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Dervişoğulları S, Pelit A. Accelerated Corneal Cross-linking in Pediatric Patients with Progressive Keratoconus: 12-Month Follow-up Results. Niger J Clin Pract 2024; 27:131-135. [PMID: 38317046 DOI: 10.4103/njcp.njcp_598_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 12/01/2023] [Indexed: 02/07/2024]
Abstract
PURPOSE To evaluate effectiveness and safety of accelerated corneal cross-linking (CXL) in the treatment of keratoconus in pediatric patients. SETTING Tertiary care hospital. DESIGN Retrospective observational study. METHODS In this study, case series of patients 18 years old or younger with progressive keratoconus who underwent accelerated CXL were observed. All consecutive patients underwent accelerated CXL with setting of 9 mW/cm2 for 10-minute Ultraviolet-A radiation, corresponding to a total dose of 5.4 J/cm2. Preoperative and 12-month postoperative data including uncorrected distance visual acuity (UDVA), best-corrected distance visual acuity (BDVA), keratometry (K) measurements, mean spherical, and cylindrical refraction were evaluated. RESULTS The group consisted of 28 eyes from 14 patients (10 males and 4 females). Mean age of the patients was 16.9 years (11-18 years). UDVA did not change significantly from 0.71 ± 0.54 to 0.65 ± 0.43 logMAR (P = 0.41). BDVA improved significantly from 0.30 ± 0.35 to 0.21 ± 0.34 (P = 0.006). The steep K-value decreased from 48.4 ± 4.3 to 48.0 ± 4.6 diopters, but there was no significant change in steep K-value (P = 0.35). There was no significant change in flat and mean K-value (P > 0.05). Mean spherical and cylindrical refraction were not significantly altered (P > 0.05). One patient with vernal keratoconjunctivitis showed sterile peripheral corneal infiltrates. Patient was treated with topical corticosteroids, antibiotics, and artificial tears. CONCLUSION The findings revealed that accelerated CXL is an effective and safe procedure that halts the progression of keratoconus in pediatric patients.
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Affiliation(s)
- S Dervişoğulları
- Department of Ophthalmology, Başkent University Medical School, Adana Clinic and Research Center, Adana, Turkey
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Wajnsztajn D, Shmueli O, Tarnovsky Y, Frucht-Pery J, Solomon A. Outcome indicators for cross linking in pediatric keratoconus. Front Med (Lausanne) 2023; 10:1149641. [PMID: 37250642 PMCID: PMC10213677 DOI: 10.3389/fmed.2023.1149641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 04/24/2023] [Indexed: 05/31/2023] Open
Abstract
Purpose To evaluate the predictive factors for successful corneal collagen cross-linking (CXL) in pediatric patients with Keratoconus (KC). Methods This retrospective study was conducted using a prospectively built database. Patients (18 years old or younger) underwent CXL for KC between 2007 and 2017, with a 1-year follow-up period or longer. The outcomes included changes in Kmax (delta [Δ] Kmax = Kmaxlast - Kmaxpre) and LogMAR visual acuity (ΔLogMAR = LogMARlast - LogMARpre).The effects of CXL type (accelerated or non-accelerated), demographics (age, sex, background of ocular allergy, ethnicity), preoperative LogMAR visual acuity, maximal corneal power (Kmax), pachymetry (CCTpre), refractive cylinder, and follow-up (FU) time on the outcomes were analyzed. Results One hundred thirty-one eyes of 110 children were included (mean age, 16 ± 2 years; range, 10-18 years). Kmax and LogMAR improved from baseline to last visit: from 53.81 D ± 6.39 D to 52.31 D ± 6.06 D (p < 0.001) and from 0.27 ± 0.23 LogMAR units to 0.23 ± 0.19 LogMAR units (p = 0.005), respectively. A negative ΔKmax (meaning corneal flattening) was associated with a long FU, low CCTpre, high Kmaxpre, high LogMARpre, and non-accelerated CXL on univariate analysis. High Kmaxpre and non-accelerated CXL were associated with negative ΔKmax in the multivariate analysis.A negative ΔLogMAR (meaning vision improvement) was associated with a high LogMARpre in univariate analysis. Conclusion CXL is an effective treatment option in pediatric patients with KC. Our results showed that the non-accelerated treatment was more effective than the accelerated treatment. Corneas with advanced disease had a greater effect on CXL.
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Prasher P, Sharma A, Sharma R, Vig VK, Nirankari VS. Paediatric cornea crosslinking current strategies: A review. ADVANCES IN OPHTHALMOLOGY PRACTICE AND RESEARCH 2023; 3:55-62. [PMID: 37846374 PMCID: PMC10577868 DOI: 10.1016/j.aopr.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 11/13/2022] [Accepted: 11/16/2022] [Indexed: 10/18/2023]
Abstract
Background In the general population, 1 in 2000 people has keratoconus. Indians and other people from Southeast Asia have a higher incidence of keratoconus. Children with keratoconus typically present earlier in life and with a more severe disease. Rubbing the eyes has been identified as a risk factor. Children have a higher incidence and a faster rate of keratoconus progression. Visual rehabilitation in children with keratoconus is challenging. They have a low compliance with contact lens use. Many of these children require penetrating keratoplasty at an early age. Therefore, stopping the progression of keratoconus in children is of paramount importance. Main text Compared to treatment, keratoconus progression prophylaxis is not only preferable, but also easier. Corneal collagen cross-linking has been shown to be safe and effective in stopping its progression in children. The Dresden protocol, which involves central corneal deepithelization (7-9 mm), saturation of the stroma with riboflavin (0.25%), and 30 min UV-A exposure, has proven to be the most successful. Two significant disadvantages of the typical Dresden regimen are the prolonged operating time and the significant post-operative pain. Accelerated-CXL (9 mW/cm2 x 10 min) has been studied to reduce operative time and has been shown to be equally effective in some studies. Compared to accelerated CXL or traditional CXL, epi-off procedures, transepithelial treatment without the need for de-epithelialization and without postoperative discomfort, have been shown to be safer but less effective. Corneal crosslinking should only be performed after treating children with active vernal keratoconjunctivitis. Corneal opacity, chronic corneal edema, sterile infiltrates, and microbial keratitis have been reported after cross-linking of corneal collagen. Conclusions The "Dresden protocol", also known as the conventional corneal cross-linking approach, should be used to halt the progression of keratoconus in young patients. However, if the procedure needs to be completed more rapidly, accelerated corneal crosslinking may be considered. Transepithelial corneal cross-linking has been proven to be less effective at stabilizing keratoconus, although being more safer.
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Affiliation(s)
- Pawan Prasher
- Department of Ophthalmology, Sri Guru Ram Das Institute of Medical Sciences and Research, Amritsar, Punjab, India
| | - Ashok Sharma
- Cornea Centre, SCO 2463 - 2464, Sector 22 C, 160022, Chandigarh, India
| | - Rajan Sharma
- Cornea Centre, SCO 2463 - 2464, Sector 22 C, 160022, Chandigarh, India
| | - Vipan K. Vig
- Amritsar Eye Hospital, GNDU Shopping Complex, Amritsar, Punjab, India
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Polido J, Araújo MEXDS, Wakamatsu TH, Alexander JG, Cabral T, Ambrósio R, Freitas D. Long-term Safety and Efficacy of Corneal Collagen Crosslinking in a Pediatric Group With Progressive Keratoconus: A 7-year Follow-up. Am J Ophthalmol 2023; 250:59-69. [PMID: 36682518 DOI: 10.1016/j.ajo.2023.01.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 01/22/2023]
Abstract
PURPOSE To assess effectiveness and safety of corneal crosslinking (CXL) to reduce keratoconus (KC) progression and improve visual acuity among children with progressive KC and to analyze the use of 20% dextran-based (Dextran) and 1% hydroxypropyl methylcellulose-based (HPMC) riboflavin. DESIGN Prospective, clinical cohort study METHODS: Standard CXL (SCXL) was performed in 74 eyes (58 patients, 45 males, mean age 13.0 ± 2.1 years): 53 eyes with HPMC and 21 with Dextran. Examinations were performed at baseline, 3 and 6 months, and 1, 2, 3, 4, 5, and 7 years of follow-up, including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), a complete ophthalmologic examination, anterior segment ocular coherence tomography, Scheimpflug corneal tomography, and specular microscopy. RESULTS UDVA and CDVA improved at all periods with statistically significant differences in CDVA at 1, 2, and 3 years. Compared with baseline, maximum K (Max K) reduced throughout the 7-year follow-up. Mean thinnest pachymetry (Th Pachy) decreased significantly at 3 months and remained low; in the Dextran group, the Th Pachy mean value returned to baseline 6 months postoperatively. After CXL, 1.5 diopter progression in max K was 1.4% to 14.6% of eyes; worsening was found at 4 to 7 years postoperatively. CONCLUSION SCXL reduced KC progression in children up to 7 years of follow-up and revealed improvement and stability of UDVA and CDVA in 82% of eyes. For visual acuity and KC stability, no statistically significant difference was observed between Dextran-HPMC. The HPMC group showed persistent cornea thinning, raising concerns about its use in SCXL.
