Excessive Corneal Flattening and Thinning After Corneal Cross-linking

Kymionis, George D.; Tsoulnaras, Konstantinos I.; Liakopoulos, Dimitris; Paraskevopoulos, Theodoros A.; Kouroupaki, A; Tsilimbaris, Miltiadis K.

doi:10.1097/ico.0000000000000424

Cited by 27 publications

(19 citation statements)

References 5 publications

(8 reference statements)

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“…13 Approximately one-third of eyes included in our study presented a flattening in keratometric values higher than 1.00 D at different follow-up time points. As previously shown in the literature, 1,11,12,[14][15][16] we were expecting an even more intense remodeling effect in this group comprising eyes with more remarkable signs of topographic abnormality and advanced stages of disease. Corneas that present signs of more severe disease (topographically represented by steeper corneas 11,12,[14][15][16] ) are theoretically more likely to present an intense remodeling effect, with a marked ongoing remodeling effect that could last years after the procedure 12 and reaching values up to 14.00 D. 12 This effect may vary with the concentration of riboflavin in the stroma and also with the UVA exposure time.…”

Section: Discussionsupporting

confidence: 76%

“…As previously shown in the literature, 1,11,12,[14][15][16] we were expecting an even more intense remodeling effect in this group comprising eyes with more remarkable signs of topographic abnormality and advanced stages of disease. Corneas that present signs of more severe disease (topographically represented by steeper corneas 11,12,[14][15][16] ) are theoretically more likely to present an intense remodeling effect, with a marked ongoing remodeling effect that could last years after the procedure 12 and reaching values up to 14.00 D. 12 This effect may vary with the concentration of riboflavin in the stroma and also with the UVA exposure time. 17 Previous studies have demonstrated that the combination of increase in regional tissue elastic modulus, 18,19 the effective depth of CXL, 18 and central cone location 19,20 probably explains the localized flattening effect of the cornea.…”

Section: Discussionsupporting

confidence: 76%

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Corneal Collagen Cross-linking in Advanced Keratoconus: A 4-Year Follow-up Study

Giacomin¹,

Netto²,

Torricelli³

et al. 2016

J Refract Surg

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orneal collagen cross-linking (CXL) theoretically strengthens the cornea and subsequently halts or slows keratoconus progression through a photochemical reaction that alters the collagen matrix of the corneal stroma, creating riboflavin ultraviolet-A (UVA)-induced intrafibrillar and interfibrillar covalent bonds. 1 CXL represents a landmark in the management of corneal ectasia because it directly targets the underlying pathology (stromal instability stemming from collagen abnormalities) rather than only addressing the refractive consequences of the disorder. 2 Encouraging CXL outcomes have been extensively reported in the treatment of several ectatic disorders, including keratoconus, pellucid marginal degeneration, and ectasia induced after refractive surgery. 3-8 Mild to moderate progressive keratoconus is still the most common indication for CXL treatment, 6 but the literature is scarce in confirming the safety and effectiveness of this method for patients with advanced keratoconus, particularly those with stage 3 and 4 of the Amsler-Krumeich classification. 9 Therefore, the current long-term follow-up study aims to analyze the visual and topographic outcomes of standard CXL in a group of eyes with advanced keratoconus after 48 months of follow-up. PATIENTS AND METHODS This study is a retrospective review of 40 consecutive CXL procedures performed between 2008 and 2010 and identified 40 patients who met the study inclusion criteria of having advanced keratoconus and 4 years of follow-up. The procedures were performed at the Instituto Oftalmológico Paulista, São C ABSTRACT PURPOSE: To analyze the safety and efficacy of standard corneal collagen cross-linking (CXL) in advanced cases of progressive keratoconus after 4 years of follow-up. METHODS: A retrospective case series of patients with advanced progressive keratoconus (stages 3 and 4 of Amsler-Krumeich classification) underwent standard CXL treatment. The parameters examined were changes in uncorrected visual acuity (UDVA), corrected visual acuity (CDVA), keratometry values (mean, flat, steep, and apical), pachymetry, and endothelial cell count at the baseline and at 12, 24, and 48 months postoperatively. RESULTS: Forty eyes of 40 patients were enrolled in the study. The mean patient age was 22.5 years (range: 15 to 37 years). Both mean UDVA and CDVA remained stable during the time points; no statistically significant change was noted. Although a slight reduction was observed in all keratometric readings, a statistically significant reduction was only reached in the apical keratometry (P = .037) at 4 years after CXL. A significant reduction in the corneal thickness was also found (ultrasonic: 388 ± 49 to 379 ± 48 µm; slit-scanning: 362 ± 48 to 353 ± 51 µm); however, this change was likely not clinically meaningful. Endothelial cell count was not significantly different at the end of the study. Treatment failure or progression was noted in two patients (5%) over the follow-up period. CONCLUSIONS: Standard CXL treatment was safe and able to stabilize both visua...

