scholarly journals Simultaneous versus Sequential Accelerated Corneal Collagen Cross-Linking and Wave Front Guided PRK for Treatment of Keratoconus: Objective and Subjective Evaluation

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Waleed Ali Abou Samra ◽  
Dalia Sabry El Emam ◽  
Rania Kamel Farag ◽  
Hossam Youssef Abouelkheir
Keyword(s):  
Wave Front ◽  
Subjective Evaluation ◽  
Cross Linking ◽  
Subjective Outcome ◽  
Subjective Data ◽  
Significant Difference ◽  
One Year ◽  
Corneal Collagen ◽  
Objective And Subjective Evaluation

Aim. To compare objective and subjective outcome after simultaneous wave front guided (WFG) PRK and accelerated corneal cross-linking (CXL) in patients with progressive keratoconus versus sequential WFG PRK 6 months after CXL.Methods. 62 eyes with progressive keratoconus were divided into two groups; the first including 30 eyes underwent simultaneous WFG PRK with accelerated CXL. The second including 32 eyes underwent subsequent WFG PRK performed 6 months later after accelerated CXL. Visual, refractive, topographic, and aberrometric data were determined preoperatively and during 1-year follow-up period and the results compared in between the 2 studied groups.Results. All evaluated visual, refractive, and aberrometric parameters demonstrated highly significant improvement in both studied groups (allP<0.001). A significant improvement was observed in keratometric andQvalues. The improvement in all parameters was stable till the end of follow-up. Likewise, no significant difference was determined in between the 2 groups in any of recorded parameters. Subjective data revealed similarly significant improvement in both groups.Conclusions. WFG PRK and accelerated CXL is an effective and safe option to improve the vision in mild to moderate keratoconus. In one-year follow-up, there is no statistically significant difference between the simultaneous and sequential procedure.

scholarly journals One-Year Results of Simultaneous Topography-Guided Photorefractive Keratectomy and Corneal Collagen Cross-Linking in Keratoconus Utilizing a Modern Ablation Software

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
A. M. Sherif ◽  
M. A. Ammar ◽  
Y. S. Mostafa ◽  
S. A. Gamal Eldin ◽  
A. A. Osman
Keyword(s):  
Photorefractive Keratectomy ◽  
Cross Linking ◽  
Safety Index ◽  
Interventional Study ◽  
Effective Option ◽  
Efficacy Index ◽  
One Year ◽  
Collagen Cross Linking ◽  
Corneal Collagen

Purpose.To evaluate effectiveness of simultaneous topography-guided photorefractive keratectomy and corneal collagen cross-linking in mild and moderate keratoconus.Methods. Prospective nonrandomized interventional study including 20 eyes of 14 patients with grade 1-2 keratoconus that underwent topography-guided PRK using a Custom Ablation Transition Zone (CATz) profile with 0.02% MMC application immediately followed by standard 3 mw/cm2UVA collagen cross-linking. Maximum ablation depth did not exceed 58 μm. Follow-up period: 12 months.Results.Progressive statistically significant improvement of UCVA from0.83±0.37logMAR preoperative, reaching0.25±0.26logMAR at 12 months (P<0.001). Preoperative BCVA (0.27±0.31logMAR) showed a progressive improvement reaching0.08±0.12logMAR at 12 months (P=0.02). MeanKmax reduced from48.9±2.8to45.4±3.1 D at 12 months (P<0.001), meanKmin reduced from45.9±2.8 D to44.1±3.2 D at 12 months (P<0.003), mean keratometric asymmetry reduced from3.01±2.03 D to1.25±1.2 D at 12 months (P<0.001). The safety index was 1.39 at 12 months and efficacy index 0.97 at 12 months.Conclusion. Combined topography-guided PRK and corneal collagen cross-linking are a safe and effective option in the management of mild and moderate keratoconus.Precis. To our knowledge, this is the first published study on the use of the CATz ablation system on the Nidek Quest excimer laser platform combined with conventional cross-linking in the management of mild keratoconus.

scholarly journals Corneal collagen cross-linking in pediatric patients with keratoconus

2020 ◽  
Vol 148 (1-2) ◽  
pp. 70-75 ◽  
Author(s):  
Svetlana Stanojlovic ◽  
Vedrana Pejin ◽  
Tanja Kalezic ◽  
Jelica Pantelic ◽  
Borivoje Savic
Keyword(s):  
Visual Acuity ◽  
Pediatric Patients ◽  
Corneal Thickness ◽  
Cross Linking ◽  
Rubbing Behavior ◽  
Distant Visual Acuity ◽  
One Year ◽  
Collagen Cross Linking ◽  
Corneal Collagen

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.