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Affiliation(s)
- Júlia Polido
- From the Department of Ophthalmology (J.P., M.E.X.A., T.H.K., J.G.A., T.C., R.A., D.F.), Federal University of São Paulo
| | - Maria Emília Xavier Dos Santos Araújo
- From the Department of Ophthalmology (J.P., M.E.X.A., T.H.K., J.G.A., T.C., R.A., D.F.), Federal University of São Paulo; Department of Ophthalmology (M.E.X.A), HSPE/IAMSPE, São Paulo
| | - Tais H Wakamatsu
- From the Department of Ophthalmology (J.P., M.E.X.A., T.H.K., J.G.A., T.C., R.A., D.F.), Federal University of São Paulo
| | - João G Alexander
- From the Department of Ophthalmology (J.P., M.E.X.A., T.H.K., J.G.A., T.C., R.A., D.F.), Federal University of São Paulo
| | - Thiago Cabral
- From the Department of Ophthalmology (J.P., M.E.X.A., T.H.K., J.G.A., T.C., R.A., D.F.), Federal University of São Paulo; Department of Ophthalmology EBSERH (T.C.), HUCAM/CCS-UFES, Federal University of Espírito Santo, Vitória.
| | - Renato Ambrósio
- From the Department of Ophthalmology (J.P., M.E.X.A., T.H.K., J.G.A., T.C., R.A., D.F.), Federal University of São Paulo; and the Department of Ophthalmology (R.A.), Federal University of the State of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Denise Freitas
- From the Department of Ophthalmology (J.P., M.E.X.A., T.H.K., J.G.A., T.C., R.A., D.F.), Federal University of São Paulo
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Achiron A, El-Hadad O, Leadbetter D, Hecht I, Hamiel U, Avadhanam V, Tole D, Darcy K. Progression of Pediatric Keratoconus After Corneal Cross-Linking: A Systematic Review and Pooled Analysis. Cornea 2022; 41:874-878. [PMID: 34294638 DOI: 10.1097/ico.0000000000002808] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/15/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE Corneal collagen cross-linking (CXL) is an effective treatment to slow down keratoconus (KC) progression in adults. Several studies have also shown efficacious outcomes in pediatric populations, yet no systematic analysis has been performed and no accepted definition for progression is available in children after CXL. This study aimed to establish the most commonly used criteria for progression and to conduct a systematic review of the literature with pooled analysis to assess children's keratoconus progression after CXL. METHODS A systemic literature review combined with pooled analysis was performed on full-length studies of KC after CXL treatment in a pediatric population and the methods used to report progression were analyzed. RESULTS Thirty-seven studies (2078 eyes) were identified on the rates of KC progression after CXL. The most common method to report progression was increased Kmax, Kmean, or Ksteep by ≥1.0 diopter (78.3% of studies). Using these criteria, the mean pooled progression rate after epithelium-off CXL was 9.9% (95% confidence interval: 6.1% -14.6%, total pooled sample size: 1508 eyes) with high heterogeneity between studies [I 2 = 86.48% (95% confidence interval: 80.98 - 90.39), P < 0.0001]. CONCLUSIONS When considering KC progression after CXL in children, with an increase in Kmax, Kmean, or Ksteep ≥ 1.0 diopter, the progression risk was roughly 10%. We encourage clear quantitative reporting of KC progression in future studies evaluating CXL efficacy in pediatric populations.
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Affiliation(s)
- Asaf Achiron
- Bristol Eye Hospital, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Omar El-Hadad
- Bristol Eye Hospital, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom
- Faculty of Medicine, Alexandria University, Egypt
| | - Duncan Leadbetter
- Bristol Eye Hospital, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom
| | - Idan Hecht
- Department of Ophthalmology, Shamir Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel; and
| | - Uri Hamiel
- Genetics Institute, Tel Aviv Sourasky Medical Center & Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Venkata Avadhanam
- Bristol Eye Hospital, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom
| | - Derek Tole
- Bristol Eye Hospital, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom
| | - Kieren Darcy
- Bristol Eye Hospital, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom
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Polido J, Dos Xavier Santos Araújo ME, Alexander JG, Cabral T, Ambrósio R, Freitas D. Pediatric Crosslinking: Current Protocols and Approach. Ophthalmol Ther 2022; 11:983-999. [PMID: 35482230 PMCID: PMC9114245 DOI: 10.1007/s40123-022-00508-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 03/31/2022] [Indexed: 11/24/2022] Open
Abstract
Keratoconus (KC) is likely to be more aggressive in the pediatric population, with a higher risk of progression and visual loss. Several techniques have been proposed for corneal crosslinking (CXL) so far. The standard CXL (SCXL) technique, or the Dresden Protocol, originally developed by Wollensak et al., has been shown to be safe and effective in the pediatric KC group. With similar efficacy to the conventional method, the accelerated CXL (ACXL) protocols proposed a reduced UVA exposure time by increasing the intensity of UVA irradiation. Transepithelial CXL (TCXL), considered an "epithelium-on" method, emerged as a strategy to improve safety and reduce postoperative complications and discomfort. For thinner corneas, we can highlight the use of hypoosmolar riboflavin and new studies, such as contact lens-assisted CXL (CACXL), the epithelial-island CXL (EI-CXL), and the Sub400 protocol. In addition to the different protocols used, another factor that changes CXL results is the type of carrier used: dextran-based or hydroxypropyl methylcellulose-based (HPMC) riboflavin solutions. There are several ways to perform a CXL surgery, and it is still unclear which method is the safest and most effective in the pediatric group. This review of the literature in English, available in PubMed, provides an update on corneal CXL in the pediatric KC group, exploring the data on the techniques currently used and under investigation, including their advantages, efficacy, safety profiles, risks, and cost analyses.
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Affiliation(s)
- Júlia Polido
- Department of Ophthalmology, Federal University of São Paulo (UNIFESP), Rua Botucatu, 806, Vila Clementino, São Paulo, SP, CEP 04023-062, Brazil.
| | - Maria Emília Dos Xavier Santos Araújo
- Department of Ophthalmology, Federal University of São Paulo (UNIFESP), Rua Botucatu, 806, Vila Clementino, São Paulo, SP, CEP 04023-062, Brazil.,Department of Ophthalmology, HSPE/IAMSPE, São Paulo, SP, Brazil
| | - João G Alexander
- Department of Ophthalmology, Federal University of São Paulo (UNIFESP), Rua Botucatu, 806, Vila Clementino, São Paulo, SP, CEP 04023-062, Brazil
| | - Thiago Cabral
- Department of Ophthalmology, Federal University of São Paulo (UNIFESP), Rua Botucatu, 806, Vila Clementino, São Paulo, SP, CEP 04023-062, Brazil.,Department of Ophthalmology EBSERH, HUCAM/CCS-UFES, Federal University of Espírito Santo (UFES), Vitória, ES, Brazil
| | - Renato Ambrósio
- Department of Ophthalmology, Federal University of São Paulo (UNIFESP), Rua Botucatu, 806, Vila Clementino, São Paulo, SP, CEP 04023-062, Brazil.,Department of Ophthalmology, The Federal University of the State of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Denise Freitas
- Department of Ophthalmology, Federal University of São Paulo (UNIFESP), Rua Botucatu, 806, Vila Clementino, São Paulo, SP, CEP 04023-062, Brazil
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Saleh S, Koo EB, Lambert SR, Manche EE. Outcomes After Corneal Crosslinking for Keratoconus in Children and Young Adults. Cornea 2022; 41:408-416. [PMID: 33859086 PMCID: PMC10659218 DOI: 10.1097/ico.0000000000002730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 02/15/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE The aim of this study was to assess the effect of corneal crosslinking on vision and keratometry in children and young adults with progressive keratoconus. METHODS A retrospective medical records review of patients aged 22 years or younger with keratoconus who underwent corneal crosslinking between January 2013 and November 2019 at Byers Eye Institute at Stanford University was conducted. Outcome measures included logarithm of the Minimum Angle of Resolution corrected distance visual acuity (CDVA); keratometry, including maximum keratometry (Kmax); pachymetry; and total wavefront aberration. Measurements were taken at baseline and at 12 and 24 months postoperatively. RESULTS Fifty-seven eyes of 49 patients aged 12 to 22 years were assessed. The mean preoperative CDVA was logarithm of the Minimum Angle of Resolution 0.38 ± 0.32 (20/48), with a mean postoperative CDVA of 0.29 ± 0.31 (20/39) and 0.31 ± 0.31 (20/41) at 12 and 24 months postoperatively, respectively. Compared with preoperative mean Kmax, there was an improvement of -0.8 diopters (D) to a mean postoperative Kmax of 59.1 ± 9.1 D at 12 months and -1.3 D to 59.7 ± 8.8 D at 24 months. Subanalysis excluding the second eye of patients who underwent bilateral crosslinking showed similar results. Linear mixed modeling showed significant improvement in Kmax at both 12 and 24 months postoperatively. Minimum central corneal thickness initially decreased but stabilized at 24 months after crosslinking. Total wavefront aberration remained stable. CONCLUSIONS Corneal crosslinking stabilizes, and in some cases improves, visual and corneal parameters in pediatric and young adult patients with keratoconus. The procedure is safe and well-tolerated and may prevent keratoconus progression in young patients.
