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Craig JP, Barsam A, Chen C, Chukwuemeka O, Ghorbani-Mojarrad N, Kretz F, Michaud L, Moore J, Pelosini L, Turnbull AMJ, Vincent SJ, Wang MTM, Ziaei M, Wolffsohn JS. BCLA CLEAR Presbyopia: Management with corneal techniques. Cont Lens Anterior Eye 2024:102190. [PMID: 38851946 DOI: 10.1016/j.clae.2024.102190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2024]
Abstract
Corneal techniques for enhancing near and intermediate vision to correct presbyopia include surgical and contact lens treatment modalities. Broad approaches used independently or in combination include correcting one eye for distant and the other for near or intermediate vision, (termed monovision or mini-monovision depending on the degree of anisometropia) and/or extending the eye's depth of focus [1]. This report provides an overview of the evidence for the treatment profile, safety, and efficacy of the range of corneal techniques currently available for managing presbyopia. The visual needs and expectations of the patient, their ocular characteristics, and prior history of surgery are critical considerations for patient selection and preoperative evaluation. Contraindications to refractive surgery include unstable refraction, corneal abnormalities, inadequate corneal thickness for the proposed ablation depth, ocular and systemic co-morbidities, uncontrolled mental health issues and unrealistic patient expectations. Laser refractive options for monovision include surface/stromal ablation techniques and keratorefractive lenticule extraction. Alteration of spherical aberration and multifocal ablation profiles are the primary means for increasing ocular depth of focus, using surface and non-surface laser refractive techniques. Corneal inlays use either small aperture optics to increase depth of field or modify the anterior corneal curvature to induce corneal multifocality. Presbyopia correction by conductive keratoplasty involves application of radiofrequency energy to the mid-peripheral corneal stroma which leads to mid-peripheral corneal shrinkage, inducing central corneal steepening. Hyperopic orthokeratology lens fitting can induce spherical aberration and correct some level of presbyopia. Postoperative management, and consideration of potential complications, varies according to technique applied and the time to restore corneal stability, but a minimum of 3 months of follow-up is recommended after corneal refractive procedures. Ongoing follow-up is important in orthokeratology and longer-term follow-up may be required in the event of late complications following corneal inlay surgery.
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Affiliation(s)
- Jennifer P Craig
- Department of Ophthalmology, Aotearoa New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand; College of Health & Life Sciences, Aston University, Birmingham, UK.
| | | | - Connie Chen
- Department of Optometry, Chung Shan Medical University, Taichung City, Taiwan
| | - Obinwanne Chukwuemeka
- Cornea, Contact Lens and Myopia Management Unit, De-Lens Ophthalmics Family and Vision Care Centre, Abuja, Nigeria
| | - Neema Ghorbani-Mojarrad
- School of Optometry and Vision Science, University of Bradford, Bradford, UK; Wolfson Centre for Applied Health Research, Bradford Royal Infirmary, Bradford, UK
| | | | | | | | | | - Andrew M J Turnbull
- Royal Bournemouth Hospital, University Hospitals Dorset, UK; Faculty of Life and Health Sciences, Ulster University, UK
| | - Stephen J Vincent
- Optometry and Vision Science, Centre for Vision and Eye Research, Queensland University of Technology, Brisbane, Australia
| | - Michael T M Wang
- Department of Ophthalmology, Aotearoa New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand
| | - Mohammed Ziaei
- Department of Ophthalmology, Aotearoa New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand
| | - James S Wolffsohn
- Department of Ophthalmology, Aotearoa New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand; College of Health & Life Sciences, Aston University, Birmingham, UK
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Beer SMC, Werner L, Nakano EM, Santos RT, Hirai F, Nitschke EJ, Francesconi Benicio C, Campos MSQ. A 3-year follow-up study of a new corneal inlay: clinical results and outcomes. Br J Ophthalmol 2019; 104:723-728. [PMID: 31446390 DOI: 10.1136/bjophthalmol-2019-314314] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 07/28/2019] [Accepted: 08/07/2019] [Indexed: 11/04/2022]
Abstract
PURPOSE Here, we report the results of a 3-year follow-up analysis of the outcomes of the Flexivue Microlens corneal inlay. PATIENTS Non-dominant eyes (n=31) of emmetropic presbyopic patients (spherical equivalent: -0.5 to 1.00 dioptre). METHODS A Flexivue Microlens corneal inlay was implanted after the creation of a 300 μm deep stromal pocket using a femtosecond laser. Patients were followed up according to a clinical protocol involving refraction, anterior segment imaging analysis (Oculyser), optical quality analysis (OPD-Scan), monocular binocular uncorrected and corrected visual acuity tests, contrast sensitivity measurements (photopic and mesopic), satisfaction questionnaire results and adverse event reporting. RESULTS Thirty patients were examined at the 3-year follow-up in this ongoing study. The mean uncorrected near visual acuity improved to Jaeger 1 in 76.9% of eyes treated with the inlays (vs 87.1% at the 1-year follow-up). All eyes improved four lines in all visits, except for four patients for whom the inlay was explanted. Patients reported that their near vision was good or excellent in 73.3% of cases (vs 90.3% in the first year). The UDVA remained stable over time. Three patients were explanted due to blurred vision for near-point and far-point distances. One patient developed a superficial corneal ulcer after 20 months. Two patients underwent cataract removal. Four patients underwent inlay exchange to increase near power correction. CONCLUSIONS The Presbia Flexivue Microlens provided presbyopia treatment by improving near vision. Manageable complications may occur over the long term. CLINICAL TRIAL REGISTRATION NUMBER U1111-1185-5684 and 0310451200000550.
