scholarly journals Corneal Collagen Cross-Linking for Keratoconus: Systematic Review

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Hidenaga Kobashi ◽  
Shi Song Rong

Purpose. To evaluate the efficacy of collagen cross-linking (CXL) one year after treatment for keratoconus compared to no treatment by summarizing randomized controlled trials (RCTs) using a systematic review. Methods. Trials meeting the selection criteria were quality appraised, and the data were extracted by two independent authors. The outcome parameters included maximum keratometry (Kmax), corneal thickness at the thinnest point, best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA), spherical equivalent (SE) refraction, and cylindrical refraction one year after CXL. We compared the changes in the above parameters with the control group. Results. We identified five RCTs involving 289 eyes that met the eligibility criteria for this systematic review. The changes in BSCVA from baseline to one year exhibited a significant difference between the two groups. There was no statistically significant difference between the two groups for changes in corneal thickness and cylindrical refraction. We did not conduct a meta-analysis in Kmax, UCVA, and SE refraction because their I2 values were greater than 50%. Conclusions. According to the systematic review, CXL may be effective in halting the progression of keratoconus for one year under certain conditions, although evidence is limited due to the significant heterogeneity and paucity of RCTs.

2020 ◽  
Vol 148 (1-2) ◽  
pp. 70-75 ◽  
Author(s):  
Svetlana Stanojlovic ◽  
Vedrana Pejin ◽  
Tanja Kalezic ◽  
Jelica Pantelic ◽  
Borivoje Savic

Introduction/Objective. The aim of this study was to report visual, refractive, and tomographic outcomes of corneal collagen cross-linking (CXL) in pediatric keratoconus. Methods. This retrospective study included 17 eyes of 12 patients with progressive keratoconus who underwent epithelium-off CXL at the age ? 18 years. Following data were analyzed at baseline and postoperatively at one, three, six, nine, 12 months for all the patients, and annually where available: uncorrected distant visual acuity (UDVA) and best spectacle-corrected distant visual acuity (CDVA), refraction and corneal tomography. Results. Mean UDVA improved significantly from 0.52 ? 0.38 at baseline to 0.24 ? 0.29 logarithm of minimum angle resolution (log MAR) at one year (p = 0.011) and remained stable at two-year follow-up (0.21 ? 0.34 log MAR). Mean CDVA was 0.15 ? 0.21 at baseline and 0.06 ? 0.13 log MAR at one year (p = 0.248). Maximum keratometry showed a significant flattening of 1.30 ? 1.99 D (p = 0.011) after a year and remained stable two years after CXL. Minimum keratometry significantly decreased with a mean change of 1.34 ? 1.37 (p = 0.001). Mean reduction of corneal thickness after CXL was 55.35 ? 64.42 ?m (P=0.003). After a year, seven (42%) eyes showed Kmax regression, nine (53%) stabilization, and one (5%) progression. Conclusion. In our study CXL effectively prevented progression of keratoconus in 95% of pediatric patients after a year, while improving UDVA and keratometry values. One patient with eye rubbing behavior showed signs of keratoconus progression after CXL treatment.


2021 ◽  
Vol 10 (12) ◽  
pp. 2626
Author(s):  
Hidenaga Kobashi ◽  
Osamu Hieda ◽  
Motohiro Itoi ◽  
Kazutaka Kamiya ◽  
Naoko Kato ◽  
...  

All corneal cross-linking techniques attenuated disease progression in patients with pediatric keratoconus for at least one year based on a meta-analysis. A standard and accelerated technique led to marked improvement in visual acuity. We determined the efficacy and safety of corneal cross-linking (CXL) in pediatric keratoconus by conducting a systematic review and meta-analysis. The PubMed and Cochrane databases were searched for relevant studies on the effects of standard, transepithelial, and/or accelerated CXL protocols in patients aged 18 years or younger. Standardized mean differences with 95% confidence intervals were calculated to compare the data collected at baseline and 12 months. The primary outcomes were maximum keratometry (Kmax) and uncorrected visual acuity (UCVA), and the secondary outcomes were the thinnest corneal thickness (TCT), best-corrected visual acuity (BCVA), and manifest refraction spherical equivalent or cylindrical refraction. Our search yielded 7913 publications, of which 26 were included in our systematic review and 21 were included in the meta-analysis. Standard CXL significantly improved the Kmax, UCVA, and BCVA, and significantly decreased the TCT. Accelerated CXL significantly improved UCVA and BCVA. In the transepithelial and accelerated-transepithelial CXL methods, each measurable parameter did not change after treatments. All CXL techniques attenuated disease progression in patients with pediatric keratoconus for at least one year. Standard and accelerated CXL led to marked improvement in visual acuity.