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Affiliation(s)
- Solin Saleh
- Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA
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Tear Levels of Inflammatory Cytokines in Keratoconus: A Meta-Analysis of Case-Control and Cross-Sectional Studies. BIOMED RESEARCH INTERNATIONAL 2021; 2021:6628923. [PMID: 34631885 PMCID: PMC8497143 DOI: 10.1155/2021/6628923] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 04/03/2021] [Accepted: 08/12/2021] [Indexed: 12/29/2022]
Abstract
Purpose To assess the tear levels of inflammatory cytokines in patients with keratoconus (KC). Design Systemic review and meta-analysis. Methods The following electronic databases and search engine were searched: PubMed, EMBASE, Web of Science, and Google Scholar. A systematic search of all relevant studies published through January 2021 was conducted, and the standardized mean difference (SMD) and 95% confidence interval (CI) of cytokine levels were calculated to estimate the pooled effects. Sensitivity analysis, subgroup analysis, and metaregression were applied to explore the sources of heterogeneity. Results A total of 7 studies with 374 participants (374 eyes) from clinical studies were included. The tear levels of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) were significantly increased in KC compared with normal controls. The SMD of IL-1β was 1.93 (95% CI 0.22 to 3.65, P = 0.03). The SMD of IL-6 was 1.22 (95% CI 0.59 to 1.84, P < 0.001). The SMD of TNF-α was 1.75 (95% CI 0.66 to 2.83, P = 0.002). There was no significant difference between the two groups on interleukin-4 (IL-4) and interleukin-10 (IL-10). The SMD for IL-4 was 2.36 (95% CI -0.28 to 5.00, P = 0.08) and for IL-10 was 0.30 (95% CI -1.29 to 1.89, P = 0.71). Meta-regression analysis indicated that the heterogeneity maybe significantly correlated with the method of detection, the different ages, and the source of population. Conclusions Our meta-analysis demonstrated that proinflammatory cytokines IL-1β, IL-6, and TNF-α were increased, indicating that cytokine profile changed in KC tears and inflammation may play an important role in the pathogenesis and development of KC.
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Jian W, Tian M, Zhang X, Sun L, Shen Y, Li M, Zhou X. One-Year Follow-Up of Corneal Biomechanical Changes After Accelerated Transepithelial Corneal Cross-Linking in Pediatric Patients With Progressive Keratoconus. Front Med (Lausanne) 2021; 8:663494. [PMID: 34307400 PMCID: PMC8292717 DOI: 10.3389/fmed.2021.663494] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 06/11/2021] [Indexed: 11/23/2022] Open
Abstract
Aims: This study aimed to investigate the corneal biomechanical changes and topographic outcomes of accelerated transepithelial corneal cross-linking (ATE-CXL) in pediatric progressive keratoconus. Methods: In this prospective longitudinal study, 31 eyes of 28 pediatric patients with keratoconus (21 boys and 7 girls; mean age, 14.35 ± 2.68 years) undergoing ATE-CXL (epithelium-on procedure with 45 mW/cm2 for 320 s) were included. Corvis ST was used to measure dynamic corneal response parameters at baseline and at 12 month after ATE-CXL. Corneal keratometry and corneal thickness were measured using Pentacam pre-operatively and 1, 6, and 12 month post-operatively. Results: No serious complications occurred during or after ATE-CXL. The maximum keratometry values were 60.10 ± 7.51 D pre-operatively and 61.42 ± 8.92, 61.17 ± 7.96, and 60.02 ± 7.58 D at 1, 6, and 12 month after ATE-CXL (P > 0.05), respectively. Corneal thickness remained stable during the 12-month follow-up (P > 0.05). At post-operative 12 month, first applanation time (P < 0.001), first applanation length (P = 0.004), second applanation velocity (P = 0.014), highest concavity time (P = 0.022), and radius of curvature at highest concavity (P = 0.031) increased significantly. The value of stiffness parameter at first applanation was significantly increased from 57.70 ± 27.57 pre-operatively to 63.36 ± 27.09 at 12 months after ATE-CXL (P = 0.018). Conclusions: ATE-CXL is safe and effective in stabilizing the progression of pediatric keratoconus. Changes in corneal biomechanical response consistent with stiffening following ATE-CXL were observed in pediatric patients with keratoconus.
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Affiliation(s)
- Weijun Jian
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Mi Tian
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xiaoyu Zhang
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Ling Sun
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Yang Shen
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Meiyan Li
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xingtao Zhou
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
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Brar S, Ganesh S, Reddy SS, Bn N, Shahanand D. A Prospective, Comparative, Clinical Study to Evaluate the Safety and Efficacy of Two Different 0.1% Riboflavin Solutions Used in Collagen Crosslinking Treatment for Patients with Keratoconus. Clin Ophthalmol 2021; 15:2607-2617. [PMID: 34188439 PMCID: PMC8232965 DOI: 10.2147/opth.s313647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 05/28/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose To compare the safety and efficacy of 0.1% riboflavin in two different solutions which is used in corneal collagen crosslinking (CXL) for the treatment of keratoconus. Methods This was a prospective, randomized, comparison study which included 100 eyes of 61 patients with progressive keratoconus who underwent CXL with riboflavin 0.1% solution as a photosensitizer, using the standard Dresden protocol of using 3mW/cm2 UV-A irradiation for 30 minutes which corresponds to a total energy of 5.4 J/cm2. The recruited patients were divided into 2 groups ie, Flavin Group and Peschke-D group by computer generated randomization. Postoperative examinations were conducted on 1 day, 1 month, 3 months, 6 months and 12 months after the crosslinking. Results For both groups, the mean manifest spherical equivalent (SE), astigmatism, best corrected distance visual acuity, keratometry values, thinnest pachymetry values, demarcation line depth and endothelial cell density preoperatively and at postoperative 12 months were comparable with no statistically significant differences. At 12 months postoperatively, 62% of eyes in the Flavin group, and 68% of eyes in the Peschke-D group had postoperative manifest SE of within ± 1.00 D. During UV-A exposure, the cornea in the Flavin group showed intraoperative thinning of 112 microns (27%) as compared with a thinning of 108.12 microns (26.5%) observed in the Peschke group (p=1.67) from the initial pachymetry readings. No eye in either group had any immediate or long-term postop vision threatening complications such as infectious keratitis, corneal melt, non-resolving corneal oedema or endothelial decompensation. Conclusion Both riboflavin solutions were equally safe and effective in the management of progressive keratoconus, and resulted in similar changes in terms of mean manifest spherical equivalent (SE), astigmatism, best corrected distance visual acuity, keratometry values, thinnest pachymetry values, demarcation line depth and endothelial cell density at the end of 12 months postoperatively. Trial Registration Number Ctri/2019/11/021841 (Www.ctri.nic.in).
