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.

Higher-order aberrations 1 year after corneal collagen crosslinking for keratoconus and their independent effect on visual acuity

2016 ◽  
Vol 42 (7) ◽  
pp. 1046-1052 ◽  
Author(s):  
Robert P.L. Wisse ◽  
Stijn Gadiot ◽  
Nienke Soeters ◽  
Daniel A. Godefrooij ◽  
Saskia M. Imhof ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Higher Order ◽  
Independent Effect ◽  
Higher Order Aberrations ◽  
Collagen Crosslinking ◽  
Corneal Collagen Crosslinking ◽  
Corneal Collagen

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 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.

scholarly journals Long-term efficacy and safety after corneal collagen crosslinking in pediatric patients: Three-year follow-up

2018 ◽  
Vol 28 (4) ◽  
pp. 415-418 ◽  
Author(s):  
Maria A Henriquez ◽  
Sandra Villegas ◽  
Mirel Rincon ◽  
Carmen Maldonado ◽  
Luis Izquierdo
Keyword(s):  
Visual Acuity ◽  
Progression Rate ◽  
Collagen Crosslinking ◽  
Corrected Visual Acuity ◽  
Uncorrected Visual Acuity ◽  
Corneal Collagen Crosslinking ◽  
Best Corrected Visual Acuity ◽  
Corneal Collagen

Purpose: To evaluate the effectiveness of standard corneal collagen crosslinking for children with progressive keratoconus. Methods: Prospective study including 26 eyes of 26 patients younger than 18 years old with progressive keratoconus at Oftalmosalud Instituto de Ojos, Lima, Peru. Standard epi-off corneal crosslinking was performed in all eyes between January 2012 and January 2013. Pre- and postoperative evaluation (at 3 years) included uncorrected and best-corrected visual acuity and Scheimpflug analysis. Crosslinking failure was defined as an increase in maximum keratometry (Kmax) of more than 1 diopter after 1 year or more. Results: Mean uncorrected visual acuity improvement was 0.24 LogMAR (p = 0.07) and mean best-corrected visual acuity improvement was 0.18 LogMAR (p = 0.01). None of the eyes lost more than one line in the best-corrected visual acuity. Four eyes (15.38%) lost two lines in the uncorrected visual acuity at 3 years postoperative. Mean steeper keratometry improvement was 1.14 diopters (p = 0.60). Progression rate was 23.07%. Conclusion: Standard epi-off corneal collagen crosslinking is safe and effective to halt the progression of the keratoconus with significant improvement in the best-corrected visual acuity at 3-year follow-up.

scholarly journals Reduced High-order Aberrations using Wavefront-guided Partial Photorefractive Keratectomy and Accelerated Epithelium-off Corneal Cross-linking for Keratoconus

2017 ◽  
Vol 6 (2) ◽  
pp. 73-77
Author(s):  
Guillermo Rocha ◽  
Victor Penner ◽  
Kylee Lewis
Keyword(s):  
Visual Acuity ◽  
Spherical Aberration ◽  
Corneal Thickness ◽  
Case Series ◽  
High Order ◽  
Photorefractive Keratectomy ◽  
Cross Linking ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
High Order Aberrations

ABSTRACT Purpose To demonstrate clinical outcomes of epithelium-off corneal cross-linking (CXL) in combination with wavefront-guided photorefractive keratectomy (PRK) for the treatment of keratoconuns. Materials and methods Total, 28 keratoconic eyes of 21 patients were included. The Sirius Wavefront Analyzer (SCHWIND eye-tech-solutions GmbH and Co. KG) was used to evaluate the high-order aberrations (HOAs). The coupled Amaris 750S excimer laser then performed a PRK of no more than 40 μm using the measured HOA. The CXL was then carried out respecting the standard of 400 μm of corneal thickness. Results The average age was 32 (15—48) years. Uncorrected distance visual acuity (UDVA) improved from 0.58 to 0.31 logMAR (p < 0.001), with best corrected distance visual acuity (CDVA) improving from 0.03 to 0.02 logMAR (p = 0.7). On manifest refraction, the average spherical component decreased from –1.87 to –1.40 D (0.47 ± 2.12, p = 0.4). Cylinder decreased from 2.18 to 0.87 D (1.31 ± 1.14 D, p < 0.001). All HOAs decreased: total HO 0.94 to 0.58 (0.36 ± 0.42, p = 0.05); spherical aberration: 0.142 to –0.018 (0.160 ± 0.160, p < 0.001); secondary astigmatism: 0.21 to 0.11 (0.10 ± 0.11, p = 0.02); coma: 0.80 to 0.42 (0.38 ± 0.47, p = 0.03); trefoil: 0.33 to 0.29 (0.04 ± 0.17, p = 0.7). Conclusion Utilizing HOA to guide the laser treatment in combination with CXL resulted in a significant decrease of HOA at 6 months postprocedure. This is a small case series, but demonstrates a promising trend of improved HOA. Considering that keratoconic eyes have very irregular surfaces with significant HOA, reducing these aberrations should improve best corrected quality of vision. Having longer follow-up and greater numbers may demonstrate a clearer improvement. How to cite this article Penner V, Lewis K, Rocha G. Reduced High-order Aberrations using Wavefront-guided Partial Photorefractive Keratectomy and Accelerated Epithelium-off Corneal Cross-linking for Keratoconus. Int J Kerat Ect Cor Dis 2017;6(2):73-77.

