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Teo ZL, Ang M. Femtosecond laser-assisted in situ keratomileusis versus small-incision lenticule extraction: current approach based on evidence. Curr Opin Ophthalmol 2024; 35:278-283. [PMID: 38700941 DOI: 10.1097/icu.0000000000001060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
PURPOSE OF REVIEW Laser keratorefractive surgery achieves excellent visual outcomes for refractive error correction. With femtosecond laser, small incision lenticule extraction (SMILE) is an increasingly viable alternative to laser-assisted in situ keratomileusis (LASIK). Comparative studies demonstrate similar efficacy and predictability between SMILE and LASIK, making it difficult for clinicians to choose which to use. This review thus compares femtosecond-LASIK (FS-LASK) and SMILE in various scenarios, to assist clinicians in deciding which refractive surgery procedure to recommend. RECENT FINDINGS SMILE may be superior for highly myopic eyes due to a smaller decrease in functional optical zone. SMILE further induces less spherical aberration and less overall higher order aberrations in mesopic conditions. SMIILE also has less postoperative dry eye, making it suitable those with preexisting dry eye. For low to moderate myopic astigmatism correction, FS-LASIK has less undercorrection compared to SMILE. Lastly, SMILE has not yet received Food and Drug Administration or Conformité Européenne approval for hyperopic correction, rendering FS-LASIK the choice of procedure for hyperopic correction. SUMMARY Both FS-LASIK and SMILE demonstrate good efficacy and predictability. Understanding specific clinical scenarios where one may be superior to the other will aid clinicians in choosing the most suitable procedure for personalized care.
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Affiliation(s)
- Zhen Ling Teo
- Singapore National Eye Centre, Singapore Eye Research Institute
| | - Marcus Ang
- Singapore National Eye Centre, Singapore Eye Research Institute
- Department of Cornea and External Eye Disease, Refractive Surgery, Singapore National Eye Centre
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore
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2
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Lan G, Twa MD, Song C, Feng J, Huang Y, Xu J, Qin J, An L, Wei X. In vivo corneal elastography: A topical review of challenges and opportunities. Comput Struct Biotechnol J 2023; 21:2664-2687. [PMID: 37181662 PMCID: PMC10173410 DOI: 10.1016/j.csbj.2023.04.009] [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: 02/14/2023] [Revised: 04/07/2023] [Accepted: 04/12/2023] [Indexed: 05/16/2023] Open
Abstract
Clinical measurement of corneal biomechanics can aid in the early diagnosis, progression tracking, and treatment evaluation of ocular diseases. Over the past two decades, interdisciplinary collaborations between investigators in optical engineering, analytical biomechanical modeling, and clinical research has expanded our knowledge of corneal biomechanics. These advances have led to innovations in testing methods (ex vivo, and recently, in vivo) across multiple spatial and strain scales. However, in vivo measurement of corneal biomechanics remains a long-standing challenge and is currently an active area of research. Here, we review the existing and emerging approaches for in vivo corneal biomechanics evaluation, which include corneal applanation methods, such as ocular response analyzer (ORA) and corneal visualization Scheimpflug technology (Corvis ST), Brillouin microscopy, and elastography methods, and the emerging field of optical coherence elastography (OCE). We describe the fundamental concepts, analytical methods, and current clinical status for each of these methods. Finally, we discuss open questions for the current state of in vivo biomechanics assessment techniques and requirements for wider use that will further broaden our understanding of corneal biomechanics for the detection and management of ocular diseases, and improve the safety and efficacy of future clinical practice.
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Affiliation(s)
- Gongpu Lan
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Michael D Twa
- College of Optometry, University of Houston, Houston, TX 77204, United States
| | - Chengjin Song
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
| | - JinPing Feng
- Institute of Engineering and Technology, Hubei University of Science and Technology, Xianning, Hubei 437100, China
| | - Yanping Huang
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Jingjiang Xu
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Jia Qin
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Lin An
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Xunbin Wei
- Biomedical Engineering Department, Peking University, Beijing 100081, China
- International Cancer Institute, Peking University, Beijing 100191, China
- Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China
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Dong R, Zhang Y, Yuan Y, Liu Y, Wang Y, Chen Y. A prospective randomized self-controlled study of LASIK combined with accelerated cross-linking for high myopia in Chinese: 24-month follow-up. BMC Ophthalmol 2022; 22:280. [PMID: 35751042 PMCID: PMC9233381 DOI: 10.1186/s12886-022-02491-y] [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: 04/07/2022] [Accepted: 06/09/2022] [Indexed: 11/29/2022] Open
Abstract
Background To assess the visual and refractive outcomes of femtosecond laser-assisted in situ keratomileusis (FS-LASIK) concurrent with accelerated cross-linking (LASIK Xtra) compared with conventional FS-LASIK (convLASIK) for high myopia in Chinese individuals. Methods In this prospective, randomized, fellow-eye comparison study, 25 patients with high myopia were treated randomly with LASIK Xtra in one eye and convLASIK in the other. A 24-month follow-up was conducted, and the main outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE) and corneal tomography. Results The UDVA was 0.09 ± 0.15 logMAR in the LASIK Xtra group, which was significantly worse than that in the convLASIK group 1 day postoperatively (P = .001), but the difference became nonsignificant from 1 week after surgery. The efficacy index was 0.88 ± 0.18 in the LASIK Xtra eyes and 0.99 ± 0.13 in the convLASIK eyes at 24 months (P = .028). Throughout the follow-up period, a slight myopic shift in the MRSE and keratometry values were observed in both groups without significant intergroup differences. The coefficient of determination was 0.9982 in the LASIK Xtra eyes and 0.9987 in the convLASIK eyes. The corneal density was significantly higher, and demarcation lines were visible in the first 6 months in LASIK Xtra eyes, but both signs of cross-linking gradually disappeared during follow-up. No severe complications were detected in either group. Conclusions LASIK Xtra showed comparable safety and predictability with convLASIK for high myopia in Chinese, but lower efficacy and no greater stability was observed up to 24-month follow-up.
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Affiliation(s)
- Ruilan Dong
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China.,Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Yu Zhang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China.,Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Yifei Yuan
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China.,Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Yan Liu
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China.,Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Yuexin Wang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China.,Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Yueguo Chen
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China. .,Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China.
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Asena BS, Donmez O. The impact of learning curve on flap thickness outcome in femtosecond laser assisted LASIK performed with new LenSx dual platform. KOREAN JOURNAL OF OPHTHALMOLOGY 2022; 36:202-209. [PMID: 35067019 PMCID: PMC9194732 DOI: 10.3341/kjo.2021.0154] [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: 09/30/2021] [Accepted: 12/30/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose To evaluate the effect of learning curve on flap thickness (FT) outcome in femtosecond (FS) laser-assisted laser in situ keratomileusis (LASIK) operation for myopia performed with recently introduced LenSx dual platform using curved applanation cone. Methods Seventy eyes of 36 patients with myopia or myopic astigmatism operated with FS laser-assisted LASIK with recently introduced LenSx dual platform were evaluated in this retrospective study. Operations were divided into two groups: first 20 operations (20 eyes of 10 patients) and next 50 operations (50 eyes of 26 patients). Data on patient demographics, preoperative and postoperative keratometric and aberrometric parameters, and FT related outcome, including mean central FT, mean total FT, intra-FT range, and FT homogeneity were compared in study groups. Results Except for significantly lower preoperative steepest keratometry values in the next 50 operations versus first 20 operations (p = 0.033), no significant difference was noted between study groups in terms of preoperative and postoperative parameters. When compared to first 20 operations, next 50 operations were associated with significantly higher values for mean central FT (median, 123 μm vs. 114 μm; p = 0.007) and mean total FT (median, 123 μm vs. 113 μm; p = 0.015), whereas significantly lower intra-FT range (median, 4.0 μm vs. 4.5 μm; p = 0.003). Conclusions In conclusion, our findings related to FS laser-assisted LASIK surgery for myopia with new LenSx dual platform using curved applanation cone revealed significant impact of learning curve on the corneal FT outcome in terms of closer FT to the intended value and lower intra-flap range.
