scholarly journals Preliminary Characterization of Predictive Factors of the Visual Change after Epi-On and Epi-Off Corneal Collagen Crosslinking Techniques

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Sidi Mohamed Hamida Abdelkader ◽  
Joaquín Fernández ◽  
Javier Sebastián ◽  
David P. Piñero
Keyword(s):  
Predictive Factors ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Collagen Crosslinking ◽  
Visual Change ◽  
High Order Aberration ◽  
Corneal Collagen Crosslinking ◽  
Retrospective Comparative Study ◽  
Relationship Of ◽  
Corneal Collagen

Purpose. To investigate the potential predictive factors of the visual change achieved with accelerated epi-on and epi-off corneal collagen crosslinking (CXL) in keratoconus. Methods. This retrospective comparative study analyzed 67 eyes treated with an accelerated epithelium-on (epi-on group) and epithelium-off (epi-off group) CXL. The clinical outcomes were evaluated and compared during a 1-year follow-up. Likewise, the relationship of the change achieved with both CXL techniques in the corrected distance visual acuity (CDVA) with different preoperative data was investigated. Results. The mean CDVA change at 3 months postoperatively was −0.04 ± 0.19 and −0.07 ± 0.25 in the epi-on and epi-off groups, respectively ( p  = 0.809). In the epi-on group, this change was significantly correlated with the preoperative apical (r = −0.375, p  = 0.045) and central corneal thickness (r = −0.402, p  = 0.031). In the epi-off group, the CDVA change was significantly correlated with not only the preoperative apical (r = 0.402, p  = 0.028) and central corneal thickness (r = 0.367, p  = 0.046) but also with some topometric and aberrometric indices (r ≤ −0.374, p  ≤ 0.042). Furthermore, the change in CDVA in the epi-on group could be predicted from age, preoperative refractive astigmatism J45 component, anterior corneal asphericity, and posterior corneal high order aberration root mean square ( p  = 0.002, R2 = 0.503). In the epi-off group, the CDVA change could be predicted from the preoperative minimum corneal thickness and magnitude of the vertical anterior corneal primary coma component ( p  = 0.001, R2 = 0.446). Conclusions. Clearly, different predictive factors of the visual change induced with the accelerated epi-on and epi-off CXL techniques are present, suggesting a different mechanism of action for stiffening the cornea and inducing changes in this structure.

Evaluation of changes in corneal biomechanics in eyes with keratectasia

2021 ◽  
pp. 179-187
Author(s):  
B.E. Malugin ◽  
◽  
E.G. Solodkova ◽  
S.V. Balalin ◽  
V.S. Kulikov ◽  
...  
Keyword(s):  
Corneal Thickness ◽  
Corneal Biomechanics ◽  
Corvis St ◽  
Collagen Crosslinking ◽  
The Third ◽  
Corneal Rigidity ◽  
Corneal Collagen Crosslinking ◽  
Early Features ◽  
Healthy Persons ◽  
Corneal Collagen

Purpose. To make a comparative analysis of topographic, tomographic and biomechanical values, measured by Pentacam HR and Corvis ST, in healthy multirefractive cohort versus patients with keratectasia of various severity. Material and methods. The prospective study comprised 237 patients aged from 18 to 47 years, subdivided into three groups. The first group included 174 healthy persons with various refraction (174 eyes). The second and the third group embraced 63 patients with keratoconus: 36 patients (36 eyes) with keratoconus of the I degree and 27 eyes with keratoconus of the II and III degrees. Besides the conventional comprehensive ocular examination the following studies were performed in all the patients: evaluation of topographic, tomographic and biomechanical corneal properties with application of Pentacam HR and Corvis ST (OCULUS Optikgerate GmbH; Wetzlar, Germany). Results. It was revealed that the following biomechanical values, assessed by means of Pentacam HR and Corvis ST, exhibited statistically significant changes (p<0,001) in all degrees of ketatoconus: a relative corneal thickness by Ambrosio, inverted radius of applanation curvature (IntRadius), DA Ratio Coefficient, values of corneal rigidity – SP-A 1 and SSI. Conclusion. The detected parameters may be applied as indicators, allowing to evaluate corneal biomechanics, to define early features of ectatic process, to assess effectiveness of the performed corneal collagen crosslinking and intralamellar keratoplasty with implantation of corneal segments. Key words: keratoconus, corneal biomechanics, pachymetry, index of pachymetric progression, corneal viscoelasticity.

