Combined cross-linking with femtosecond laser Myoring implantation versus combined cross-linking with femtosecond laser Keraring implantation for treatment of keratoconus

Purpose

The aim of this study was to compare the results with regard to efficacy, safety, and patient satisfaction between two combined procedures: combined femtosecond laser Myoring implantation with cross-linking (CXL) and combined femtosecond laser Keraring implantation with CXL for treatment of keratoconus.

Setting

This study was conducted in Sohag University Hospital, Sohag University, Egypt, in association with Sohag Future Femtosecond Laser Center.

Design

This was a prospective nonrandomized clinical comparative study.

Patients and methods

A total of 46 eyes of 30 patients with keratoconus were included in this study.

Group A included 27 eyes of 17 patients who were subjected to combined CXL with femtosecond laser Myoring implantation, and group B included 19 eyes of 13 patients who were subjected to combined CXL with femtosecond laser Keraring implantation. All eyes were subjected to preoperative and postoperative uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), manifest refraction, slit lamp examination of anterior segment, intraocular pressure, fundus examination, and keratometry and pachymetry assessment with Pentacam corneal topographies at 3 and 6 months of follow-up.

Results

In group A, the preoperative mean ± SD UCVA was 1.30 ± 0.28 (logMAR), whereas the postoperative mean UCVA was 0.90 ± 0.12. The preoperative mean BCVA was 0.70 ± 0.23, whereas the postoperative mean BCVA was 0.30 ± 0.17. The preoperative keratometric average ± SD was 53.27 ± 0.62 D, whereas the postoperative keratometric average was 45.83 ± 0.64 D. The postoperative astigmatic correction was 1.51 ± 0.42 D. In group B, the preoperative mean UCVA was 1.30 ± 0.33, whereas the postoperative mean UCVA was 1 ± 0.16. The preoperative mean BCVA was 0.90 ± 0.46, whereas the postoperative mean BCVA was 0.60 ± 0.32. The preoperative keratometric average was 50.97 ± 0.48, whereas the postoperative keratometric average was 49.01 ± 0.32. The postoperative astigmatic correction was 3.07 ± 0.15.

Conclusion

This study proved that combined CXL with Myoring implantation is effective in the correction of the myopic component of keratoconus. Combined CXL with Keraring implantation is effective in the correction of the astigmatic component in keratoconus. The type and the site of keratoconus cone together with the K readings can help in the preoperative decision of which type of ring is best in each keratoconus case. This study proved that there is a synergistic action when CXL is combined with intracorneal rings (Myoring or Keraring).