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Affiliation(s)
- Sheetal Brar
- Department of Phaco-Refractive Surgery, Nethradhama Superspecialty Eye Hospital, Bangalore, Karnataka, India
| | - Sri Ganesh
- Department of Phaco-Refractive Surgery, Nethradhama Superspecialty Eye Hospital, Bangalore, Karnataka, India
| | - Shilpa S Reddy
- Department of Phaco-Refractive Surgery, Nethradhama Superspecialty Eye Hospital, Bangalore, Karnataka, India
| | - Nagesh Bn
- Department of Phaco-Refractive Surgery, Nethradhama Superspecialty Eye Hospital, Bangalore, Karnataka, India
| | - Dhwni Shahanand
- Department of Phaco-Refractive Surgery, Nethradhama Superspecialty Eye Hospital, Bangalore, Karnataka, India
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12
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Kobashi H, Hieda O, Itoi M, Kamiya K, Kato N, Shimazaki J, Tsubota K. Corneal Cross-Linking for Paediatric Keratoconus: A Systematic Review and Meta-Analysis. J Clin Med 2021; 10:jcm10122626. [PMID: 34203646 PMCID: PMC8232120 DOI: 10.3390/jcm10122626] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/28/2021] [Accepted: 06/03/2021] [Indexed: 12/20/2022] Open
Abstract
All corneal cross-linking techniques attenuated disease progression in patients with pediatric keratoconus for at least one year based on a meta-analysis. A standard and accelerated technique led to marked improvement in visual acuity. We determined the efficacy and safety of corneal cross-linking (CXL) in pediatric keratoconus by conducting a systematic review and meta-analysis. The PubMed and Cochrane databases were searched for relevant studies on the effects of standard, transepithelial, and/or accelerated CXL protocols in patients aged 18 years or younger. Standardized mean differences with 95% confidence intervals were calculated to compare the data collected at baseline and 12 months. The primary outcomes were maximum keratometry (Kmax) and uncorrected visual acuity (UCVA), and the secondary outcomes were the thinnest corneal thickness (TCT), best-corrected visual acuity (BCVA), and manifest refraction spherical equivalent or cylindrical refraction. Our search yielded 7913 publications, of which 26 were included in our systematic review and 21 were included in the meta-analysis. Standard CXL significantly improved the Kmax, UCVA, and BCVA, and significantly decreased the TCT. Accelerated CXL significantly improved UCVA and BCVA. In the transepithelial and accelerated-transepithelial CXL methods, each measurable parameter did not change after treatments. All CXL techniques attenuated disease progression in patients with pediatric keratoconus for at least one year. Standard and accelerated CXL led to marked improvement in visual acuity.
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Affiliation(s)
- Hidenaga Kobashi
- Department of Ophthalmology, School of Medicine, Keio University, Tokyo 160-8582, Japan; (N.K.); (K.T.)
- Tsubota Laboratory Inc., Tokyo 160-0016, Japan
- Correspondence: or
| | - Osamu Hieda
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan; (O.H.); (M.I.)
| | - Motohiro Itoi
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan; (O.H.); (M.I.)
| | - Kazutaka Kamiya
- Department of Ophthalmology, School of Medicine, University of Kitasato, Kanagawa 252-0329, Japan;
| | - Naoko Kato
- Department of Ophthalmology, School of Medicine, Keio University, Tokyo 160-8582, Japan; (N.K.); (K.T.)
- Department of Ophthalmology, Ichikawa General Hospital, Tokyo Dental College, Chiba 272-8513, Japan;
| | - Jun Shimazaki
- Department of Ophthalmology, Ichikawa General Hospital, Tokyo Dental College, Chiba 272-8513, Japan;
| | - Kazuo Tsubota
- Department of Ophthalmology, School of Medicine, Keio University, Tokyo 160-8582, Japan; (N.K.); (K.T.)
- Tsubota Laboratory Inc., Tokyo 160-0016, Japan
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Corneal collagen cross-linking in pediatric keratoconus with three protocols: a systematic review and meta-analysis. J AAPOS 2020; 24:331-336. [PMID: 33279597 DOI: 10.1016/j.jaapos.2020.08.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/31/2020] [Accepted: 08/16/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND Keratoconus is a bilateral progressive noninflammatory degenerative disease of the cornea characterized by corneal thinning, irregular astigmatism, and subsequent visual impairment. It has an aggressive course in children. This systematic review evaluates the efficacy of available corneal collagen cross-linking (CXL) protocols for stabilizing the cornea in pediatric patients with keratoconus. METHODS We searched all peer-reviewed publications from 2000 to 2019 indexed in PubMed, Google Scholars, Web of Science, and Cochrane's Database for the terms keratoconus and cross-linking. The following data were extracted from eligible studies: study design, type of intervention, number of the eyes and mean age of patients for each study, duration of follow-up period, mean pre- and postoperative uncorrected and corrected visual acuity, keratometric and aberrometric indices, were analyzed with RevMan 5.3 software. Intra-and intergroup post hoc analyses of outcome variables were performed using t tests. RESULTS A total of 28 studies, including 1,300 eyes, were reviewed. In conventional and accelerated epithelium-off techniques, there was a significant improvement in uncorrected and corrected visual acuities. Similarly, the keratometric indices improved significantly after CXL. Uncorrected visual acuity did not alter after CXL using transepithelial method. CONCLUSIONS Both conventional and accelerated collagen CXL of the cornea are effective therapeutic options in management of keratoconus in children.
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Antunes-Foschini R, Faria-E-Sousa SJ. Three-year follow-up in advanced pediatric keratoconus: thin corneas may not have pachymetry properly assessed after crosslinking. Int J Ophthalmol 2020; 13:1561-1566. [PMID: 33078105 DOI: 10.18240/ijo.2020.10.08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 05/18/2020] [Indexed: 11/23/2022] Open
Abstract
AIM To analyze the crosslinking (CXL) effects in pediatric keratoconus, and to identify the patients' corneal characteristics whose pachymetry could not be adequately evaluated by Scheimpflug method after procedure. METHODS Consecutive pediatric patients with progressive keratoconus underwent CXL were included. Best-corrected visual acuity (BCVA) and spheric equivalent (SE) were measured before and after CXL. After CXL, groups 1 and 2 were divided based on the posterior surface Pentacam quality specifications (QS): "OK" (Group 1) and "not OK" (Group 2). The mean (RmF and RmB) and minimum (RminF and RminB) radius of curvatures of the anterior and posterior corneal surfaces, and the thinnest pachymetry (Pmin) were measured preoperatively at 3, 6, 12, 24, and 36mo. Haze was annotated. RESULTS Twenty-six patients (14 men, mean age 14±1.8y) and median Kmax of 59.9 D initially and 61.4 D preoperatively were treated. BCVA was not different before and 24mo after CXL. Group 2 statistically differed to group 1 in that SE was more myopic before and with no difference 24mo after CXL; RmF and RmB were steeper and Pmin was thinner pre-surgically. Group 2, in which pachymetric changes could not be adequately evaluated after surgery, presented with significant RmF flattening, a shift to hyperopia, and more haze after CXL. CONCLUSION Patients whose pachymetry could not be adequately evaluated after CXL had steeper and thinner corneas before surgery. The predictive factors for impaired QS after CXL are RmF, RmB, and Pmin. In advanced keratoconus, alternative methods to analyze pachymetry and the posterior surface should be considered.
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Affiliation(s)
- Rosalia Antunes-Foschini
- Hospital das Clínicas, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto 14049-900, Brazil
| | - Sidney Júlio Faria-E-Sousa
- Department of Ophthalmology, Otorhinolaryngology, Head and Neck Surgery, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto 14049-900, Brazil
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Iqbal M, Elmassry A, Saad H, AM Gad A, Ibrahim O, Hamed N, Saeed A, S. Khalil A, Tawfik M, Said A, Amer I, Nooreldin A, Said O, Reffat M, Anwar S, Badawi A. Standard cross-linking protocol versus accelerated and transepithelial cross-linking protocols for treatment of paediatric keratoconus: a 2-year comparative study. Acta Ophthalmol 2020; 98:e352-e362. [PMID: 31654497 PMCID: PMC7216930 DOI: 10.1111/aos.14275] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 09/18/2019] [Indexed: 01/14/2023]
Abstract
PURPOSE To compare the efficacy, safety and stability of standard epithelium-off cross-linking (SCXL) versus accelerated epithelium-off cross-linking (ACXL) and transepithelial epithelium-on cross-linking (TCXL) in the treatment of progressive keratoconus (KC) in children. METHODS This prospective multicentre controlled trial included 271 eyes (136 children) with grade 1-3 progressive KC who were randomized to undergo SCXL (n = 91, as a control group), ACXL (n = 92) or TCXL (n = 88). Uncorrected and corrected distance visual acuity, subjective refraction, pachymetry, keratometry and corneal topography measurements were recorded preoperatively and 6, 12 and 24 months postoperatively. RESULTS At 1 year, there was no significant difference in uncorrected distance visual acuity, refractive sphere, cylinder, spherical equivalent or Kmax between the ACXL and SCXL groups; however, during year 2, ACXL regressed while SCXL continued to improve. After 2 years, there were significant differences in all visual, refractive and keratometric components between SCXL and both ACXL and TCXL (p < 0.0001) and between ACXL and TCXL (p < 0.0001). KC progressed in 5.4% of patients who had ACXL and 28.4% of those who had TCXL but in none of those who had SCXL. Vernal keratoconjunctivitis was documented in 43.3% of eyes that progressed postoperatively. CONCLUSION SCXL was more effective for paediatric KC and achieved greater stability than either ACXL or TCXL, and ACXL was superior to TCXL. SCXL also achieved marked improvement in both myopia and spherical equivalent; however, these refractive outcomes were unpredictable and uncontrollable. TCXL had a 28.4% failure rate within 2 years. SCXL is preferable for management of paediatric KC.