scholarly journals High Order Aberration Outcomes of Corneal Collagen Crosslinking in Eyes with Keratoconus and Post-LASIK Ectasia

2014 ◽  
Vol 3 (3) ◽  
pp. 107-112
Author(s):  
Adam Muzychuk ◽  
Victor Penner ◽  
Guillermo Rocha
Keyword(s):  
Visual Acuity ◽  
Spherical Aberration ◽  
Retrospective Chart Review ◽  
High Order ◽  
Collagen Crosslinking ◽  
Distance Visual Acuity ◽  
High Order Aberration ◽  
Manifest Refraction ◽  
Corneal Collagen Crosslinking ◽  
Corneal Collagen

ABSTRACT Purpose To evaluate the effect of riboflavin and ultraviolet- A-induced corneal collagen crosslinking (CXL) on high order aberrations (HOA) up to third-order at 6 months using the iTrace wavefront aberrometer in patients with progressive keratoconus and post-LASIK ectasia. Materials and methods Ongoing retrospective chart review of patients having undergone CXL. The iTrace (Tracey Technologies, Houston, TX) was used to evaluate HOA. Patient data was collected from a single clinical site pre- and 6 months postoperatively. Data collected included logMAR uncorrected distance visual acuity (UDVA), logMAR corrected distance visual acuity (CDVA), manifest refraction, and HOA measurements. Data was analyzed with paired two-tailed student's t-test. Results 18 eyes (9M:4F, mean age 29.2 years, range 16-45) had 6 months of follow-up. Total HOAs, total coma and total trefoil were significantly reduced at 6 months by 16, 33 and 26% respectively (p < 0.05). Nonsignificant trends toward improvement were seen in spherical aberration, secondary astigmatism and UDVA. There were no statistically significant changes in manifest refraction or CDVA. Conclusion Improvement in high order aberration profile is one mechanism by which corneal collagen crosslinking enhances visual function in ectatic corneas. Total HOA and total coma measures are the most commonly reported improvements in HOA measures in previous studies, while total trefoil has only been observed in one other study. The improvements seen in HOAs remain fairly modest which likely accounts for the lack of measureable improvement in high-contrast visual acuity measures, such as Snellen UDVA and CDVA. This study is the first to report HOA outcomes with the iTrace wavefront aberrometer. How to cite this article Muzychuk A, Penner V, Rocha G. High Order Aberration Outcomes of Corneal Collagen Crosslinking in Eyes with Keratoconus and Post-LASIK Ectasia. Int J Kerat Ect Cor Dis 2014;3(3):107-112.

scholarly journals Keratoconus in Children. Мodern Treatment Options

2021 ◽  
Vol 18 (4) ◽  
pp. 840-844
Author(s):  
E. Yu. Markova ◽  
G. V. Avakyants ◽  
E. V. Kechin
Keyword(s):  
Visual Acuity ◽  
Treatment Options ◽  
Corneal Thickness ◽  
High Tech ◽  
Cross Linking ◽  
Posterior Surface ◽  
Collagen Crosslinking ◽  
Optical Correction ◽  
Corneal Collagen Crosslinking ◽  
Corneal Collagen

