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Alkayid H, Asena L, Yüce A, Yavuz Çolak M, Altınörs DD. Comparison of ocular discomfort after three different epithelial debridement techniques for corneal collagen cross-linking in keratoconus treatment. Ther Adv Ophthalmol 2021; 13:25158414211020147. [PMID: 34250443 PMCID: PMC8239960 DOI: 10.1177/25158414211020147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 05/06/2021] [Indexed: 11/17/2022] Open
Abstract
Purpose To compare the severity and duration of ocular discomfort after three different epithelial debridement techniques for corneal collagen cross-linking in the treatment of keratoconus. Methods Fifty-five patients (65 eyes) known to have keratoconus were enrolled in this retrospective study. The eyes were divided into three groups based on the technique used for epithelial debridement for corneal collagen cross-linking procedure; excimer laser transepithelial phototherapeutic keratectomy was used in group 1 (18 eyes), alcohol-assisted epithelial removal was used in group 2 (27 eyes), and mechanical epithelial debridement was used in group 3 (20 eyes). Preoperative and postoperative (third month) best-corrected visual acuity (BCVA) using Snellen chart, objective refraction, and keratometry results were recorded. The results of the questionnaire obtained from the patient's medical records were reviewed regarding their subjective evaluation of postoperative symptoms including foreign body sensation, tearing, photophobia, and burning at the end of the first postoperative week. Paired-samples t test was used to compare preoperative and postoperative clinical findings. One-way analysis of variance (ANOVA) was used to analyze the differences between three independent groups. Results BCVA improved from 0.51 ± 0.27 to 0.58 ± 0.21 (p = 0.05). Objective mean spherical and cylindrical refraction decreased from -5.08 ± 2.78D to -4.46 ± 2.91D (p = 0.22) and from -3.45 ± 2.73D to -3.03 ± 1.97D (p = 0.25). Mean maximum keratometry reading (K max) decreased from 57.63 ± 4.73D to 56.13 ± 4.47D (p = 0.001). The mean score for foreign body sensation was the highest in group 3 (4.50 ± 0.53) and the lowest in group 1 (2.10 ± 1.85) (p = 0.01). The mean scores for tearing, photophobia, and burning sensation were comparable in three groups (p = 0.84, p = 0.13, and p = 0.61, respectively). The duration of photophobia was the shortest in group 1 (1.50 ± 2.37 days), followed by group 3 (2.00 ± 1.31 days) and group 2 (4.00 ± 1.83 days) (p = 0.04). Conclusions The severity and duration of adverse subjective symptoms during the first postoperative week after corneal collagen cross-linking appear to be milder with epithelial debridement using excimer laser transepithelial technique compared with -assisted debridement and mechanical debridement.
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Affiliation(s)
- Hosamadden Alkayid
- Jordanian Royal Medical Services, King Hussein Medical Center, Amman, Jordan
| | - Leyla Asena
- Department of Ophthalmology, Faculty of Medicine, Başkent University, Ankara, Turkey
| | - Aslihan Yüce
- Department of Ophthalmology, Faculty of Medicine, Başkent University, Ankara, Turkey
| | - Meriç Yavuz Çolak
- Department of Ophthalmology, Faculty of Medicine, Başkent University, Ankara, Turkey
| | - Dilek Dursun Altınörs
- Department of Ophthalmology, Faculty of Medicine, Başkent University, Ankara, Turkey
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Stock RA, Gaio JL, Moretto G, Grossi B, Mergener RA, Bonamigo EL. Use of gabapentin in management of postoperative pain after crosslinking. REVISTA BRASILEIRA DE OFTALMOLOGIA 2021. [DOI: 10.37039/1982.8551.20210005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Rubinfeld RS, Gum GG, Talamo JH, Parsons EC. The Effect of Sodium Iodide on Stromal Loading, Distribution and Degradation of Riboflavin in a Rabbit Model of Transepithelial Corneal Crosslinking. Clin Ophthalmol 2021; 15:1985-1994. [PMID: 34007152 PMCID: PMC8123948 DOI: 10.2147/opth.s300886] [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: 03/05/2021] [Accepted: 04/19/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose To evaluate effects of sodium iodide (NaI) on riboflavin concentration in corneal stroma before and during ultraviolet