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Du K, Liu E, Li N, Yuan B, Peng R, Hong J. Comparison of Femtosecond Laser Assistance and Manual Trephination in Deep Anterior Lamellar Keratoplasty in the Treatment of Keratoconus: A Meta-Analysis. Am J Ophthalmol 2023; 256:126-137. [PMID: 37553035 DOI: 10.1016/j.ajo.2023.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 07/31/2023] [Accepted: 08/02/2023] [Indexed: 08/10/2023]
Abstract
PURPOSE To compare the efficacy and safety of femtosecond laser-assisted deep anterior lamellar keratoplasty (F-DALK) with those of manual-trephination DALK (M-DALK) in treating keratoconus. DESIGN Systematic review and meta-analysis. METHODS Through November 2022, we comprehensively searched PubMed, EMBASE, the Cochrane Library, and 4 Chinese databases. Studies that involved comparisons between F-DALK and M-DALK groups and that reported on relevant efficacy and/or safety parameters were included. Primary outcomes were uncorrected- and corrected-distance visual acuity and intraoperative complication rates. Secondary outcomes were spherical equivalent, topographic astigmatism, refractive cylinder, mean keratometry, endothelial cell density, suture removal time, and postoperative complication rates. These data were analyzed using Cochrane Review Manager software version 5.3. RESULTS This meta-analysis included 9 nonrandomized controlled studies involving 1713 eyes. In eyes treated with F-DALK, corrected-distance visual acuity at 1 to 6 months (weighted mean difference = -0.07 [95% confidence interval {CI} -0.10 to -0.03]; I2 = 0%; P < .001) after surgery was better and intraoperative Descemet membrane perforation occurred less often (odds ratio = 0.53 [95% CI 0.31-0.92]; I2 = 6%; P = .02) than in eyes treated with M-DALK. No clinically significant differences in other outcomes were found among the groups. CONCLUSIONS Both F-DALK and M-DALK are safe and efficacious for patients with keratoconus. Compared with M-DALK, F-DALK can provide better early visual acuity and reduce the intraoperative perforation rate, and its likely improvements to long-term visual quality and endothelial cell preservation warrant further investigation. In addition, the 2 techniques seem to be comparable regarding refractive outcomes and other complications.
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Affiliation(s)
- Kaiyue Du
- Department of Ophthalmology (K.D., E.L., B.Y., R.P., J.H.), Peking University Third Hospital, Beijing, China; Key Laboratory of Vision Loss and Restoration (K.D., E.L., B.Y., R.P., J.H.), Ministry of Education, Beijing, China
| | - Enshuo Liu
- Department of Ophthalmology (K.D., E.L., B.Y., R.P., J.H.), Peking University Third Hospital, Beijing, China; Key Laboratory of Vision Loss and Restoration (K.D., E.L., B.Y., R.P., J.H.), Ministry of Education, Beijing, China
| | - Nan Li
- Peking University Third Hospital (N.L.), Beijing, China
| | - Bowei Yuan
- Department of Ophthalmology (K.D., E.L., B.Y., R.P., J.H.), Peking University Third Hospital, Beijing, China; Key Laboratory of Vision Loss and Restoration (K.D., E.L., B.Y., R.P., J.H.), Ministry of Education, Beijing, China
| | - Rongmei Peng
- Department of Ophthalmology (K.D., E.L., B.Y., R.P., J.H.), Peking University Third Hospital, Beijing, China; Key Laboratory of Vision Loss and Restoration (K.D., E.L., B.Y., R.P., J.H.), Ministry of Education, Beijing, China
| | - Jing Hong
- Department of Ophthalmology (K.D., E.L., B.Y., R.P., J.H.), Peking University Third Hospital, Beijing, China; Key Laboratory of Vision Loss and Restoration (K.D., E.L., B.Y., R.P., J.H.), Ministry of Education, Beijing, China.