Objective: to evaluate the results of corneal collagen crosslinking in children with keratoconus.Patients and methods. Since 2017, 125 children aged 4 to 17 years have been under observation, who have applied to the Eye Microsurgery named after Academician S.N. Fedorov with complaints of reduced visual acuity and, in some cases, the inability to select optical correction. All patients were examined, including using high-tech methods (Sheimpflug camera, OCT). Based on the anamnesis and the data obtained, the diagnosis of keratoconus stage I–III was made. Corneal collagen crosslinking was performed in 30 patients with stage II–III.Results. The study included 30 eyes of 30 patients (21 (68 %) boys, 9 (32 %) girls) with a median age — 16 (15; 17) years (12 to 17 years), who underwent accelerated “epi-off” crosslinking. No intra-and postoperative complications were observed. 12 months after CXL, there was a slowdown in the progression of keratoconus in children (minimum corneal thickness before surgery 460.00 (445.00; 477.00), after surgery 457.00 (441.00; 477.00), p = 0.112; K1 before surgery 44.60 (43.20; 46.90), after surgery 44.60 (42.90; 46.50), p = 0.481; K2 before surgery 48.30 (47.30; 51.25), after surgery 48.20 (47.21; 49.20), p = 0.779; elevation of the posterior surface before surgery 25.00 (18.00; 42.00), after surgery 26.00 (21.00; 42.00), p = 0.074, and increased visual acuity (NCOZ from 0.30 (0.05; 0.40) to 0.30 (0.20; 0.40) (p = 0.039) and MCOZ from 0.60 (0.40; 0.80) to 0.60 (0.50; 1.00) (p = 0.010)).Conclusion. 1. Keratoconus is also found in the child population. 2. Timely cross-linking of corneal collagen can slow the progression of keratoconus in children

scholarly journals Impact of COVID-19 on keratoconus patients waiting for corneal cross linking

2021 ◽  
pp. 112067212110013
Author(s):  
Haider Shah ◽  
Luca Pagano ◽  
Anuj Vakharia ◽  
Giulia Coco ◽  
Kunal A Gadhvi ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Observational Study ◽  
Corneal Thickness ◽  
Treatment Delay ◽  
Cross Linking ◽  
Corneal Surface ◽  
Collagen Crosslinking ◽  
Time Period ◽  
Corneal Collagen Crosslinking ◽  
Corneal Collagen

Purpose: Royal College of Ophthalmologist recent guidance recommended delaying cross-linking services during the COVID-19 pandemic. This study investigates the effects of such delays in the delivery of cross-linking services in patients with keratoconus progression. Methods: Retrospective observational study of 46 patients with keratoconus progression, whose cross-linking was delayed due to the COVID-19 pandemic. Demographic and clinical details were obtained from assessments on the day of listing, and subsequent review on the day of the procedure. Topographic indices included keratometry of the posterior and anterior corneal surface, maximum keratometry ( Kmax), thinnest corneal thickness, ABCD progression and progression based on standard criteria recommendations (1.5 D Kmax & 20 microns thinning). Results: A total of 46 eyes were analysed with an average time between being listed for CXL and having the procedure done was 182 ± 65 days. The delay due to COVID-19 was of 3 months. In this time period they had a significant worsening of all keratometric indices and lost almost one line of visual acuity (0.19 ± 0.19 to 0.26 ± 0.18 LogMAR, p: 0.03). Thirty two eyes (70%) demonstrated progression in accordance with the ABCD progression criteria, while 18 eyes (39%) showed either an increase in Kmax of more than 1.5D or a thinning in corneal thickness of at least 20 μm. Conclusions: The treatment delay for the keratoconus patients caused further progression and vision worsening. We recommend that corneal collagen crosslinking needs to be considered as a high priority intervention.

scholarly journals MyoRing Implantation in Comparison with MyoRing Implantation Combined with Corneal Collagen Crosslinking for Keratoconus

2019 ◽  
Vol 16 (1S) ◽  
pp. 85-90
Author(s):  
G. M. Kazakbaeva
Keyword(s):  
Corneal Thickness ◽  
Efficacy And Safety ◽  
Collagen Crosslinking ◽  
Corrected Visual Acuity ◽  
Number Of Patients ◽  
Significant Difference ◽  
Corneal Collagen Crosslinking ◽  
The Difference ◽  
Corneal Collagen

