Optical Performance of the Cornea One Year Following Keratoconus Treatment with Corneal Collagen Cross-Linking

Uysal, Betül Seher; Saraç, Özge; Yaman, Derya; Akçay, Emine; Çağıl, Nurullah

doi:10.1080/02713683.2018.1501802

Cited by 15 publications

(4 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…27 The biomechanical implication of the DL depth can be explained by considering that ectasia originates in almost all cases from the posterior float of the cornea. 86 The well-known structure of the human corneal stromal has been revealed by many studies based on X ray diffraction [87][88][89][90][91] . The anisotropy, the orientation, the intersection and the distribution of corneal lamellar structure and collagen fibrils interweaves are not uniform across the thickness of the stroma, but the reinforcing structure characterizes a stronger cornea in the anterior third (160-180µm) and a progressively weaker stroma in the posterior part (over 160-180).…”

Section: Discussionmentioning

confidence: 99%

The meaning of the demarcation line after riboflavin-UVA corneal collagen crosslinking

Mazzotta

Wollensak

Raiskup³

et al. 2019

Expert Review of Ophthalmology

View full text Add to dashboard Cite

Since at least two decades, corneal cross-linking by riboflavin and UV-A irradiation stands as an established treatment option of progressive corneal ectasia. More than ten years ago, the histological evaluation of animal corneas and later of human corneas by means of in vivo biomicroscopy and scanning laser confocal microscopy demonstrated in corneas treated with cross-linking procedure the occurrence of a demarcation line running almost parallel to the corneal surface. The feature is a direct consequence of the cross-linking-induced photooxidative modification of the stromal tissue due to riboflavin stromal concentration, light distribution within the corneal stroma, riboflavin activation, oxygen availability and diffusion in the corneal stroma, radicals release, and UV-A exposure time. In this study, the general role of the demarcation line observed after a corneal cross-linking process, in particular its mechanical relevance, clinical consequences, and other various findings in the numerous nowadays available modalities of this treatment, are reviewed objectively.

show abstract

Section: Discussionmentioning

confidence: 99%

The meaning of the demarcation line after riboflavin-UVA corneal collagen crosslinking

Mazzotta

Wollensak

Raiskup³

et al. 2019

Expert Review of Ophthalmology

View full text Add to dashboard Cite

show abstract

“…Recently, different degrees of improvement in K max were recorded within a one-year follow-up after CXL. Uysal et al [25] reported that 109 eyes had a stable K max (45.9%) or a decreased K max up to 3.0 D (52.2%) one year after CXL treatment based on a retrospective study with 111 eyes recruited. Kumar et al [26] reported that the preoperative K max was 55.11 D (SD±5.34), whereas the mean of postoperative K max was reduced to 53.87 D (SD±4.99) based on their retrospective study recruiting 34 eyes.…”

Section: Discussionmentioning

confidence: 99%

Whether Keratectasia Area Shown in Corneal Topography Is Appropriate for Evaluating the Effect of Corneal Cross-Linking for Keratoconus: A 12-Month Follow-Up Study

Wang

Zhang

et al. 2019

BioMed Research International

View full text Add to dashboard Cite

Purpose. To analyze the keratectasia area (KEA) shown in corneal topography before and after corneal cross-linking (CXL) in patients with progressive keratoconus (KC) and figure out whether KEA is appropriate for evaluating the effect of CXL. Methods. A retrospective analysis was conducted in 34 eyes from 24 progressive KC patients who have underwent CXL from 2015 to 2017. Area with K-value more than 47D shown in the corneal topography was marked and identified as KEA. Keratometry (K1, K2, and Kmax), KEA, thinnest corneal thickness (TCT), and endothelial cell density (ECD) were evaluated preoperatively or at months 3, 6, and 12 postoperatively. The changes of KEA before and after operation were evaluated. The relation of KEA and other parameters, including Kmax and TCT, was analyzed. Results. Linear regression model revealed the KEA, Kmax, K1, and K2 decreased after CXL in model y = 0.9622 -0.02408 x (P<0.05), y = 0.9982 -0.003469 x(P<0.05), y = 0.9977 + -0.001347 x(P<0.05), y = 0.9992 + -0.001779 x(P<0.05) (y represents KEA, Kmax, K1, or K2; x represents time (month)). The KEA is significantly decreased in early stage (before month 3) (P<0.05); however, the Kmax, K1, and K2 have no significant decrease in early stage (P= 0.09, 0.19, 0.32). Conclusions. The KEA is more sensitive than K-value in describing the morphological changes of cornea after CXL, especially in early stage after treatment.