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Affiliation(s)
| | - Oya Donmez
- Department of Ophthalmology, Tinaztepe Galen Hospital, Izmir,
Turkey
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Customized eye modeling for optical quality assessment in myopic femto-LASIK surgery. Sci Rep 2021; 11:16049. [PMID: 34362982 PMCID: PMC8346559 DOI: 10.1038/s41598-021-95730-z] [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: 04/04/2021] [Accepted: 07/27/2021] [Indexed: 02/07/2023] Open
Abstract
Refractive surgery is recognized as an effective method for myopia treatment, but it can induce night vision disturbances such as glare. We present an eye modeling method for the optical quality assessment in response to the structural changes in the eyes by femto-LASIK surgery. Customized eye models were built from the measurements of 134 right eyes pre- and post-operatively. Optical performance was evaluated using spot diagrams, point spread functions (PSFs), modulation transfer functions (MTFs), and chromatic aberrations at various fields (0°-30°), different pupil diameters (2-6 mm), and initial myopias (- 1.25 to - 10.5 D). Pupil size and initial myopia are the two major factors that affect visual performance of post-operative eyes. The results of spot diagrams, PSFs, and MTFs indicated that post-operative visual performance deteriorated as the visual field and pupil size increased, and it was significantly influenced by initial myopia. Post-operative chromatic aberrations were also affected by initial myopia. As pupil size increased, the post-operative longitudinal chromatic aberrations tended to decrease slightly, while the transverse chromatic aberrations remained similar. The use of eye modeling for refractive surgery assessment could possibly provide a more personalized surgical approach, could improve the prediction accuracy of refractive surgery outcomes, and promote the invention and development of better surgical methods.
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One-Year Visual and Refractive Outcomes following LASIK for Myopia and Myopic Astigmatism with MEL 90 versus Schwind Amaris 750S Excimer Laser: A Comparative Study. J Ophthalmol 2021; 2021:9929181. [PMID: 34258051 PMCID: PMC8257363 DOI: 10.1155/2021/9929181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 06/19/2021] [Indexed: 11/18/2022] Open
Abstract
Purpose To compare clinical outcomes following LASIK for myopia performed with MEL 90 vs. Schwind Amaris 750S excimer laser. Methods Data were collected retrospectively for patients who underwent Femto-LASIK, using the MEL 90 and Schwind Amaris 750S excimer laser for correction of myopia and myopic astigmatism within the range of -1.00 to -10.00 D SE from January 2013 till June 2018. Outcomes were analysed at 12 months for safety, efficacy, enhancement rate, and long-term complications. Results A total of 328 eyes of 328 patients were analysed. One hundred and sixty-three eyes were treated with Schwind Amaris and the remaining 165 eyes with the MEL 90 laser. Twelve months postoperatively, the mean UDVA, CDVA, residual SE, and cylinder in the Amaris group were -0.10 ± 0.09 logMAR, -0.14 ± 0.06 logMAR, -0.21 ± 0.22 D, -0.13 ± 0.18 D versus -0.05 ± 0.07 logMAR, -0.09 ± 0.08 logMAR, -0.23 ± 0.23 D, and -0.14 ± 0.21 D for the MEL 90 group (p values >0.05). For the Amaris group, safety and efficacy indices were 1.12 and 1.02, whereas for the MEL 90 group, these indices were 1.08 and 1.00, respectively. No eye in either group had any postop flap-related complications, infectious keratitis, diffuse lamellar keratitis, or keratectasia. Two eyes in the Amaris and 4 eyes in MEL 90 group required enhancement for the progression of myopia. Conclusion At 12 months, both Schwind Amaris 750S and MEL 90 lasers demonstrated comparable clinical outcomes for myopic LASIK in a single surgeon setting.
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Gershoni A, Reitblat O, Mimouni M, Livny E, Nahum Y, Bahar I. Femtosecond laser assisted in situ keratomileusis (FS-LASIK) yields better results than transepithelial photorefractive keratectomy (Trans-PRK) for correction of low to moderate grade myopia. Eur J Ophthalmol 2020; 31:2914-2922. [PMID: 33307790 DOI: 10.1177/1120672120980346] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
INTRODUCTION The purpose of this study was to compare the outcomes of transepithelial photorefractive keratectomy (Trans-PRK) with femtosecond laser assisted in situ keratomileusis (FS-LASIK) for the correction of low to moderate myopia. METHODS A retrospective cohort study design was used. The study group included patients with myopia less than -6.0 D, with or without concomitant astigmatism under 2.0 D, who were treated with FS-LASIK or Trans-PRK in 2013 through 2014. Background, clinical and outcome data were collected from the patient files. A comparison between eyes treated with FS-LASIK or Trans-PRK was performed. RESULTS The Trans-PRK group was comprised of 1793 eyes and the FS-LASIK group of 666 eyes. Mean ± SD spherical equivalent (SE) refraction prior to surgery was -3.43 ± 1.27 D in the Trans-PRK group and -3.18 ± 1.34 D in the FS-LASIK group (p < 0.001). Efficacy index values were 0.95 ± 0.14 in the Trans-PRK group and 0.98 ± 0.12 in the FS-LASIK group (p < 0.001), and corresponding safety index values were 0.96 ± 0.13 and 0.99 ± 0.12 (p < 0.001). Distance from target refraction was 0.45 ± 0.42 D in Trans-PRK group and 0.43 ± 0.38 D in the FS-LASIK group (p = 0.537); 71.6% and 74.2% of eyes were within ±0.5 D of attempted correction, respectively (p = 0.193). CONCLUSIONS Both Trans-PRK and FS-LASIK demonstrated excellent results, mostly comparable with the current literature. FS-LASIK achieved better results than Trans-PRK surgery in the efficacy and safety parameters.
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Affiliation(s)
- Assaf Gershoni
- Assuta Optic Laser Center, Assuta Medical Center, Tel Aviv, Israel.,Department of Ophthalmology, Rabin Medical Center - Beilinson Hospital, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Olga Reitblat
- Department of Ophthalmology, Rabin Medical Center - Beilinson Hospital, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Michael Mimouni
- Department of Ophthalmology, Rambam Health Care Campus, Haifa, Israel
| | - Eitan Livny
- Assuta Optic Laser Center, Assuta Medical Center, Tel Aviv, Israel.,Department of Ophthalmology, Rabin Medical Center - Beilinson Hospital, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yoav Nahum
- Assuta Optic Laser Center, Assuta Medical Center, Tel Aviv, Israel.,Department of Ophthalmology, Rabin Medical Center - Beilinson Hospital, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Irit Bahar
- Assuta Optic Laser Center, Assuta Medical Center, Tel Aviv, Israel.,Department of Ophthalmology, Rabin Medical Center - Beilinson Hospital, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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8
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Asif MI, Bafna RK, Mehta JS, Reddy J, Titiyal JS, Maharana PK, Sharma N. Complications of small incision lenticule extraction. Indian J Ophthalmol 2020; 68:2711-2722. [PMID: 33229647 PMCID: PMC7856979 DOI: 10.4103/ijo.ijo_3258_20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The procedure of small incision lenticule extraction (SMILE) was introduced in 2011, and since then there has been an increase in the number of cases undergoing this procedure worldwide. The surgery has a learning curve and may be associated with problems in the intraoperative and postoperative periods. The intraoperative problems during SMILE surgery include the loss of suction, the occurrence of altered or irregular opaque bubble layer and black spots, difficulty in lenticular dissection and extraction, cap perforation, incision-related problems, and decentered ablation. Most of the postoperative problems are similar as in other laser refractive procedures, but with decreased incidence. The identification of risk factors, clinical features, and management of complications of SMILE help to obtain optimum refractive outcomes.