A (UVA) light exposure using a novel transepithelial corneal collagen crosslinking (CXL) procedure (EpiSmart CXL system, CXL Ophthalmics, Encinitas CA). Methods Riboflavin solutions with NaI (Ribostat, CXL Ophthalmics, Encinitas CA) and without NaI were used for CXL in rabbits using EpiSmart. A pilot study determined sufficient riboflavin loading time. Four rabbits were dosed and monitored. Riboflavin fluorescence intensity was assessed from masked slit-lamp photos. A 12 min loading time was selected. Sixteen additional rabbits received the two formulae in contralateral eyes for CXL. Riboflavin uptake was assessed at 0, 10, 15, 20, 25, and 30 min of UVA exposure using a scale for riboflavin fluorescence previously validated against stromal concentration. Post sacrifice, corneal stromal samples were analyzed for concentrations of riboflavin and riboflavin 5ʹ-phosphate. Results Eyes dosed with NaI riboflavin had higher riboflavin grades compared to eyes dosed with the NaI-free riboflavin formulation immediately after riboflavin loading and persisting throughout UVA exposure, with significantly higher (P < 0.01 to < 0.05) riboflavin grades from 15 through 25 min of UVA exposure. Riboflavin grades decreased more slowly in eyes dosed with NaI riboflavin through 25 minutes of UVA exposure. Minor conjunctival irritation was noted with or without NaI. Conclusion The addition of NaI to riboflavin solution is associated with increased riboflavin concentration in corneal stroma throughout a clinically relevant time course of UVA exposure. This effect may be a combination of enhanced epithelial penetration and reduced riboflavin photodegradation and should enhance intrastromal crosslinking.
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Affiliation(s)
| | | | - Jonathan H Talamo
- CXL Ophthalmics, LLC, Encinitas, CA, USA.,Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
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Sorbara L, Lopez JCL, Gorbet M, Bizheva K, Lamarca JM, Pastor JC, Maldonado López MJ, Hileeto D. Impact of contact lens wear on epithelial alterations in keratoconus. JOURNAL OF OPTOMETRY 2021; 14:37-43. [PMID: 32376120 PMCID: PMC7752984 DOI: 10.1016/j.optom.2020.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 11/29/2019] [Accepted: 02/29/2020] [Indexed: 06/11/2023]
Abstract
PURPOSE The purpose of this study was to characterize the central epithelial thickness (CET) of penetrating keratoplasty corneal specimens obtained from patients with keratoconus (KC) and correlate the histological patterns with their clinical history. METHODS Ex vivo histological imaging was performed to measure CET and total corneal thickness (TCT) in 56 patients with KC. Microscopic slides from penetrating keratoplasty corneal specimens, stained with hematoxylin and eosin were evaluated using bright field microscopy. CET and TCT were measured, and morphological features were studied. Clinical history regarding duration of KC prior to surgery and length of and tolerance to contact lens wear were compared and analyzed. RESULTS The microscopic slides of all patients available for follow up (n=48) were analyzed and CET and TCT were measured. The histological evaluation revealed 3 distinctive epithelial patterns. Pattern 1 with central hypertrophic and hydropic changes (n=19) measured 70.89±25.88μm in CET and 308.63±100.74μm in TCT; Pattern 2 (n=14) had not changed, similar to normal epithelium CET and TCT measuring 36.5±7.02μm and 260.14±87.93μm respectively. Pattern 3 (n=15) demonstrated thinner central epithelium characterized by atrophy and focal hydropic changes measuring 19.93±4.60μm and 268.00±79.39μm in CET and TCT respectively (all p<0.0001). The presence of Pattern 2 characterized by similar to normal CET was correlated with the duration of the condition (R=0.600, p=0.030). There was a significant difference in the length of CL wear comparing those with patterns 1 and 2 versus 3 (least no. of CL years) (p=0.05 and p=0.33 respectivelly). CONCLUSIONS Patients with advanced disease have various central corneal epithelial changes detected with histology. Although each central epithelial pattern type was distinctive comparing the 3 patterns, there was no correlation with years of CL wear but only with the duration of the condition.