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2
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Lee YW, Cho KS, Hyon JY, Han SB. Application of Femtosecond Laser in Challenging Cataract Cases. Asia Pac J Ophthalmol (Phila) 2023; 12:477-485. [PMID: 37844256 DOI: 10.1097/apo.0000000000000627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 06/01/2023] [Indexed: 10/18/2023] Open
Abstract
Femtosecond laser can provide precise and customized incision of ocular tissue with excellent accuracy and predictability. Thus, femtosecond laser-assisted cataract surgery (FLACS) can theoretically enhance the safety and efficacy of cataract surgery by providing reproducible and reliable clear corneal incision, limbal relaxing incision, anterior capsulotomy, and lens fragmentation. However, thus far, the superiority of the anatomical and visual outcomes of FLACS over those of conventional cataract surgery have been unclear. Nevertheless, studies have indicated that FLACS can potentially be helpful in improving the safety of cataract surgery in challenging situations, such as zonular weakness, preexisting capsular tear, white cataract, shallow anterior chamber, and pediatric cataracts, which may contribute to enhanced visual and anatomical outcomes. In this review, we provide a summary of the application of femtosecond laser in general cataract cases. In addition, we introduce the application of FLACS in the abovementioned challenging situations and discuss the results of studies regarding the safety and outcome of FLACS in these challenging cases.
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Affiliation(s)
- Yong Woo Lee
- Department of Ophthalmology, Kangwon National University School of Medicine, Kangwon National University Hospital, Chuncheon, Gangwon Province, Korea
| | - Kyu Seong Cho
- Department of Ophthalmology, Kangwon National University School of Medicine, Kangwon National University Hospital, Chuncheon, Gangwon Province, Korea
| | - Joon Young Hyon
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi Province, Korea
| | - Sang Beom Han
- Department of Ophthalmology, Kangwon National University School of Medicine, Kangwon National University Hospital, Chuncheon, Gangwon Province, Korea
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3
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Yusef YN, Ermakova SV, Sheludchenko VM, Alkharki L. [Complications of femto-LASIK and features of cavitation injuries]. Vestn Oftalmol 2023; 139:119-125. [PMID: 37379118 DOI: 10.17116/oftalma2023139031119] [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: 06/30/2023]
Abstract
Modern approach to refractive laser surgery features three main types of lamellar surgery. Two of them are types of open laser keratomileusis (LASIK and femtosecond laser-assisted LASIK), and the third - closed (SMILE). All of these techniques allow achieving good clinical outcomes but differ in possible complications. This article reviews the complications of femto-LASIK and specifically the post-operative cavitation injuries, describes the mechanism of their occurrence, variants of their course, and presents the prevention measures.
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Affiliation(s)
- Yu N Yusef
- Krasnov Research Institute of Eye Diseases, Moscow, Russia
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - S V Ermakova
- Krasnov Research Institute of Eye Diseases, Moscow, Russia
| | | | - L Alkharki
- Krasnov Research Institute of Eye Diseases, Moscow, Russia
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4
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Boiko EV, Togo ES, Suetov AA, Kachanov AB, Litvin IB. [Direct assessment of changes in biomechanical properties of the cornea after ReLEx SMILE and FemtoLASIK surgeries]. Vestn Oftalmol 2023; 139:41-48. [PMID: 37379108 DOI: 10.17116/oftalma202313903141] [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: 06/30/2023]
Abstract
The aim of this study was to evaluate corneal biomechanical properties in myopic patients after ReLEx SMILE and FemtoLASIK surgeries using the Corvis ST analyzer. MATERIAL AND METHODS The SMILE group comprised 23 patients (46 eyes) with spherical refraction -3.8±1.8 diopters (D), the FemtoLASIK group included 18 patients (36 eyes) with spherical refraction -3.5±1.3 D. Analysis of the biomechanical properties of the cornea was carried out using the CORVIS ST device (Oculus, Germany) before and seven days after corneal refractive surgery. RESULTS In the SMILE group, with intraoperative decrease in corneal thickness of 91.43±19.43 µm, a significant increase in the following parameters was observed: deformation coefficient (DA ratio; p=0.0001), peak distance (PD; p=0.02) and inverse concave radius (ICR; p=0.003); a decrease in the stiffness parameter at first applanation (SP-A1; p=0.0001), Corvis biomechanical index (CBI; p=0.0001), intraocular pressure (IOP; p=0.001). In the FemtoLASIK group, with intraoperative decrease in corneal thickness of 75.33±32.3 µm, we observed a significant increase in DA ratio (p=0.0002), PD (p=0.04), ICR (p=0.0002), a decrease in SP-A1 (p<0.0001), IOP values (p=0.0003). In comparison with the FemtoLASIK group, the deformation amplitude DA changed significantly less in the SMILE group (p=0.04). In the FemtoLASIK group, in comparison with the SMILE group, the DA ratio (p=0.0009) and SP-A1 (p=0.0003) significantly increased. Intraoperative corneal thickness change correlates with ICR both in SMILE (R=0.52) and in FemtoLASIK (R=0.65). CONCLUSION Corneal biomechanical properties determined with CORVIS ST in eyes with mild to moderate myopia change to a lesser extent after ReLEx SMILE compared to FemtoLASIK.