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Affiliation(s)
- Mohamed Ibrahime Asif
- Department of Ophthalmology, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Rahul Kumar Bafna
- Department of Ophthalmology, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Jodhbir Singh Mehta
- Singapore Eye Research Institute; Singapore National Eye Centre, 168751; Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore
| | - Jagadesh Reddy
- Cataract and Refractive Services, Cornea Institute, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Jeewan Singh Titiyal
- Department of Ophthalmology, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Prafulla K Maharana
- Department of Ophthalmology, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Namrata Sharma
- Department of Ophthalmology, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
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Sheludchenko VM, Osipyan GA, Yusef NY, Khraystin K, Alharki L, Dzhalili RA. [Bandage lamellar-optical keratoplasty for post-excimer laser keratectasia]. Vestn Oftalmol 2019; 135:171-176. [PMID: 31691656 DOI: 10.17116/oftalma2019135052171] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
INTRODUCTION According to various sources, occurrence rate of keratectasia (KE) after Laser in situ Keratomileusis (LASIK) ranges from 0.04 to 0.2%. No known technique for keratorefractive surgery eliminates the probability. Neither corneal cross-linking, nor implantation of polymeric segments can completely prevent its development. PURPOSE To treat KE after LASIK with bandage lamellar-optical keratoplasty (BLOK) surgery and to evaluate the results. MATERIAL AND METHODS The study included 22 patients with KE after LASIK divided into two groups. The first group consisted of 6 patients; they underwent BLOK surgery using a segment transplant 1.5 mm in width and 180-220 µm in thickness. The second group included 16 patients who underwent BLOK surgery using 2.75 mm wide, 290-350 µm thick allogeneic transplant of individual length. The follow-up lasted 4 years. RESULTS In the first group, uncorrected visual acuity (UCVA) improved by 0.4±007, in the second group - by 0.46±0.15. After two years, two patients had their transplant exchanged for a wider one due to ectasia progression. Corneal refraction was stable at 45.36±1.47 Diopters in all other patients of the first group. In the second group, it was consistently between 40.6 and 45.7 Diopters. The main complication of the BLOK surgery was displacement of the edge of the corneal flap formed during LASIK - occurred in 4 patients. CONCLUSION Bandage lamellar-optical keratoplasty proved effective in treating patients with KE after LASIK, leading to improvement of visual acuity, strengthening of the cornea and normalization of its surface; it slows further progression of ectasia.
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Affiliation(s)
- V M Sheludchenko
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - G A Osipyan
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021; Center Vision Recovery, 108 Lobachevskogo St., Moscow, Russian Federation, 119361
| | - N Yu Yusef
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021; Center Vision Recovery, 108 Lobachevskogo St., Moscow, Russian Federation, 119361
| | - Kh Khraystin
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - L Alharki
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - R A Dzhalili
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
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10
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Voronin GV, Bubnova IA. [Changes in biomechanical properties of the cornea after keratorefractive surgery]. Vestn Oftalmol 2019; 135:108-112. [PMID: 31573565 DOI: 10.17116/oftalma2019135041108] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Biomechanical properties of the cornea are important for the functioning of the ocular optical system. They affect such qualities of the system as correct diffraction and resistance to different external action. Keratorefractive surgery widely used in clinical practice nowadays significantly upsets corneal biomechanics, which introduces a margin of error for IOP measurements done by different methods. The article reviews literature devoted to the problem of changes of corneal biomechanical properties after refractive surgeries.
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Affiliation(s)
- G V Voronin
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021; I.M. Sechenov First Moscow State Medical University, Department of Ophthalmology, 8-2 Trubetskaya St., Moscow, Russian Federation, 119991
| | - I A Bubnova
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
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11
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Jin H, Liu L, Ding H, He M, Zhang C, Zhong X. Small Incision Femtosecond Laser-assisted X-ray-irradiated Corneal Intrastromal Xenotransplantation in Rhesus Monkeys: A Preliminary Study. Curr Mol Med 2019; 18:612-621. [PMID: 30698112 PMCID: PMC6463400 DOI: 10.2174/1566524019666190129123935] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 12/18/2018] [Accepted: 01/27/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Gamma-ray irradiation could significantly induce widespread apoptosis in corneas and reduced the allogenicity of donor cornea. And the X-rays may have similar biological effects. The feasibility and effects of X-ray-irradiated corneal lamellae have not been assessed yet. METHODS Different doses (10 gray unit (Gy), 20 Gy, 50 Gy, 100 Gy) of X-ray irradiated corneal lamellae were collected from SMILE surgery. These corneal lamellae were assessed by physical characterization, hematoxylin and eosin (H-E) staining, Masson's staining, TdT-mediated dUTP nick end labeling (TUNEL), cell viability assay and transmission electron microscopy (TEM). We selected the optimum dose (100Gy) to treat the corneal lamellae to be the grafts. The human grafts and fresh allogeneic monkey corneal lamellae were implanted into rhesus monkeys via the small incision femtosecond laser-assisted surgery, respectively. Clinical examinations and the immunostaining were performed after surgery. RESULTS There were no significant changes in the transparency of the corneal lamellae, but the absorbency of the corneal lamellae was increased. According to the H-E and Masson's staining results, irradiation had little impact on the corneal collagen. The TUNEL assay and cell viability assay results showed that 100Gy X-ray irradiation resulted in complete apoptosis in the corneal lamellae, which was also confirmed by TEM observations. In the following animal model study, no immune reactions or severe inflammatory responses occurred, and the host corneas maintained transparency for 24 weeks of observation. And the expression of CD4 and CD8 were negative in the all host corneas. CONCLUSION X-ray irradiated corneal lamellae could serve as a potential material for xenogeneic inlay, and the small incision femtosecond laser-assisted implantation has the potential to become a new corneal transplantation surgical approach.
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Affiliation(s)
- He Jin
- Zhongshan Ophthalmic Center and State Key Laboratory of Ophthalmology, Sun Yat-sen University. Guangzhou 510060, China.,Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin 541001, China
| | - Liangping Liu
- Zhongshan Ophthalmic Center and State Key Laboratory of Ophthalmology, Sun Yat-sen University. Guangzhou 510060, China
| | - Hui Ding
- Hainan Eye Hospital, Hainan Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University. Haikou 570311, China
| | - Miao He
- Zhongshan Ophthalmic Center and State Key Laboratory of Ophthalmology, Sun Yat-sen University. Guangzhou 510060, China
| | - Chi Zhang
- Zhongshan Ophthalmic Center and State Key Laboratory of Ophthalmology, Sun Yat-sen University. Guangzhou 510060, China
| | - Xingwu Zhong
- Zhongshan Ophthalmic Center and State Key Laboratory of Ophthalmology, Sun Yat-sen University. Guangzhou 510060, China.,Hainan Eye Hospital, Hainan Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University. Haikou 570311, China
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12
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Moussa S, Dietrich M, Lenzhofer M, Ruckhofer J, Reitsamer HA. Femtosecond laser in refractive corneal surgery. Photochem Photobiol Sci 2019; 18:1669-1674. [PMID: 31265052 DOI: 10.1039/c9pp00039a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The introduction of the femtosecond (fs) laser has revolutionized ophthalmic surgery. With the worldwide application of fs-lasers, clinical outcomes and safety in corneal procedures have improved significantly and they have become an ideal tool for ultra-precise corneal refractive surgery. Flap creation in laser in situ keratomileusis (LASIK) is the most common use of this laser. It can also be used for other corneal refractive procedures including channel creation for the insertion of intrastromal corneal ring segments (ICRS), performing astigmatic keratotomies (AK), femtosecond lenticule extraction including small incision lenticule extraction (SMILE), and the insertion of corneal inlays. This article summarizes recent advanced applications of fs laser technology in corneal refractive surgery.
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Affiliation(s)
- Sarah Moussa
- Paracelsus Medical University Salzburg, Department of Ophthalmology and Optometry, Müllner Hauptstr. 48, 5020 Salzburg, Austria.
| | - Marie Dietrich
- Paracelsus Medical University Salzburg, Department of Ophthalmology and Optometry, Müllner Hauptstr. 48, 5020 Salzburg, Austria.
| | - Markus Lenzhofer
- Paracelsus Medical University Salzburg, Department of Ophthalmology and Optometry, Müllner Hauptstr. 48, 5020 Salzburg, Austria.
| | - Josef Ruckhofer
- Paracelsus Medical University Salzburg, Department of Ophthalmology and Optometry, Müllner Hauptstr. 48, 5020 Salzburg, Austria.
| | - Herbert A Reitsamer
- Paracelsus Medical University Salzburg, Department of Ophthalmology and Optometry, Müllner Hauptstr. 48, 5020 Salzburg, Austria.