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Affiliation(s)
- Luigina Sorbara
- School of Optometry & Vision Science, University of Waterloo, Waterloo, Ontario, Canada.
| | | | - Maud Gorbet
- Department of System Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Kostadinka Bizheva
- School of Optometry & Vision Science, University of Waterloo, Waterloo, Ontario, Canada; Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, Canada
| | | | | | - Miguel José Maldonado López
- School of Optometry & Vision Science, University of Waterloo, Waterloo, Ontario, Canada; Department of System Design Engineering, University of Waterloo, Waterloo, Ontario, Canada; Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, Canada; IOBA, University of Valladolid, Spain; Barraquer Ophthalmology Institute, Barcelona, Spain; Barking Havering and Redbridge University Hospitals, Romford, UK
| | - Denise Hileeto
- School of Optometry & Vision Science, University of Waterloo, Waterloo, Ontario, Canada
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Histological Patterns of Epithelial Alterations in Keratoconus. J Ophthalmol 2020; 2020:1468258. [PMID: 32802486 PMCID: PMC7414345 DOI: 10.1155/2020/1468258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 06/23/2020] [Accepted: 07/13/2020] [Indexed: 11/18/2022] Open
Abstract
Purpose The purpose of this study was to confirm the presence of specific patterns of epithelial response in corneal buttons from keratoconus patients. Methods This was a retrospective and descriptive study. 90 penetrating keratoplasty specimens obtained from patients diagnosed with keratoconus were evaluated using bright-field microscopy. Morphologically identifiable characteristics including epithelial cell density and epithelial thickness were analyzed on hematoxylin and eosin- (H&E-) and periodic acid of Schiff- (PAS-) stained slides. Results Three distinctive patterns of epithelial alteration of the central cornea were established. Pattern 3, in which the central epithelium was as thick as peripheral epithelium, was the commonest (44.4%), followed by the pattern 2, defined as central epithelium thinner than periphery epithelium (38.9%), and the uncommonest pattern was number 1, with central epithelium thicker than the periphery (16.7%). Conclusions Three distinctive histologic patterns that could potentially have a diagnostic and prognostic value in keratoconus patients were found.
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Cunha AM, Sardinha T, Torrão L, Moreira R, Falcão-Reis F, Pinheiro-Costa J. Transepithelial Accelerated Corneal Collagen Cross-Linking: Two-Year Results. Clin Ophthalmol 2020; 14:2329-2337. [PMID: 32884233 PMCID: PMC7434572 DOI: 10.2147/opth.s252940] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 06/30/2020] [Indexed: 11/23/2022] Open
Abstract
PURPOSE To report 2-year outcomes of trans-epithelial accelerated corneal collagen crosslinking (TE-ACXL) procedure in the treatment of progressive keratoconus patients. PATIENTS AND METHODS Twenty-four eyes from 24 patients who underwent TE-ACXL (6mW/cm2 for 15 minutes) were included in this retrospective interventional study. Best-corrected visual acuity (BCVA), keratometry values, thinnest corneal thickness (PachyMin) and topometric indexes were analysed preoperatively and at 6-month, 12-month, 18-month and 24-month postoperative. Progression was assessed by increase ≥1.00D in maximum keratometry (Kmax); increase ≥1.00D in corneal astigmatism; decrease ≥2% in PachyMin; increase ≥0.42 in D-index. RESULTS There were no complications during or after TE-ACXL. No significant differences (Δ) were observed between baseline and 12-month or 24-month postoperative: ∆BCVA (-0.08 ± 0.25, p=0.190; -0.04 ± 0.17, p=0.588), ∆Kmax (-0.08 ± 1.32, p=0.792; -1.04 ± 1.89, p=0.135), ∆Astigmatism (-0.15 ± 0.89, p=0.485; -0.24 ± 1.38, p=0.609), ∆PachyMin (-0.56 ± 15.70, p=0.882; 0.56 ± 18.74, p=0.931), ∆Index Surface Variation (∆ISV) (-2.11 ± 10.27, p=0.395; -4.67 ± 17.32, p=0.442), ∆Index Vertical Asymmetry (∆IVA) (-0.05 ± 0.17, p=0.208; -0.08 ± 0.26, p=0.397), ∆Index Height Decentration (∆IHD) (0.00 ± 0.02, p=0.368; -0.01 ± 0.04, p=0.484), ∆KI (0.00 ± 0.05, p=0.851; 0.01 ± 0.06, p=0.877) and ∆D-index (0.15 ± 1.14, p=0.572; 0.06 ± 1.36, p=0.892). Eleven to 33% of patients had disease progression at 24-month postoperative according to the parameters used to determine progression. CONCLUSION Although some patients maintain disease progression, TE-ACXL seems to be a safe and effective treatment for keratoconus over the 2-year follow-up period. Studies with longer follow-up periods and larger patient cohorts are recommended.
