To compare 2 sequences of combined intrastromal corneal ring segment (ICRS) implantation and corneal collagen crosslinking (CXL) in progressive keratoconus.Methods
In this retrospective study, CXL was followed by ICRS implantation (group A) or ICRS implantation was followed by CXL (group B). Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, spherical equivalent (SE), manifest cylinder and mean keratometry (K) were compared preoperatively and postoperatively.Results
17 eyes of 10 patients with progressive keratoconus were included in this study, 11 eyes in group A and 6 in group B. The mean interval between treatments was 4.3+/-2.9 months in group A and 5+/-4.4 months in group B. The mean age is 27.6 years in group A and 28.4 years in group B. The 2 groups are equivalent preoperatively. The mean UDVA and CDVA improved in both groups (UDVA:0.50+/-0.22 to 0.60+/-0.20, group A, and 0.28+/-0.19 to 0.62+/-0.22(p<0.05), group B; CDVA:0.60+/-0.15 to 0.70+/-0.14 and 0.70+/-0.14 to 0.88+/-0.17 respectively). The cylinder and mean k values decreased in both groups (cylinder -3.63D+/-1.27 to -0.95D+/-1.54 (p<0.05), group A and -3.60D+/-1.85 to -2.80D+/-2.19 group B; mean K:44.8+/-1.45 to 42.8D+/-1.7 (p<0.05) and 43.98+/-1.74 to 43.8D+/-1.8, respectively). SE: values decreased in group A (-3.4D+/-1.5 to -1.3D+/-1.4 (p<0.05)) instead increased in group B (-1.1D+/-0.8 to -1.7D+/-1.0). Overall, the 2 sequences observed show an improvement in UDVA, CDVA, cylinder and mean K.Conclusion
In our study, there is no statistical difference between the 2 sequences: ICRS implantation followed by CXL or CXL followed by ICRS implantation.