Corneal thickness changes after corneal collagen crosslinking for keratoconus and corneal ectasia: One-year results

Greenstein, Steven A.; Shah, Vaishali; Fry, K. L.; Hersh, Peter S.

doi:10.1016/j.jcrs.2010.10.052

Cited by 207 publications

(169 citation statements)

References 40 publications

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“…Similarly, Wollensak et al reported a reduction in the mean keratometry reading of 2.01 D (11) . Similar to previous studies, the corneal thickness decreased from the preoperative to the final time point, indicating corneal compaction (20,22,23) . In our study, statistically significant differences between the pre-and postoperative measurements were detected when the corneal thicknesses at the apex of the keratoconus (MCT) and pupil center (CCT) were measured.…”

Section: Discussionsupporting

confidence: 89%

Six-month outcomes of corneal crosslinking with dextran-free isotonic riboflavin solution

Oltulu¹,

Şatırtav²,

Donbaloğlu³

et al. 2016

Arquivos Brasileiros De Oftalmologia

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Keratoconus is a bilateral, asymmetric, non-inflammatory, and slowly progressive corneal disease with an approximate incidence of 1 in 2000 individuals. This condition is characterized by corneal thinning and protrusion, progressive myopia, and irregular astigmatism (1) and has conventionally been treated using modalities, such as rigid contact lenses, intrastromal corneal ring segment implantation, and keratoplasty. However, current treatment objectives include not only improved visual acuity but also the prevention of disease progression (2) . Accordingly, corneal cross-linking (CXL) is a relatively new treatment method designed to increase the mechanical and biochemical strength of the stromal tissue via exposure of the ectatic cornea to riboflavin and ultraviolet-A (UVA) light (3) . This procedure is the only currently available semisurgical therapeutic approach for patients with progressing keratoconus and has been shown to delay ABSTRACT Purpose: To analyze the short-term clinical and topographic outcomes in patients with keratoconus after corneal collagen cross-linking treatment (CXL) with dextran-free isotonic riboflavin solution. Methods: In this retrospective case series, 26 eyes from 26 patients with keratoconus were studied. The best corrected visual acuity (BCVA) and refractive and topographic findings were analyzed at a 6-month follow-up. Results: The mean BCVA (Snellen lines) values before and 1, 3, and 6 months after CXL were 0.51 ± 0.2, 0.48 ± 0.2, 0.57 ± 0.2, and 0.64 ± 0.2, respectively, and the difference between the preoperative and 6-month values was statistically significant (p=0.006). The mean spherical equivalent refraction decreased from -5.6 ± 2.4 diopters (D) preoperatively to -5.0 ± 2.1 D, and mean simulated ke ratometry decreased from 48.5 ± 2.5 D to 47.8 ± 2.6 D at 6 months. (p=0.145 and p=0.001, respectively). In addition, the maximum keratometry decreased progressively and significantly from the preoperative value during follow-up (p=0.003). The central and minimal corneal thicknesses, including those of the epithelium, also decreased from 442.8 ± 25.6 μm and 430.5 ± 23.9 μm preoperatively to 420.7 ± 31.8 μm and 409.3 ± 28.7 μm at the most recent follow-up (p<0.001), respectively. No intraoperative or postoperative complications were observed. Conclusions: CXL with dextran-free isotonic riboflavin solution appears to be a safe treatment alternative for keratoconus and yields sustained short-term improvements in visual acuity, keratometric readings, and corneal thickness. However, long-term results are needed to confirm these outcomes.