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Affiliation(s)
| | - Liliana Werner
- Department of Ophthalmology and Visual Sciencies, University of Utah, Salt Lake City, Utah, USA
| | - Eliane Mayumi Nakano
- Department of Refractive Surgery, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
| | - Rodrigo T Santos
- Department of Refractive Surgery, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
| | - Flavio Hirai
- Department of Ophthalmology, Universidade Federal de Sao Paulo Escola Paulista de Medicina, Sao Paulo, Brazil
| | - Enrico J Nitschke
- Department of Ophthalmology, Universidade Federal de Sao Paulo Escola Paulista de Medicina, Sao Paulo, Brazil
| | | | - Mauro S Q Campos
- Department of Refractive Surgery, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
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Abstract
PURPOSE To report the results of a 1-year follow-up analysis of the safety and efficacy of the Flexivue Microlens corneal inlay. METHODS The Flexivue Microlens corneal inlay was implanted in the nondominant eye of patients with emmetropic presbyopia (a spherical equivalent of -0.5 to 1.00 diopter) after the creation of a 300-μm deep stromal pocket, using a femtosecond laser. The patients were followed up according to a clinical protocol involving refraction, anterior segment imaging analysis (Oculyzer), and optical quality analysis (OPD-Scan). RESULTS Thirty-one patients were enrolled in this ongoing study. The mean age was 50.7 years (range 45-60 yrs), and 70% of the patients were female. The mean uncorrected near visual acuity improved to Jaeger 1 in 87.1% of the eyes treated with the inlays. All eyes improved 4 lines at all visits. The binocular uncorrected distance visual acuity was 20/20 in all patients. Ninety percent of the patients reported that their near vision was good or excellent. Some of the patients (16.1%) lost more than 3 lines of corrected distance visual acuity. At the latest follow-up, induction of a corneal spherical aberration to improve near visual acuity was statistically significant. No other intraoperative or postoperative complication was noted. CONCLUSIONS The Flexivue Microlens provided patients with improved near vision, as a result of a negative spherical aberration. A significant loss of corrected distance visual acuity in the operated eyes was observed. Overall, this intracorneal inlay was an effective alternative to other procedures for the correction of presbyopia.
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Mohammadpour M, Heidari Z, Hashemi H. Updates on Managements for Keratoconus. J Curr Ophthalmol 2017; 30:110-124. [PMID: 29988906 PMCID: PMC6034171 DOI: 10.1016/j.joco.2017.11.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 10/07/2017] [Accepted: 11/05/2017] [Indexed: 12/26/2022] Open
Abstract
Purpose Keratoconus is a progressive disease of the cornea which can lead to blindness as irregular astigmatism increases. Currently, a variety of methods are available for the treatment of keratoconus, and in certain cases, it may be difficult to choose the most appropriate option. This article reviews available treatment modalities for keratoconus to provide the practitioner with practical and useful information for selecting the most suitable option for each individual patient. Methods To review treatment methods for different stages of keratoconus, PubMed (United States National Library of Medicine) and Scopus (Elsevier BV) databases were searched using the keywords “keratoconus”, “contact lens”, “cross-linking”, “Intacs”, “keratoplasty”, “gene therapy”, and “irregular astigmatism”, and related articles were reviewed based on disease assessment parameters and treatment methods. Results Various methods are available for the treatment of keratoconus: eyeglasses and contact lenses in the early stages, cross-linking for stabilizing disease progression, intrastromal corneal ring segments (ICRS) for reducing refractive errors or flattening the cornea, and penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK), conductive keratoplasty, gene therapy and more recently, bowman layer transplantation (BL transplantation) in advanced stages of the disease. To achieve optimum results, it is essential to choose the best option for each individual patient. Conclusions A commonality of the reviewed papers was the advancement of novel diagnostic and treatment methods in ophthalmology, which can delay the need for corneal grafting. A better understanding of keratoconus treatment options can help enhance visual rehabilitation and prevent blindness in keratoconus patients.
