To estimate the effectiveness of complete corneal ring (MyoRing) implantation compared with MyoRing implantation combined with corneal collagen crosslinking (CXL) for keratoconus treatment for 36 months follow-up.
Retrospective cohort study.
MyoRing implantation was performed in a series of 78 patients (80 eyes) with keratoconus II–III Amsler classification, of these 39 eyes had MyoRing implantation combined with CXL. Implantation of a MyoRing in the corneal pocket was performed using a PocketMaker microkeratome and corneal intrastromal implantation system. During CXL, riboflavin solution 0.1% was injected into the corneal pocket through the incision tunnel and standard surface UVA irradiation (370 nm, 3 mW/cm2) was then applied from 5-cm distance for 30 min.
Significant improvements in uncorrected distance visual acuity and corrected distance visual acuity were observed for both groups, which was relatively better 12 months after procedure in MyoRing alone group; however, in 36 months there was no difference between groups. Keratometry was reduced in both groups; after MyoRing implantation for 8.45 D and MyoRing + CXL for 9.43 D, the spherical equivalent decreased from 8.45 to 7.72 D and from 9.43 to 6.25 D, respectively. The cylinder decreased to 3.33 D with MyoRing alone and to 3.31 D with MyoRing + CXL. Corneal thickness remained nearly unchanged (from 433.69 ± 38.76 to 434.21 ± 34.98) in MyoRing group and decreased from baseline (from 426.93 ± 46.58 to 401.24 ± 39.12 µm) in MyoRing + CXL group 36 months postoperatively, which corresponds with pachymetry reduction after conventional CXL.
Both MyoRing implantation and MyoRing combined with CXL were effective for treating keratoconus. At 36 months, there were slightly better outcomes in MyoRing + CXL group; however, in MyoRing alone group visual and refractive outcomes were stable overtime.
Alio JL, Piñero DP, Daxer A (2011) Clinical outcomes after complete ring implantation in corneal ectasia using the femtosecond technology: a pilot study. Ophthalmology 118:1282–1290 PubMed
Studeny P, Krizova D, Stranak Z (2014) Clinical outcomes after complete intracorneal ring implantation and corneal collagen cross-linking in an intrastromal pocket in one session for keratoconus. J Ophthalmol 568128:5
Nobari S, Villena C, Jadidi K (2016) Myoring implantation alone versus corneal collagen crosslinking following Myoring implantation for management of keratoconus: 1 year follow-up. Acta Med Mediterr 32:1077
Mazzotta C, Traversi C, Baiocchi S, Caporossi O, Bovone C, Sparano MC, Balestrazzi A, Caporossi A (2008) Corneal healing after riboflavin ultraviolet-A collagen cross-linking determined by confocal laser scanning microscopy in vivo: early and late modifications. Am J Ophthalmol 146:527–533 CrossRefPubMed
El-Reggal TM, Abdel Fattah AA (2007) Sequential Intacs and Verisyse phakic intraocular lens for refractive improvement in keratoconic eyes. J Cataract Refract Surg 33:966–970 CrossRef
Daxer A (2012) MyoRing for central and noncentral keratoconus. Int J Keratoconus Ectatic Corneal Dis 1:117–119 CrossRef
Renesto Ada C, Melo LA Jr, Sartori Mde F, Campos M (2012) Sequential topical riboflavin with or without ultraviolet A radiation with delayed intracorneal ring segment insertion for keratoconus. Am J Ophthalmol 153(982–993):e3
- Complete corneal ring (MyoRing) implantation versus MyoRing implantation combined with corneal collagen crosslinking for keratoconus: 3-year follow-up
- Springer Netherlands