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Affiliation(s)
- Mohammed Iqbal
- Department of OphthalmologyFaculty of MedicineSohag UniversitySohagEgypt
| | - Ahmed Elmassry
- Department of OphthalmologyFaculty of MedicineAlexandria UniversityAlexandriaEgypt
| | - Hisham Saad
- Department of OphthalmologyFaculty of MedicineTanta UniversityTantaEgypt
| | - Ahmed AM Gad
- Department of OphthalmologyFaculty of MedicineZagazig UniversityZagazigEgypt
| | - Ola Ibrahim
- Department of OphthalmologyFaculty of MedicineAin Shams UniversityCairoEgypt
| | - Noha Hamed
- Department of OphthalmologyFaculty of MedicineAin Shams UniversityCairoEgypt
| | - Ahmed Saeed
- Department of OphthalmologyFaculty of MedicineBenha UniversityBenhaEgypt
| | - Ahmad S. Khalil
- Department of OphthalmologyFaculty of MedicineZagazig UniversityZagazigEgypt
| | - Mohamed Tawfik
- Department of OphthalmologyMemorial Institute of OphthalmologyGizaEgypt
| | - Amr Said
- Department of OphthalmologyFaculty of MedicineAlexandria UniversityAlexandriaEgypt
| | - Ibrahim Amer
- Department of OphthalmologyFaculty of MedicineAlazhar UniversityAssuitEgypt
| | - Asaad Nooreldin
- Department of OphthalmologyFaculty of MedicineAlazhar UniversityAssuitEgypt
| | - Omar Said
- Department of OphthalmologyFaculty of MedicineFayoum UniversityFayoumEgypt
| | - Mohamed Reffat
- Department of OphthalmologyMansoura Ophthalmic HospitalMansouraEgypt
| | - Seif Anwar
- Department of OphthalmologyMansoura Ophthalmic HospitalMansouraEgypt
| | - Amani Badawi
- Department of OphthalmologyFaculty of MedicineMansoura UniversityMansouraEgypt
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Tian M, Jian W, Zhang X, Sun L, Zhou X. Three-year follow-up of accelerated transepithelial corneal cross-linking for progressive paediatric keratoconus. Br J Ophthalmol 2020; 104:1608-1612. [PMID: 32051139 PMCID: PMC7587222 DOI: 10.1136/bjophthalmol-2019-315260] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 12/22/2019] [Accepted: 01/28/2020] [Indexed: 11/24/2022]
Abstract
Purpose To investigate the long-term safety and efficacy of accelerated transepithelial cornealcross-linking (ATE-CXL) in children with progressive keratoconus. Methods Fifty-three eyes of 41 paediatric patients (34 boys, 7 girls; mean age 14.81±1.96 years) undergoing ATE-CXL were enrolled in the study. Corrected distance visual acuity (CDVA) and manifest refraction were assessed preoperatively and 36 months postoperatively. Corneal keratometry, corneal thickness and posterior elevation were measured using Pentacam preoperatively and 1, 6, 12 and 36 months postoperatively. Pachymetry and epithelial thicknesses were measured using optical coherence tomography preoperatively and 6, 12, and 36 months postoperatively. Results Thirty-six months postoperatively, CDVA improved from 0.32±0.28 to 0.26±0.25 in logarithm of the minimum angle resolution (p=0.025). Maximum keratometry was 58.73±9.70 D preoperatively and 59.20±10.24, 58.28±9.33, 57.88±9.99 and 58.98±10.79 D at 1, 6, 12 and 36 months postoperatively throughout the 36-month follow-up period (p>0.05). Similarly, corneal central thickness, which was 492.42±33.83 µm postoperatively, also remained stable during the 36-month follow-up (p>0.05). Both posterior central elevation and posterior highest elevation were stable at 12 months after ATE-CXL (p>0.05), but increased at 36 months postprocedure (p<0.05). Corneal pachymetry and epithelial thicknesses remained stable throughout the follow-up period (p>0.05). Conclusions ATE-CXL is a safe and effective treatment in paediatric progressive keratoconus patients, leading to stable keratometry and corneal thickness throughout the 36-month follow-up.
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Affiliation(s)
- Mi Tian
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Shanghai, China
| | - Weijun Jian
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Shanghai, China
| | - Xiaoyu Zhang
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Shanghai, China
| | - Ling Sun
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Shanghai, China
| | - Xingtao Zhou
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China .,NHC Key Laboratory of Myopia, Shanghai, China
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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. BIOMED RESEARCH INTERNATIONAL 2019; 2019:1762537. [PMID: 31073520 PMCID: PMC6470445 DOI: 10.1155/2019/1762537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 02/03/2019] [Accepted: 03/20/2019] [Indexed: 11/24/2022]
Abstract
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.
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Mukhtar S, Ambati BK. Pediatric keratoconus: a review of the literature. Int Ophthalmol 2018; 38:2257-2266. [PMID: 28852910 PMCID: PMC5856649 DOI: 10.1007/s10792-017-0699-8] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 08/18/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE To describe the epidemiology and prevalence, rates of progression, difference between adult and pediatric populations, and therapeutic approaches to pediatric keratoconus from documented literature. METHODS A literature search was done on PubMed using key words including pediatric keratoconus, children with keratoconus, adult keratoconus, penetrating keratoplasty, corneal cross-linking and intracorneal ring segments. The literature was reviewed and reported to explore the key epidemiological differences between the pediatric and adult population with regards to presentation and treatment options. RESULTS Pediatric keratoconus is more aggressive than adult keratoconus, which has been explained by structural differences in the cornea between both populations. High rates of progression were documented in pediatric populations. While corneal collagen cross-linking, intracorneal ring segments and penetrating keratoplasties have been used as therapies in the pediatric population, the literature overwhelmingly shows higher rates of failure and progression despite these measures as compared to adults. CONCLUSION Pediatric keratoconus is more aggressive than adult keratoconus, and current therapies used in adults may not be sufficient for the pediatric population.
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Affiliation(s)
- Sabrina Mukhtar
- School of Medicine, Virginia Commonwealth University, 1201 E. Marshall St., 4th Floor, Richmond, VA, 232983, USA.
| | - Balamurali K Ambati
- Moran Eye Center, University of Utah, 64 Mario Capecchi Dr, Salt Lake City, UT, 84132, USA
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19
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Kato N, Konomi K, Shinzawa M, Kasai K, Ide T, Toda I, Sakai C, Negishi K, Tsubota K, Shimazaki J. Corneal crosslinking for keratoconus in Japanese populations: one year outcomes and a comparison between conventional and accelerated procedures. Jpn J Ophthalmol 2018; 62:560-567. [PMID: 29987530 DOI: 10.1007/s10384-018-0610-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 06/06/2018] [Indexed: 01/03/2023]
Abstract
PURPOSE We retrospectively investigated the efficacy of corneal crosslinking (CXL) on progressive keratoconus in a Japanese population and compared the outcomes of conventional and accelerated CXL. STUDY DESIGN A retrospective cohort study METHODS: A total of 108 consecutive eyes in 95 patients (75 men; 21.9 ± 6.2 years) with progressive keratoconus were enrolled. The epithelium was ablated in all eyes. After presoaking the corneal stroma in riboflavin, UV-A was irradiated at 3.0 mW/cm2 (conventional CXL) for 30 min on 23 eyes and 18.0 mW/cm2 for 5 min (accelerated CXL) on 85 eyes. Best spectacle-corrected visual acuity (BSCVA), manifest refraction, keratometric value, corneal thickness, corneal endothelial cell density (ECD), intraocular pressure, and complications were evaluated at 1, 3, 6, and 12 months after the procedure. RESULTS BSCVA, manifest refraction, ECD, and corneal thickness did not change significantly after both procedures. The keratometric value was significantly decreased from the preoperative value at 12 months (p < 0.001). Progression to more than 1.0 D after CXL was observed in 10 eyes (9.3%). The ΔKmax was negatively associated with preoperative Kmax (p < 0.001) and positively associated with preoperative thinnest corneal thickness (p < 0.001). Both treatment modules showed no significant difference in all parameters. CONCLUSION CXL was as effective in treating keratoconus in Japanese patients as in individuals of other ethnicities. Overall, CXL could be performed using either the conventional or accelerated approach to halt the progression of keratoconus in Japanese populations.