2021 ◽  
pp. 112067212110183
Author(s):  
Yasin Cinar ◽  
Cagla Cilem Han ◽  
Alparslan Sahin ◽  
Zeba A Syed

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.


2020 ◽  
pp. 112067212094479
Author(s):  
Mahmoud Jabbarvand ◽  
Zahra Moravvej ◽  
Kianoush Shahraki ◽  
Hessam Hashemian ◽  
Hamed Ghasemi ◽  
...  

Purpose: A 6-month evaluation of the topographic and biomechanical changes induced by corneal collagen cross-linking (CXL) in keratoconic eyes using Pentacam and Corvis ST. Design: Longitudinal prospective case series. Methods: In this study, 67 eyes of 67 patients with progressive keratoconus (KCN) treated with “Epithelium-off” CXL were evaluated. Patients with stages 1 or 2 of KCN and a corneal thickness of at least 400 μm at the thinnest point were included. Standard ophthalmologic examinations were carried out for all patients. The topographic and biomechanical measurements of the cornea were obtained by Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) and Corvis ST (Oculus Optikgeräte GmbH, Wetzlar, Germany) preoperatively and 6-month postoperatively. Results: The mean age of the participants was 21.68 ± 4.23 years. There was significant difference in mean spherical equivalent (SE) before and 6 months after CXL. Uncorrected and best corrected visual acuity improved postoperatively, although not statistically significant. The mean and maximum keratometry showed a significant decrease 6 months after CXL (0.93 ± 0.38 D and 1.43 ± 0.62 D, respectively p < 0.001). Among Corvis ST parameters, first applanation length and velocity (AL1 and AV1) showed statistically significant changes. The radius at highest concavity changed significantly (0.13 ± 0.37 mm mean increase after CXL; p < 0.001). A significant increase was observed in stiffness parameter A1 (SP-A1; p < 0.001) and significant decreases were noted in integrated radius (IR) and deformation amplitude ratio (DAR; p < 0.001). Conclusion: Analyzing biomechanical changes after corneal cross-linking can provide basis for efficient KCN treatment. Corvis ST parameters demonstrated changes in corneal biomechanical characteristics indicative of stiffing after CXL.


2021 ◽  
Author(s):  
Mustafa Berhuni ◽  
Cem Ozturkmen

Abstract Purpose: To investigate the short-term results of accelerated crosslinking (A-CXL) treatment for progressive keratoconus in the pediatric and adult age groups. Materials and methods: The records of the 62 eyes of 40 patients who had undergone the A-CXL procedure (9 mV/cm2, 10 min) for progressive keratoconus between January 2015 and January 2019 were evaluated retrospectively. The patients were divided into 2 groups as the pediatric group (aged 17 years or less) and the adult group (aged 18 years or more) for statistical analysis. Pre- and post- 12th month A-CXL best-corrected visual acuity (BCVA), maximum keratometry (Kmax), sim K1, sim K2, corneal thickness at the thinnest point (thCT), and corneal astigmatism (CA) values of the patient groups were recorded. Results: The 29 eyes of 16 patients were included in the pediatric group and the 33 eyes of 24 patients were included in the adult group. The mean age was 13.50±3.05 years in the pediatric group and 23.58±4.37 years in the adult group. A significant improvement in BCVA and a significant decrease in thCT values were present in both groups 12 months after the surgery compared to the preoperative period. A decrease was present in the Kmax, sim K1, sim K2 and CA values in the pediatric group, but was not statistically significant. The decrease in Kmax, sim K1 and sim K2 values compared to the preoperative period was significant in the adult group, but the decrease in CA values was not significant. When the two groups were compared at the end of 12 months, only the sim K1 value was significantly lower in the adult group, and there was no significant difference between the other measurements. Conclusions: Better visual acuity improvement, a higher flattening rate, and less progression occur after 12 months with A-CXL treatment for progressive keratoconus in the adult age group compared to the pediatric age group.