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Affiliation(s)
- Mehrdad Mohammadpour
- Eye Research Center, Ophthalmology Department, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
- Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran
| | - Zahra Heidari
- Eye Research Center, Ophthalmology Department, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
- Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran
- Corresponding author. No. 96 Esfandiar Blvd., Vali'asr Ave., Tehran, Iran.
| | - Hassan Hashemi
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
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Optimal Keratoplasty for the Correction of Presbyopia and Hypermetropia. J Ophthalmol 2017; 2017:7545687. [PMID: 28484647 PMCID: PMC5412173 DOI: 10.1155/2017/7545687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 01/09/2017] [Accepted: 02/14/2017] [Indexed: 11/24/2022] Open
Abstract
Purpose. To evaluate prospectively the safety and efficacy of optimal keratoplasty for the correction of hyperopia and presbyopia. Methods. Consecutive patients undergoing bilateral optimal keratoplasty for refractive presbyopic and hypermetropic corrections were enrolled. Each patient received a complete ophthalmologic examination at baseline, 1 hour, 1 day, 1 week, 1 month, 3 months, and 6 months after treatment. Results. The study included 40 consecutive eyes of 20 patients. All patients reached the 6-month follow-up. No serious intra- or postoperative complications were recorded. Monocular and binocular uncorrected near visual acuities improved significantly during the follow-up (p < 0.001). Binocular uncorrected distance visual acuity in presbyopic patients improved from 0.28 logMAR to a maximum of 0.04 logMAR (from 20/38 to 20/22 Snellen equivalent) the day after the treatment and remained significantly better than baseline until the end of the follow-up. A significant improvement of patient satisfaction for near (p < 0.001) and distance (p = 0.007) activities was seen the day after treatment and was maintained throughout the follow-up. Conclusions. Optimal keratoplasty is a safe, noninvasive, rapid, pain-free, office-based procedure. It offers low to moderate hyperopes and presbyopes an improvement in uncorrected near visual acuity while maintaining or improving their distance visual acuity.
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Waring GO, Faria-Correia F. Cornea-Based Techniques and Technology for Surgical Correction of Presbyopia. CURRENT OPHTHALMOLOGY REPORTS 2014. [DOI: 10.1007/s40135-013-0035-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Celik U, Alagoz N, Yildirim Y, Agca A, Marshall J, Muller D, Demirok A, Yilmaz OF. New method of microwave thermokeratoplasty to correct myopia in 33 eyes: one-year results. J Cataract Refract Surg 2013; 39:225-33. [PMID: 23332252 DOI: 10.1016/j.jcrs.2012.08.066] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Revised: 08/17/2012] [Accepted: 08/25/2012] [Indexed: 11/19/2022]
Abstract
PURPOSE To assess the safety, predictability, and stability of a new microwave thermokeratoplasty procedure to correct myopia. SETTING Cornea and refractive surgery subspecialty. DESIGN Prospective clinical trial. METHOD Thermokeratoplasty was performed in myopic eyes at a single center in Turkey from June 2009 to June 2010. The attempted corrections ranged from -1.25 to -5.75 diopters (D). The main outcome measures were changes in logMAR uncorrected distance visual acuity (UDVA) and in keratometry (K) values. RESULTS The procedure was performed in 33 eyes (patients aged 20 to 45 years). The mean preoperative logMAR UDVA (0.76 ± 0.24 [SD]) significantly improved to 0.19 ± 0.20 at 1 month, postoperatively. By 3 months, the mean UDVA had markedly regressed to 0.59 ± 0.29; however, the residual improvement remained statistically significant. At 12 months, the mean logMAR UDVA was 0.72 ± 0.26. The mean K values were 43.9 ± 1.36 D preoperatively, 41.25 ± 2.63 D at 1 month, 43.4 ± 1.69 D at 3 months, and 44.1 ± 1.09 D at 12 months. The mean endothelial cell density was 2836 ± 342 cells/mm(2) preoperatively and were statistically unchanged 12 months postoperatively (2732 ± 353 cell/mm(2)). No patient lost lines of corrected distance visual acuity by 12 months postoperatively. CONCLUSIONS The new thermokeratoplasty procedure produced the desired reduction in myopia and improvement in postoperative UDVA 1 month postoperatively without significant side effects. However, early and complete regression shows the need for further development of this technique. FINANCIAL DISCLOSURE Drs. Yilmaz and Marshall are paid consultants to Avedro, Inc., and Dr. Muller is president and CEO of Avedro, Inc. No other author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Ugur Celik
- Beyoglu Eye Training and Research Hospital, Istanbul, Turkey.