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Affiliation(s)
- Ana Maria Cunha
- Department of Ophthalmology, Centro Hospitalar De São João, Porto, Portugal
| | - Tiago Sardinha
- Faculty of Medicine, University of Porto, Porto, Portugal
| | - Luís Torrão
- Department of Ophthalmology, Centro Hospitalar De São João, Porto, Portugal
| | - Raúl Moreira
- Department of Ophthalmology, Centro Hospitalar De São João, Porto, Portugal
| | - Fernando Falcão-Reis
- Department of Ophthalmology, Centro Hospitalar De São João, Porto, Portugal
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
| | - João Pinheiro-Costa
- Department of Ophthalmology, Centro Hospitalar De São João, Porto, Portugal
- Department of Biomedicine, Faculty of Medicine, University of Porto, Porto, Portugal
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Zaheryani SMS, Movahedan H, Salouti R, Mohaghegh S, Javadpour S, Shirvani M, Kasraei F, Bamdad S. Corneal Collagen Cross-Linking Using Epithelium Disruptor Instrument in Progressive Keratoconus. J Curr Ophthalmol 2020; 32:256-262. [PMID: 32775800 PMCID: PMC7382520 DOI: 10.4103/joco.joco_59_20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/24/2020] [Accepted: 03/31/2020] [Indexed: 11/10/2022] Open
Abstract
Purpose: To compare the effects of accelerated corneal collagen cross-linking (CXL) in progressive keratoconus (KCN) patients via epithelium removal and transepithelial techniques, using Daya Disruptor (Duckworth and Kent, Hertfordshire, UK). Methods: This study is a double-blinded, randomized clinical trial. Patients with documented bilateral progressive KCN were randomized into two groups: one eye underwent epithelium removal (Group 1), and the fellow eye underwent epithelium disruption (Group 2). The primary outcomes were best corrected visual acuity (BCVA) and uncorrected visual acuity (UCVA), Scheimpflug-extracted keratometric indices, and anterior segment-optical coherence tomography-derived epithelial thickness profiles. These parameters were evaluated before and 12 months after CXL. Results: Sixty-four eyes from 34 patients with progressive KCN (34 eyes in the epithelium-removal group and 30 eyes in the epithelium-disruption group) were included. The mean ± standard deviation (SD) of age was 23.4 ± 3.8 years in the epithelium-removal group and 23.2 ± 3.5 years in the epithelium-disruption group. The mean ± SD of the preoperative spherical equivalent (SE), front maximum keratometry (K-max), back K-max, thickness of thinnest point, and corneal apex thickness were − 2.9 ± 3.0 diopter (D) and − 3.7 ± 3.1 D (P = 0.183), 53.8 ± 5.15 D and 54.4 ± 5.53 D (P = 0.653), −6.63 ± 2.40 D and − 6.68 ± 2.48 D (P = 0.131), 459.2 ± 37.4 μm and 460.8 ± 32.7 μm (P = 0.708), 470.5 ± 37.7 μm and 469.7 ± 33.1 μm (P = 0.679), and 55.4 ± 4.97 μm and 54.6 ± 7.16 μm (P = 0.767) in the epithelium-removal and epithelium-disruption groups, respectively. The mean ± SD changes of the UCVA and BCVA 12 months after CXL were − 0.1 ± 0.11 and − 0.02 ± 0.18 and − 0.04 ± 0.12 and − 0.02 ± 0.14 in the epithelium-removal and epithelium-disruption groups, respectively. No statistically significant improvement was observed in the UCVA and BCVA between the two groups (P = 0.868 and P = 0.937, respectively). The mean ± SD changes of the SE, superior epithelial thickness, corneal apex thickness, and thickness of thinnest point 12 months after CXL were − 0.21 ± 1.1 D and + 0.32 ± 1.6 D (P = 0.0001), −0.08 ± 0.26 μm and + 0.03 ± 0.33 μm (P = 0.028), −23 ± 11 μm and − 2 ± 6 μm (P = 0.0001), and − 25 ± 8 μm and − 3 ± 7 μm (P = 0.0001) in the epithelium-removal and epithelium-disruption groups, respectively. Conclusions: This study showed that the epithelium-disruption CXL using Daya has a similar potential for halting KCN progression as the epithelium-removal CXL. However, regarding the 12-month changes, the epithelium-disruption CXL is superior to the epithelium-removal CXL in the SE and corneal pachymetry.
