No abstract

Purpose. The aim of our study was to compare the long-term efficacy and safety of “epi-off” conventional and “epi-off” accelerated corneal cross-linking (CXL) in patients with progressive keratoconus. Methods. “Epithelial-off” (“Epi-off”) CXL using the conventional technique (3 mW/cm2, 30 minutes) was performed in 93 eyes of 93 patients (S-CXL group) and “epi-off” accelerated method (9 mW/cm2, 10 minutes) in 76 eyes of 76 patients with progressive KCN (A-CXL group). Cases with different stages of keratoconus and topographic evidence of progression were included. Main outcomes comprised refraction, keratometry measurements, uncorrected (UCVA) and best-corrected visual acuity (BCVA), and topographical indices. Micromorphological analysis was assessed by anterior segment ocular coherence tomography (AS-OCT). The follow-up period was 5 years. Results. In both groups, Kflat presented similar results: decrease at 1 year (p=0.465), at 2 years (p=0.672), at 3 years (p=0.198), at 4 years (p=0.32), and at 5 years (p=0.864). In both groups, Ksteep presented a similar decrease at 1 year (p=0.709), at 2 years (p=0.455), at 3 years (p=0.43), at 4 years (p=0.57), and at 5 years (p=0.494), with no statistically significant difference. Decrease in Kavg was similar in both groups at all analyzed time points (p=0.18 at 1 year, p=0.093 at 2 years, p=0.57 at 3 years, p=0.154 at 4 years, and p=0.247 at 5 years). Kmax had a similar decrease in both groups at 1 year (p=0.06), at 2 years (p=0.09), at 3 years (p=0.126), at 4 years (p=0.113), and at 5 years (p=0.114). There was no statistically significant difference between the cylinder decrease in both groups (p=0.349 at 1 year, p=0.6782 at 2 years, p=0.299 at 3 years, p=0.0943 at 4 years, and p=0.144 at 5 years). The BCVA values were statistically significantly higher than the preoperative values in both groups at all time points (p<0.05). Topographical indices such as thinnest corneal point (TP), corneal volume (CV), index vertical asymmetry (IVA), index of vertical asymmetry (ISV), index of height asymmetry (IHA), index of height decentration (IHD), Belin/Ambrosio Enhanced Ectasia Display (BAD_D), and Ambrosio retinal thickness (ART Max) were significantly statistically decreased compared with baseline at all time points, in both groups. Conclusion. “Epi-off” accelerated and conventional CXL have the same efficacy in terms of improvement in visual and topographic outcomes.

Purpose. The purpose of the current study was to evaluate the long-term functional results based on keratometric measurements, spherical and cylinder equivalent in patients with progressive keratoconus treated with conventional “epi-off” corneal collagen cross-linking (CXL). Methods. We conducted a retrospective study in which 113 eyes from 90 keratoconus-treated patients with CXL between 2006 and 2008 in Oculens Eye Clinic from Cluj-Napoca, Romania, were included. The diagnosis of keratoconus was based on corneal topography and its clinical signs. All patients were evaluated preoperatively, and a follow-up was performed at 1, 3, and 6 months and every year from 1 to 10 years after conventional CXL. Results. All keratometry measurements improved significantly during the follow-up. Compared to preoperative values, the improvement of Kmax become statistically significant at 1 year after CXL (mean change compared to baseline −0.9 D, p<0.001) and remained statistically significant thereafter up to 10 years (mean change compared to baseline −2.3 D, p<0.001). As compared to preoperative values, mean spherical equivalent and mean cylinder improved during the follow-up, from a mean of −6.22 D before CXL to a mean value of −5.0 at 10 years, following CXL for spherical equivalent and from −4.4 D at baseline to −3.4 D at 10 years for cylinder (p<0.05 for both). Uncorrected visual acuity increased, remaining statistically significant, by 0.104 logMAR at 10 years after CXL (p=0.0015), and best-corrected visual acuity increased by 0.135 logMAR at 10 years after CXL (p=0.015). We did not observe any case of severe complication. Conclusion. Our results show that CXL has a favorable effect on the progression of KC. The reduced K values, cylinder and spherical equivalent, and increased visual acuity remained the same 10 years after the procedure.