scholarly journals Comparison of correcting myopia and astigmatism with SMILE or FS-LASIK and postoperative higher-order aberrations

2021 ◽  
Vol 14 (4) ◽  
pp. 523-528
Author(s):  
Peng-Fei Zhao ◽  
◽  
Yue Wang ◽  
Cai-Yun Fu ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Spherical Aberration ◽  
Higher Order ◽  
High Order ◽  
Controlled Study ◽  
Spherical Equivalent ◽  
Higher Order Aberrations ◽  
Post Surgery ◽  
Significant Difference ◽  
High Order Aberration

AIM: To compare the effect of myopia and astigmatism correction and postoperative change in higher-order aberration as results of receiving small-incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK). METHODS: A prospective and non-randomized controlled study was conducted. The subjects are divided into two groups according to different operations received: 229 eyes of 116 patients in the SMILE group and 168 eyes of 86 patients in the FS-LASIK group. All subjects were followed up for 3mo by monitoring their uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical equivalent, higher-order aberrations, and the preoperative and postoperative complications. RESULTS: At 1wk, 1, and 3mo post-surgery, 224 eyes (97.8%), 227 eyes (99.1%) and 229 eyes (100%) had UCVA≥20/20 in the SMILE group, while 165 eyes (98.2%), 167 eyes (99.4%) and 167 eyes (99.4%) had UCVA≥20/20 in the FS-LASIK group, respectively (χ2=0.146, 2.135, and 1.124; all P&#x0026;#x003E;0.05). BCVA reduction was not observed in both groups at 1 and 3mo of post-surgery (χ2=0.734 and 1.898, P&#x0026;#x003E;0.05). There was no statistically significant difference in the spherical equivalent between the two groups at 1 and 3mo post-surgery, though the percentage of the spherical equivalent within ±0.50 D at 3mo post-surgery was 98% in the SMILE group, which was higher than that of the FS-LASIK group (92%, χ2=1.872, P&#x0026;#x003E;0.05). The root mean square (RMS) values of total high-order aberration, coma, and spherical aberration of the two groups increased significantly in the early postoperative period and decreased after 3mo, but the values were still higher than the preoperative levels (P&#x0026;#x003C;0.05); there was no significant difference between the two groups in the RMS values of total higher-order aberrations and specific higher-order aberrations (P&#x0026;#x003E;0.05). The incidence of complications in the SMILE group was lower than that in the FS-LASIK group (χ2=14.52, P&#x0026;#x003C;0.05). CONCLUSION: SMILE and FS-LASIK can effectively treat myopia, significantly improve visual acuity, and increase the total high-order aberration, spherical aberration, and coma. The incidence of complications after SMILE is relatively low.

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.

Efficacy of pulsed-light accelerated crosslinking in the treatment of progressive keratoconus: Two-year results

2019 ◽  
Vol 30 (6) ◽  
pp. 1256-1260 ◽  
Author(s):  
Selman Belviranli ◽  
Refik Oltulu
Keyword(s):  
Visual Acuity ◽  
Total Dose ◽  
First Year ◽  
Ultraviolet A ◽  
Pulsed Light ◽  
Collagen Crosslinking ◽  
Corrected Visual Acuity ◽  
Corneal Collagen Crosslinking ◽  
Second Year ◽  
Corneal Collagen

Purpose: The aim of this study was to evaluate the 2-year results of epithelium-off pulsed-light accelerated corneal collagen crosslinking treatment in progressive keratoconus using 30 mW/cm2 ultraviolet A light for 6 min with a total dose of 5.4 J/cm2. Methods: A total of 30 eyes of 22 patients with documented progressive keratoconus and treated with epithelium-off pulsed-light accelerated corneal collagen crosslinking using the KXL® crosslinking device (Avedro Inc, Waltham, MA, USA) were included in this retrospective study. Corneal tomographic measurements and best spectacle-corrected visual acuity were compared using analysis of variance with repeated measurements between the baseline visit (before the corneal collagen crosslinking treatment), and the sixth month, first, and second year visits. Results: Flat keratometry (K1), steep keratometry (K2), and mean keratometry (Km) decreased significantly at sixth month, first, and second years ( p < 0.001, p = 0.001, and p < 0.001, respectively). Maximum keratometry (Kmax) decreased from 55.40 ± 4.90 D at baseline to 54.82 ± 4.68 D, 54.80 ± 5.12 D, and 54.65 ± 5.36 D at sixth month, first year, and second year, respectively ( p = 0.007). The best spectacle-corrected visual acuity improved from 0.34 ± 0.24 logMAR at baseline to 0.25 ± 0.16 logMAR, 0.22 ± 0.15 logMAR, and 0.17 ± 0.13 logMAR at sixth month, first year, and second year, respectively ( p < 0.001). At the second year visit, best spectacle-corrected visual acuity remained stable (no lines lost) with respect to the baseline in 8 eyes and increased 1 or more lines in 22 eyes. Conclusion: Pulsed-light accelerated corneal collagen crosslinking using 30 mW/cm2 ultraviolet A light for 6 min with a total dose of 5.4 J/cm2 is an effective treatment modality in cases with progressive keratoconus—it stops progression at 2 years also regresses some of the cases.

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