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Applicator for RF Thermokeratoplasty: Feasibility Study Using Theoretical Modeling and Ex Vivo Experiments. Ann Biomed Eng 2011; 40:1182-91. [DOI: 10.1007/s10439-011-0492-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 12/14/2011] [Indexed: 10/14/2022]
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Felipe AF, Agahan ALD, Cham TL, Evangelista RP. Photorefractive keratectomy using a 213 nm wavelength solid-state laser in eyes with previous conductive keratoplasty to treat presbyopia: Early results. J Cataract Refract Surg 2011; 37:518-24. [DOI: 10.1016/j.jcrs.2010.09.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 08/30/2010] [Accepted: 09/18/2010] [Indexed: 11/24/2022]
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Tomita M, Watabe M, Ito M, Tsuru T. Conductive keratoplasty for the treatment of presbyopia: comparative study between post- and non-LASIK eyes. Clin Ophthalmol 2011; 5:231-7. [PMID: 21386916 PMCID: PMC3046993 DOI: 10.2147/opth.s16791] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Indexed: 11/23/2022] Open
Abstract
Purpose: To evaluate the efficacy and safety of conductive keratoplasty (CK) for the treatment of presbyopia and analyze the differences in the effects between post- and non-laser in situ keratomileusis (LASIK) eyes. Clinical preoperative factors that could affect the predictability of CK were also analyzed. Methods: The visual and refractive outcomes of CK for the treatment of presbyopia in 14 eyes of 13 post-LASIK patients (post-LASIK group mean age 50.9 ± 3.4 years) and those of 25 eyes of 25 non-LASIK patients (non-LASIK group mean age 52.4 ± 4.0 years) were studied. The clinical efficacy, safety, stability, and predictability of CK were statistically evaluated. Results: The mean (logarithm of the minimum angle of resolution [logMAR] ± standard deviation [SD]) of preoperative uncorrected near visual acuity (UNVA) and manifest refraction spherical equivalent (MRSE) were 0.64 ± 0.25 diopter (D) and 0.35 ± 0.48 D, respectively, in the post-LASIK group, and 0.71 ± 0.20 D and 0.64 ± 0.61 D, respectively, in the non-LASIK group. At 6 months after CK, the mean UNVA and MRSE were 0.07 ± 0.13 D and −1.59 ± 0.86 D, respectively, in the post-LASIK group, and 0.07 ± 0.12 D and −1.06 ± 0.56 D, respectively, in the non-LASIK group. At 1 year after CK, the mean UNVA and MRSE were 0.30 ± 0.17 D and −0.58 ± 0.52 D, respectively, in the post-LASIK group, and 0.28 ± 0.34 D and −1.56 ± 0.62 D, respectively, in the non-LASIK group. There was no significant difference between the two groups in either factor at 6 months postoperative (Student’s t-test, P > 0.05). At 1 year after CK, all the treated eyes maintained corrected distance visual acuity better than −0.08 (logMAR). The mean cylindrical errors were within ±1.00 D in 100% of the post-LASIK and non-LASIK patients. As for the preoperative clinical factors evaluated for their potential relationship to the predictability of CK, none showed significant effect on the clinical outcomes. Conclusion: CK is demonstrated to be safe for the treatment of presbyopia in post-LASIK patients as well as in non-LASIK patients, though needed longer observation in terms of factors affecting predictability.