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Affiliation(s)
- E V Boiko
- Saint Petersburg branch of S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery", St. Petersburg, Russia
- North-Western State Medical University named after I.I. Mechnikov, St. Petersburg, Russia
| | - E S Togo
- Saint Petersburg branch of S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery", St. Petersburg, Russia
- North-Western State Medical University named after I.I. Mechnikov, St. Petersburg, Russia
| | - A A Suetov
- Saint Petersburg branch of S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery", St. Petersburg, Russia
| | - A B Kachanov
- Saint Petersburg branch of S.N. Fedorov National Medical Research Center "MNTK "Eye Microsurgery", St. Petersburg, Russia
- North-Western State Medical University named after I.I. Mechnikov, St. Petersburg, Russia
| | - I B Litvin
- North-Western State Medical University named after I.I. Mechnikov, St. Petersburg, Russia
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5
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Intraoperative complications of cataract surgery using a low-energy femtosecond laser: Results from a real-world high-volume setting. PLoS One 2022; 17:e0279023. [PMID: 36520860 PMCID: PMC9754167 DOI: 10.1371/journal.pone.0279023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022] Open
Abstract
In this study, we report data on intraoperative complications occurring after cataract surgery in a high-volume single-center setting using a low-energy, mobile femtosecond laser. We retrospectively reviewed the medical records of patients who underwent femtosecond laser-assisted cataract surgery (FLACS) in our hospital between August 2015 and December 2019. Among the sample of 1,806 eyes of 1,131 patients (903 left and 903 right eyes), the mean age was 75.8 years (range, 21-99 years). The overall intraoperative complication rate was 0.28% (n = 5), with three cases of anterior capsule tear (0.17%) and two cases of posterior capsule tear (0.11%). No further complications occurred. This study underlines the safety of low-energy femtosecond-assisted cataract surgery in a real-world setting with a very low rate of intraoperative complications.
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6
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Pellegrini M, Yu AC, Busin M. Deep anterior lamellar keratoplasty for keratoconus: Elements for success. Saudi J Ophthalmol 2022; 36:36-41. [PMID: 35971490 PMCID: PMC9375458 DOI: 10.4103/sjopt.sjopt_100_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 12/20/2021] [Indexed: 11/05/2022] Open
Abstract
Advanced keratoconus may require keratoplasty when the patient can no longer achieve functional vision with glasses and contact lenses. Deep anterior lamellar keratoplasty (DALK) has become the surgical treatment of choice due to its undisputed advantages over penetrating keratoplasty including the reduced risk of intraoperative complications, the absence of endothelial immune rejection, and the longer graft survival. Albeit "big-bubble" DALK still represents the most popular surgical method, several modifications have been developed over the years. This allowed standardization of the technique, with improved success rates and clinical outcomes. This review presents an overview on the literature on DALK surgery for keratoconus. We discuss state-of-the art surgical techniques, current evidence on the clinical outcomes and complications as well as possible future directions.