show abstract

“…MTF reveals the degree of detail preservation in the image of the object in various spatial frequencies and serves as a measure of ocular contrast sensitivity. Sharper retinal images show less light deviation from the optical system, and PSF represents the retinal image from a light source [ 12 – 14 ]. There are several studies report the results of each technique individually, but there are limited studies that compared these two techniques regarding visual outcome, corneal biomechanics, specular microscopy, keratometry, contrast sensitivity and high order aberrations.…”

Section: Introductionmentioning

confidence: 99%

Comparison of visual outcomes, keratometric parameters and biomechanical profiles between deep anterior lamellar keratoplasty with big-bubble technique vs. Melles technique for keratoconus: a retrospective study

et al. 2023

View full text Add to dashboard Cite

Objective Comparing results of two different DALK surgery techniques (big bubble vs. Melles) in patients with advanced keratoconus. Design a retrospective comparative clinical study. Participants This study conducted on 72 eyes of 72 participants. Introduction This study designed to compare the results of two different DALK surgery techniques (big bubble vs. Melles) in patients with advanced keratoconus. Method Thirty-seven eyes were treated using the big bubble DALK method, while 35 eyes were treated using the Melles approach. Uncorrected visual acuity (UCVA), best corrected spectacle visual acuity (BCSVA), manifest refraction, keratometric characteristics, contrast sensitivity, corneal aberrations, corneal biomechanical characteristics, and endothelial cell profile are the outcome measurements. Results Mean UCVA in big bubble group was 0.61 ± 25 LogMAR and in Melles group was 0.89 ± 0.41 LogMAR (p-value 0.043). Mean BCSVA in big bubble group (0.18 ± 0.12 Log MAR) was significantly better than Melles group (0.35 ± 0.16 Log MAR). Mean of sphere and cylinder refraction showed no significant difference between two groups. Comparing the endothelial cell profile, corneal aberrations, corneal biomechanical properties and keratometry had no significantdifferences. Contrast sensitivity reported as modulation transfer function (MTF) showed higher values in big bubble group and differences with Melles group weresignificant. Results of point spread function (PSF) in big bubble group had superiority to Melles group with considerable statistical P value of 0.023. Conclusion When opposed to the Melles approach, the big bubble technique generates a smooth interface with less stromal residue, which results in higher visual quality and contrast sensitivity.

show abstract

Optical Performance of the Cornea One Year Following Keratoconus Treatment with Corneal Collagen Cross-Linking

Abstract: CXL treatment for keratoconus led to an improvement in visual, refractive, topographic, and most corneal HOAs outcomes at the 12-month follow-up. However, these improvements were not enough to increase corneal MTF and the Strehl ratio of PSF.

Cited by 15 publications

References 22 publications

The meaning of the demarcation line after riboflavin-UVA corneal collagen crosslinking

The meaning of the demarcation line after riboflavin-UVA corneal collagen crosslinking

Whether Keratectasia Area Shown in Corneal Topography Is Appropriate for Evaluating the Effect of Corneal Cross-Linking for Keratoconus: A 12-Month Follow-Up Study

Comparison of visual outcomes, keratometric parameters and biomechanical profiles between deep anterior lamellar keratoplasty with big-bubble technique vs. Melles technique for keratoconus: a retrospective study

Contact Info

Product

Resources

About