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Kato N, Toda I, Kawakita T, Sakai C, Tsubota K. Topography-guided conductive keratoplasty: treatment for advanced keratoconus. Am J Ophthalmol 2010; 150:481-489.e1. [PMID: 20692643 DOI: 10.1016/j.ajo.2010.05.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2010] [Revised: 05/12/2010] [Accepted: 05/13/2010] [Indexed: 11/19/2022]
Abstract
PURPOSE To evaluate the use of topography-guided conductive keratoplasty in eyes with keratoconus. DESIGN Interventional case series. METHODS We examined 21 eyes in 21 patients with advanced keratoconus. Topography-guided conductive keratoplasty was performed with intraoperative monitoring of corneal astigmatism using a surgical keratometer. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal topography, manifest refraction, intraocular pressure (IOP), corneal endothelial cell counts, complications, and eventual outcomes were evaluated. RESULTS UCVA (logarithm of the minimal angle of resolution [logMAR]), which was 1.65 ± 0.49 preoperatively, improved to 1.04 ± 0.64 at 1 week (P < .001) and 1.12 ± 0.61 at 1 month after surgery (P < .001). BSCVA, which was 1.02 ± 0.56 preoperatively, improved to 0.76 ± 0.65 at 1 week (P = .026) and 0.76 ± 0.60 at 1 month after surgery (P = .003). Manifest refraction, which was -15.13 ± 6.66 diopters (D) before surgery, declined to -9.97 ± 6.71 D at 1 month after surgery (P = .002). Although corneal topography reverted to the preoperative pattern and UCVA and BSCVA also regressed toward preoperative values, 12 of 21 eyes were better able to tolerate and conduct normal daily activities using contact lenses. Five subjects have undergone or are considering corneal transplantation after unsatisfactory postoperative results. No serious perioperative complication was observed. CONCLUSIONS Topography-guided conductive keratoplasty may be effective in reshaping corneal configuration in eyes with keratoconus, without serious complications, and possibly contributed to avoiding or delaying corneal transplantation.
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Affiliation(s)
- Naoko Kato
- Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan.
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Jo B, Aksan A. Prediction of the extent of thermal damage in the cornea during conductive keratoplasty. J Therm Biol 2010. [DOI: 10.1016/j.jtherbio.2010.02.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Conductive keratoplasty followed by collagen cross-linking with riboflavin-UV-A in patients with keratoconus. Cornea 2010; 29:239-43. [PMID: 20023583 DOI: 10.1097/ico.0b013e3181a818ab] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the combined effect of conductive keratoplasty (CK) followed by corneal collagen cross-linking (CXL) in 2 patients with keratoconus. METHODS CK spots were applied on the flatter side of the cornea followed by CXL using riboflavin and UV-A light. RESULTS Immediately after CK, a significant corneal topographic improvement was observed. The CK effect regressed 3 months postoperatively and remained unchanged until the sixth postoperative month in both patients. CONCLUSION Corneal remodeling with CK in patients with keratoconus seems to have a temporary effect despite the subsequent application of CXL.
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Chang JSM, Lau SYF. Conductive keratoplasty to treat hyperopic overcorrection after LASIK for myopia. J Refract Surg 2010; 27:49-55. [PMID: 20166620 DOI: 10.3928/1081597x-20100212-10] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2009] [Accepted: 01/13/2010] [Indexed: 11/20/2022]
Abstract
PURPOSE to investigate the refractive outcomes and stability of conductive keratoplasty (CK) for retreatment of myopic LASIK overcorrection. METHODS seven eyes (six patients) that were overcorrected after myopic LASIK by +1.00 to +2.75 diopters (D) manifest refraction spherical equivalent (MRSE) were retreated using CK. All eyes had insufficient stromal thickness for LASIK retreatment. LightTouch CK was performed at least 1 year after LASIK. Either 8 or 16 spots were applied at 7- and/or 8-mm zones on the cornea. Uncorrected distance visual acuity, manifest refraction, corrected distance visual acuity (CDVA), and postoperative complications were analyzed. RESULTS mean MRSE after CK at last follow-up was +0.38 ± 0.52 D (range: -0.38 to +1.13 D). The change in MRSE ranged from -0.63 to -2.38 D. Mean MRSE after CK changed from -0.60 ± 2.07 D (range: -3.38 to +1.50 D) at 1 week to +0.45 ± 0.69 D (range: -0.38 to +1.38 D) at 12 months. Two eyes experienced an initial overcorrection of -2.75 D and -3.38 D, respectively, at 1 week after CK. Cylinder ≤0.75 D was induced in four eyes, whereas one eye had a 0.75-D reduction in cylinder. All eyes had CDVA of logMAR 0.10 or better. Two eyes lost one line of CDVA and no eyes lost more than one line. CONCLUSIONS lighttouch CK retreatment for over-corrected myopic LASIK can reduce the hyperopia but produces minimal change in cylinder, and may be appropriate for eyes with insufficient stromal tissue for repeated excimer laser surgery. Early regression occurs commonly.