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Affiliation(s)
- Marco Pellegrini
- Department of Translational Medicine, University of Ferrara, Forlì, Italy,Department of Ophthalmology, Ospedali Privati Forlì “Villa Igea”, Forlì, Italy,Istituto Internazionale per la Ricerca e Formazione in Oftalmologia (IRFO), Forlì, Italy
| | - Angeli Christy Yu
- Department of Translational Medicine, University of Ferrara, Forlì, Italy,Department of Ophthalmology, Ospedali Privati Forlì “Villa Igea”, Forlì, Italy,Istituto Internazionale per la Ricerca e Formazione in Oftalmologia (IRFO), Forlì, Italy
| | - Massimo Busin
- Department of Translational Medicine, University of Ferrara, Forlì, Italy,Department of Ophthalmology, Ospedali Privati Forlì “Villa Igea”, Forlì, Italy,Istituto Internazionale per la Ricerca e Formazione in Oftalmologia (IRFO), Forlì, Italy,Address for correspondence: Prof. Massimo Busin, Ospedali Privati Forlì ‘Villa Igea’, Forlì 47122, Italy. E-mail:
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7
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Kloft LJ, Hill JE, Leang RS, Gwon AE, Huang LC. Preclinical Safety and Efficacy Assessments for Novel Femtosecond Lasers in Corneal Refractive Surgery. Ophthalmol Ther 2022; 11:521-532. [PMID: 35122607 PMCID: PMC8927562 DOI: 10.1007/s40123-022-00465-3] [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: 12/10/2021] [Accepted: 01/11/2022] [Indexed: 11/24/2022] Open
Abstract
Preclinical safety requirements and test methods have been standardized over time to guide medical device developers in the path needed to manufacture safe devices and achieve regulatory approval. Today, femtosecond lasers are commonly used in cataract and refractive surgeries. Currently, an industry standard to guide developers in preclinical testing of ophthalmic lasers does not exist. Consequently, the data presented in regulatory submissions may vary between manufacturers, making the regulatory review process more ambiguous. Here, the authors present a comprehensive discussion of preclinical test methods applied to the evaluation of an ophthalmic laser. We include in vitro and ex vivo models, as well as an in vivo rabbit model subject to corneal refractive treatments, for consideration in a preclinical safety evaluation plan. Scientific rationale to support the ocular endpoints of evaluation in the rabbit model to demonstrate safety is also presented and discussed.
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Affiliation(s)
- Lisa J Kloft
- Research & Development, Johnson & Johnson Surgical Vision, Inc., 1700 East Saint Andrew Place, Santa Ana, CA, 92705, USA
| | - James E Hill
- Research & Development, Johnson & Johnson Surgical Vision, Inc., 1700 East Saint Andrew Place, Santa Ana, CA, 92705, USA
| | - Ronika S Leang
- Research & Development, Johnson & Johnson Surgical Vision, Inc., 1700 East Saint Andrew Place, Santa Ana, CA, 92705, USA
| | - Arlene E Gwon
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, USA
| | - Ling C Huang
- Research & Development, Johnson & Johnson Surgical Vision, Inc., 1700 East Saint Andrew Place, Santa Ana, CA, 92705, USA.
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8
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Abdelhalim I, Hamdy O, Hassan AA, Elnaby SH. Nd:YAG fourth harmonic (266-nm) generation for corneal reshaping procedure: An ex-vivo experimental study. PLoS One 2021; 16:e0260494. [PMID: 34843558 PMCID: PMC8629266 DOI: 10.1371/journal.pone.0260494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 11/10/2021] [Indexed: 11/18/2022] Open
Abstract
Corneal reshaping is a common medical procedure utilized for the correction of different vision disorders relying on the ablation effect of the UV pulsed lasers, especially excimer lasers (ArF) at 193 nm. This wavelength is preferred in such medical procedures since laser radiation at 193 nm exhibits an optimum absorption by corneal tissue. However, it is also significantly absorbed by the water content of the cornea resulting in an unpredictability in the clinical results, as well as the high service and operation cost of the commercial ArF excimer laser device. Consequently, other types of solid-state UV pulsed lasers have been introduced. The present work investigates the ablation effect of solid-state laser at 266 nm in order to be utilized in corneal reshaping procedures. Different number of pulses has been applied to Polymethyl Methacrylate (PMMA) and ex-vivo rabbit cornea to evaluate the ablation effect of the produced laser radiation. PMMA target experienced ellipse-like ablated areas with a conical shape in the depth. The results revealed an almost constant ablation area regardless the number of laser pulses, which indicates the stability of the produced laser beam, whereas the ablation depth increases only with increasing the number of laser pulses. Examination of the ex-vivo cornea showed a significant tissue undulation, minimal thermal damage, and relatively smooth ablation surfaces. Accordingly, the obtained 266-nm laser specifications provide promising alternative to the traditional 193-nm excimer laser in corneal reshaping procedure.