Purpose: tо estimate the effectiveness of complete corneal ring (MyoRing) implantation compared with MyoRing implantation combined with corneal collagen crosslinking (CXL) for keratoconus treatment for 36 months follow-up. Patients and Methods. There were 101 patients (124 eyes) with progressing keratoconus aged 18–59 years in the study. Intracorneal rings were implanted in all patients. The patients were divided into 2 groups. MyoRing implantation was performed in a series of 59 patients (76 eyes) with keratoconus II–III Amsler classification, 42 patients (48 eyes) had MyoRing implantation combined with CXL. Implantation of a MyoRing in the corneal pocket was performed using a PocketMaker microkeratome and corneal intrastromal implantation system. Results. Keratometry was reduced in both groups; after MyoRing implantation for 8,45 D and MyoRing combined with CXL for 7,44 D, the spherical equivalent decreased for 7,72 and 6,29 D respectively, after 36 months. The cylinder decreased to 3,33 D with MyoRing alone and to 3,11 D with MyoRing combined with CXL. The smallest corneal thickness remained stable during 36 months after the procedure. There was an improvement in uncorrected and corrected visual acuity, and the difference in the CRF within the period of up to 12 months after the operation. It can be explained by the pseudochase formation in the group with a combined procedure. Conclusion. The implantation of the MyoRing IRC and the combination of MyoRing with CXL showed efficacy and safety in stabilizing keratoconus stabilization, as well as correction of comorbided ametropia 3 years after surgery. Both MyoRing implantation and MyoRing combined with CXL were effective in the stabilization of progressive keratoconus, as well as the correction of ametropia 3 years after surgery. There was no significant difference in MyoRing implantation and its combination with corneal crosslinking in visual and refractive results. The refractive power of the cornea was only one exeption. Long follow-up and randomized prospective studies with a large number of patients are needed.

scholarly journals Corneal Collagen Crosslinking for Keratectasia after Laser in situ Keratomileusis: A Review of the Literature

2013 ◽  
Vol 2 (3) ◽  
pp. 113-120
Author(s):  
Leopoldo Spadea ◽  
Francesca Verboschi ◽  
Stefano Valente ◽  
Enzo Maria Vingolo
Keyword(s):  
Corneal Thickness ◽  
Laser In Situ Keratomileusis ◽  
Lamellar Keratoplasty ◽  
Review Of The Literature ◽  
Covalent Bonds ◽  
Collagen Crosslinking ◽  
Corneal Ectasia ◽  
Corneal Collagen Crosslinking ◽  
Corneal Collagen

ABSTRACT Corneal ectasia is a serious vision-threatening complication of laser in situ keratomileusis (LASIK). It is associated with progressive corneal steepening, an increase in myopia and astigmatism, and decrease in uncorrected visual acuity. Before LASIK presence of risk factors (corneal thickness, refractive error, presence of clinical and subclinical corneal pathologies) should be studied so patients should be risk-stratified. Forme fruste keratoconus or marginal pellucid degeneration should be investigated before LASIK in order to inform the patients of the possibility to develop a corneal complication. Management of post-LASIK ectasia enlists crosslinking, INTACTS, contact lenses and, in the most serious cases, lamellar keratoplasty and corneal transplantation. Crosslinking is a technique to treat and even prevent post-LASIK corneal ectasia. LASIK is a technique that reduces the corneal strength and stability. Crosslinking increases the number of collagen interfibrillar covalent bonds, using ultraviolet A and riboflavin. This result increases stability in corneal strength, reducing the risk to develop corneal ectasia (if performed simultaneously with LASIK) or it treats ectasia (if performed after LASIK keratectasia). How to cite this article Spadea L, Verboschi F, Valente S, Vingolo EM. Corneal Collagen Crosslinking for Keratectasia after Laser in situ Keratomileusis: A Review of the Literature. J Kerat Ect Cor Dis 2013;2(3):113-120.

