Investigation Of The Efficiency Of Intrastromal Ring Segments With Different Sequential Cross-linking For Keratoconus

AIM:To evaluate and compare the efficacy and stability of intrastromal corneal ring segment(ICRs) implantation with cross-linking (CXL) using different sequence and timing.METHODS:In this single retrospective study,86 keratoconic eyes subjected the ICRs implantation.We analyzed only 41 eyes who had complete follow-ups.They were divided into three groups:ICRs implantation is applied only(Group Normal),ICRs first followed CXL immediately(Group CXL-S),CXL first followed ICRs long after(CXL-B).The visual acuity,refractive results,keratometry were compared preoperatively and 1-year postoperatively.Their differences among the three groups were also compared.RESULTS:Group Normal comprised 25 eyes,Group CXL-S 8 eyes,and Group CXL-B 8 eyes.There were improvement in the mean uncorrected distance visual acuity(UDVA)and the mean corrected distance visual acuity (CDVA) compared preoperatively and 1-year postoperatively(UDVA:0.31(P=0.030)logarithmic minimum angle of resolution(logMAR) group Normal,0.4(P=0.020) group CXL-S,0.45(P=0.001)CXL-B;CDVA:0.211ogMAR(P=0.013)group Normal,0.30(P=0.036)group CXL-S;0.26(P=0.000)CXL-B).The refractive results and topography also showed improvements.In terms of comparisons among the three goups,all the P values were above 0.05,showing no significant difference.But only Group CXL-B had improvement in UDVA and CDVA for all the patients.CONCLUSION:With safety and good visual outcomes,ICRs implantation is a viable alternative for keratoconus.No significant difference is found among these three groups.