mojaled Nobari(PhDc), Consuelo Villena(PhD), Khosrow Jadidi(MD)

INTRODUCTION

MyoRing is a full-ring intracorneal implant (DIOPTEX GmbH)

that inserts into the cornea by means of PocketMaker

Microkeratome or femtosecond laser. The mechanism of

action for MyoRing implantation is volume added in the

periphery which leads to a new biomechanical equilibrium of

the cornea, thereby flattening its center. The MyoRing

implantation has been used to manage high myopia,

keratoconus and post LASIK ectasia.

PURPOSE

To assess the stability of visual and refractive outcomes that was compared between 3 and 12 months after MyoRing implantation in moderate and severe keratoconus.

PATIENTS AND METHODS

Retrospective cohort study: 54 eyes of 50 patients (27 males and 23 females) with stage II and III keratoconus according to Amsler classification.

Surgical technique: MyoRing (Dioptex GmbH) implantation by means of PocketMaker Microkeratome.

MyoRing dimensions : MyoRing nomogram (Daxer): corneal thickness at its thinnest point and the mean central keratometry (K) – reading.

Inclusion criteria: +19 years, contact lens intolerance, clear central corneas, proof of keratoconus evolution and minimal corneal thickness >350μm.

Exclusion criteria: stage I and IV keratoconus, hydrops, corneal opacity, corneal dystrophy, herpetic keratitis, previous ocular surgery (including CXL), pregnancy, autoimmune or other systemic disease.

RESULTS

The mean age was 28.48± 6.3 years old [range 20 to 45].

Patients were followed at 1, 3, 6, and 12 months postoperatively..

The results of this study showed an overall 10 and 4 lines (logMAR) improvement in the mean UDVA and CDVA at 12 months postoperatively., respectively.

Both the spherical equivalent (SE) and the maximum keratometry value decreased significantly by 6.00 D (p<0.001).

There was no significant difference in visual and refractive outcomes between 3 and 12 months postoperatively.

There was no complication in any case during the surgery or follow-up.

In terms of refractive predictability, 47 eyes (87%) were within ± 1.00 D and 31 eyes (57.4%) were within ±0.50 D of emmetropia.

RESULTS

RESULTS

CONCLUSION

MyoRing implantation leads to an impressive reduction of spherical and cylinder components of manifest refraction by flattening the central cornea.

MyoRing implantation was a safe and effective procedure for the management of moderate and severe keratoconus.

MyoRing implantation significantly improved both UDVA and CDVA, although the improvement of UDVA was more impressive (approximately 10 lines of log MAR).

CONCLUSION

The remarkable improvement in UDVA and spherical component of refraction is probably due to the specific circular shape of MyoRIng which impacts strongly on corneal power and spherical component of refraction.

The stability of visual and refractive outcomes between 3 and 12 months postoperatively indicates that MyoRing could affect keratoconus progression.

Further prospective, randomize studies are recommended to establish the role of MyoRing in controlling the progression of keratoconus.