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Affiliation(s)
- Ibrahim Abdelhalim
- Engineering Applications of Lasers Dept., National Institute of Laser Enhanced Sciences, Cairo University, Giza, Egypt
| | - Omnia Hamdy
- Engineering Applications of Lasers Dept., National Institute of Laser Enhanced Sciences, Cairo University, Giza, Egypt
| | - Aziza Ahmed Hassan
- Medical Applications of Lasers Dept., National Institute of Laser Enhanced Sciences, Cairo University, Giza, Egypt
| | - Salah Hassab Elnaby
- Engineering Applications of Lasers Dept., National Institute of Laser Enhanced Sciences, Cairo University, Giza, Egypt
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9
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Yang LWY, Mehta JS, Liu YC. Corneal neuromediator profiles following laser refractive surgery. Neural Regen Res 2021; 16:2177-2183. [PMID: 33818490 PMCID: PMC8354117 DOI: 10.4103/1673-5374.308666] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/02/2020] [Accepted: 01/22/2021] [Indexed: 01/07/2023] Open
Abstract
Laser refractive surgery is one of the most commonly performed procedures worldwide. In laser refractive surgery, Femtosecond Laser in Situ Keratomileusis and Refractive Lenticule Extraction have emerged as promising alternatives to microkeratome Laser in Situ Keratomileusis and Photorefractive Keratectomy. Following laser refractive surgery, the corneal nerves, epithelial and stromal cells release neuromediators, including neurotrophins, neuropeptides and neurotransmitters. Notably, nerve growth factor, substance P, calcitonin gene-related peptide and various cytokines are important mediators of neurogenic inflammation and corneal nerve regeneration. Alterations in neuromediator profiles and ocular surface parameters following laser refractive surgery are attributed to the surgical techniques and the severity of tissue insult induced. In this review, we will discuss the (1) Functions of neuromediators and their physiological and clinical significance; (2) Changes in the neuromediators following various laser refractive surgeries; (3) Correlation between neuromediators, ocular surface health and corneal nerve status; and (4) Future directions, including the use of neuromediators as potential biomarkers for ocular surface health following laser refractive surgery, and as adjuncts to aid in corneal regeneration after laser refractive surgery.
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Affiliation(s)
- Lily Wei Yun Yang
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore
| | - Jodhbir S. Mehta
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore
- Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - Yu-Chi Liu
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore
- Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore
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10
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Yusef YN, Yusef SN, Vvedenskiy AS, Ivanov MN, Alhumidi K, Dudieva FK. [Femtosecond laser-assisted phacoemulsification of hypermature cataract in patients with lens subluxation]. Vestn Oftalmol 2021; 137:209-216. [PMID: 34669329 DOI: 10.17116/oftalma2021137052209] [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: 11/17/2022]
Abstract
Studying the modern capabilities of femtosecond laser in the treatment of complicated cataracts is a topical problem in cataract surgery. PURPOSE To develop a technique for femtosecond laser-assisted phacoemulsification of hypermature cataract in patients with degree I-II lens subluxation. MATERIAL AND METHODS Phacoemulsification of hypermature cataract with comorbid lens subluxation was performed in 78 patients (78 eyes) divided into two groups. In the 1st group (45 eyes), capsulorhexis was performed using a femtosecond laser. Patients of the 2nd group (33 eyes) underwent manual capsulorhexis. The study assessed the possible frequency of using modern methods of capsular bag fixation and complete all-in-the-bag intraocular lens (IOL) implantation, as well as the number of various types of intraoperative capsular bag ruptures. RESULTS In all patients of the 1st group, capsulorhexis of the correct round shape and the required diameter was achieved, allowing the use of modern methods of fixation and centering of the capsular bag. Insignificant tear of the edge of the capsulorhexis after IOL implantation was detected only in 1 (2.2%) patient. Vitreous prolapse was noted in 1 (2.2%) case. In the 2nd group, manual technique resulted in oval capsulorhexis with a smooth edge, allowing the use of modern methods of fixation of the capsular bag only in 7 (21.2%) cases. Vitreous prolapse was noted in 4 (12.1%) cases. The complete in-the-bag IOL implantation was possible in 44 (97.8%) cases in the 1st group and only in 7 (21.2%) in the 2nd group. CONCLUSION The use of femtosecond laser in patients with hypermature cataract and lens subluxation allows achieving capsulorhexis of ideally round shape with a smooth edge. This creates the necessary conditions for the use of modern methods of fixation of the capsular bag and provides the possibility of complete all-in-the-bag IOL implantation.
