Comparison of two different 360-degree intrastromal corneal rings combined with simultaneous accelerated-corneal cross-linking

Purpose to compare five-year outcomes of two complete intracorneal implants (MyoRing versus annular-shaped intracorneal implant [AICI]) combined with accelerated corneal cross-linking (A-CXL) in progressive KCN. Methods In this historical cohort study, preoperative and postoperative visual, refractive, tomographic, biomechanical, and aberrometric parameters of 27 eyes of 27 patients who underwent implantation of two complete rings (13 AICI and 14 MyoRing) combined with A-CXL were recorded. Results The mean age of patients in AICI plus A-CXL and MyoRing plus A-CXL groups were 28.1 +/- 4.6 and 26.3 +/- 3.8 years, respectively. All pre- and postoperative visual and refractive parameters between the two groups were not significantly different (p > 0.05). Comparing pre- and postoperative tomographic measurements showed that anterior corneal surface (ACS) flat-K and corneal thickness at pachymetric apex significantly improved for MyoRing plus A-CXL group after five years (p < 0.05). On the other hand, ACS K-max and mean-K values were significantly improved for AICI plus A-CXL group after five years (p < 0.05). Both groups revealed significant improvements in ACS steep-K and corneal astigmatism (p < 0.05). Five years after surgery, the high order aberration in the AICI group (2.60 +/- 0.83) was significantly better than the MyoRing group (1.70 +/- 0.43) (p = 0.007). Conclusions Both complete intrastromal rings (MyoRing or AICI) combined with A-CXL significantly Improved visual, refractive, and corneal aberrometric, biomechanical, and tomographic parameters and halt the progression of KCN with comparable long-term outcomes.

Automated summary

This study compared the five-year outcomes of two complete intracorneal implants (MyoRing and annular-shaped intracorneal implant [AICI]) combined with accelerated corneal cross-linking (A-CXL) in progressive keratoconus (KCN). The results showed that both AICI plus A-CXL and MyoRing plus A-CXL groups had similar pre- and postoperative visual, refractive, tomographic, biomechanical, and aberrometric parameters. After five years, MyoRing plus A-CXL group had significant improvements in anterior corneal surface (ACS) flat-K and corneal thickness, while AICI plus A-CXL group had significant improvements in ACS K-max and mean-K values. Both groups showed significant improvements in ACS steep-K and corneal astigmatism. Additionally, the AICI group had significantly better high order aberration compared to the MyoRing group. In conclusion, both MyoRing and AICI combined with A-CXL can significantly improve visual, refractive, and corneal aberrometric, biomechanical, and tomographic parameters and effectively halt the progression of KCN with comparable long-term outcomes.