MyoRing Implantation with and without Corneal Collagen Crosslinking for the Management of Keratoconus


Purpose: To evaluate the safety and efficacy of femtosecond laser-assisted MyoRing implantation with concurrent corneal collagen crosslinking (CXL) compared to MyoRing alone for the treatment of progressive keratoconus.

Methods: A total of 60 patients were enrolled in this randomized controlled trial. The patients were randomly allocated into two groups. In the first group, MyoRing was implanted, while in the second, it was inserted in the corneal stroma using the same technique, along with simultaneous CXL. Visual, refractive, topographic, and abberometric outcomes were measured preoperatively and at every postoperative visit.

Results: Data of 47 patients were available at the end of the study; 28 in the MyoRing group and 19 in the MyoRing + CXL group. The mean uncorrected distance visual acuity (UDVA) improved from 0.79 ± 0.39 logMAR to 0.52 ± 0.31 logMAR (P < 0.05) in the MyoRing + CXL group and from 0.65 ± 0.38 logMAR to 0.62 ± 0.23 logMAR (P = 0.70) in the MyoRing group. CDVA changed from 0.33 ± 0.19 logMAR to 0.25 ± 0.16 logMAR (P = 0.10) in the MyoRing + CXL group and 0.32 ± 0.22 logMAR to 0.33 ± 0.17 logMAR (P > 0.5) in the MyoRing group. The mean keratometry (Km) decreased from 47.5 ± 2.7 D to 43.8 ± 3.2 D (P < 0.001) in the MyoRing group and 49.3 ± 3.4 D to 45.1 ± 3.0 D (P < 0.001) in the MyoRing + CXL group. Besides, horizontal coma was significantly lower in the MyoRing + CXL group (P = 0.022).

Conclusion: MyoRing insertion combined with CXL is a safe and effective method for the treatment of keratoconus. The visual and topographic outcomes were comparable to that for MyoRing insertion after 10 months; however, horizontal coma was significantly lower in the MyoRing + CXL group.


CXL, Keratoconus, MyoRing

1. Rabinowitz YS. Keratoconus. Surv Ophthalmol 1998;42:297–319.

2. Assil KK, Barrett AM, Fouraker BD, Schanzlin DJ. One-year results of the intrastromal corneal ring in nonfunctional human eyes. Arch Ophthalmol 1995;113:159–167.

3. Nosé W, Neves RA, Burris TE, Schanzlin DJ, Belfort R. Intrastromal corneal ring: 12-month sighted myopic eyes. J Refract Surg 1996;12:20–28.

4. Schanzlin DJ, Asbell PA, Burris TE, Durrie DS. The Intrastromal Corneal Ring Segments: Phase II Results for the Correction of Myopia. Ophthalmology 1997;104:1067– 1078.

5. Colin J, Cochener B, Savary G, Malet F. Correcting keratoconus with intracorneal rings. J Cataract Refract Surg 2000;26:1117–1122.

6. Colin J, Cochener B, Savary G, Malet F, Holmes-Higgin D. INTACS inserts for treating keratoconus: one-year results. Ophthalmology 2001;108:1409–1414.

7. Wachler BSB, Chandra NS, Chou B, Korn TS, Nepomuceno R, Christie JP. Intacs for keratoconus. Ophthalmology 2003;110:1031–1040.

8. Jabbarvand M, SalamatRad A, Hashemian H, Mazloumi M, Khodaparast M. Continuous intracorneal ring implantation for keratoconus using a femtosecond laser. J Cataract Refract Surg 2013;39:1081–1087.

9. Ratkay-Traub I, Ferincz IE, Juhasz T, Kurtz RM, Krueger RR. First clinical results with the femtosecond neodyniumglass laser in refractive surgery. J Refract Surg 2003;19:94–99.

10. Raiskup F, Spoerl E. Corneal crosslinking with riboflavin and ultraviolet A. Part II. Clinical indications and results. Ocul Surf 2013;11:93–108.