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Affiliation(s)
- Seyed Mohammad Salar Zaheryani
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Department of Ophthalmology, Urmia University of Medical Sciences, Bukan, Iran
| | - Hossein Movahedan
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Ramin Salouti
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Sahar Mohaghegh
- Department of Optometry, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sara Javadpour
- Department of Cardiology, Deputy of Health, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Shirvani
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Farzaneh Kasraei
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Shahram Bamdad
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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Bamdad S, Zaheryani SMS, Mohaghegh S, Shirvani M. Fourier Analysis of Keratometric Data in Epithelium Removal versus Epithelial Disruption Corneal Cross-linking. J Ophthalmic Vis Res 2020; 15:16-23. [PMID: 32095204 PMCID: PMC7001009 DOI: 10.18502/jovr.v15i1.5934] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 07/18/2019] [Indexed: 12/20/2022] Open
Abstract
Purpose To compare epithelium-removal and epithelium-disruption corneal crosslinking (CXL) methods in Fourier analysis of keratometric data and clinical outcomes. Methods In this double masked randomized clinical trial, each eye of 34 patients with bilateral keratoconus was randomly allocated to either the epithelium-removal or epithelium-disruption CXL treatment groups. Ocular examination, refraction, uncorrected and best spectacle-corrected visual acuity (UCVA and BSCVA, respectively) measurements, and Pentacam imaging (keratometry, pachymetry, and Fourier analysis) were performed at baseline and at six-month follow-up period. Results Patients' mean age was 23.3 ± 3.6 years. The preoperative thickness of the thinnest point was 459.20 ± 37.40 µm and 455.80 ± 32.70 µm in the epithelium-removal and epithelial-disruption CXL groups, respectively (P > 0.05). The corresponding figures were 433.50 ± 33.50 µm and 451.90 ± 39.70 µm, respectively, six months after the treatment (P = 0.0001). Irregularity component of the fourier analysis was 0.030 ± 0.016 µm in the epithelium-removal group and 0.028 ± 0.011 µm in the epithelium-disruption group preoperatively (P > 0.05). This measurement was 0.031 ± 0.016 µm and 0.024 ± 0.009 µm, respectively at month 6 (P = 0.04). The epithelium-disruption CXL group had better results in terms of the thickness of the thinnest point and the irregularity component as compared to the epithelium-removal group. The two study groups were comparable in spherical equivalent, mean keratometry, UCVA, BSCVA, or other Fourier analysis components (spherical R min, spherical eccentricity, central, peripheral regular astigmatism, and maximum decentration) (P > 0.05). Conclusion This study shows that epithelium-disruption CXL is superior to epithelium-removal CXL regarding the short-term changes in pachymetry and corneal irregularity. Other evaluated parameters were comparable between the two techniques.
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Affiliation(s)
- Shahram Bamdad
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Sahar Mohaghegh
- School of Rehabilitation, Shahid Beheshti University of Medical Science, Tehran, Iran
| | - Mohammad Shirvani
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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Serna-Ojeda JC, Santana-Cruz O, Quiroz-Casian N, González-Mendoza E, Mercado-Orozco JL, Navas A, Lichtinger A, Graue-Hernandez EO. Pain Management in Corneal Collagen Crosslinking for Keratoconus: A Comparative Case Series. J Ocul Pharmacol Ther 2019; 35:325-330. [DOI: 10.1089/jop.2019.0021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Juan Carlos Serna-Ojeda
- Department of Cornea and Refractive Surgery, Instituto de Oftalmologia “Conde de Valenciana,” Mexico City, Mexico
- Patronato Banco de Ojos y Tejidos de Aguascalientes, Aguascalientes, Mexico
| | - Omar Santana-Cruz
- Department of Cornea and Refractive Surgery, Instituto de Oftalmologia “Conde de Valenciana,” Mexico City, Mexico
| | - Natalia Quiroz-Casian
- Department of Cornea and Refractive Surgery, Instituto de Oftalmologia “Conde de Valenciana,” Mexico City, Mexico
| | - Edgar González-Mendoza
- Department of Cornea and Refractive Surgery, Instituto de Oftalmologia “Conde de Valenciana,” Mexico City, Mexico
| | - José Luis Mercado-Orozco