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Affiliation(s)
- John S M Chang
- Guy Hugh Chan Refractive Surgery Centre, Department of Ophthalmology, Hong Kong Sonatorium and Hospital, Happy Valley, Hong Kong.
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Conductive Keratoplasty for the Treatment of Astigmatism Induced by CornealTrauma or Incision. J Refract Surg 2010; 26:33-42. [DOI: 10.3928/1081597x-20101215-05] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Accepted: 12/16/2008] [Indexed: 11/20/2022]
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Zhang L, Aksan A. Fourier transform infrared analysis of the thermal modification of human cornea tissue during conductive keratoplasty. APPLIED SPECTROSCOPY 2010; 64:23-29. [PMID: 20132594 DOI: 10.1366/000370210790571918] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This paper presents a study using in vitro Fourier transform infrared spectroscopy (FT-IR) analysis to determine the thermal damage induced to the human cornea by the conductive keratoplasty (CK) procedure. Human cornea tissues were treated with CK at different radiofrequency power (58-64%) and pulse duration (0.6-1.0 s) settings. The cornea tissues were cryo-sectioned and FT-IR analysis was performed to detect the extent of thermal damage by the second-derivative analysis of the infrared (IR) spectral bands corresponding to protein secondary structure. The protein amide I and II spectral bands measured in vitro mainly arose from collagen. The denatured cornea tissue showed a higher beta-sheet content than the native tissue. The extent of the thermal damage created by the CK treatment depended on power and duration settings, with the latter having a stronger effect. With clinical settings (60%, 0.6 s), the thermal damage area was confined within a radius of 100 microm. CK treatment duration had a more significant effect on the damage zone than the power setting.
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Affiliation(s)
- Li Zhang
- Mechanical Engineering Department, University of Minnesota, Minneapolis 55455, USA
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Ruiz LA, Cepeda LM, Fuentes VC. Intrastromal correction of presbyopia using a femtosecond laser system. J Refract Surg 2009; 25:847-54. [PMID: 19835324 DOI: 10.3928/1081597x-20090917-05] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Accepted: 08/26/2009] [Indexed: 11/20/2022]
Abstract
PURPOSE To introduce a new, minimally invasive intrastromal correction for presbyopia (INTRACOR procedure) using the TECHNOLAS femtosecond laser system (Technolas Perfect Vision GmbH). METHODS The INTRACOR procedure was performed in 83 eyes of 45 patients aged 44 to 67 years. Follow-up was 6 to 12 months. Data recorded included age; pre- and postoperative refraction; uncorrected distance (UDVA), intermediate, and near visual acuity (UNVA); corrected distance visual acuity (CDVA); distance corrected near visual acuity; corneal hysteresis (CH), corneal resistance factor (CRF), and asphericity; pachymetry; endothelial cell density; contrast sensitivity; and ocular aberrations. RESULTS At 6 months postoperatively, all 83 (100%) eyes had improved UNVA, with minimal or no change in UDVA. Twenty-two eyes were available at 12 months; UNVA improved to J1 in these eyes with continued improvement in mean UDVA. At last follow-up, a mild myopic shift in refraction was noted with only 3 (3.6%) eyes showing a 2- or 3-line decrease of UDVA, and 74 (89.2%) eyes achieved both J2 and 20/25 or better. Mean CDVA and distance corrected near visual acuity continued to improve with time. Two (2.4%) eyes lost 2 lines of CDVA at 6 months, but this did not occur in the 22 eyes seen at 1 year. Overall stability was noted in CH, CRF, pachymetry, endothelial cell density, and contrast sensitivity. Primary spherical aberrations shifted toward negative values and secondary spherical aberration shifted toward positive values. No corneal structural complications were observed. CONCLUSIONS The INTRACOR intrastromal procedure using the TECHNOLAS femtosecond laser is a promising procedure for presbyopia correction. It preserves the corneal epithelium and anterior stromal fibers.