Corneal collagen cross-linking with and without simultaneous intrastromal corneal ring segment implantation: One-year pilot study

2019 ◽  
pp. 112067211988787 ◽  
Author(s):  
Indra Prasad Sharma ◽  
Ramendra Bakshi ◽  
Monica Chaudhry
Keyword(s):  
Visual Acuity ◽  
Confidence Interval ◽  
Randomized Study ◽  
Cross Linking ◽  
Intrastromal Corneal Ring ◽  
Ring Segment ◽  
One Year ◽  
Collagen Cross Linking ◽  
Corneal Collagen

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.

scholarly journals One-year follow-up of accelerated transepithelial corneal collagen cross-linking for progressive pediatric keratoconus

2018 ◽  
Vol 18 (1) ◽  
Author(s):  
Mi Tian ◽  
Weijun Jian ◽  
Ling Sun ◽  
Yang Shen ◽  
Xiaoyu Zhang ◽  
...  
Keyword(s):  
Cross Linking ◽  
One Year ◽  
Collagen Cross Linking ◽  
Corneal Collagen

scholarly journals Outcomes of Corneal Collagen Cross-linking for Keratoconus the Effect of Cone Location

2013 ◽  
Vol 2 (1) ◽  
pp. 16-19 ◽  
Author(s):  
Vinay Agrawal
Keyword(s):  
Mean Shift ◽  
Cross Linking ◽  
Significant Shift ◽  
Central Cone ◽  
The Difference ◽  
One Year ◽  
D 12 ◽  
Collagen Cross Linking ◽  
Corneal Collagen

ABSTRACT Aim One-year outcome of corneal collagen cross-linking (CXL) for keratoconus with reference to topographic cone location. Materials and methods Clinical audit of the results of CXL were used. Three hundred and seventy-eight eyes of 225 patients with preoperative and 12-month completed follow-up were included. Cone location was defined by cone location magnitude index (CLMI) using the Keratron scout topography system. The eyes were divided into two groups–central with cone location within 3 mm zone of the topography map and paracentral with cone location between the 3 and 5 mm zones. Results The overall group showed a mean flattening of the CLMI of 1.67 D [preoperative 53.35 ± 5.63 D, 12 months 51.69 ± 4.67 (p = 0.095)]. The flattening in central cone group was 2.67 D [preoperative 54.01 ± 5.3819, at 12 months to 51.341 ± 4.588 (p = 0.016)]. In paracentral cone group the flattening was lesser at 1.73 D [preoperative apex K 52.805 ± 6.382, at 12 months 51.03 ± 4.82 (p = 0.006)]. The difference between groups was statistically significant (p < 0.001). The central cone group showed no significant shift in cone position [preoperative 1.0059 ± 0.24, at 12 months 0.986 ± 0.206 (p = 0.45)]. The paracentral cone group showed a significant mean shift of 1.05 mm in cone location [preoperative 2.224 ± 0.440, at 12 months 1.196 ± 0.529 (p = 0.001)]. Conclusion Cone location has an impact on the results of corneal cross-linking. The paracentral cones show a significant shift toward the center of the cornea and the central cones show a larger flattening. How to cite this article Agrawal V. Outcomes of Corneal Collagen Cross-linking for Keratoconus the Effect of Cone Location. Int J Kerat Ect Cor Dis 2013;2(1):16-19.

scholarly journals One-Year Follow-Up of Changes in Corneal Densitometry After Accelerated (45 mW/cm2) Transepithelial Corneal Collagen Cross-Linking for Keratoconus

Cornea ◽  
2016 ◽  
Vol 35 (11) ◽  
pp. 1434-1440 ◽  
Author(s):  
Yang Shen ◽  
Weijun Jian ◽  
Ling Sun ◽  
Meng Li ◽  
Tian Han ◽  
...  
Keyword(s):  
Cross Linking ◽  
Corneal Densitometry ◽  
One Year ◽  
Collagen Cross Linking ◽  
Corneal Collagen

scholarly journals The Effects of Epithelium-off Corneal Collagen Cross-linking on Peripheral Corneal Keratometry, Pachymetry as well as Scheimpflug Imaging Calculated Corneal Indices in Keratoconus