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Affiliation(s)
- Yu N Yusef
- Research Institute of Eye Disease, Moscow, Russia
| | - S N Yusef
- Research Institute of Eye Disease, Moscow, Russia
| | | | - M N Ivanov
- Research Institute of Eye Disease, Moscow, Russia
| | - K Alhumidi
- Research Institute of Eye Disease, Moscow, Russia
| | - F K Dudieva
- Research Institute of Eye Disease, Moscow, Russia
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11
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Riau AK, Boey KPY, Binte M Yusoff NZ, Goh TW, Yam GHF, Tang KF, Phua CSH, Chen HJ, Chiew YF, Liu YC, Mehta JS. Experiment-Based Validation of Corneal Lenticule Banking in a Health Authority-Licensed Facility. Tissue Eng Part A 2021; 28:69-83. [PMID: 34128385 DOI: 10.1089/ten.tea.2021.0042] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
With the expected rise in patients undergoing refractive lenticule extraction worldwide, the number of discarded corneal stromal lenticules will increase. Therefore, establishing a lenticule bank to collect, catalog, process, cryopreserve, and distribute the lenticules (for future therapeutic needs) could be advantageous. In this study, we validated the safety of lenticule banking that involved the collection of human lenticules from our eye clinic, transportation of the lenticules to a Singapore Ministry of Health-licensed lenticule bank, processing, and cryopreservation of the lenticules, which, after 3 months or, a longer term, 12 months, were retrieved and transported to our laboratory for implantation in rabbit corneas. The lenticule collection was approved by the SingHealth Centralised Institutional Review Board (CIRB). Both short-term and long-term cryopreserved lenticules, although not as transparent as fresh lenticules due to an altered collagen fibrillar packing, did not show any sign of rejection and cytotoxicity, and did not induce haze or neovascularization for 16 weeks even when antibiotic and steroidal administration were withdrawn after 8 weeks. The lenticular transparency progressively improved and was mostly clear after 4 weeks, the same period when we observed the stabilization of corneal hydration. We showed that the equalization of the collagen fibrillar packing of the lenticules with that of the host corneal stroma contributed to the lenticular haze clearance. Most importantly, no active wound healing and inflammatory reactions were seen after 16 weeks. Our study suggests that long-term lenticule banking is a feasible approach for the storage of stromal lenticules after refractive surgery.
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Affiliation(s)
- Andri K Riau
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore, Singapore
| | - Kenny P Y Boey
- Group Laboratory Operations, Cordlife Group Limited, Singapore, Singapore
| | | | - Tze-Wei Goh
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Gary H F Yam
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Kin F Tang
- Group Laboratory Operations, Cordlife Group Limited, Singapore, Singapore.,Singapore Laboratory, Cordlife Group Limited, Singapore, Singapore
| | | | - Hui-Jun Chen
- Singapore Laboratory, Cordlife Group Limited, Singapore, Singapore
| | - Yoke F Chiew
- Singapore Laboratory, Cordlife Group Limited, Singapore, Singapore
| | - Yu-Chi Liu
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore, Singapore.,Corneal and External Eye Disease Department, Singapore National Eye Centre, Singapore, Singapore
| | - Jodhbir S Mehta
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore, Singapore.,Corneal and External Eye Disease Department, Singapore National Eye Centre, Singapore, Singapore
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12
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Abdelhalim I, Hamdy O, Hassan AA, Elnaby SH. Assessing the local temperature of human cornea exposed to surface ablation by different laser refractive-surgery devices: a numerical comparative study. Lasers Med Sci 2021; 36:1725-1731. [PMID: 34117538 DOI: 10.1007/s10103-021-03347-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/07/2021] [Indexed: 10/21/2022]
Abstract
To evaluate the local temperature at corneal tissue after applying single laser pulse from six commercial devices; Medilex™, Katana laser-soft, MEL90, Technolas-Teneo317, Alcon EX500, and PulzarTMZ1. The temperature distribution is simulated using finite element solution of the Penne's bio-heat transfer equation on a 3-D model of human cornea using the manufacturer's assigning parameters. The obtained results showed that the heating effect of Katana laser soft is 40% lower than MEL90 and Pulzar™ Z1, while the broad beam Medilex™ showed the minimum temperature rise especially at 248-nm laser radiation. The change in laser parameters selected for ablation has significant effect on the corneal local temperature. The broad beam-based device produces lower local corneal temperature than other flying spot types.