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Affiliation(s)
- Naoko Kato
- Department of Ophthalmology, Saitama Medical University, Morohongo 38, Moroyamamachi, Iruma, Saitama, 350-0495, Japan.
- Department of Ophthalmology, Ichikawa General Hospital, Tokyo Dental College, Chiba, Japan.
- Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan.
| | - Kenji Konomi
- Department of Ophthalmology, Ichikawa General Hospital, Tokyo Dental College, Chiba, Japan
| | - Megumi Shinzawa
- Department of Ophthalmology, Ichikawa General Hospital, Tokyo Dental College, Chiba, Japan
| | - Kozue Kasai
- Department of Ophthalmology, Ichikawa General Hospital, Tokyo Dental College, Chiba, Japan
| | - Takeshi Ide
- Tokyo Vision Eye Clinic Asagaya, Tokyo, Japan
| | | | - Chikako Sakai
- Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan
| | - Kazuno Negishi
- Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan
| | - Kazuo Tsubota
- Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan
| | - Jun Shimazaki
- Department of Ophthalmology, Ichikawa General Hospital, Tokyo Dental College, Chiba, Japan
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Abstract
PURPOSE To comprehensively review the available published literature for cross-linking in the pediatric population. METHODS Review of the literature published in English in PubMed. RESULTS Two hundred ten publications were considered. One hundred fifteen were considered relevant to this review. CONCLUSIONS Studies of cross-linking in pediatric patients are sparse, with relatively short follow-up times, and mostly on small groups of patients. Treatment with cross-linking halts progression of keratoconus in the pediatric population, and early treatment seems to be cost-effective compared with later penetrating keratoplasty. Long-term effects and regression rates remain unclear, and further studies are needed in this population.
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Affiliation(s)
- Claudia Perez-Straziota
- Department of Ophthalmology, University of Southern California, Los Angeles, CA
- Cornea Eye Institute, Beverly Hills, CA
| | - Ronald N Gaster
- Cornea Eye Institute, Beverly Hills, CA
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
| | - Yaron S Rabinowitz
- Cornea Eye Institute, Beverly Hills, CA
- Ophthalmology Research, Cedars-Sinai Medical Center, Los Angeles, CA
- Department of Ophthalmology, Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, CA
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21
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Accelerated Epi-On Versus Standard Epi-Off Corneal Collagen Cross-Linking for Progressive Keratoconus in Pediatric Patients. Cornea 2018; 36:1503-1508. [PMID: 28938381 DOI: 10.1097/ico.0000000000001366] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate and compare the effectiveness and safety of accelerated transepithelial (A-epi-on) corneal collagen cross-linking (CXL) with standard CXL (epi-off) for children with progressive keratoconus. METHODS Prospective, cohort study including 61 eyes of 51 patients younger than 18 years with progressive keratoconus at Oftalmosalud Instituto de Ojos, Lima, Peru. A-epi-on CXL was performed for 36 eyes using 30 minutes of impregnation (0.25% riboflavin, 1.0% phosphate hydroxypropyl methylcellulose, 0.007% benzalkonium chloride) and 5 minutes of irradiation (18 mW/cm). Epi-off CXL was performed for 25 eyes using 30 minutes of impregnation (riboflavin 0.1% solution plus 20% dextran 500) and 30 minutes of irradiation (3 mW/cm). Scheimpflug imaging parameters were evaluated preoperatively and at 6 and 12 months postoperatively. RESULTS Mean uncorrected visual acuity improvement was 0.12 logarithm of the minimum angle of resolution (logMAR) for both groups (P = 0.09 for A-epi-on and P = 0.16 for Epi-off). Mean improvements in the best-corrected visual acuity were 0.09 logMAR (P = 0.05) and 0.06 logMAR (P = 0.05) at 12 months postoperatively for the A-epi-on group and the epi-off group, respectively. Mean maximum keratometry changes were +0.1 D (P = 0.62) and -0.94 D (P = 0.11) for the A-epi-on group and the epi-off group, respectively, at 12 months postoperatively. There were no significant differences between groups regarding changes in pachymetry and posterior elevation values (P > 0.05). Keratoconus progression was observed in 5.6% and 12% of eyes in the A-epi-on group and the epi-off group, respectively. CONCLUSIONS Accelerated epi-on CXL and standard epi-off CXL are safe and effective for stopping the progression of keratoconus at 12 months postoperatively.
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22
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Subasinghe SK, Ogbuehi KC, Dias GJ. Current perspectives on corneal collagen crosslinking (CXL). Graefes Arch Clin Exp Ophthalmol 2018; 256:1363-1384. [PMID: 29623463 DOI: 10.1007/s00417-018-3966-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 02/20/2018] [Accepted: 03/23/2018] [Indexed: 12/13/2022] Open
Abstract
Corneal collagen crosslinking has revolutionized the treatment of keratoconus and post-refractive corneal ectasia in the past decade. Corneal crosslinking with riboflavin and ultraviolet A is proposed to halt the progression of keratectasia. In the original "Conventional Dresden Protocol" (C-CXL), the epithelium is removed prior to the crosslinking process to facilitate better absorption of riboflavin into the corneal stroma. Studies analyzing its short- and long-term outcomes revealed that although there are inconsistencies as to the effectiveness of this technique, the advantages prevail over the disadvantages. Therefore, corneal crosslinking (CXL) is widely used in current practice to treat keratoconus. In an attempt to improve the visual and topographical outcomes of C-CXL and to minimize time-related discomfort and endothelial-related side effects, various modifications such as accelerated crosslinking and transepithelial crosslinking methods have been introduced. The comparison of outcomes of these modified techniques with C-CXL has also returned contradictory results. Hence, it is difficult to clearly identify an optimal procedure that can overcome issues associated with the CXL. This review provides an up-to-date analysis on clinical and laboratory findings of these popular crosslinking protocols used in the treatment of keratoconus. It is evident from this review that in general, these modified techniques have succeeded in minimizing the immediate complications of the C-CXL technique. However, there were contradictory viewpoints regarding their effectiveness when compared with the conventional technique. Therefore, these modified techniques need to be further investigated to arrive at an optimal treatment option for keratoconus.
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Affiliation(s)
- Sandeepani K Subasinghe
- Department of Anatomy, University of Otago, P.O. Box 913, 270 Great King Street, Dunedin, 9054, New Zealand.
| | - Kelechi C Ogbuehi
- Ophthalmology Section, Department of Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - George J Dias
- Department of Anatomy, University of Otago, P.O. Box 913, 270 Great King Street, Dunedin, 9054, New Zealand
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Henriquez MA, Villegas S, Rincon M, Maldonado C, Izquierdo L. Long-term efficacy and safety after corneal collagen crosslinking in pediatric patients: Three-year follow-up. Eur J Ophthalmol 2018; 28:415-418. [DOI: 10.1177/1120672118760149] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
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.
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Affiliation(s)
| | - Sandra Villegas
- Research Department, Oftalmosalud Institute of Eyes, Lima, Peru
| | - Mirel Rincon
- Research Department, Oftalmosalud Institute of Eyes, Lima, Peru
| | | | - Luis Izquierdo
- Research Department, Oftalmosalud Institute of Eyes, Lima, Peru
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One-year follow-up of accelerated transepithelial corneal collagen cross-linking for progressive pediatric keratoconus. BMC Ophthalmol 2018. [PMID: 29523106 PMCID: PMC5845167 DOI: 10.1186/s12886-018-0739-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Background Keratoconus typically presents in the teenage years and is more advanced in younger patients when compared with adults. In the present study, we aimed to assess the safety and efficacy of accelerated transepithelial corneal collagen cross-linking (ATE-CXL) in children with progressive keratoconus. Methods In this retrospective consecutive study, 18 eyes were enrolled from 17 pediatric patients (15 boys and 2 girls) with a mean age of 14.44 ± 1.98 years. Manifest refraction, best-corrected visual acuity (BCVA), steepest meridian keratometry (K1), flattest meridian keratometry (K2), maximum keratometry (Kmax), thinnest corneal thickness (TCT), posterior central elevation (PCE), and posterior mean elevation (PME) were measured before and after ATE-CXL. The patients were followed-up at 1, 6, and 12 months. Repeated measures analysis of variance was used for statistical analysis. P < 0.05 was considered statistically significant. Results There were no complications in any case during or after ATE-CXL. BCVA improved from 0.64 ± 0.32 preoperatively to 0.69 ± 0.32 at 1-year postoperatively. The Kmax value was 56.67 ± 9.60 D before the treatment and 56.19 ± 8.55 D, 56.08 ± 8.85 D, and 55.94 ± 8.46 D at 1, 6, and 12 months postoperatively, respectively. No statistically significant differences were present in K1, K2, Kmax, PCE, and TCT before and after ATE-CXL during the 12-month follow-up (P > 0.05). Conclusions ATE-CXL is a safe and effective treatment in pediatric progressive keratoconus patients. The long-term effects need further observation. Trial registration Retrospectively registered. Registration number: ChiCTR-OIC-16008181. Registered 29 March 2016.
