scholarly journals Current and new indications for corneal cross-linking in the therapy of corneal diseases

2021 ◽  
Vol 8 (3) ◽  
pp. 186-193
Author(s):  
Katarzyna Przewłócka ◽  
Piotr Kanclerz
Keyword(s):  
Visual Acuity ◽  
Invasive Surgery ◽  
Refractive Surgery ◽  
Cross Linking ◽  
Bullous Keratopathy ◽  
Common Indication ◽  
Corneal Ectasia ◽  
Corneal Refractive Surgery ◽  
Collagen Cross Linking ◽  
Corneal Collagen

Corneal collagen cross-linking, a technique used in ophthalmology, involves the creation of new bonds between collagen fibers, thus leading to stabilization and corneal stiffening. The most common indication for corneal collagen cross-linking procedures is to prevent the progression of corneal ectasia,\ i.e., keratoconus, pellucid marginal degeneration, and ectasia after corneal refractive surgery. Clinical data also indicate that it is effective in the treatment of bacterial corneal infections and bullous keratopathy. Corneal collagen cross-linking was shown to inhibit the progression of corneal ectasia, and the treatment commonly leads to the improvement in visual acuity, decreases the maximum keratometry values, and improves the corneal topography image. In addition, it is possible to avoid or postpone the need for more complex and invasive surgery.

Long term results of accelerated corneal collagen cross-linking in pediatric keratoconus

2021 ◽  
pp. 112067212110183
Author(s):  
Yasin Cinar ◽  
Cagla Cilem Han ◽  
Alparslan Sahin ◽  
Zeba A Syed
Keyword(s):  
Visual Acuity ◽  
Corneal Thickness ◽  
University Hospital ◽  
Long Term Results ◽  
Cross Linking ◽  
Distance Visual Acuity ◽  
The Mean ◽  
Collagen Cross Linking ◽  
Corneal Collagen

Purpose: To evaluate the long term visual, refractive, and corneal tomographic outcomes of epithelium-off accelerated corneal collagen cross-linking (ACXL) in the management of pediatric keratoconus (KC). Methods: This retrospective study included patients under 18 years old with progressive KC who underwent ACXL between 2012 and 2019 at Dicle University Hospital. Complete ophthalmic examination was performed including uncorrected distance visual acuity (UDVA), best spectacle-corrected distance visual acuity (CDVA), manifest refraction, and corneal tomography. Evaluations were performed preoperatively and at 6 months intervals postoperatively. Results: Forty-nine eyes of 49 patients were included in the study. The mean age of patients at the time of ACXL was 14.2 ± 1.8 (range: 9.5–17.3) years. Mean follow up was 4.61 ± 1.90 (range: 2.0–8.1) years. The mean LogMAR UDVA improved from 0.94 ± 0.41 to 0.81 ± 0.43, 0.69 ± 0.41, and 0.67 ± 0.33 after 1, 3, and 5 years respectively ( p = 0.001). The mean LogMAR CDVA improved from 0.58 ± 0.36 to 0.46 ± 0.31, 0.34 ± 0.23, and 0.39 ± 0.27 after 1, 3, and 5 years respectively ( p = 0.015). The mean refractive cylinder improved significantly from 6.01 ± 2.07 diopters (D) to 5.46 ± 1.87, 5.38 ± 2.18, and 5.02 ± 2.31 D after 1, 3, and 5 years respectively ( p = 0.005). As compared to preoperative values, steep keratometry and maximum keratometry were not significantly different ( p = 0.805 and 0.448, respectively) following ACXL, while flat keratometry significantly improved after ACXL ( p = 0.012). Although central corneal thicknesses decreased significantly ( p = 0.029), the decrease in thinnest corneal thickness was not statistically significant ( p = 0.205). Conclusion: Epithelium-off ACXL seems to be effective for halting KC progression with long term clinical benefits in pediatric patients.

Comparison between OrbscanIIz, Pentacam, Ultrasound Pachymetry (Tomey SP-100) at Different Stages of Keratoconus

2020 ◽  
pp. 7-33
Author(s):  
E. Pateras ◽  
Ch. Koufala
Keyword(s):  
Correlation Coefficient ◽  
Study Design ◽  
Refractive Surgery ◽  
Corneal Thickness ◽  
Cross Linking ◽  
Moderate Correlation ◽  
Measurement Systems ◽  
Ultrasound Pachymetry ◽  
Collagen Cross Linking ◽  
Corneal Collagen