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Three-Year Outcome Comparison Between Femtosecond Laser-Assisted and Manual Descemet Membrane Endothelial Keratoplasty. Cornea 2019; 38:812-816. [PMID: 30973405 DOI: 10.1097/ico.0000000000001956] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate 3-year outcomes of femtosecond laser-assisted Descemet membrane endothelial keratoplasty (F-DMEK) compared with manual Descemet membrane endothelial keratoplasty (M-DMEK) in patients with Fuchs endothelial corneal dystrophy (FECD). METHODS A retrospective, interventional study, including eyes with FECD and cataract that underwent either F-DMEK or M-DMEK combined with cataract extraction at either the Toronto Western Hospital or Kensington Eye Institute, and that had at least 18 months' follow-up was conducted. EXCLUSION CRITERIA complicated anterior segments, previous vitrectomy, previous keratoplasty, corneal opacity, or any other visually significant ocular comorbidity. RESULTS Included were 16 eyes of 15 patients in the F-DMEK group (average follow-up 33.0 ± 9.0 months) and 45 eyes of 40 patients in the M-DMEK group (average follow-up 32.0 ± 7.0 months). There were no issues with the creation of femtosecond descemetorhexis (in the F-DMEK group)-all descemetorhexis cuts were complete. Best spectacle-corrected visual acuity improvement did not differ significantly between the groups at 1, 2, and 3 years (P = 0.849, P = 0.465 and P = 0.936, respectively). Rates of significant detachment in F-DMEK and M-DMEK were 1 of 16 eyes (6.25%) and 16 of 45 eyes (35.6%) (P = 0.027). Rebubbling rates were 1 of 16 eyes (6.25%) and 15 of 45 eyes (33.3%) (P = 0.047). Cell-loss rates following F-DMEK and M-DMEK were 26.8% and 36.5% at 1 year (P = 0.042), 30.5% and 42.3% at 2 years (P = 0.008), 37% and 47.5% at 3 years (P = 0.057), respectively. Graft failure rate was 0% in F-DMEK and 8.9% in M-DMEK (all were primary failures; P = 0.565). CONCLUSIONS F-DMEK showed good efficacy with reduced detachment, rebubble, and cell-loss rates, compared with M-DMEK.
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Kim TI, Alió Del Barrio JL, Wilkins M, Cochener B, Ang M. Refractive surgery. Lancet 2019; 393:2085-2098. [PMID: 31106754 DOI: 10.1016/s0140-6736(18)33209-4] [Citation(s) in RCA: 164] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 11/29/2018] [Accepted: 12/11/2018] [Indexed: 01/19/2023]
Abstract
Refractive surgery has evolved beyond laser refractive techniques over the past decade. Laser refractive surgery procedures (such as laser in-situ keratomileusis), surface ablation techniques (such as laser epithelial keratomileusis), and photorefractive keratectomy have now been established as fairly safe procedures that produce excellent visual outcomes for patients with low-to-moderate amounts of ametropia. Additionally, a broader selection of options are now available to treat a wider range of refractive errors. Small incision lenticule extraction uses a femtosecond laser to shape a refractive lenticule, which is removed through a small wound. The potential advantages of this procedure include greater tectonic strength and less dry eye. In the future, intracorneal implants could be used to treat hyperopia or presbyopia. Phakic intraocular implants and refractive lens exchange might be useful options in carefully selected patients for correcting high degrees of ametropia. Thus, physicians are now able to provide patients with the appropriate refractive corrective option based on the individual's risk-benefit profile.
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Affiliation(s)
- Tae-Im Kim
- Department of Ophthalmology, The Institute of Vision Research, Yonsei University College of Medicine, Seoul, South Korea
| | - Jorge L Alió Del Barrio
- Cornea, Cataract and Refractive Surgery Unit, Research & Development Department VISSUM Innovation Alicante, Alicante, Spain; Division of Ophthalmology, School of Medicine, Universidad Miguel Hernández, Alicante, Spain
| | - Mark Wilkins
- Department of Ophthalmology, Moorfields Eye Hospital, London, UK
| | - Beatrice Cochener
- Department of Ophthalmology, University Hospital Morvan, Brest, France
| | - Marcus Ang
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Department of Ophthalmology and Visual Science, Duke-NUS Graduate Medical School, Singapore.
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Abstract
PURPOSE To analyze the incidence, indications, and outcomes associated with early flap relifting after uncomplicated laser in situ keratomileusis (LASIK). METHODS All LASIK cases from a single surgical center between 2007 and 2015 were reviewed. Early postoperative flap lift cases (<15 d after surgery) were identified. RESULTS Overall, 25,712 eyes were included, of which 366 (1.42%) underwent early postoperative flap lifting. There was a significant reduction in early postoperative flap lifting rates from 2006 (2.46%) to 2015 (0.92%) (P = 0.001). Reasons for early flap lifting included striae (n = 301, 1.17%), diffuse lamellar keratitis (n = 62, 0.24%), flap dislocation (n = 20, 0.08%), epithelial ingrowth (n = 18, 0.07%), and interface debris (n = 15, 0.06%). There was a significant difference in rates and outcomes of flap relifting among high-volume surgeons (P < 0.001). The flap lift group had a significantly lower final safety index (0.95 ± 0.16 vs. 1.01 ± 0.15, P < 0.001), efficacy index (0.85 ± 0.26 vs. 0.94 ± 0.26, P < 0.001), and a higher distance from target refraction (0.39 ± 0.61 vs. 0.21 ± 0.46 D). In unilateral cases, the study eye had a lower safety index (P < 0.001), efficacy index (P < 0.001), and greater distance from target refraction (P = 0.003) compared with the fellow eye. After intervention, 81.1% of cases achieved full resolution, 10.1% achieved partial resolution, 4.1% required additional flap relifting, and 4.7% were nonresolved by the end of follow-up. CONCLUSIONS The main indication for early flap relifting after LASIK was striae, and most cases achieved full resolution. Although refractive and visual outcomes are lower in this group, they are, nevertheless, satisfactory.
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Comparing wavefront-optimized, wavefront-guided and topography-guided laser vision correction. Curr Opin Ophthalmol 2018; 29:277-285. [DOI: 10.1097/icu.0000000000000495] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Gros-Otero J, Garcia-Gonzalez M, Teus MA, Iglesias-Iglesias M, Gimenez-Vallejo C. Femtosecond laser-assisted sub-Bowman keratomileusis versus laser-assisted subepithelial keratomileusis to correct myopic astigmatism. JOURNAL OF OPTOMETRY 2018; 11:33-39. [PMID: 27751694 PMCID: PMC5777929 DOI: 10.1016/j.optom.2016.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/12/2016] [Accepted: 09/12/2016] [Indexed: 06/06/2023]
Abstract
PURPOSE To compare femtosecond laser-assisted sub-Bowman keratomileusis (FSBK) versus laser-assisted subepithelial keratomileusis (LASEK) to correct moderate to high myopic astigmatism. METHODS Retrospective, nonrandomized, interventional, comparative case series. A total of eight hundred and fifty-two eyes with myopic astigmatism of -1.5 diopters (D) or higher were included in the study. We compared 427 eyes treated with FSBK versus 425 eyes treated with LASEK with or without mitomycin C. Visual and refractive results were evaluated 1 day, 1 week, 3 and 6 months postoperatively. RESULTS Six months postoperatively, the residual spherical defect was slightly but significantly higher in the LASEK group (+0.15±0.62D) than in the FSBK group (+0.09±0.35D) (P=0.05). The postoperative residual astigmatism was also slightly but significantly higher in the LASEK group (-0.38±0.52D) than in the FSBK group (-0.26±0.45D) (P=0.0005). No significant differences were found in the efficacy (0.98±0.17 versus 0.98±0.36, P=0.6) and safety indexes (1.04±0.16 versus 1.05±0.37, P=0.1) between FSBK and LASEK. The enhancement rate was significantly higher in the FSBK group (22.6%) than in the LASEK group (15.5%) (P=0.01). CONCLUSIONS Both FSBK and LASEK are safe and effective procedures to correct moderate to high myopic astigmatism. Slightly better visual and refractive results were observed in FSBK-treated eyes in a 6-month follow-up.