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Olivo-Payne A, Serna-Ojeda JC, Hernandez-Bogantes E, Abdala-Figuerola A, Pedro-Aguilar L, Lichtinger A, Ramirez-Miranda A, Navas A, Graue-Hernandez EO. Trans-epithelial accelerated corneal cross-linking for keratoconus in children. Int J Ophthalmol 2017; 10:1919-1921. [PMID: 29259913 DOI: 10.18240/ijo.2017.12.20] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 07/13/2017] [Indexed: 11/23/2022] Open
Abstract
The aim of the study is to evaluate the safety and efficacy of trans-epithelial accelerated corneal cross-linking (TE-ACXL) in children with progressive keratoconus. Retrospective, case-series of 23 eyes of 14 children who underwent TE-ACXL. Evaluations were performed at baseline and 1, 3, 6, 12 and 18mo postoperatively. Mean follow-up time of 23.82±3.15mo and mean age was 13.7±1.4y (range 11 to 16y). Mean preoperative uncorrected distance visual acuity changed from 0.92±0.45 logMAR (20/160) to 0.71±0.40 logMAR (20/100) (P=0.001). Mean keratometry (Km) changed from 53.87± 6.03 to 53.00±5.81 (P=0.001). Pachymetry did not have significant changes at last follow-up (P=0.30). The mean preoperative sphere was -5.58±2.48 and -4.89±4.66 D (P=0.11) at last follow-up; refractive cylinder from -5.58±2.48 to -5.02±2.23 (P=0.046). In conclusion, tomographic and refractive stability are shown in over 91% of eyes with pediatric progressive keratoconus who underwent TE-ACXL.
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Affiliation(s)
- Andrew Olivo-Payne
- Department of Cornea and Refractive Surgery, Institute of Ophthalmology "Conde de Valenciana", Cuauhtémoc 06800, Mexico City, Mexico
| | - Juan Carlos Serna-Ojeda
- Department of Cornea and Refractive Surgery, Institute of Ophthalmology "Conde de Valenciana", Cuauhtémoc 06800, Mexico City, Mexico
| | - Erick Hernandez-Bogantes
- Department of Cornea and Refractive Surgery, Institute of Ophthalmology "Conde de Valenciana", Cuauhtémoc 06800, Mexico City, Mexico
| | - Alexandra Abdala-Figuerola
- Department of Cornea and Refractive Surgery, Institute of Ophthalmology "Conde de Valenciana", Cuauhtémoc 06800, Mexico City, Mexico
| | - Lucero Pedro-Aguilar
- Department of Cornea and Refractive Surgery, Institute of Ophthalmology "Conde de Valenciana", Cuauhtémoc 06800, Mexico City, Mexico
| | - Alejandro Lichtinger
- Department of Cornea and Refractive Surgery, Institute of Ophthalmology "Conde de Valenciana", Cuauhtémoc 06800, Mexico City, Mexico
| | - Arturo Ramirez-Miranda
- Department of Cornea and Refractive Surgery, Institute of Ophthalmology "Conde de Valenciana", Cuauhtémoc 06800, Mexico City, Mexico
| | - Alejandro Navas
- Department of Cornea and Refractive Surgery, Institute of Ophthalmology "Conde de Valenciana", Cuauhtémoc 06800, Mexico City, Mexico
| | - Enrique O Graue-Hernandez
- Department of Cornea and Refractive Surgery, Institute of Ophthalmology "Conde de Valenciana", Cuauhtémoc 06800, Mexico City, Mexico
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Abstract
PURPOSE To report the long-term outcome of corneal collagen cross-linking (CXL) for progressive keratoconus in pediatric patients. METHODS "Epithelium-off" CXL was performed in pediatric eyes with progressive keratoconus. Spectacle-corrected distance visual acuity (CDVA), retinoscopy, topography, and tomography were documented preoperatively and postoperatively at 3 months, 6 months, 1 year, and annually thereafter. RESULTS A total of 377 eyes of 336 pediatric patients aged 8 to 18 years with progressive keratoconus underwent CXL. Of these, 194 eyes had a follow-up beyond 2 years and up to 6.7 years. At last follow-up, there was significant improvement in mean CDVA from 0.33 ± 0.22 to 0.27 ± 0.19 logMAR (P ≤ 0.0001), reduction in mean topographic astigmatism from 7.22 ± 3.55 to 6.13 ± 3.28 D (P = 0.0001), mean flattening of 1.20 ± 3.55 diopters in maximum keratometry (Kmax) (P = 0.0002), and mean corneal thinning of 31.1 ± 36.0 μm (P < 0.0001) after CXL. The mean change in Kmax was most significant in moderately advanced keratoconus (average keratometry 48-53 diopters). Central cones showed more corneal flattening than peripheral cones. Stabilization or flattening of Kmax was seen in 85% of eyes at 2 years and in 76% after 4 years. Stabilization or improvement of CDVA was seen in 80.1% of eyes at 2 years and in 69.1% after 4 years. CONCLUSIONS CXL remains effective in stabilizing keratoconus for longer than 2 years in a majority of pediatric eyes. Flattening of Kmax was greater in moderately advanced keratoconus and central cones. Long-term follow-up beyond 4 years, however, revealed that a few eyes showed features suggestive of reversal of the effect of CXL.
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McAnena L, Doyle F, O'Keefe M. Cross-linking in children with keratoconus: a systematic review and meta-analysis. Acta Ophthalmol 2017; 95:229-239. [PMID: 27678078 DOI: 10.1111/aos.13224] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Keratoconus can behave more aggressively in pediatric than in adult patients. We systematically reviewed the literature to determine the effectiveness of corneal collagen cross-linking (CXL) in children. For this study, MEDLINE® and Cochrane databases were searched for all studies examining the effects of standard, trans-epithelial or accelerated CXL protocols in patients age 18 years or younger. Primary outcomes were; uncorrected visual acuity (UCVA) and maximum keratometry (Kmax) and secondary outcomes were; best-corrected visual acuity (BCVA), mean refractive spherical equivalent (MRSE), central corneal thickness (CCT) and endothelial cell density (ECD). Standardized mean differences (SMD) and 95% confidence intervals were calculated, comparing baseline values with those at 6, 12 and 24 months. A total of 13 papers, published between May 2011 and December 2014 examining 490 eyes of 401 patients with a mean age of 15.25 (±1.5) years, were included in the qualitative analysis in this review. Nine papers were included in the meta-analysis, showing significant improvement in UCVA and BCVA and stable Kmax at 12 months, and stable UCVA, improved BCVA and improved Kmax at 24 months in the standard protocol group UCVA, BCVA and KMax were stable at 12 months in the trans-epithelial group. Mean refractive spherical equivalent (MRSE), CCT and ECD remained stable in both groups. In conclusion it was found that standard CXL may be effective in halting progression of keratoconus in pediatric patients at 1 year. However, larger, more long-term studies are required to ascertain its effectiveness.
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Affiliation(s)
- Lisa McAnena
- Eye Department; Temple Street Children's University Hospital; Dublin Ireland
| | - Frank Doyle
- Royal College of Surgeons in Ireland (RCSI); Dublin Ireland
| | - Michael O'Keefe
- Eye Department; Temple Street Children's University Hospital; Dublin Ireland
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Balparda K, Maldonado MJ. Corneal collagen cross-linking. A review of its clinical applications. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2017; 92:166-174. [PMID: 27914659 DOI: 10.1016/j.oftal.2016.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 10/13/2016] [Accepted: 10/14/2016] [Indexed: 06/06/2023]
Abstract
OBJECTIVE To perform a literature review of the current clinical applications of corneal collagen cross-linking. METHODS An exhaustive literature search was made, including the main biomedical databases, and encompassing all years since the introduction of cross-linking in ophthalmology practice. RESULTS Corneal collagen cross-linking using UVA irradiation and riboflavin is a surgical technique that is currently being optimised, and is supported by a good amount of pre-clinical and clinical studies. These papers found show the beneficial effect of the surgery on preventing the progression of corneal ectasia, especially keratoconus, but also on pellucid marginal degeneration and keratectasia after refractive surgery. The effect of cross-linking on avoiding the occurrence of iatrogenic keratectasia when combined with a photo-ablative procedure is less clear to date. Additionally, it appears that cross-linking may have a considerable beneficial effect on controlling corneal infection caused by fungi, bacteria and amoebae. However, its effect on viral keratitis can be detrimental. The benefit on bullous keratopathy seems to be rather transient. CONCLUSIONS Corneal collagen cross-linking may be used with relative safety and efficacy in patients with progressive keratoconus. Its use could also be considered in patients with other corneal ectasias or with corneal infections of non-viral origin. Currently, there is still a need for more studies as regards its effect on preventing iatrogenic keratectasia.