- Department of Cornea and Refractive Surgery, Instituto de Oftalmologia “Conde de Valenciana,” Mexico City, Mexico
| | - Alejandro Navas
- Department of Cornea and Refractive Surgery, Instituto de Oftalmologia “Conde de Valenciana,” Mexico City, Mexico
| | - Alejandro Lichtinger
- Department of Cornea and Refractive Surgery, Instituto de Oftalmologia “Conde de Valenciana,” Mexico City, Mexico
| | - Enrique O. Graue-Hernandez
- Department of Cornea and Refractive Surgery, Instituto de Oftalmologia “Conde de Valenciana,” Mexico City, Mexico
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Abstract
PURPOSE There has been a recent explosion in the variety of techniques used to accomplish corneal cross-linking (CXL) for the treatment of ectatic corneal diseases. To understand the success or failure of various techniques, we review the physicochemical basis of corneal CXL and re-evaluate the current principles and long-standing conventional wisdom in the light of recent, compelling, and sometimes contradictory research. METHODS Two clinicians and a medicinal chemist developed a list of current key topics, controversies, and questions in the field of corneal CXL based on information from current literature, medical conferences, and discussions with international practitioners of CXL. RESULTS Standard corneal CXL with removal of the corneal epithelium is a safe and efficacious procedure for the treatment of corneal ectasias. However, the necessity of epithelium removal is painful for patients, involves risk and requires significant recovery time. Attempts to move to transepithelial corneal CXL have been hindered by the lack of a coherent understanding of the physicochemistry of corneal CXL. Misconceptions about the applicability of the Bunsen-Roscoe law of reciprocity and the Lambert-Beer law in CXL hamper the ability to predict the effect of ultraviolet A energy during CXL. Improved understanding of CXL may also expand the treatment group for corneal ectasia to those with thinner corneas. Finally, it is essential to understand the role of oxygen in successful CXL. CONCLUSIONS Improved understanding of the complex interactions of riboflavin, ultraviolet A energy and oxygen in corneal CXL may provide a successful route to transepithelial corneal CXL.
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Corneal crosslinking without epithelial removal. J Cataract Refract Surg 2018; 44:1363-1370. [PMID: 30228014 DOI: 10.1016/j.jcrs.2018.07.029] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 07/08/2018] [Accepted: 07/17/2018] [Indexed: 11/21/2022]
Abstract
PURPOSE To evaluate the effect of riboflavin-ultraviolet (UV)-A corneal crosslinking (CXL) without epithelial removal on ectatic corneal disease. SETTING Woolfson Eye Institute, Atlanta, Georgia, USA. DESIGN Prospective observational study. METHODS Patients were treated with a new riboflavin formulation without epithelial removal, then exposed to UV light (365 nm) at 4 mW/cm2 with on-off cycling for 30 minutes. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, maximum corneal curvature (maximum keratometry [Kmax]), total higher-order aberrations (HOAs), and coma were measured at 3, 6, 12, and 24 months postoperatively. Progression was defined as an increase of more than 1 diopter (D) in Kmax and loss of more than 1 line of CDVA. RESULTS Five hundred twelve eyes of 308 patients with keratoconus or forme fruste keratoconus and 80 eyes of 55 patients with ectasia after laser in situ keratomileusis (LASIK) were treated with the new riboflavin formulation without epithelial removal; 229 patients received bilateral treatments, 95 of which were simultaneous. The mean UDVA and CDVA improved by 1 to 1.5 Snellen lines at 1 and 2 years postoperatively (P < .0001). Mean Kmax decreased by 0.48 D at 2 years postoperatively (P = .0002). Mean total HOAs and coma decreased by 36% (P < .0001) and 37% (P = .0002), respectively, at 2 years postoperatively. Kmax decreased more than 1 D in three times as many eyes as it increased more than 1 D (P < .0001). No eyes progressed, and there was no loss of effect between 1 and 2 years postoperatively. No vision-threatening events were observed. Pain typically resolved within 24 hours, and visual acuity returned to preoperative levels in 1 to 2 days. CONCLUSION Epithelium-on CXL using this new protocol halted the progression of keratoconus and ectasia after LASIK. It was safer and provided more rapid visual recovery than CXL with epithelial removal, allowing routine bilateral, simultaneous treatment.