Aims: To compare results of OrbscanIIz and Pentacam and Ultrasound pachymetry at different stages of keratoconus on corneal thickness. Sample and Study Design: 94 keratoconic patients participated in the study, of which 52 were men and 42 women. Keratoconus patients were measured with OrbscanIIz, Pentacam and Ultrasound pachymetry in pre-operation examinations for corneal collagen cross-linking. The patients belong to different keratoconus stages. Place and Duration of Study: University of West Attica Dept Biomedical Sciensce Course Optics & Optometry in collaboration with Athens “Ophthalmologico” Clinic during the period between October 2017 to January 2019. Methodology: Corneal Pachymetry maps correlation of three types of corneal pachymeters OrbscanIIz, Pentacam and Ultrasound pachymetry (Tomey SP-100 Pachymeter). The measurements of the thinnest point of the cornea from each patient were collected at different stages of keratoconus and compared. Results: A sample of 188 eyes were measured at different stages of keratoconus and compared for the thinnest corneal thickness with three different measurement systems, OrbscanIIz ,Pentacam and Ultrasound pachymetry. At sublinical stage Orbscan-Pentacam had Correlation coefficient r=0,7971, Orbscan-Ultrasound r=0,7483 and Pentacam-Ultrasound r=0,9442. At 1st stage Orbscan-Pentacam had Correlation coefficient r=0,8913, Orbscan-Ultrasound r=0,8151 and Pentacam-Ultrasound r=0,8151. At 2nd stage Orbscan-Pentacam had Correlation coefficient r=0,9339, Orbscan-Ultrasound r=0,8819 and Pentacam-Ultrasound r=0,9633. For 3rd stage Orbscan-Pentacam had Correlation coefficient r=0,8317, Orbscan-Ultrasound r=0,8457 and Pentacam-Ultrasound r=0,9633. For 4th stage Orbscan-Pentacam had Correlation coefficient r=-0,4655, Orbscan-Ultrasound r=0,3089 and Pentacam-Ultrasound r=0,9633. In Iatrogenic keratoectasiaafter refractive surgery Orbscan-Pentacam had Correlation coefficient r=0,9327, Orbscan-Ultrasound r=0,3089 and Pentacam-Ultrasound r=0,9859. Conclusion: Statistical differences between OrbscanIIz, Pentacam and Ultrasound pachymetry were found for corneal thickness in all stages of keratoconus for the thinnest point measured. Orbscan-Pentacam have statistical significant differences but weak to moderate correlation. Orbscan-Ultasound have also statistical significant differences their correlation is very weak, while Pentacam-Ultrasound have statistical significant differences smaller as the previous but their correlation is very strong at all stages of keratoconus.

scholarly journals Treatment of bullous keratopathy with corneal collagen cross-linking in two dogs

2013 ◽  
Vol 18 (2) ◽  
pp. 168-173 ◽  
Author(s):  
Simon A. Pot ◽  
Nicolin S. Gallhöfer ◽  
Ladina Walser-Reinhardt ◽  
Farhad Hafezi ◽  
Bernhard M. Spiess
Keyword(s):  
Cross Linking ◽  
Bullous Keratopathy ◽  
Collagen Cross Linking ◽  
Corneal Collagen

scholarly journals Safety and Visual Outcome of Visian Toric ICL Implantation after Corneal Collagen Cross-Linking in Keratoconus: Up to 2 Years of Follow-Up

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Rafic Antonios ◽  
Ali Dirani ◽  
Ali Fadlallah ◽  
Elias Chelala ◽  
Adib Hamade ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Visual Outcome ◽  
Cross Linking ◽  
Implantable Collamer Lens ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Effective Option ◽  
Collagen Cross Linking ◽  
Corneal Collagen

Purpose. To evaluate the long-term safety and clinical outcome of phakic Visian toric implantable collamer lens (ICL) insertion after corneal collagen cross-linking (CXL) in progressive keratoconus.Methods. This was a retrospective study of 30 eyes (19 patients), with progressive keratoconus, who underwent sequential CXL followed by Visian toric ICL implantation after 6 months.Results. At baseline, 6 eyes had stage I, 14 eyes stage II, and 10 eyes stage III keratoconus graded by Amsler-Krumeich classification. At 6 months after CXL, onlyK(steep) andK(max) decreased significantly from baseline, with no change in visual acuity or refraction. Flattening in keratometric readings was stable thereafter. There was significant improvement in mean uncorrected distance visual acuity (1.57 ± 0.56 to 0.17 ± 0.06 logMAR,P<0.001) and mean corrected distance visual acuity (0.17 ± 0.08 to 0.11 ± 0.05 logMAR,P<0.001) at 12 months after ICL implantation that was maintained at the 2-year follow-up. Mean cylinder power and mean spherical equivalent (SE) also decreased significantly after ICL implantation. A small hyperopic shift in SE (+0.25 D) was observed at 2 years that did not alter visual outcomes.Conclusions. Visian toric ICL implantation following CXL is an effective option for improving visual acuity in patients with keratoconus up to 2 years.

scholarly journals Comparison for Kmean and Astigmatism for Orbscan IIz and Pentacam at Different Stages of Keratoconus - A Clinical Study