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Affiliation(s)
- Juan Gros-Otero
- Clínica Rementería, C/Almagro 36, 28010 Madrid, Spain; Hospital Universitario "Príncipe de Asturias," University of Alcalá, Carretera de meco s/n, Alcalá de Henares, Madrid, Spain.
| | - Montserrat Garcia-Gonzalez
- Clínica Rementería, C/Almagro 36, 28010 Madrid, Spain; Clínica Novovisión, C/Castellana 54, 28046 Madrid, Spain
| | - Miguel A Teus
- Hospital Universitario "Príncipe de Asturias," University of Alcalá, Carretera de meco s/n, Alcalá de Henares, Madrid, Spain; Clínica Novovisión, C/Castellana 54, 28046 Madrid, Spain
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Jin H, Liu L, Ding H, He M, Zhang C, Zhong X. Comparison of femtosecond laser-assisted corneal intrastromal xenotransplantation and the allotransplantation in rhesus monkeys. BMC Ophthalmol 2017; 17:202. [PMID: 29121878 PMCID: PMC5680765 DOI: 10.1186/s12886-017-0595-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 10/31/2017] [Indexed: 11/11/2022] Open
Abstract
Background In our previous study, we showed that both allogeneic and autogeneic small-incision femtosecond laser-assisted corneal intrastromal transplantation are safe and effective surgeries. However, the results of small-incision femtosecond laser-assisted intrastromal xenotransplantation have not yet been explored. Additionally, we suggest that glycerol-dehydrated corneal lamellae might provide a possible alternative for this xenogenic implantation approach. Methods Corneal inlay lamellae were produced from rabbits and humans using femtosecond laser-assisted surgeries and were dehydrated in glycerol for 1 week at 4 °C. These xenogeneic glycerol-dehydrated grafts and fresh allogeneic monkey lamellae were then implanted into rhesus monkeys using small-incision femtosecond laser assistance. Postoperatively, clinical examinations, AS-OCT measurements and tear inflammatory mediator assays were performed. Results There were no significant changes in the transparency of the corneal lamellae after glycerol dehydration. Following implantation, no evidence of tissue rejection or severe inflammatory responses was observed in the monkeys, and the host corneas remained transparent throughout a 6-month observation period. The grafts were clearly visible via AS-OCT. Corneal thickness increased 1 week postoperatively but subsequently declined and remained unchanged 1 month after surgery. Significant changes were observed in all tear inflammatory mediators in the ‘Rabbit to Monkey’ group. The trends in changes of tear inflammatory mediators in the ‘Human to Monkey’ group were similar to those in the ‘Rabbit to Monkey’ group. At 1 month post-surgery, the levels of most tear inflammatory mediators had decreased, with the exception of IL-1β, TGF-β1 and IFN-γ in the allotransplantation group. Conclusion Small-incision femtosecond laser-assisted intrastromal transplantation minimized invasiveness and improved surgical efficiency. In addition, the host cornea maintained a high level of biocompatibility. Glycerol-dehydrated corneal lamellae might be potentially useful as an alternative inlay xenogeneic material. In this study, we also describe a new treatment that can be used in keratoconus, corneal ectasia, presbyopia, hyperpresbyopia and other diseases.
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Affiliation(s)
- He Jin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Liangping Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Hui Ding
- Hainan Eye Hospital, Hainan Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Haikou, 570000, China
| | - Miao He
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Chi Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Xingwu Zhong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China. .,Hainan Eye Hospital, Hainan Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Haikou, 570000, China.
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Dawood YF, Al Hassany U, Issa AF. Temporal and Spatial Flap Variability in Laser In-Situ Keratomileusis by Optical Coherence Tomography. J Ophthalmic Vis Res 2017; 12:368-373. [PMID: 29090044 PMCID: PMC5644401 DOI: 10.4103/jovr.jovr_173_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Purpose: To study changes in flap thickness made with two different microkeratome heads across different corneal locations using anterior segment optical coherence tomography (OCT). Methods: In this prospective, non-randomized, consecutive case series, subjects who had their laser in-situ keratomileusis (LASIK) flaps made using 90 μm (MSU90) or 130 μm (MSU130) disposable M2 microkeratome heads were examined using OCT. The measurements were performed at three locations (central and 2.5 mm to either side) at 1 day, 1 week, and 1 month postoperatively. Results: The central flap thickness was 123 ± 15, 130 ± 14, and 127 ± 13 μm, respectively, at 1 day, 1 week, and 1 month postoperatively in the MSU90 group (41 eyes) and 142 ± 20, 147 ± 19, and 143 ± 15 μm, respectively, in the MSU130 group (47 eyes). At 1 month, peripheral flap thickness was 161 ± 17 and 159 ± 13 μm, respectively, at 2.5 mm to the right and left of corneal center in the MSU90 group. The corresponding figures were 170 ± 14 and 167 ± 13 μm, respectively, in the MSU130 group. There was a statistically significant difference between the two groups at all locations (P < 0.001). No statistically significant change in flap thickness was detected in either group at any assessment time. There was a partial positive correlation (after controlling for preoperative manifest refractive spherical equivalent) between central flap thickness and preoperative ultrasound central pachymetry (r = 0.739, P = 0.036) in the MSU90 group but not in the MSU130 group. Conclusion: Using OCT, changes in flap thickness were minimal in the first month after LASIK. Flap thickness correlated strongly with central corneal thickness if a 90 μm head was used.
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Affiliation(s)
- Yousif Farhan Dawood
- Department of Ophthalmology, College of Medicine, University of Anbar, Anbar, Iraq.,Department of Ophthalmology, Ibn Al Haitham Teaching Eye Hospital, Baghdad, Iraq
| | | | - Ammar F Issa
- Department of Ophthalmology, Ibn Al Haitham Teaching Eye Hospital, Baghdad, Iraq.,Jenna Ophthalmic Center, Baghdad, Iraq.,Dr Sulaiman Al Habib Medical Center, Dubai, UAE
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Jumelle C, Hamri A, Egaud G, Mauclair C, Reynaud S, Dumas V, Pereira S, Garcin T, Gain P, Thuret G. Comparison of four methods of surface roughness assessment of corneal stromal bed after lamellar cutting. BIOMEDICAL OPTICS EXPRESS 2017; 8:4974-4986. [PMID: 29188095 PMCID: PMC5695945 DOI: 10.1364/boe.8.004974] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/30/2017] [Accepted: 09/02/2017] [Indexed: 06/07/2023]
Abstract
Corneal lamellar cutting with a blade or femtosecond laser (FSL) is commonly used during refractive surgery and corneal grafts. Surface roughness of the cutting plane influences postoperative visual acuity but is difficult to assess reliably. For the first time, we compared chromatic confocal microscopy (CCM) with scanning electron microscopy, atomic force microscopy (AFM) and focus-variation microscopy (FVM) to characterize surfaces of variable roughness after FSL cutting. The small area allowed by AFM hinders conclusive roughness analysis, especially with irregular cuts. FVM does not always differentiate between smooth and rough surfaces. Finally, CCM allows analysis of large surfaces and differentiates between surface states.