The purpose of the present study was to assess the long-term efficiency and safety of the "epi-off" accelerated CXL (9 mW/cm 2 for 10 minutes) in comparison to the standard "epi-off" CXL (3 mW/cm 2 for 30 minutes) in terms of topographical and keratometric parameters, refractive data and visual outcomes at 7 years of follow-up, in progressive keratoconus. Material and Method: A retrospective and comparative study was performed. A total of 183 eyes from 183 patients with documented progressive keratoconus were included in the study. The patients were divided in two groups: 93 eyes from 93 patients underwent "epi-off" standard cross-linking technique (3 mW/cm 2 for 30 minutes) (S-CXL group) and 90 eyes from 90 patients underwent accelerated "epi-off" corneal CXL technique (9 mW/cm 2 for 10 minutes) (A-CXL group). Results: Improvements in uncorrected distance visual acuity (UDVA) were statistically significant compared to baseline values in both groups at each time-point visit (p=0.0421 at 1 year, p=0.0411 at 7 years for A-CXL and p=0.0375 at 1 year, p=0.0389 at 7 years for S-CXL). At 7 years there was a statistically significant increase in CDVA (p=0.039 in the A-CXL group and p=0.0343 in the S-CXL group at 7 years). Statistically significant reduction was noticed in Ksteep (p=0.0411 in A-CXL group and p=0.0224 in S-CXL group), Kflat (p=0.0198 in A-CXL group and p=0.008 in S-CXL group), K mean (p=0.0106 in A-CXL group and p=0.0193 in S-CXL group) and Kmax (p=0.0413 in A-CXL group and p=0.054 in S-CXL group) at 7 years, compared to baseline values, in both groups, but without any statistically difference between the two procedures, at all time-point visits (p>0.05). Conclusion:The long-term outcomes of "epi-off" accelerated corneal collagen crosslinking-UVA (9 mW/cm 2 for 10 minutes) are similar to standard "epi-off" corneal collagen crosslinking procedure in the treatment of progressive keratoconus.

PurposeThe aim of our study was to evaluate the efficacy and safety of epi-off conventional and accelerated corneal collagen cross-linking in the treatment of progressive keratoconus in pediatric patients up to 4 years after treatment.Patients and methodsConventional (standard) CXL epi-off technique was performed in 37 eyes (S-CXL group) and accelerated CXL in 27 eyes (A-CXL group). Refraction, keratometry, cylindrical equivalent, spherical equivalent, slit lamp examination, pachymetry, corneal tomography, anterior segment ocular coherence tomography and visual acuity were performed up to 4 years.ResultsIn the S-CXL group: the flat K values decreased from 47.41±3.39 D to 45.36±3.62 D at 4 years (p=0.004); steep K decreased from 51.98±4.11 to 50.21±4.81 D at 4 years (p=0.0078); mean K decreased with 1.99 D at 4 years (p=0.009). In the A-CXL group: the flat K values decreased from 46.97±4.17 D to 44.97±4.24 D at 4 years (p=0.048); steep K decreased from 50.55±4.10 D to 48.75±4.17 D at 4 years (p=0.0287); mean K decreased from 48.79±3.86 D to 46.86±4.11 D at 4 years (p=0.0356). The preoperative mean UCVA in the S-CXL group was 0.8 ±0.23 logMar and improved during the follow-up reaching 0.65 ±0.24 logMar at 4 years (p=0.072). The baseline mean UCVA in A-CXL group was 0.77±0.25 logMar and increased during the follow-up to 0.63 ±0.25 logMar at 4 years (p=0.0039). A similar improvement of BCVA was observed during the follow-up.ConclusionEpi-off conventional and accelerated CXL are efficient procedures for progressive keratoconus in pediatric patients. Accelerated and conventional CXL were comparable at all time points and both represent viable options for the therapy of KC in these patients.