2014 ◽  
Vol 3 (3) ◽  
pp. 113-117
Author(s):  
Adam Muzychuk ◽  
Victor Penner ◽  
Guillermo Rocha ◽  
Ahmed Al-Ghoul
Keyword(s):  
Case Series ◽  
Cross Linking ◽  
Collagen Crosslinking ◽  
Post Procedure ◽  
Scheimpflug Imaging ◽  
Corneal Collagen Crosslinking ◽  
One Year ◽  
Collagen Cross Linking ◽  
Corneal Collagen

ABSTRACT Purpose To utilize Scheimpflug imaging to describe corneal changes in keratoconic patients undergoing collagen cross- linking. Study type Case series. Study design Retrospective chart review at two sites: Calgary, Alberta and Brandon, Manitoba, Canada. All patients were diagnosed with keratoconus and had undergone corneal collagen crosslinking. All patients had pre- and post-procedure imaging done with Oculus Pentacam. Results Sixty-one eyes of 48 patients with 6 months follow- up and 36 eyes of 27 patients with one year follow-up were included. Average age was 27 ± 12 years (15-48 years). Fifty- one males and 10 females were studied. At 1 year follow-up, all Pentacam indices were found to improve: ISV −4.44 ± 18.6 (p = 0.16), IVA −0.07 ± 0.27 (p = 0.12), KI −0.009 ± 0.082 (p = 0.49), CKI −0.012 ± 0.027 (p = 0.01), IHA −3.87 ± 23.3 (p = 0.33) and IDH −0.062 ± 0.308 (p = 0.24). Keratometry measurements were flatter at the pupil centre by 0.87 ± 2.53 D (p = 0.05). Kmax and Kmin were flatter by 0.58 ± 1.37 D (p = 0.02) and 0.33 ± 1.70 D (p = 0.25) respectively. Pupil center pachymetry was thinner by 12.9 ± 21.1 µm (p = 0.0006) at 6 months, as were the corneal apex and thinnest local by 12.9 ± 22.3 µm (p = 0.001) and 21.8 ± 54.6 µm (p = 0.05) respectively. However, all central pachymetry readings were not statistically different from baseline at the one year measurements. Peripheral corneal measurements at 6 mm diameter were no different from baseline at 6 months, however, were significantly thicker at the 1 year follow-up. Conclusion The data, in this study, points to a more uniform cornea post corneal collagen crosslinking. The inferior cornea becomes flatter and superior cornea steeper with less variation when comparing the corneal curvatures. The peripheral cornea becomes thicker at 1 year post-procedure. Collagen cross- linking stabilizes the cornea. How to cite this article Penner V, Muzychuk A, Al-Ghoul A, Rocha G. The Effects of Epithelium-off Corneal Collagen Crosslinking on Peripheral Corneal Keratometry, Pachymetry as well as Scheimpflug Imaging Calculated Corneal Indices in Keratoconus. Int J Kerat Ect Cor Dis 2014;3(3):113-117.

scholarly journals Efficacy of Collagen-Based Membranes in Alveolar Bone Augmentation

2018 ◽  
Vol 8 (11) ◽  
pp. 2048 ◽  
Author(s):  
Na-Rae Choi ◽  
George Sándor ◽  
Yong-Deok Kim
Keyword(s):  
Alveolar Bone ◽  
Cross Linking ◽  
Bone Augmentation ◽  
Inclusion Criteria ◽  
X Ray ◽  
Bone Maintenance ◽  
Significant Difference ◽  
The Subject ◽  
One Year

Collagen-based membranes (CBMs) have similar permissive bone formation capabilities when compared to non-absorbable membranes. CBMs have been classified as non-cross-linked membranes (NCLMs) and cross-linked membranes (CLMs) depending on whether the cross-linking between the collagen fibers was artificially increased. The purpose of this study is to evaluate the bone maintenance capacity between NCLMs and CLMs by comparing resorption of regenerated bone. The inclusion criteria consisted of: (1) The use of a CBM, either being an NCLM or CLM for coverage of grafted bone; (2) follow-up for more than one year; (3) the presence of the patient's orthopantomographic X-ray (OPTG) immediately following the installation of implants and one year after. The bone resorption observed in the OPTG was determined by measuring the number of exposed threads of the implant. The number of thread exposures in the implant was compared according to CBM types. OPTGs taken immediately following the installation of implants and at one year after installation were compared. The subject of the measurement was always the implant in which the greatest number of exposed threads were present in each patient. A total of 56 subjects and 97 implants were used in this study. There was no significant difference between NCLM and CLM groups (p > 0.05). However, there was a statistically significant difference (p = 0.02) between the groups when a bone graft was applied to both the maxilla and the mandible. The average number of thread exposures was less than 1.5. In this study, no comparison was made between commonly known causes of bone loss and membrane types.

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