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Mohammadpour M, Farhadi B, Mirshahi R, Masoumi A, Mirghorbani M. Simultaneous photorefractive keratectomy and accelerated collagen cross-linking in high-risk refractive surgery (Tehran protocol): 3-year outcomes. Int Ophthalmol 2020; 40:2659-2666. [PMID: 32607947 DOI: 10.1007/s10792-020-01447-9] [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: 03/16/2020] [Accepted: 05/23/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE To evaluate safety and efficacy of performing simultaneous photorefractive keratectomy (PRK) and collagen cross-linking (CXL) in myopic patients with preoperative risk factors for developing keratectasia. METHODS Seventeen eyes of 15 patients with at least one of the following risk factors were recruited: central keratometry (Kmax) between 48 and 50, difference between inferior, superior corneal power (I-S value) between 1.4 and 1.9 and corneal thickness between 450 and 480 µm. Upon final stage of standard PRK, 0.02% mitomycin was applied for 30-50 s, and then, accelerated CXL was performed for 5 min. Pre- and postoperative Oculus Pentacam® imaging for keratometry values, measurement of uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were done for all patients. RESULTS Mean follow-up time was 32.08 ± 7.79 months (range 25-49 months). Mean age of patients was 28.78 ± 3.80 years. Mean postoperative spherical equivalent was + 0.19 ± 0.42 (- 0.5 to + 1.0 [D]). Mean UDVA and CDVA improved from 0.9062 ± 0.485 log MAR and 0.0148 ± 0.043 log MAR to 0.0173 ± 0.040 log MAR and 0.0057 ± 0.023 log MAR, respectively (P = 0.011, P = 0.735). Mild degree of early postoperative stromal haze was seen which did not persist more than 6 months. There was no late stromal haze, corneal ectasia or other major postoperative complication in the follow-up period. CONCLUSION Combined PRK and accelerated CXL is an efficient and safe procedure for high-risk refractive surgery candidates, with no increased risk of persistent corneal haze.
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Affiliation(s)
- Mehrdad Mohammadpour
- Ophthalmology Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, 1336616351, Iran
| | - Behnaz Farhadi
- Ophthalmology Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, 1336616351, Iran
| | - Reza Mirshahi
- Ophthalmology Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, 1336616351, Iran.,Eye Research Center, Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Ahmad Masoumi
- Ophthalmology Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, 1336616351, Iran.
| | - Masoud Mirghorbani
- Ophthalmology Department, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, 1336616351, Iran
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Marafon SB, Kwitko S, Marinho DR. Long-term results of accelerated and conventional corneal cross-linking. Int Ophthalmol 2020; 40:2751-2761. [DOI: 10.1007/s10792-020-01462-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 06/02/2020] [Indexed: 12/11/2022]
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Aytekin E, Öztürk N, Vural İ, Polat HK, Çakmak HB, Çalış S, Pehlivan SB. Design of ocular drug delivery platforms and in vitro - in vivo evaluation of riboflavin to the cornea by non-interventional (epi-on) technique for keratoconus treatment. J Control Release 2020; 324:238-249. [PMID: 32413453 DOI: 10.1016/j.jconrel.2020.05.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/08/2020] [Accepted: 05/10/2020] [Indexed: 10/24/2022]
Abstract
AIM Keratoconus is a common and progressive eye disease characterized by thinning and tapering of the cornea. This degenerative eye disease is currently treated in the clinic with an interventional technique ("epi-off") that can cause serious side effects as a result of the surgical procedure. The aim of this project is to design innovative formulations for the development of a riboflavin-containing medicinal product to develop a non-invasive ("epi-on") keratoconus treatment as an alternative to current treatment modalities. METHODS Nanostructured lipid carriers (NLCs) were successfully loaded with either riboflavin base of riboflavin-5-phosphate sodium and designed with either Stearylamine (positive charge) or Trancutol P (permeation enhancer). In vitro characterization studies, cytotoxicity and permeability studies were performed. Selected formulations and commercial preparations were applied and compared in ex-vivo corneal drug accumulation and transition studies. Furthermore, in vivo studies were performed to assess drug accumulation in the rat cornea and the corneal stability after NLC treatment was investigated via a biomechanical study on isolated rabbit corneas. RESULTS Both in vitro and ex-vivo as well as in vivo data showed that from the prepared NLC formulations, the most effective formulation was riboflavin-5-phosphate sodium containing NLC with Transcutol P as permeation enhancer. It possessed the highest drug loading content, low accumulation in the cornea but high permeability through the cornea as well as the highest functional performance in corneal crosslinking. CONCLUSION Topical application of riboflavin-5-phosphate sodium loaded NLC systems designed with permeation enhancer Transcutol P may act as a potential alternative for non-invasive keratoconus treatments.