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Affiliation(s)
- Ibrahim Abdelhalim
- Engineering Applications of Laser Department, National Institute of Laser Enhanced Sciences, Cairo University, Giza, 12613, Egypt
| | - Omnia Hamdy
- Engineering Applications of Laser Department, National Institute of Laser Enhanced Sciences, Cairo University, Giza, 12613, Egypt.
| | - Aziza Ahmed Hassan
- Medical Applications of Laser Department, National Institute of Laser Enhanced Sciences, Cairo University, Giza, 12613, Egypt
| | - Salah Hassab Elnaby
- Engineering Applications of Laser Department, National Institute of Laser Enhanced Sciences, Cairo University, Giza, 12613, Egypt
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13
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Yusef YN, Yusef SN, Vvedenskiy AS, Alkharki L, Fokina ND, Alkhumidi K. [Results of hybrid (femtosecond laser-assisted) phacoemulsification of hypermature cataract in patients with lens subluxation]. Vestn Oftalmol 2021; 137:40-45. [PMID: 33610148 DOI: 10.17116/oftalma202113701140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Studying the use of femtosecond laser in patients with complicated cataracts remains a topical issue in phaco surgery. PURPOSE To comparatively analyze the results of using hybrid (femtosecond laser-assisted) phacoemulsification in hypermature cataract in patients with lens subluxation. MATERIAL AND METHODS The study included 78 patients (78 eyes) with hypermature cataract in combination with lens subluxation of I-II degree. In the 1st group (45 eyes) capsulorhexis was performed using a femtosecond laser. In the 2nd group (33 eyes) manual capsulorhexis was performed. RESULTS On the first day after surgery, best corrected visual acuity of 0.8-1.0 was obtained in 57.8% of cases in the 1st group and 33.3% in the 2nd group. Transient corneal edema during the first 1-3 days was noted in 4.4% of cases in the 1st group and in 15.2% - in the 2nd group of patients. Pachymetry in the center of the cornea showed an increase in its thickness on the 1st day after surgery from 0.564±0.027 mm to 0.591±0.033 mm in the 1st group and from 0.561±0.023 mm to 0.637±0.043 mm (p<0.05) in the 2nd group of patients. The loss of corneal endothelial cells amounted to 10.9±1.8% in the 1st group and 17.4±2.9% in the 2nd group (p<0.05). Macular edema with decreased visual acuity confirmed by OCT was detected in the 1st group of patients in 2.2% of cases, in the 2nd group - in 9.1% of cases. With a follow-up period of up to 3 years, IOL optics decentration by more than 1 mm was detected in 2.2% of cases in the 1st group of patients and in 12.1% of cases in the 2nd group. CONCLUSION Femtosecond laser-assisted capsulorhexis significantly improves the results of surgery in patients with hypermature cataract combined with lens subluxation.
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Affiliation(s)
- Yu N Yusef
- Research Institute of Eye Disease, Moscow, Russia
| | - S N Yusef
- Research Institute of Eye Disease, Moscow, Russia
| | | | - L Alkharki
- Research Institute of Eye Disease, Moscow, Russia
| | - N D Fokina
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - K Alkhumidi
- Research Institute of Eye Disease, Moscow, Russia
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Dependence of the heating effect on tissue absorption coefficient during corneal reshaping using different UV lasers: A numerical study. Phys Eng Sci Med 2021; 44:221-227. [PMID: 33475960 DOI: 10.1007/s13246-021-00971-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 01/05/2021] [Indexed: 10/22/2022]
Abstract
Corneal reshaping using laser ablation effect is a well-known ophthalmologic operation implemented to correct many vision disorders. UV pulsed lasers are utilized in this surgery due to their high absorption in corneal tissue without affecting the other parts of the eye. Ideally ablation may not be associated with heat transport, since high temperature is the enemy of soft tissues. However, the thermal effect of this procedure can cause tissue damage if the temperature rises above the safety level without appropriate handling. In the present study, we try to find the trade-off between efficient ablation and minimal temperature rise. So the thermal effect on the corneal tissue after applying five UV wavelengths; 193, 210, 213, 223 and 248 nm has been simulated and investigated by solving Penne's bio-heat transfer equation using the finite element method. A 3D model of the human cornea is constructed using COMSOL Multiphysics computer software and the temperature rise is determined at the end of the laser pulse. The same spot size and pulse duration are used for each wavelength. While the absorption coefficient of the corneal tissue is the only variable as it is a wavelength dependent. The proposed results show that, the heating effect is directly proportional to the absorption coefficient. The highest recorded temperature was 259 °C at 193 nm, while, the minimum value was (70.1 °C) recorded at 248 nm at which the cornea has the lowest absorption coefficient.
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