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Affiliation(s)
- K Balparda
- Instituto Universitario de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid (UVa), Valladolid, España
| | - M J Maldonado
- Instituto Universitario de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid (UVa), Valladolid, España.
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Abstract
PURPOSE To assess the efficacy and safety of cross-linking in pediatric patients with keratoconus and to provide a systematic literature overview regarding this subject. METHODS In this prospective cohort, 54 eyes of 36 pediatric patients with keratoconus underwent standard epithelium-off cross-linking. Follow-up measurements taken up to 5 years after treatment were compared with baseline values. Logistic regression was used to identify the underlying cause in case of progression despite treatment. Finally, a systematic search was performed in PubMed and Embase, and data were extracted and summarized. RESULTS At all follow-up visits up to 5 years, maximum keratometry values improved significantly (mean change at 5 years -2.06 diopters (D), P = 0.01); moreover, average keratometry, uncorrected distance visual acuity, and corrected distance visual acuity improved at all follow-up times, though not always to the level of statistical significance. In 12 eyes (22%), keratoconus had progressed by ≥1.0 D by the last follow-up visit, despite corneal cross-linking. Cones that were more decentralized were identified as the underlying cause of disease progression. The systematic search yielded 17 unique articles: 10 articles on epithelium-off cross-linking, 2 on accelerated cross-linking, 2 on transepithelial cross-linking, 1 on both epithelium-off and transepithelial cross-linking, and 2 on transepithelial cross-linking with iontophoresis. CONCLUSIONS Our long-term follow-up reveals that epithelium-off cross-linking is both apparently safe and effective when used to prevent keratoconus progression in pediatric patients. However, disease progression occurred in 22% of the treated eyes; this progression was attributed to a more decentralized cone location.
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el-Khoury S, Abdelmassih Y, Hamade A, Slim E, Cherfan CG, Chelala E, Bleik J, Jarade EF. Pediatric Keratoconus in a Tertiary Referral Center: Incidence, Presentation, Risk Factors, and Treatment. J Refract Surg 2016; 32:534-41. [DOI: 10.3928/1081597x-20160513-01] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 04/14/2016] [Indexed: 11/20/2022]
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Accelerated corneal crosslinking for treatment of progressive keratoconus in pediatric patients. Eur J Ophthalmol 2016; 27:319-325. [PMID: 27445064 DOI: 10.5301/ejo.5000848] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2016] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate the safety and efficacy of accelerated corneal crosslinking (CXL) in patients with progressive keratoconus aged 18 years or less. METHODS A total of 28 eyes from 19 patients with progressive keratoconus aged 18 years or less were enrolled. We divided participants into 2 groups according to corneal thickness (CT). Group 1 included 13 eyes of 8 patients with CT ≥450 µm; group 2 included 15 eyes of 11 patients with CT <450 µm. Each participant underwent accelerated CXL using 10-minute ultraviolet A irradiance at 9 mW/cm2 for a total energy dose of 5.4 J/cm2. The efficacy and safety of the procedure were assessed postoperatively at 1, 3, 6, and 12 months with Pentacam and visual acuity. RESULTS In uncorrected visual acuity, group 1 showed a statistically significant +0.12 logMAR improvement at 3 months postoperatively (p = 0.003), and in group 2, there was a statistically significant +0.3 logMAR improvement at 1 month postoperatively (p = 0.005). In best-corrected visual acuity, there was a +0.15 logMAR (p<0.001) and +0.22 logMAR (p = 0.005) improvement in group 1 and group 2, respectively, at 12 months postoperatively. All mean keratometric values including K1 and K2 dropped by at least 1 D or remained stable (< ± 1 D) in both groups after accelerated CXL treatment. CONCLUSIONS The findings showed that accelerated CXL treatment seems to be effective in slowing or halting the progression of keratoconus and that no permanent apparent complications are noted 6 months after accelerated CXL.
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Mastropasqua L. Collagen cross-linking: when and how? A review of the state of the art of the technique and new perspectives. EYE AND VISION 2015; 2:19. [PMID: 26665102 PMCID: PMC4675057 DOI: 10.1186/s40662-015-0030-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 11/23/2015] [Indexed: 01/01/2023]
Abstract
Since the late 1990s corneal crosslinking (CXL) has been proposed as a new possibility to stop progression of keratoconus or secondary corneal ectasia, with the promising aim to prevent progressive visual loss due to the evolution of the pathology and to delay or avoid invasive surgical procedures such as corneal transplantation. The possibility of strengthening corneal tissue by means of a photochemical reaction of corneal collagen by the combined action of Riboflavin and ultraviolet A irradiation (UVA), radically modified the conservative management of progressive corneal ectasia. This is a review of the state of the art of CXL, reporting basic and clinical evidence. The paper describes basic principles, advantages and limits of different CXL techniques and possible future evolution of the procedure.
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Affiliation(s)
- Leonardo Mastropasqua
- Ophthalmology Department, Policlinico SS Annunziata, Center of Excellence and National High-Tech Center (CNAT) in Ophthalmology, University "G. d'Annunzio" of Chieti-Pescara, Via dei Vestini, 31 66100 Chieti, Italy
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An Update on the Safety and Efficacy of Corneal Collagen Cross-Linking in Pediatric Keratoconus. BIOMED RESEARCH INTERNATIONAL 2015; 2015:257927. [PMID: 26491663 PMCID: PMC4603314 DOI: 10.1155/2015/257927] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 09/06/2015] [Indexed: 11/30/2022]
Abstract
Keratoconus is a degenerative disease that affects adolescents and young adults and presents with variable thinning and conical deformation of the corneal apex. The resultant irregular astigmatism can progress to levels that can significantly affect everyday activities and overall quality of life. Therefore, stopping the progression of the disease is an essential part in managing patients with keratoconus. Corneal collagen cross-linking is a minimally invasive procedure that stiffens the anterior corneal stroma by creating strong covalent bonds between collagen fibrils. Over the past decade, many studies have proved its safety and efficacy in halting keratoconus progression in adults. This review of the literature highlights the growing trend towards using this treatment in pediatric keratoconic patients. In children, keratoconus tends to be more severe and fast progression is often encountered requiring closer follow-up intervals. Standard cross-linking shows comparable results in children with a good safety-efficacy profile during follow-up periods of up to three years. Further research is needed to standardize and evaluate transepithelial and accelerated cross-linking protocols as these could be of tremendous help in a population where cooperation and compliance are major issues.
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Ozgurhan EB, Kara N, Cankaya KI, Kurt T, Demirok A. Accelerated corneal cross-linking in pediatric patients with keratoconus: 24-month outcomes. J Refract Surg 2015; 30:843-9. [PMID: 25437484 DOI: 10.3928/1081597x-20141120-01] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 10/29/2014] [Indexed: 11/20/2022]
Abstract
PURPOSE To compare the efficiency and safety of accelerated corneal cross-linking in pediatric patients with progressive keratoconus. METHODS In this retrospective interventional case series, 44 eyes of 38 pediatric patients with progressive keratoconus were enrolled. All consecutive patients underwent accelerated corneal cross-linking with settings of 30 mW/cm(2) for 4 minutes, corresponding to a total dose of 7.2 J. The efficacy and safety of the procedure were assessed over a 24-month follow-up period. RESULTS Mean ± standard deviation age of 10 girls and 28 boys was 15.3 ± 2.1 years (range: 9 to 18 years). Uncorrected distance visual acuity improved significantly from 0.52 ± 0.36 to 0.39 ± 0.26 logMAR (P = .002), and corrected distance visual acuity improved significantly from 0.38 ± 0.24 to 0.30 ± 0.20 logMAR (P < .001). Mean spherical and cylindrical refraction were not significantly altered (P > .001 for both). At the last follow-up visit, the flat keratometry value decreased from baseline from 46.4 ± 3.0 to 46.0 ± 2.9 diopters and the steep keratometry value decreased from 50.6 ± 4.2 to 50.1 ± 4.0 diopters (P < .001 for both). The total higher-order aberrations, coma, and astigmatism II values were also significantly decreased at 24 months after treatment (P < .05 for all). No serious complications were recorded during the follow-up. CONCLUSIONS The findings revealed that accelerated corneal cross-linking halted the keratoconus progression without relevant side effects in pediatric patients over a 24-month follow-up period. Visual acuity, keratometric values, and corneal aberrations also improved.
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