11. Caporossi A, Baiocchi S, Mazzotta C, Traversi C, Caporossi T. Parasurgical therapy for keratoconus by riboflavin– ultraviolet type A rays induced cross-linking of corneal collagen: preliminary refractive results in an Italian study. J Cataract Refract Surg 2006;32:837–845.

12. Caporossi A, Mazzotta C, Baiocchi S, Caporossi T. Longterm results of riboflavin ultraviolet a corneal collagen cross-linking for keratoconus in Italy: the Siena eye cross study. Am J Ophthalmol 2010;149:585–593.

13. Kymionis GD, Grentzelos MA, Liakopoulos DA, Paraskevopoulos TA, Klados NE, Tsoulnaras KI, et al. Long-term follow-up of corneal collagen cross-linking for keratoconus—the Cretan study. Cornea 2014;33:1071– 1079.

14. Hafezi F, Kanellopoulos J, Wiltfang R, Seiler T. Corneal collagen crosslinking with riboflavin and ultraviolet A to treat induced keratectasia after laser in situ keratomileusis. J Cataract Refract Surg 2007;33:2035–2040.

15. Hafez MI. Combined cross-linking with femtosecond laser Myoring implantation versus combined cross-linking with femtosecond laser Keraring implantation for treatment of keratoconus. Delta J Ophthalmol 2016;17:1–8.

16. Kazakbaeva G, Bikbov M, Usubov E. The evaluation of intrastromal MyoRing implantation with corneal collagen cross‐linking in keratoconus treatment. Acta Ophthalmologica 2016;94:S256.

17. Wang SL, Kanellopoulos AJ. Safety and efficacy of crosslinking following intacs implantation for the stabilization of keratoconus. Invest Ophthalmol Vis Sci 2011;52:5200.

18. Wollensak G. Crosslinking treatment of progressive keratoconus: new hope. Curr Opin Ophthalmol 2006;17:356–360.

19. Spadea L. Corneal collagen cross-linking with riboflavin and UVA irradiation in pellucid marginal degeneration. J Refract Surg 2010;26:375–377.

20. Sherwin T, Brookes NH. Morphological changes in keratoconus: pathology or pathogenesis. Clin Experiment Ophthalmol 2004;32:211–217.

21. Gkika M, Labiris G, Kozobolis V. Corneal collagen crosslinking using riboflavin and ultraviolet-A irradiation: a review of clinical and experimental studies. Int Ophthalmol 2011;31:309–319.

22. Meiri Z, Keren S, Rosenblatt A, Sarig T, Shenhav L, Varssano D. Efficacy of corneal collagen cross-linking for the treatment of keratoconus: a systematic review and meta-analysis. Cornea 2016;35:417–428.

23. Leccisotti A, Islam T. Transepithelial corneal collagen cross-linking in keratoconus. J Refract Surg 2010;26:942– 948.

24. Kanellopoulos AJ. Collagen cross-linking in early keratoconus with riboflavin in a femtosecond lasercreated pocket: initial clinical results. J Refract Surg 2009;25:1034–1037.

25. El-Raggal TM. Effect of corneal collagen crosslinking on femtosecond laser channel creation for intrastromal corneal ring segment implantation in keratoconus. J Cataract Refract Surg 2011;37:701–705.

26. Bikbova G, Kazakbaeva G, Bikbov M, Usubov E. Complete corneal ring (MyoRing) implantation versus MyoRing implantation combined with corneal collagen crosslinking for keratoconus: 3-year follow-up. Int Ophthalmol 2018;38:1285–1293.

27. El-Raggal TM. Sequential versus concurrent KERARINGS insertion and corneal collagen cross-linking for keratoconus. Br J Ophthalmol 2011;95:37–41.

28. Coskunseven E, Jankov MR, Hafezi F, Atun S, Arslan E, Kymionis GD. Effect of treatment sequence in combined intrastromal corneal rings and corneal collagen crosslinking for keratoconus. J Cataract Refract Surg 2009;35:2084–2091.