2020 ◽  
pp. 30-40
Author(s):  
E. Pateras ◽  
Ch. Koufala
Keyword(s):  
Clinical Study ◽  
Correlation Coefficient ◽  
Strong Correlation ◽  
Refractive Surgery ◽  
Topographic Maps ◽  
Cross Linking ◽  
Stage 4 ◽  
Stage 1 ◽  
Collagen Cross Linking ◽  
Corneal Collagen

Aims: To compare results of Orbscan IIz and Pentacam at different stages of keratoconus on Kmean and Astigmatism. Sample and Study Design: 94 keratoconus patients were included in the study, of which 52 were men and 42 women. Keratoconus patients were screened with Orbscan IIz and Pentacam before undergoing corneal collagen cross-linking. The patients were distributed according to different keratoconus stages. Place and Duration of Study: University of West Attica Dept Biomedical Sciensce Course Optics & Optometry in collaboration with Athens “Ophthalmiatrio” Clinic during the period between October 2017 to January 2019. Methodology: Topographic maps correlation of two types of corneal topographers Orbscan IIz and Pentacam. The Kmean values and the Astigmatism presented at different stages of keratoconus were compared. Results: A Sample of 188 eyes were measured having, 20 eyes (10.6%) with subclinical keratoconus, the correlation coefficient r for Kmean values between Orbscan IIz and Pentacam was 0.9758 (P<0.0001), 44 eyes (23.3%) at stage 1 with the correlation coefficient r=0.8482 (P<0.0001),  33 eyes (17.6%) at stage 2 with the correlation coefficient r=0.8147 (P<0.0001), 67 eyes (35.6%) at stage 3 with the correlation coefficient r=0.797 (P<0.0001), 10 eyes (5.3%) at stage 4 with the correlation coefficient r=0.8455 (P=0.0021), 8 eyes (4.4%) with iatrogenic keratoectasia after refractive surgery having correlation coefficient r=0.928 (P=0.0009). Conclusion: Statistical differences between Orbscan IIz and Pentacam were found for Kmean in all stages of keratoconus. The performance for Kmean measurement of the corneal topographers Orbscan IIz and Pentacam is satisfactory for both systems in various stages of keratoconus having a very strong correlation (Correlation coefficient r ranged from 0.9758 to 0.7970). Statistical differences between Orbscan IIz and Pentacam were evident also at the Astigmatism measurements at stage 3 and 4.

scholarly journals Epi-off-lenticule-on corneal collagen cross-linking in thin keratoconic corneas

2020 ◽  
Vol 40 (12) ◽  
pp. 3403-3412
Author(s):  
Carlo Cagini ◽  
F. Riccitelli ◽  
M. Messina ◽  
F. Piccinelli ◽  
G. Torroni ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Endothelial Cell ◽  
Cell Density ◽  
Corneal Thickness ◽  
Endothelial Cell Density ◽  
Cross Linking ◽  
Corneal Transplant ◽  
Collagen Cross Linking ◽  
Corneal Collagen

Abstract Purpose To evaluate the safety and efficacy of corneal collagen cross-linking (CXL) performed on overlaying a corneal lenticule to thin recipient corneas of progressive keratoconus (KC) patients. Methods In this study were enrolled eyes of patients affected by progressive KC with a minimum corneal thickness less than 400 µm, after overlaying a lenticule of human corneal stroma prepared with the femtosecond laser. The lenticules used were 100 µm thick and of 8.5 mm diameter in all the cases. Both the host cornea and the lenticules were subjected to epithelial debridement. CXL was carried out according to the standard protocol. Visual acuity, refraction, slit-lamp examination, endothelial cell density, pachymetry and keratometry, anterior segment tomography (AS-OCT) and confocal microscopy were evaluated preoperatively and at 1, 3, 6 and 12 months postoperatively. Results CXL was performed in 10 eyes of 8 patients (main age 23), corneal thickness range 379–414 µm, mean 387.6 µm. One patient was lost at follow-up. In all other cases, visual acuity and the endothelial cell density remained stable over a 12-month follow-up. Preoperative mean K1 and mean K2 were 46.91 ± 1.9 and 50.75 ± 2.93, respectively, and at 12 months mean K1 was 47.36 ± 2.66 and mean K2 50.53 ± 3.35. The AS-OCT clearly showed a demarcation line in all patients at 1, 3 (mean depth 283 µm and 267 µm, respectively) and in some cases at 6 months. Reduced keratocyte density and stromal oedema were observed immediately up to 1 month after treatment, while a slight subepithelial haze was present at 1-month and completely disappeared by 6 months. Conclusion This new technique seems to offer a therapeutic opportunity for young patients suffering from progressive KC with very thin corneas, in which the standard treatment is not indicate, and delay or avoid the need for a corneal transplant.

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