2020 ◽  
Vol 40 (12) ◽  
pp. 3403-3412
Author(s):  
Carlo Cagini ◽  
F. Riccitelli ◽  
M. Messina ◽  
F. Piccinelli ◽  
G. Torroni ◽  
...  

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.


2020 ◽  
Vol 17 (4) ◽  
pp. 699-704
Author(s):  
S. Yu. Astakhov ◽  
S. A. Novikov ◽  
S. S. Papanyan ◽  
I. A. Riks

The article discusses the effectiveness of accelerated collagen crosslinking in the treatment of patients with corneal diseases, a common basic pathogenetic link of which is endothelial corneal decompensation. This method was used to treat patients with bullous keratopathy and endothelial dystrophy of Fuchs’ cornea with a long postoperative follow-up. In connection with the controversial results of researchers, reflecting the positive dynamics of the postoperative period, the question of the expediency of accelerated collagen cross-linking in patients with this pathology as a monotherapy is discussed.The study included 25 patients (26 eyes) with mean age 69.10 ± 10.61 years (40 to 82 years). There was Fuchs corneal endothelial dystrophy in 16 patients (17 eyes), in 9 patients (10 eyes) — stage II, in 7 patients (7 eyes) — stage III. Bullous keratopathy was present in 9 patients (9 eyes). All patients underwent treatment according to the method of accelerated collagen corneal crosslinking. In patients with bullous keratopathy (9 eyes), the data on the central thickness of the cornea and the maximum corrected visual acuity did not differ from the initial data at any of the postoperative visits, and did not differ from each other (p > 0.83). On the contrary, in some patients the dystrophic process progressed in the form of the appearance of fibrotic changes in the stroma of the cornea. Corneal transplantation was recommended to all patients under observation after treatment at different periods of observation. In patients with Fuchs endothelial dystrophy, a significant difference in the maximum corrected visual acuity from the initial data was observed only 6 months after surgery.The expediency of accelerated collagen cross-linking in the treatment of patients with corneal diseases accompanied by endothelial decompensation as monotherapy is very doubtful. The study of combined surgical methods for treating this complex corneal pathology using cross-linking as an auxiliary method seems promising. 


2019 ◽  
Author(s):  
Chung Young Kim ◽  
Mee Kum Kim

Abstract Background: To investigate the efficacy and safety of the retention ring-assisted continuous application of 0.1% riboflavin in pulsed-light accelerated corneal collagen cross-linking on the progression of keratoconus. Methods: The medical records of 20 eyes of 18 patients with progressive keratoconus who received collagen cross-linking at Seoul National University Hospital were retrospectively reviewed. Isotonic 0.1% riboflavin was continuously applied for 10 minutes using an 8.0-mm retention ring before the irradiation and accelerated cross-linking was applied with 30-mW pulsed-ultraviolet light at a wavelength 365 nm for eight minutes (1 second on/1 second off; 30 mW/cm2, cumulative dose of 7.2J/cm2) without further intermittent application of riboflavin. Visual acuity, refractive error, topographic index, corneal thickness, and endothelial cell density were evaluated before the operation and at 1, 3, 6, and 12 months. Results: The best corrected visual acuity in logMAR improved from preoperative 0.43 to 0.17 in 12 months (p = 0.050). Maximum keratometry decreased from 51.8 D to 50.4 D at six months (p = 0.015) and 50.1 D at 12 months (p = 0.0003). Astigmatism decreased from preoperative 5.5 D to 4.1 D at 12 months (p < 0.0001). Thinnest corneal thickness decreased at three and six months but recovered in 12 months (p > 0.05). Endothelial cell density decreased at postoperative one month (p = 0.02) but gradually recovered in 12 months (p > 0.05). Conclusions: Retention ring-assisted continuous application of riboflavin for ten minutes in pulsed-light accelerated cross-linking is a comparably safe and effective treatment for halting the progression of keratoconus in 12 months when compared to outcomes of the standard Dresden protocol shown in previous reports.