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Section: Discussionsupporting

confidence: 76%

Section: Discussionsupporting

confidence: 76%

Corneal Collagen Cross-linking in Advanced Keratoconus: A 4-Year Follow-up Study

Giacomin¹,

Netto²,

Torricelli³

et al. 2016

J Refract Surg

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“…When we analyze the relationship of the differences at the initial and final values between C grade and Kmax values, the change in C grade in the Kmax <2 D flattening group approached meaningfulness at most but no significant difference was obtained (Table 5). Hence, the greater amount of pachymetric thinning in this group might have developed as a result of excessive corneal thinning rather than the severity of the disease, as previously reported by Kymonis et al (20).…”

Section: Discussionsupporting

confidence: 72%

Progression Analysis With ABCD Grading System Following Corneal Collagen Cross-Linking in Keratoconus

Sağlık¹

2019

Beyoglu Eye J

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To evaluate the ABCD grading system used in follow-up of keratoconus progression after the corneal collagen cross-linking (CXL) treatment in different Kmax groups. Methods: This study included 57 eyes of 43 patients applied with CXL treatment for progressive keratoconus. All the patients were applied with the standard CXL protocol (Dresden). According to the changes in the Kmax value at the end of 12 months postoperatively (0-1D, 1-2D, >2D), the groups were separated as steepening and flattening. Scheimpflug progression parameters, such as ABCD keratoconus grading systems, were evaluated in six different groups. The Paired Samples t-test was used in the evaluation of parameters with normal distribution and the Wilcoxon test for parameters not showing normal distribution. A value of p<0.05 was accepted as statistically significant. Results: Mean age of patients was 18.37±3.86 years (11-28 years). According to the ABCD grading system, 0.19 significant regression was determined in grade A (p=0.014) and 0.24 in grade D (p<0.0001). 0.10 progression was seen in grade B (p=0.089), and 0.11 in grade C (p=0.011). In the mean Kmax value 0.25±0.42, D flattening was seen (p=0.137). Conclusion: The anterior corneal surface grade in ABCD system is correlated with Kmax in different groups. However, the posterior corneal surface parameter is not correlated with Kmax in 1-2 D steepening and >2D flattening groups. Although there is an increase in posterior elevation after CXL, despite excessive Kmax flattening, it would be inaccurate to consider this increase as an indicator of topographic progress.

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“…Kymionis reported a case of excessive corneal flattening following treatment of progressive KCN with conventional CXL. 129 During the 5 year follow-up, the patient demonstrated significant corneal flattening (11.1 D change in spherical equivalent) and thinning (from a preoperative value of 464 μm to 243 μm).…”

Section: Complications Of CXLmentioning

confidence: 89%

Updates on corneal collagen cross-linking: Indications, techniques and clinical outcomes

Mohammadpour

Masoumi

Mirghorbani

et al. 2017

Journal of Current Ophthalmology

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PurposeTo review the historical background and basic principles of collagen cross-linking, to bring together the data regarding the outcomes and complications of collagen cross-linking and finally to explore the efficacy and safety of new variations of this technique.MethodsA literature review was performed using PubMed and Scopus. The following keywords were used for literature search: cross linking, crosslinking, cross-linking, keratoconus, keratectasia.ResultsIn contrast to traditional treatment modalities for keratoconus (KCN), this new technique addresses the progression of the disease. Several clinical studies have been conducted to assess the efficacy of corneal collagen cross-linking (CXL) in the last decade. The results were promising as collagen cross-linking showed significant improvement in visual acuity and keratometric values. Moreover, initial results show that it is a safe procedure with few reported complications.ConclusionCXL is an emerging treatment method in ophthalmology that offers the possibility to effectively treat progressive KCN.

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Excessive Corneal Flattening and Thinning After Corneal Cross-linking

Abstract: This is the first case report of significant progressive corneal flattening and thinning after undergoing CXL treatment for progressive keratoconus.

Cited by 27 publications

References 5 publications

Corneal Collagen Cross-linking in Advanced Keratoconus: A 4-Year Follow-up Study

Corneal Collagen Cross-linking in Advanced Keratoconus: A 4-Year Follow-up Study

Progression Analysis With ABCD Grading System Following Corneal Collagen Cross-Linking in Keratoconus

Updates on corneal collagen cross-linking: Indications, techniques and clinical outcomes

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