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Cantemir A, Alexa AI, Galan BG, Anton N, Ciuntu RE, Danielescu C, Chiselita D, Costin D. Outcomes of iontophoretic corneal collagen crosslinking in keratoconic eyes with very thin corneas. Medicine (Baltimore) 2017; 96:e8758. [PMID: 29381972 PMCID: PMC5708971 DOI: 10.1097/md.0000000000008758] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The purpose of this retrospective study was to report the results of iontophoretic corneal collagen crosslinking (I-CXL) with riboflavin and ultraviolet A irradiation in patients affected by keratoconus, each with thinnest pachymetry values of <400 μ (with epithelium) and not treatable using standard epithelium-off technique.Fifteen eyes of 15 patients affected by progressive keratoconus and with thinnest pachymetry values <400 μ underwent I-CXL. The uncorrected (UDVA) and corrected (CDVA) distance visual acuity, maximum and minimum keratometry (K max and K min) readings, corneal thickness at the thinnest point (CTTP), endothelial cell density (ECD), and intraocular pressure (IOP) were assessed before I-CXL, at 1, 3, 6, and 12 months postoperatively.The mean UDVA and CDVA significantly increased 12 months after I-CXL (P = .002 for both comparisons). The K max readings significantly decreased at 6 and 12 months postoperatively (P = .04 and P = .02, respectively). The mean CTTP improved at the end of the follow-up (P = .008). ECD was unchanged. No side effects or damage to the limbal region was observed during the follow-up period.I-CXL has been proved to be effective in halting keratoconus progression in eyes with very thin corneas, with no side effects during the follow-up period. This procedure could be used in patients with more advanced keratoconus.
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Affiliation(s)
| | | | | | | | | | | | | | - Danut Costin
- Grigore T. Popa University of Medicine and Pharmacy
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Choy BNK, Zhu MM, Shum JWH, Ho WL, Chan JCH, Ng ALK, Lai JSM. Collagen crosslinking in the management of leaking cystic blebs: a prospective study. Graefes Arch Clin Exp Ophthalmol 2015; 254:529-33. [PMID: 26686512 DOI: 10.1007/s00417-015-3245-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/29/2015] [Accepted: 12/09/2015] [Indexed: 10/22/2022] Open
Abstract
PURPOSE To evaluate the effectiveness and safety of collagen crosslinking for leaking cystic blebs. METHODS A prospective study was conducted on subjects with cystic bleb leaks without indications for urgent surgical intervention. Collagen crosslinking with riboflavin 0.1 % and ultraviolet A irradiation for 30 min was applied to the cystic bleb surface in five patients. Subjects were followed up for at least 20 weeks (mean: 35.5 ± 11.5 weeks) to monitor the length of time to the cessation of bleb leak, as well as visual acuity, intraocular pressure, and the presence of adverse effects arising from the treatment. RESULTS Results showed that a single session of collagen crosslinking was effective in stopping cystic bleb leak. In two of the five subjects, the bleb leak subsided 1 week post-treatment, in one patient after 2 weeks, and in the two more complicated cases, after 4 weeks. This effect was maintained for a mean period of 33.5 ± 10.2 weeks after bleb leak cessation. Treatment was effective even in patients with friable conjunctiva following multiple surgical interventions and severe leak, although a longer period was needed for resolution of the bleb leak. The intraocular pressure and visual acuity were largely stable before and after treatment. No side effects or complications arose from this treatment. CONCLUSIONS We recommend a trial of collagen crosslinking on leaking cystic blebs without indications for immediate surgical interventions. It is a relatively easy, non-invasive, pain-free, and potential repeatable procedure for treating leaking cystic blebs, with the aim of strengthening the underlying pathological conjunctiva.
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Affiliation(s)
- Bonnie Nga Kwan Choy
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Room 301, Block B, Cyberport 4, Hong Kong, SAR, China.
| | - Ming Ming Zhu
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Room 301, Block B, Cyberport 4, Hong Kong, SAR, China
| | - Jennifer Wei Huen Shum
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Room 301, Block B, Cyberport 4, Hong Kong, SAR, China
| | - Wing Lau Ho
- Department of Ophthalmology, Queen Mary Hospital, Hong Kong, SAR, China
| | | | - Alex Lap Ki Ng
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Room 301, Block B, Cyberport 4, Hong Kong, SAR, China
| | - Jimmy Shiu Ming Lai
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Room 301, Block B, Cyberport 4, Hong Kong, SAR, China
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