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Affiliation(s)
- Clotilde Jumelle
- Corneal Graft Biology, Engineering and Imaging Laboratory, BiiGC, EA2521, Federative Institute of Research in Sciences and Health Engineering, Faculty of Medicine, Jean Monnet University, 10 rue de la Marandière, 42055 Saint-Etienne Cédex 02, France
| | - Alina Hamri
- GIE-Manutech-Ultrafast Surface Design, 20 rue Benoit Lauras, 42000 Saint-Etienne, France
| | - Gregory Egaud
- GIE-Manutech-Ultrafast Surface Design, 20 rue Benoit Lauras, 42000 Saint-Etienne, France
| | - Cyril Mauclair
- GIE-Manutech-Ultrafast Surface Design, 20 rue Benoit Lauras, 42000 Saint-Etienne, France
- Hubert Curien Laboratory, UMR-CNRS 5516, Jean Monnet University, 18 rue Benoit Lauras, 42000 Saint-Etienne, France
| | - Stephanie Reynaud
- Hubert Curien Laboratory, UMR-CNRS 5516, Jean Monnet University, 18 rue Benoit Lauras, 42000 Saint-Etienne, France
| | - Virginie Dumas
- Ecole Nationale d’Ingénieurs de Saint-Etienne (ENISE), Laboratoire de Tribologie et Dynamique des Systèmes, UMR 5513 CNRS, 58 rue Jean Parot, 42023 Saint-Etienne, France
| | - Sandrine Pereira
- Eye Bank, French Blood Center, 25 boulevard Pasteur, 42023 Saint-Etienne, France
| | - Thibaud Garcin
- Corneal Graft Biology, Engineering and Imaging Laboratory, BiiGC, EA2521, Federative Institute of Research in Sciences and Health Engineering, Faculty of Medicine, Jean Monnet University, 10 rue de la Marandière, 42055 Saint-Etienne Cédex 02, France
- Ophthalmology Department, University Hospital, avenue Albert Raimond, 42055 Saint-Etienne Cédex 02, France
| | - Philippe Gain
- Corneal Graft Biology, Engineering and Imaging Laboratory, BiiGC, EA2521, Federative Institute of Research in Sciences and Health Engineering, Faculty of Medicine, Jean Monnet University, 10 rue de la Marandière, 42055 Saint-Etienne Cédex 02, France
- Ophthalmology Department, University Hospital, avenue Albert Raimond, 42055 Saint-Etienne Cédex 02, France
| | - Gilles Thuret
- Corneal Graft Biology, Engineering and Imaging Laboratory, BiiGC, EA2521, Federative Institute of Research in Sciences and Health Engineering, Faculty of Medicine, Jean Monnet University, 10 rue de la Marandière, 42055 Saint-Etienne Cédex 02, France
- Ophthalmology Department, University Hospital, avenue Albert Raimond, 42055 Saint-Etienne Cédex 02, France
- Institut Universitaire de France, 1 rue Descartes, 75231 Paris, France
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Einan-Lifshitz A, Sorkin N, Boutin T, Showail M, Borovik A, Alobthani M, Chan CC, Rootman DS. Comparison of Femtosecond Laser-Enabled Descemetorhexis and Manual Descemetorhexis in Descemet Membrane Endothelial Keratoplasty. Cornea 2017; 36:767-770. [PMID: 28594697 DOI: 10.1097/ico.0000000000001217] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To introduce a novel method to perform descemetorhexis in Descemet membrane endothelial keratoplasty (DMEK) using the femtosecond laser and to compare it with Descemet membrane endothelial keratoplasty performed with manual descemetorhexis (M-DMEK). METHODS A retrospective medical chart review of 2 groups of patients who underwent DMEK surgery combined with cataract surgery secondary to Fuchs corneal endothelial dystrophy and cataract: 17 patients underwent femtosecond laser-enabled descemetorhexis Descemet membrane endothelial keratoplasty (FE-DMEK) and 89 patients underwent DMEK surgery with M-DMEK. Best spectacle-corrected visual acuity, endothelial cell density (ECD), graft detachment rate, and complications were compared. RESULTS Average age of the 106 patients (64 women and 42 men) was 68 ± 11 years. Postoperative best spectacle-corrected visual acuity was 0.19 ± 0.13 logarithm of the minimum angle of resolution in the FE-DMEK group and 0.35 ± 0.48 logarithm of the minimum angle of resolution in the M-DMEK group (P = 0.218). One day after surgery, there were no significant graft detachments in the FE-DMEK group, compared with 20% graft detachment rate in the M-DMEK group (P = 0.041). Rebubbling was performed in 17% of eyes in the M-DMEK group compared with none in the FE-DMEK group (P = 0.066). The mean endothelial cell count in the FE-DMEK and M-DMEK groups at 6 months after surgery were 2105 ± 285 cells per square millimeter (24% cells loss) and 1990 ± 600 cells per square millimeter (29% cells loss), respectively (P = 0.579). CONCLUSIONS FE-DMEK shows efficacy similar to that of M-DMEK with apparently less graft detachment and reduced need for rebubbling.
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Affiliation(s)
- Adi Einan-Lifshitz
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
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Topographic typology in a consecutive series of refractive surgery candidates. Int Ophthalmol 2017; 38:1611-1619. [PMID: 28676992 DOI: 10.1007/s10792-017-0631-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 06/26/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE The term 'keratoconus (KC) suspect' is used as a blanket term to refer to any deviation of virgin cornea shape toward KC features. We intend to subclassify such topographies in meaningful and informative designations. METHODS Pentacam corneal topographies of 199 consecutive refractive surgery candidates (398 eyes) are examined. Features of steepness, inferior-superior asymmetry, focal steepening, thinning, and bounded anterior or posterior elevations are observed in the quad map. Scissoring on retinoscopy, loss of best spectacle-corrected visual acuity, and iron ring deposition were looked for. Through iterative observation and refinement of classification criteria-partly taken from the literature-all eyes were designated a specific topographic diagnosis, i.e., circumventing the usage of the expression KC 'suspect'. RESULTS Topographies of 308, 48, 21, 13, 6, 1, and 1 (collectively 398 eyes) were designated: normal, 'atypical normal,' forme fruste KC, posterior KC, subclinical/mild KC, superior KC, and pseudo-KC, respectively. CONCLUSION Current imaging modalities of the cornea and our accumulated experience in refractive science allow assignment of distinctive designations for abnormal corneal shapes along the topography spectrum. We devised and used the expressions: normal, atypical normal, forme fruste (arrested-incomplete) KC, posterior KC, subclinical (active latent) KC, superior KC, and pseudo-keratoconus. Identification of 1.5% (mild) KC highlights the importance of screening for ultraviolet cross-linkage candidacy in refractive surgery referrals.
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Hashmani S, Hashmani N, Rajani H, Ramesh P, Soomro JA, Hussain Shah SR, Kumar J, Mahmood Shah SM. Comparison of visual acuity, refractive outcomes, and satisfaction between LASIK performed with a microkeratome and a femto laser. Clin Ophthalmol 2017; 11:1009-1014. [PMID: 28579752 PMCID: PMC5449167 DOI: 10.2147/opth.s137451] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Purpose To compare refractive outcomes, visual acuities, and satisfaction of patients between those treated with laser-assisted in situ keratomileusis (LASIK) using a Hansatome microkeratome (HM) and femto-assisted laser (FAL). Methods This was a retrospective analysis of 1,366 eyes in 687 patients who underwent LASIK with an HM (n=1,137) and an FAL (n=229) at the two centers of Hashmanis Hospital, Karachi, Pakistan. Refractive outcomes, including sphere, cylinder, and spherical equivalent in diopters (D), and visual acuities were assessed both preoperatively and at 1 month follow-up. Patient satisfaction was gauged by contacting the patient at the time of chart review. Results The postoperative median sphere, cylinder, and spherical equivalent values for those treated with FAL were 0.3±0.7 (−5.5–1.8), −0.5±0.6 (−5.0–1.0), and 0.0±0.7 (−6.0–1.6), respectively. For the HM arm, they were 0.0±1.28 (−10.8–6.8), −0.5±0.5 (−4.5–1.5), and −0.3±1.3 (−11.6–6.8), respectively. All preoperative values were statistically insignificant between the groups, while postoperative values were significant with P-values <0.001. Predictability and efficacy index was higher for the FAL (92.1%, 1.00) than the HM group (82.2%, 0.84). Similarly, patient satisfaction was slightly higher for those treated with FAL (93.3%) than HM (91.4%). Conclusion Our large retrospective analysis of eyes that have undergone LASIK using HM and FAL shows superior refractive outcomes in the latter, with special regard to procedural efficacy and predictability.
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Affiliation(s)
- Sharif Hashmani
- Department of Ophthalmology, Hashmanis Hospital, Karachi, Pakistan
| | - Nauman Hashmani
- Department of Ophthalmology, Hashmanis Hospital, Karachi, Pakistan
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Meidani A, Tzavara C. Comparison of efficacy, safety, and predictability of laser in situ keratomileusis using two laser suites. Clin Ophthalmol 2016; 10:1639-46. [PMID: 27601880 PMCID: PMC5003563 DOI: 10.2147/opth.s110626] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Purpose The main aim of this study was to compare the efficacy, safety, and predictability of femtosecond laser-assisted in situ keratomileusis performed by two different laser suites in the treatment of myopia for up to 6 months. Methods In this two-site retrospective nonrandomized study, myopic eyes that underwent laser-assisted in situ keratomileusis using IntraLase FS 60 kHz formed group 1 and those using WaveLight FS200 femtosecond laser system formed group 2. Ablation was performed with Visx Star S4 IR and WaveLight EX500 Excimer lasers, respectively, in groups 1 and 2. Both groups were well matched for age, sex, and mean level of preoperative refractive spherical equivalent (MRSE). Uncorrected distance visual acuity, corrected distance visual acuity, and MRSE were evaluated preoperatively and at 1 week, 1 month, and 6 months after treatment. Results Fifty-six eyes of 28 patients were included in the study. At 6-month follow-up postop, 78.6% of eyes in group 1 and 92.8% of eyes in group 2 achieved an uncorrected distance visual acuity of 20/20 or better (P=0.252). 35.7% and 50% in group 1 and group 2, respectively, gained one line (P=0.179). No eye lost lines of corrected distance visual acuity. Twenty-five eyes in group 1 (92.7%) and 27 eyes in group 2 (96.3%) had MRSE within ±0.5 D in the 6-month follow-up (P>0.999). The mean efficacy index at 6 months was similar in group 1 and group 2 (mean 1.10±0.12 [standard deviation] vs 1.10±0.1) (P=0.799). The mean safety index was similar in group 1 and group 2 (mean 1.10±0.10 [standard deviation] vs 1.10±0.09) (P=0.407). Conclusion: The outcomes were excellent between the two laser suites. There were no significant differences at 6-month follow-up postop between the two laser systems.