scholarly journals Changes in the 3D Corneal Structure and Morphogeometric Properties in Keratoconus after Corneal Collagen Crosslinking

Diagnostics ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 397 ◽  
Author(s):  
Ramón Alifa ◽  
David Piñero ◽  
José Velázquez ◽  
Jorge Alió del Barrio ◽  
Francisco Cavas ◽  
...  
Keyword(s):  
Corneal Thickness ◽  
Minimum Thickness ◽  
Collagen Crosslinking ◽  
Several Variables ◽  
Structure Changes ◽  
Corneal Structure ◽  
Corneal Collagen Crosslinking ◽  
Significant Regression ◽  
Corneal Collagen

Keratoconus is an ectatic disorder that is presently considered one of the most prevalent reasons for keratoplasty. Corneal collagen crosslinking (CXL) is the only proven treatment option available that is capable of halting the progression of the disease by stabilizing the cone in 90% of cases, and by also reducing refractive error and maximal keratometry. This study assesses, by means of a 3D morphogeometric analysis procedure developed by our research team, the corneal structure changes that occur immediately after CXL treatment and during a 6 month follow-up period. A total of 19 eyes from 19 patients diagnosed with keratoconus who underwent CXL were included, and several variables derived from the morphogeometric analysis were calculated and evaluated for the pre-operative, 3 month postoperative, and 6 month postoperative states. Significant reductions were detected in central corneal thickness and corneal spherical-like root mean square (RMS) 3 months after surgery, with non-significant regression of the effect afterward. Significant reductions in the total corneal area/volume were found, with some levels of regression after 6 months in certain volumetric parameters. In conclusion, the eyes with higher values for morphogeometric parameters—posterior apex deviation (PAD), anterior minimum thickness point deviation (AMTPD), and posterior minimum thickness point deviation (PMTPD)—seemed more likely to undergo aberrometric improvement as a result of CXL surgery.

scholarly journals Thinner Corneas Appear to Have More Striking Effects of Corneal Collagen Crosslinking in Patients with Progressive Keratoconus

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Yunfei Han ◽  
Yanyun Xu ◽  
Wei Zhu ◽  
Yuling Liu ◽  
Zhen Liu ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Corneal Thickness ◽  
Collagen Crosslinking ◽  
Group 4 ◽  
Negative Linear Correlation ◽  
Corneal Collagen Crosslinking ◽  
Group 3 ◽  
Group 2 ◽  
Corneal Collagen ◽  
Group 1

Purpose.To analyze the outcomes and difference after UVA/riboflavin corneal collagen crosslinking (CXL) in four different corneal thickness groups of patients with progressive keratoconus.Methods.Retrospective study. Eyes with progressive keratoconus after CXL were divided into 4 subgroups as follows: group 1, thinnest corneal thickness (TCT) ≤ 400 µm; group 2, 400 µm < TCT ≤ 450 µm; group 3, 450 µm < TCT ≤ 500 µm; group 4, TCT ≥ 500 µm. Baseline, 6-month, and 12-month visual acuity, corneal topography, TCT, and endothelial cell density were evaluated.Results.The analysis included 123 eyes of 101 patients. At 6 and 12 months after CXL, there was a mean improvement about visual acuity and keratometry values in all patients. There was a reduction in the change of maximum keratometry (Kmax) with the increase of TCT. After 1 year of treatment, it was 3.04 ± 0.75 D in group 1, 2.38 ± 0.51 D in group 2, 1.57 ± 0.35 D in group 3, and 0.31 ± 0.20 D in group 4.Conclusion.CXL is successful in halting the progression of keratoconus and there was a negative linear correlation between TCT andKmax. Advanced cases of progressive keratoconus seemed to obtain more benefits from the flatting effects of CXL.

Sign in / Sign up

Export Citation Format

Share Document