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Affiliation(s)
- Eren Aytekin
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, 06100 Ankara, Turkey
| | - Naile Öztürk
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Inonu University, 44280 Malatya, Turkey
| | - İmran Vural
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, 06100 Ankara, Turkey
| | - H Kerem Polat
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, 06100 Ankara, Turkey
| | - Hasan Basri Çakmak
- Department of Ophthalmology, Faculty of Medicine, Hitit University, 19030 Çorum, Turkey
| | - Sema Çalış
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, 06100 Ankara, Turkey
| | - Sibel Bozdağ Pehlivan
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, 06100 Ankara, Turkey.
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Ameerh MAA, Bdour MDA, Al-Till M, Faouri MA. Trans-epithelial corneal collagen cross-linking with iontophoresis for progressive keratoconus. Int Ophthalmol 2018; 39:1089-1095. [PMID: 29675563 DOI: 10.1007/s10792-018-0920-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 04/07/2018] [Indexed: 11/30/2022]
Abstract
PURPOSE To evaluate the efficacy of trans-epithelial corneal collagen cross-linking (CXL) with Iontophoresis among patients with progressive keratoconus. METHODS It is a prospective interventional study, which is based on 41 eyes of 23 patients, suffering from progressive keratoconus and treated with trans-epithelial corneal cross-linking, using iontophoresis with ETDA and trometamol-enriched riboflavin 5 phosphates 0.1% hypotonic solution (Ricrolin+, Soot Italia SpA, Italy). RESULTS The mean of uncorrected distance visual acuity and best corrected distant visual acuity was improved at 6 months with statistically significant differences from baseline (p < 0.05). There was no statistically significant difference in keratometric values, including K1, K2, Km, topographic astigmatism, and central corneal thickness. Patients, who had completed 1 year (21 eyes of 12 patients) of the treatment, showed similar results. CONCLUSION The data indicated that corneal collagens cross-linking with iontophoresis using Ricroli+ may be an effective method in halting the progression of keratoconus without the side effects of epithelial removal, which may be encountered in the standard epi-off CXL procedure.
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Bonzano C, Di Zazzo A, Barabino S, Coco G, Traverso CE. Collagen Cross-Linking in the Management of Microbial Keratitis. Ocul Immunol Inflamm 2018; 27:507-512. [DOI: 10.1080/09273948.2017.1414856] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Chiara Bonzano
- Clinica Oculistica, Di.N.O.G.M.I. University of Genoa and Ospedale Policlinico San Martino, Genoa, Italy
| | - Antonio Di Zazzo
- Department of Ophthalmology, IRCCS, GB Bietti Foundation, Rome, Italy
| | - Stefano Barabino
- Clinica Oculistica, Di.N.O.G.M.I. University of Genoa and Ospedale Policlinico San Martino, Genoa, Italy
| | - Giulia Coco
- Ophthalmology Department, University of Rome Tor Vergata, Rome, Italy
| | - Carlo Enrico Traverso
- Clinica Oculistica, Di.N.O.G.M.I. University of Genoa and Ospedale Policlinico San Martino, Genoa, Italy
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Filev F, Boriskova J, Kromer R, Mitova D. Photorefraktive Keratektomie in Kombination mit Hornhautquervernetzung – eine Alternative zur Keratoplastik bei Keratokonus? SPEKTRUM DER AUGENHEILKUNDE 2017. [DOI: 10.1007/s00717-017-0336-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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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: 40] [Impact Index Per Article: 5.7] [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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Corneal collagen crosslinking for corneal ectasias: a review. Eur J Ophthalmol 2016; 27:253-269. [PMID: 28009397 DOI: 10.5301/ejo.5000916] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2016] [Indexed: 11/20/2022]