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Affiliation(s)
- Alexandra Meidani
- Hypervision Laser Centre; Eye Day Clinic; Department of Hygiene, University of Athens Medical School, Centre for Health Services Research, Epidemiology and Medical Statistics, Athens, Greece
| | - Chara Tzavara
- Department of Hygiene, University of Athens Medical School, Centre for Health Services Research, Epidemiology and Medical Statistics, Athens, Greece
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Zheng Y, Zhou YH, Zhang J, Liu Q, Zhang L, Deng ZZ, Li SM. Comparison of Visual Outcomes After Femtosecond LASIK, Wave Front-Guided Femtosecond LASIK, and Femtosecond Lenticule Extraction. Cornea 2016; 35:1057-61. [PMID: 27348719 DOI: 10.1097/ico.0000000000000891] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To compare the mesopic contrast sensitivity (CS) and higher order aberrations (HOAs) at 3 months after femtosecond-laser in situ keratomileusis (LASIK) (FS-LASIK), wave front-guided femtosecond LASIK (WF-LASIK), and femtosecond lenticule extraction (FLEx) for the correction of myopia and myopic astigmatism. METHODS In this prospective nonrandomized study, 332 right eyes of 332 patients were treated with FS-LASIK, WF-LASIK, or FLEx. The HOAs and mesopic CS were evaluated preoperatively and at 3 months postoperatively. RESULTS At 3 months of follow-up, 98 eyes (96.1%) of the FS-LASIK group, 92 eyes (98.9%) of the WF-LASIK group, and 133 eyes (96.4%) of the FLEx group had an uncorrected distance visual acuity of 20/20 or better. The HOAs improved from 0.34 μm during preoperative examination to 0.56 μm of the end of the follow-up in the FS-LASIK group, from 0.31 to 0.41 μm in the WF-LASIK group, and from 0.32 to 0.54 μm in the FLEx group (all P < 0.01). At a spatial frequency of 12 cycles per degree, a better mesopic CS was observed in the WF-LASIK group (1.47) than in the FS-LASIK (1.36) and FLEx (1.33) groups (P < 0.01); a better mesopic CS with glare was also noted in the WF-LASIK group (1.37) than in the FS-LASIK (1.25) and FLEx (1.29) groups (P < 0.01). CONCLUSIONS The FS-LASIK, WF-LASIK, and FLEx procedures result in comparable refractive results at 3 months postoperatively. However, there is improvement in the mesopic CS and HOAs after WF-LASIK.
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Affiliation(s)
- Yan Zheng
- Beijing Tongren Eye Center, Beijing Key Laboratory of Ophthalmology and Visual Science, Beijing Tongren Hospital, Capital Medical University, Beijing, China
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Al-Zeraid FM, Osuagwu UL. Induced Higher-order aberrations after Laser In Situ Keratomileusis (LASIK) Performed with Wavefront-Guided IntraLase Femtosecond Laser in moderate to high Astigmatism. BMC Ophthalmol 2016; 16:29. [PMID: 27000109 PMCID: PMC4802649 DOI: 10.1186/s12886-016-0205-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 03/07/2016] [Indexed: 11/10/2022] Open
Abstract
Background Wavefront-guided Laser-assisted in situ keratomileusis (LASIK) is a widespread and effective surgical treatment for myopia and astigmatic correction but whether it induces higher-order aberrations remains controversial. The study was designed to evaluate the changes in higher-order aberrations after wavefront-guided ablation with IntraLase femtosecond laser in moderate to high astigmatism. Methods Twenty-three eyes of 15 patients with moderate to high astigmatism (mean cylinder, −3.22 ± 0.59 dioptres) aged between 19 and 35 years (mean age, 25.6 ± 4.9 years) were included in this prospective study. Subjects with cylinder ≥ 1.5 and ≤2.75 D were classified as moderate astigmatism while high astigmatism was ≥3.00 D. All patients underwent a femtosecond laser–enabled (150-kHz IntraLase iFS; Abbott Medical Optics Inc) wavefront-guided ablation. Uncorrected (UDVA), corrected (CDVA) distance visual acuity in logMAR, keratometry, central corneal thickness (CCT) and higher-order aberrations (HOAs) over a 6 mm pupil, were assessed before and 6 months, postoperatively. The relationship between postoperative change in HOA and preoperative mean spherical equivalent refraction, mean astigmatism, and postoperative CCT were tested. Results At the last follow-up, the mean UDVA was increased (P < 0.0001) but CDVA remained unchanged (P = 0.48) and no eyes lost ≥2 lines of CDVA. Mean spherical equivalent refraction was reduced (P < 0.0001) and was within ±0.50 D range in 61 % of eyes. The average corneal curvature was flatter by 4 D and CCT was reduced by 83 μm (P < 0.0001, for all), postoperatively. Coma aberrations remained unchanged (P = 0.07) while the change in trefoil (P = 0.047) postoperatively, was not clinically significant. The 4th order HOAs (spherical aberration and secondary astigmatism) and the HOA root mean square (RMS) increased from −0.18 ± 0.07 μm, 0.04 ± 0.03 μm and 0.47 ± 0.11 μm, preoperatively, to 0.33 ± 0.19 μm (P = 0.004), 0.21 ± 0.09 μm (P < 0.0001) and 0.77 ± 0.27 μm (P < 0.0001), six months postoperatively. The change in spherical aberration after the procedure increased with an increase in the degree of preoperative myopia. Conclusions Wavefront-guided IntraLASIK offers a safe and effective option for vision and visual function improvement in astigmatism. Although, reduction of HOA is possible in a few eyes, spherical-like aberrations are increased in majority of the treated eyes.
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Affiliation(s)
- Ferial M Al-Zeraid
- Department of Optometry & Vision Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, P.O Box 10219, Riyadh, 11433, Saudi Arabia
| | - Uchechukwu L Osuagwu
- Department of Optometry & Vision Sciences, Faculty of Health, Ophthalmic and Visual Optics Laboratory Group (Chronic Disease & Ageing), Institute of Health and Biomedical Innovation, Q Block, Room 5WS36 60 Musk Avenue Kelvin Grove, Brisbane, QLD, 4059, Australia.
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Huhtala A, Pietilä J, Mäkinen P, Uusitalo H. Femtosecond lasers for laser in situ keratomileusis: a systematic review and meta-analysis. Clin Ophthalmol 2016; 10:393-404. [PMID: 27022236 PMCID: PMC4788361 DOI: 10.2147/opth.s99394] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Purpose The aim of this study was to review and meta-analyze whether there are differences between reported femtosecond (FS) lasers for laser-assisted in situ keratomileusis (LASIK) in terms of efficacy, predictability, and safety as primary outcomes and corneal flap thickness measurements and pre- and postoperative complications as secondary outcomes. Methods A comprehensive literature search of PubMed, Science Direct, Scopus, and Cochrane CENTRAL Trials Library databases was conducted to identify the relevant prospective randomized controlled trials of FS lasers for LASIK. Thirty-one articles describing a total of 5,404 eyes were included. Results Based on efficacy, IntraLase FS 10 and 30 kHz gave the best results. Based on predictability and safety, there were no differences between various FS lasers. FEMTO LDV and IntraLase FS 60 kHz produced the most accurate flap thicknesses. IntraLase and Wavelight SF200 had the fewest intraoperative complications. IntraLase, Visumax, and Wavelight FS200 had the most seldom postoperative complications. Conclusion There were dissimilarities between different FS lasers based on efficacy and intraoperative and postoperative complications. All FS lasers were predictable and safe for making corneal flaps in LASIK.