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Ehrlich JS, Manche EE. Regression of effect over long-term follow-up of conductive keratoplasty to correct mild to moderate hyperopia. J Cataract Refract Surg 2009; 35:1591-6. [PMID: 19683158 DOI: 10.1016/j.jcrs.2009.05.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2008] [Revised: 05/18/2009] [Accepted: 05/27/2009] [Indexed: 10/20/2022]
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Abstract
PURPOSE OF REVIEW Conductive keratoplasty is a noninvasive, in-office procedure for the correction of hyperopia, hyperopic astigmatism, and management of presbyopia. It serves as an alternative to laser-based refractive surgery with essentially no intraoperative or postoperative complications. RECENT FINDINGS In the past decade, photorefractive keratectomy and laser in-situ keratomileusis have been the most popular refractive surgical procedures to correct myopia, hyperopia and astigmatism. Although relatively safe, flap-related complications often result in undesirable visual acuity. Since US Food and Drugs Administration approval in 2002, conductive keratoplasty has become a promising technique to correct low to moderate hyperopia and astigmatism. The procedure was first used by Mendez and colleagues in 1993. It is a nonlaser, no cutting procedure that delivers radio-frequency energy to corneal stroma in a circular fashion to steepen the cornea. Multiple studies have shown that conductive keratoplasty offers equal or superior efficacy, predictability, stability and safety than currently used refractive procedures to correct hyperopia or hyperopic astigmatism. In addition, monovision conductive keratoplasty has been shown to be successful for the management of presbyopia. SUMMARY Conductive keratoplasty, an alternative to the laser-based procedure, is effective, predictable, and safe to correct low to moderate hyperopia, astigmatism, and manage presbyopia.
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Affiliation(s)
- Ted T Du
- Department of Ophthalmology, Mount Sinai School of Medicine, New York, NY 10029, USA.
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Asbell P. Is conductive keratoplasty the treatment of choice for presbyopia? EXPERT REVIEW OF OPHTHALMOLOGY 2007. [DOI: 10.1586/17469899.2.1.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Naoumidi TL, Kounis GA, Astyrakakis NI, Tsatsaronis DN, Pallikaris IG. Two-year follow-up of conductive keratoplasty for the treatment of hyperopic astigmatism. J Cataract Refract Surg 2006; 32:732-41. [PMID: 16765788 DOI: 10.1016/j.jcrs.2006.01.062] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Accepted: 10/13/2005] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the safety, efficacy, predictability, and stability of conductive keratoplasty (CK) for the treatment of hyperopic astigmatism. SETTING University of Crete Medical School, Vardinoyannion Eye Institute of Crete, Heraklion, Greece. METHODS In this prospective nonrandomized noncontrolled single-center study, 47 eyes of 34 patients (15 women and 19 men) were treated for hyperopic astigmatism (up to + 3.50 diopters [D]) with a Refractec ViewPoint CK system and followed for 24 months +/- 0.6 (SD). The treatment consisted of 4 to 36 spots applied to the periphery of the cornea. Mean age was 48.5 years +/- 9.7 years, range 25 to 68 years. All the treated eyes were analyzed for safety, efficacy, predictability, and stability. RESULTS The mean patient age was 48.5 +/- 9.7 years (range 25 to 68 years). Preoperatively, the mean manifest refraction spherical equivalent (MRSE) was +2.11 +/- 0.88 D (range -0.50 to + 4.13 D); at 12 months, it was -0.52 +/- 0.73 D and at 24 months, -0.50 +/- 0.77 D. At 24 months, the mean MRSE was within +/-0.50 D in 61% of eyes, within +/-1.00 D in 83%, and within +/-2.00 D in all eyes. At 24 months, the uncorrected visual acuity was 20/20 or better in 37% of eyes and 20/40 or better in 97%. By the end of the follow-up period, no eye had lost > or =2 Snellen lines or had an induced cylinder > or =1.50 D. CONCLUSIONS Conductive keratoplasty for low hyperopic astigmatism was a safe, effective, and stable procedure. Nomogram adjustments and careful patient selection should contribute to higher levels of predictability when treating hyperopic astigmatism.
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Affiliation(s)
- Tatiana L Naoumidi
- University of Crete Medical School, Vardinoyannion Eye Institute of Crete, Heraklion, Greece.
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