Abstract
PURPOSE To review the published literature on corneal collagen crosslinking (CXL). METHODS Importance has been placed on seminal publications, systemic reviews, meta-analyses, and randomized controlled clinical trials. Where such evidence was not available, cohort studies, case-controlled studies, and case series with follow-up greater than 12 months were examined. RESULTS Corneal collagen crosslinking with riboflavin and ultraviolet A (UVA) 370 nm radiation appears to be capable of arresting the progression of ectatic corneal disorders, with most studies reporting significant improvements in visual, keratometric, and topographic measurements. Its mode of action at the molecular level is undetermined. Follow-up is limited to 5-10 years but suggests sustained stability and enhancement in corneal shape with time. Nearly all published long-term data and comparative studies are with epithelium-off techniques. Epithelium-on investigations suggest some efficacy but less than with epithelium-off treatments and long-term data are unavailable. Accelerated techniques with higher UVA fluencies and shorter treatments times, delivering the same UVA energy dosage, are the subject of recent investigation, with some laboratory and clinical studies suggesting reduced efficacy compared to the standard 3 mW/cm2 for 30 minutes irradiation procedure. Combined methodologies of CXL with techniques such as photorefractive keratectomy and intrastromal rings show promise but long-term follow-up is indicated. Sight-threatening complications of CXL are rare. CONCLUSIONS Studies of epithelium-off CXL with irradiation at 3 mW/cm2 for 30 minutes support its efficacy. Refinement in techniques may allow for safer and more rapid procedures with less patient discomfort but require further investigation.
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Prospective, randomized, double-blind trial to investigate the efficacy and safety of corneal cross-linking to halt the progression of keratoconus. BMC Ophthalmol 2015; 15:78. [PMID: 26194634 PMCID: PMC4508968 DOI: 10.1186/s12886-015-0070-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 07/13/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Corneal cross-linking is widely used to treat keratoconus. However, to date, only limited data from randomized trials support its efficacy. METHODS The efficacy and safety of corneal cross-linking for halting progression of keratoconus were investigated in a prospective, randomized, blinded, placebo controlled, multicentre trial. Twenty-nine keratoconus patients were randomized in three trial centres. The mean age at inclusion was 28 years. Longitudinal changes in corneal refraction were assessed by linear regression. The best corrected visual acuity, surface defects and corneal inflammation were also assessed. These data were analysed with a multifactorial linear regression model. RESULTS A total of 15 eyes were randomized to the treatment and 14 to the control group. Follow-up averaged 1098 days. Corneal refractive power decreased on average (+/-standard deviation) by 0.35 +/- 0.58 dioptres/year in the treatment group. The controls showed an increase of 0.11 +/- 0.61 dioptres/year. This difference was statistically significant (p = 0.02). CONCLUSIONS Our data suggest that corneal cross-linking is an effective treatment for some patients to halt the progression of keratoconus. However, some of the treated patients still progressed, whereas some untreated controls improved. Therefore, further investigations are necessary to decide which patients require treatment and which do not. TRIAL REGISTRATION NCT00626717, Date of registration: February 20, 2008.