Author(s):  
Hassenien Safa Shuber

ABSTRACT Objective The purpose of this study is to assess the predictability, safety, efficacy and stability of correction of refractive errors in patients with keratoconus using Visian implantable collamer lens (ICL) following collagen cross-linking. Materials and methods This prospective, non-comparative study evaluated 20 eyes of 14 patients with keratoconus subjected to implantation of intraocular collamer lens at least 1 year following collagen cross-linking and stable refraction. Mean preoperative myopia was −8.43 ± 5.13 Diopters (D) (–3.5 to −20.0D and mean cylinder was −2.19 ± 1.28D (0.0 to −4.5D). The preoperative spherical equivalent (SE) was −9.52 ± 5.33D (–3.75 to −21.25D). During the 12 months follow-up, uncorrected visual acuity, best corrected visual acuity, refraction, intraocular pressure and vaulting are measured. Results At 12 months postoperatively, 90% of eye had refractive cylinder of <1.0D with (p = 0.003) and 20 (100%) eyes was within ±0.75D of sphere at 1 year (r2 = 0.99) and (p = 0.0085). The mean postoperative BCVA in decimal was 0.498 ± 0.232, while the mean preoperative BCVA was 0.484 ± 0.285. The safety index at 12 months was 1.02. The mean postoperative UCVA in decimal was 0.498 ± 0.232 and the mean preoperative BCVA is 0.484 ± 0.29 and the efficacy index at 12 months was 1.01. Conclusion Implantation of Visian Intraocular collamer lens is predictable, safe and effective way to correct refractive error in patients with keratoconus following collagen cross-linking. How to cite this article Shuber HS. Implantable Collamer Lens for Correction of Refractive Errors in Patients with Keratoconus following Collagen Cross-Linking: One Year Follow-up. Int J Kerat Ect Cor Dis 2014;3(1):29-35.


2019 ◽  
pp. 112067211988787 ◽  
Author(s):  
Indra Prasad Sharma ◽  
Ramendra Bakshi ◽  
Monica Chaudhry

Aim: The aim of this study was to assess and compare the visual, refractive, and topographic outcomes of keratoconic eyes treated with corneal collagen cross-linking combined with and without same day intrastromal corneal ring segment over the first 12 months. Methods: This prospective randomized study analyzed 38 eyes of 30 consecutive keratoconus patients aged 26.21 ± 6.97 (range = 15–41) years. A total of 20 eyes were treated with collagen cross-linking alone, and 18 eyes underwent collagen cross-linking combined with simultaneous femtosecond laser-assisted intrastromal corneal ring segment. Visual acuity, manifest refraction, and corneal topography (using a rotating Scheimpflug topographer) were assessed and compared between the two groups at baseline, 6, and 12 months. Results: On an average follow-up duration of 12.2 ± 0.50 (range = 11–13) months, both collagen cross-linking alone and collagen cross-linking with simultaneous intrastromal corneal ring segment implantation were effective. However, collagen cross-linking plus intrastromal corneal ring segment resulted in an additional improvement of uncorrected distance visual acuity of 0.16 (95% confidence interval = 0.01 to 0.32) logarithm of the minimum angle of resolution units (p = 0.035), cylindrical power by 1.16 D (95% confidence interval = 0.25 to 2.06, p = 0.014), and spherical equivalent by 1.40 D (95% confidence interval = −2.71 to −0.08, p = 0.038) at 1 year. During the study period, no serious intraoperative or postoperative complications were noted in either group. Conclusion: One-year follow-up results suggest that collagen cross-linking with simultaneously combined intrastromal corneal ring segment implantation could yield an additive visual and refractive outcome. The combined procedure is safe and merits consideration for the treatment of progressive keratoconus to achieve better visual rehabilitation.


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