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Section: Discussionsupporting

confidence: 89%

Six-month outcomes of corneal crosslinking with dextran-free isotonic riboflavin solution

Oltulu¹,

Şatırtav²,

Donbaloğlu³

et al. 2016

Arquivos Brasileiros De Oftalmologia

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“…This finding was in all central readings including pupil centre, apex, and thinnest local pachymetry values and comparable to other studies. 14,15,18,21,28 There appears to be initial thinning, followed by a return to baseline at 1 year. Greenstein et al summarizes multiple factors that could contribute to this phenomenon.…”

Section: Discussionmentioning

confidence: 98%

“…Greenstein et al summarizes multiple factors that could contribute to this phenomenon. 28 Possibilities include epithelial remodeling, anatomic and structural changes of the corneal collagen fibrils, 29,30 alterations in corneal hydration 31 and edema, 32,33 keratocyte apoptosis, [34][35][36] and changes in glycosaminoglycans. 37 The centrifugal measurements of corneal thickness reflect the concept that at 6 months follow-up the more central readings are significantly thinner, but interestingly the 6 mm diameter measurements are no different.…”

Section: Discussionmentioning

confidence: 99%

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

Muzychuk¹,

Penner²,

Rocha³

et al. 2014

International Journal of Keratoconus and Ectatic Corneal Diseases

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Purpose: To utilize Scheimpflug imaging to describe corneal changes in keratoconic patients undergoing collagen crosslinking.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 followup and 36 eyes of 27 patients with one year follow-up were included. Average age was 27 ± 12 years (15-48 years). Fiftyone 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). K max and K min 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 crosslinking stabilizes the cornea.

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“…Crosslinking studies with long-term follow-up have shown that corneal thickness as well as central keratometry follows a dynamic curve over the first 6 months. 7,8 Although complete epithelial healing is achieved in the first few days postoperatively, epithelium remodeling is an acceptable explanation for the continuous changes seen over several months. Avoidance of contact lens corneal bearing and mechanical trauma to the center of the cornea seems to be crucial for undisrupted epithelium remodeling and normal corneal nerve proliferation after CXL.…”

Section: Discussionmentioning

confidence: 99%

Silicone Hydrogel Miniscleral Contact Lenses after Corneal Collagen Crosslinking for Post-LASIK Keratoectasia

Severinsky¹

2014

International Journal of Keratoconus and Ectatic Corneal Diseases

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Purpose: To report successful visual rehabilitation of post refractive surgery keratoectasia shortly after corneal collage crosslinking (CXL) procedure achieved with silicone hydrogel mini-scleral (SHmS) contact lens. Materials and methods:A 29-year-old woman attended to our clinic with complaints on decreased vision in her left eye. Twelve years earlier she underwent bilateral laser-assisted in situ keratomileusis (LASIK) procedure for myopia correction. Corneal topography revealed bilateral central keratoectasia with maximal keratometry values of 55.4 Diopter (D) for her right eye and 59.7 D for the left, corneal thicknesses were 422 and 443 respectively. The patient underwent an uneventful CXL procedure in her left eye and was fitted with SHmS lens 5 weeks later. The lens was designed to rest over the patients' sclera and perilimbal cornea and vault the central cornea with minimal support over it.Results: SHmS lens fitting resulted in significant subjective improvement in visual acuity (from 20/200, unaided to 20/25, contact lens corrected). The patient was able to wear the lens upto 10 hours a day with stable contact lens corrected vision. No contact lens related complications, such as edema or neovascularization were observed during 3 months follow-up period. As a result of successful restoration of vision in the CXL-treated eye, the patient was scheduled for the procedure in her other eye.Conclusion: SHmS contact lens should be considered as an option for the visual rehabilitation of corneas shortly after collagen corneal crosslinking procedure. This novel contact lens modality made from flexible and highly gas permeable material minimizes contact lens influence on corneal recovery after CXL and provides an excellent visual outcome.

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Corneal thickness changes after corneal collagen crosslinking for keratoconus and corneal ectasia: One-year results

Abstract: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.

Cited by 207 publications

References 40 publications

Six-month outcomes of corneal crosslinking with dextran-free isotonic riboflavin solution

Six-month outcomes of corneal crosslinking with dextran-free isotonic riboflavin solution

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

Silicone Hydrogel Miniscleral Contact Lenses after Corneal Collagen Crosslinking for Post-LASIK Keratoectasia

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