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Safety and efficacy of epithelium removal and transepithelial corneal collagen crosslinking for keratoconus. Eye (Lond) 2014; 29:15-29. [PMID: 25277300 DOI: 10.1038/eye.2014.230] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 08/28/2014] [Indexed: 11/08/2022] Open
Abstract
This review aims to assess the efficacy and safety of epithelial removal (ER) and transepithelial (TE) corneal collagen crosslinking (CXL) for the treatment of keratoconus. We used MEDLINE to identify all ER and TE CXL studies on keratoconic eyes (n≥20, follow-up ≥12 months). Ex vivo and studies for non-keratoconus indications or in conjunction with other procedures were excluded. Data on uncorrected (UDVA) and corrected (CDVA) distance visual acuity, refractive cylinder, maximum keratometry (Kmax), and adverse events were collected at the latest follow-up and 1 year. Only one randomised controlled trial (RCT) qualified inclusion. Forty-four ER and five TE studies were included. For logMAR UDVA, CDVA, mean spherical equivalent, refractive cylinder and Kmax, at latest follow-up 81, 85, 93, 62, and 93% ER studies vs 66.7, 80, 75, 33, and 40% TE studies reported improvement, respectively. Whereas at 1 year, 90, 59, and 91% ER studies vs 80, 50, and 25% TE studies reported improvement, respectively. The majority of studies showed reduced pachymetry in both groups. Treatment failure, retreatment rates, and conversion to transplantation were reported to be up to 33, 8.6, and 6.25%, respectively, in ER studies only. Stromal oedema, haze, keratitis, and scarring were only reported in ER studies, whereas endothelial cell counts remained variable in both groups. Both ER and TE studies showed improvement in visual acuity, refractive cylinder but Kmax worsened in most TE studies. Adverse events were reported more with ER studies. This review calls for more high quality ER and TE studies with comparable parameters for further assessment of safety and efficacy.
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O'Brart DPS. Corneal collagen cross-linking: a review. JOURNAL OF OPTOMETRY 2014; 7:113-24. [PMID: 25000866 PMCID: PMC4087180 DOI: 10.1016/j.optom.2013.12.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 11/14/2013] [Indexed: 05/04/2023]
Abstract
The aim was to review the published literature on corneal collagen cross-linking. The emphasis was on the seminal publications, systemic reviews, meta-analyses and randomized controlled trials. Where such an evidence did not exist, selective large series cohort studies, case controlled studies and case series with follow-up preferably greater than 12 months were included. Riboflavin/Ultraviolet A (UVA) corneal collagen cross-linking appears to be the first treatment modality to halt the progression of keratoconus and other corneal ectatic disorders with improvement in visual, keratometric and topographic parameters documented by most investigators. Its precise mechanism of action at a molecular level is as yet not fully determined. Follow-up is limited to 4-6 years at present but suggests continued stability and improvement in corneal shape with time. Most published data are with epithelium-off techniques. Epithelium-on studies suggest some efficacy but less than with the epithelium-off procedures and long-term data are not currently available. The use of Riboflavin/UVA CXL for the management of infectious and non-infectious keratitis appears very promising. Its use in the management of bullous keratopathy is equivocal. Investigation of other methodologies for CXL are under investigation.
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Affiliation(s)
- David P S O'Brart
- Keratoconus Research Institute, Department of Ophthalmology, St. Thomas' Hospital, London SE1 7EH, United Kingdom.
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Seiler TG, Schmidinger G, Fischinger I, Koller T, Seiler T. [Complications of corneal cross-linking]. Ophthalmologe 2014; 110:639-44. [PMID: 23760422 DOI: 10.1007/s00347-012-2682-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND More than 10 years after the clinical introduction of corneal cross-linking (CXL) the indications and contraindications are still not yet defined. Fundamental for such a list is the incidence of complications. METHODS A PubMed search for complications of corneal crosslinking published up to March 2013 was carried out. RESULTS The published complication rates ranged from 1 % to 10 % depending on the stage of keratoconus. Early postoperative complications were transient stromal haze, sterile infiltrates, endothelium decompensation, delayed epithelial healing and infectious keratitis. Stromal opacity can be a delayed postoperative event. CONCLUSIONS Complications after corneal cross-linking treatment for keratoconus are rare but the management of these complications may need keratoplasty.
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Affiliation(s)
- T G Seiler
- Institut für Refraktive und Ophthalmo-Chirurgie, Stockerstr. 37, 8002, Zürich, Schweiz.
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Corneal Cross-Linking as a Treatment for Keratoconus. Ophthalmology 2013; 120:908-16. [DOI: 10.1016/j.ophtha.2012.10.023] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 10/07/2012] [Accepted: 10/17/2012] [Indexed: 11/18/2022] Open
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Current world literature. Curr Opin Ophthalmol 2012; 23:330-5. [PMID: 22673820 DOI: 10.1097/icu.0b013e32835584e4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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