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Affiliation(s)
- Anne Huhtala
- Silmäasema Eye Hospital, School of Medicine, School of Medicine, University of Tampere, Tampere, Finland
| | - Juhani Pietilä
- Silmäasema Eye Hospital, School of Medicine, School of Medicine, University of Tampere, Tampere, Finland; SILK, Department of Ophthalmology, School of Medicine, University of Tampere, Tampere, Finland
| | - Petri Mäkinen
- Silmäasema Eye Hospital, School of Medicine, School of Medicine, University of Tampere, Tampere, Finland; SILK, Department of Ophthalmology, School of Medicine, University of Tampere, Tampere, Finland
| | - Hannu Uusitalo
- Silmäasema Eye Hospital, School of Medicine, School of Medicine, University of Tampere, Tampere, Finland; SILK, Department of Ophthalmology, School of Medicine, University of Tampere, Tampere, Finland; TAUH Eye Center, Tampere University Hospital, Tampere, Finland
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Wei S, Wang Y, Wu D, Zu P, Zhang H, Su X. Ultrastructural Changes and Corneal Wound Healing After SMILE and PRK Procedures. Curr Eye Res 2016; 41:1316-1325. [PMID: 26863271 DOI: 10.3109/02713683.2015.1114653] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To compare keratocyte activation, cellular morphologic changes and wound healing after SMILE and PRK procedures using transmission electron microscope (TEM). METHODS In this study, 22 New Zealand white rabbits (10- to 15-week old) were used. The right eyes of all animals underwent SMILE procedure and the left eyes underwent PRK procedure. Cornea samples taken 1 day and 1 week postoperatively were examined using TEM. RESULTS Using TEM 1 day after SMILE procedure, the organization of collagen fibers seemed to have been preserved without thermal alterations. Keratocyte activation was observed in the anterior stroma. Disrupted collagen arrangement and debris of cells are visible in the area of damage, and some phagocytic cells and a large number of secondary lysosomes are visible in those cells. At the perimeter zone of the interface, many coenocytes and collagen fragments could be found within the phagocytic cell. One week after SMILE procedure, potential lacuna could be discerned. A large part of the interface of the lenticule extracted had an appearance of clearly being adhered to some mucus secretions. One day after PRK procedure, an irregular epithelial surface was visible using TEM. Keratocytes had been activated and the rough endoplasmic reticulum in those cells had expanded. One week after PRK procedure, the epithelial surface still was irregular and keratinization of the epithelium was still visible in some areas. Corneal endothelium cells were mildly damaged and some vacuoles within the cytoplasm could be discerned. In the anterior stroma, some unhealthy activated keratocytes could still be observed. New collagen fibrils were found present near the activated keratocytes. CONCLUSION Using TEM, keratocyte activation could still be observed after SMILE compared to after PRK procedure. Fewer cellular ultrastructural changes were seen after SMILE procedure. Unlike in PRK procedure, no damaged epithelium and endothelium were found after SMILE.
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Affiliation(s)
- Shengsheng Wei
- a Tianjin Eye Hospital & Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science , Tianjin Medical University , Tianjin , China
| | - Yan Wang
- a Tianjin Eye Hospital & Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science , Tianjin Medical University , Tianjin , China
| | - Di Wu
- a Tianjin Eye Hospital & Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science , Tianjin Medical University , Tianjin , China
| | - PeiPei Zu
- a Tianjin Eye Hospital & Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science , Tianjin Medical University , Tianjin , China
| | - Hui Zhang
- a Tianjin Eye Hospital & Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science , Tianjin Medical University , Tianjin , China
| | - Xiaolian Su
- a Tianjin Eye Hospital & Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science , Tianjin Medical University , Tianjin , China
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Santos AMD, Torricelli AAM, Marino GK, Garcia R, Netto MV, Bechara SJ, Wilson SE. Femtosecond Laser-Assisted LASIK Flap Complications. J Refract Surg 2016; 32:52-9. [DOI: 10.3928/1081597x-20151119-01] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 11/01/2015] [Indexed: 01/13/2023]
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Liu HH, Hu Y, Cui HP. Femtosecond laser in refractive and cataract surgeries. Int J Ophthalmol 2015; 8:419-26. [PMID: 25938066 DOI: 10.3980/j.issn.2222-3959.2015.02.36] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 09/15/2014] [Indexed: 11/02/2022] Open
Abstract
In the past few years, 9 unique laser platforms have been brought to the market. As femtosecond (FS) laser-assisted ophthalmic surgery potentially improves patient safety and visual outcomes, this new technology indeed provides ophthalmologists a reliable new option. But this new technology also poses a range of new clinical and financial challenges for surgeons. We provide an overview of the evolution of FS laser technology for use in refractive and cataract surgeries. This review describes the available laser platforms and mainly focuses on discussing the development of ophthalmic surgery technologies.
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Affiliation(s)
- Han-Han Liu
- Department of Ophthalmology, Shanghai East Hospital Affiliated to Tongji University, Shanghai 200120, China
| | - Ying Hu
- Department of Ophthalmology, Shanghai East Hospital Affiliated to Tongji University, Shanghai 200120, China
| | - Hong-Ping Cui
- Department of Ophthalmology, Shanghai East Hospital Affiliated to Tongji University, Shanghai 200120, China
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Donoso R, Díaz C, Villavicencio P. [Long-term results of lasik refractive error correction after penetrating keratoplasty in patients with keratoconus]. ACTA ACUST UNITED AC 2015; 90:308-11. [PMID: 25817948 DOI: 10.1016/j.oftal.2014.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 10/10/2014] [Accepted: 11/03/2014] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To evaluate the long term results of Lasik for residual refractive errors (RE) after penetrating keratoplasty (PKP) for keratoconus (KC). DESIGN Retrospective cohort. METHOD Records of 14 consecutive patients (19 eyes) who had Lasik after PKP for KC were retrospectively reviewed. In all eyes with refractive stability and suture removed before Lasik, far distance Visual Acuity with (AVCC) and without correction (AVSC), spherical equivalent (EE), refractive (Ast) and keratometric (dK) astigmatism were analyzed pre- and post-operatively before and after one year of follow up. Data were analyzed using Shapiro-Wilk normality test, Student t test and Mann-Whitney test. A P-value of <0,05 was considered statistically significant. RESULTS The mean follow-up time was 3.16 months for the follow-up before one year postoperative and 5.8 years for the follow-up after one year postoperative. The best spectacle corrected visual acuity of 0,11 LogMAR (DE 0,07) before Lasik remained stable throughout the study. The SE decreased from -2.6 (DE 3.53) to -0,36 D (DE 1.33) (P<.05) for the follow-up before one year postoperative and -1.28 D (DE 1.63) (P=.07) for the follow-up after one year postop. The refractive cylinder was reduced from -3.43 (DE 1.35) preoperative to -1.37 D (DE 1.24) (P<.05) and -3.21 D (DE 2.29) (P=.36) in the long term after one year of follow-up. CONCLUSIONS Lasik refractive results regress one year after the operation; therefore it is not an effective long-term surgical refractive procedure for residual refractive errors after PKP for KC.
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Affiliation(s)
- R Donoso
- Clínica Oftalmológica Pasteur, Servicio de Oftalmología, Hospital del Salvador, Universidad de Chile, Santiago, Chile.
| | - C Díaz
- Clínica Oftalmológica Pasteur, Servicio de Oftalmología, Hospital del Salvador, Universidad de Chile, Santiago, Chile
| | - P Villavicencio
- Clínica Oftalmológica Pasteur, Servicio de Oftalmología, Hospital del Salvador, Universidad de Chile, Santiago, Chile
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Alio JL, Grzybowski A, El Aswad A, Romaniuk D. Refractive lens exchange. Surv Ophthalmol 2014; 59:579-98. [DOI: 10.1016/j.survophthal.2014.04.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 04/16/2014] [Accepted: 04/22/2014] [Indexed: 10/25/2022]
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Abstract
PURPOSE OF REVIEW To update the knowledge on differences between mechanical microkeratome and femtosecond flaps for laser in-situ keratomileusis (LASIK) in terms of accuracy and complications. RECENT FINDINGS Corneal flaps created with the femtosecond laser present a more planar architecture and provide greater precision in flap diameter and thickness; a more uniform flap thickness across the flap diameter and it allows the surgeon to programme the angulation of the flap periphery. Femtosecond LASIK flaps are classically related to complications derived from a more intense inflammatory response, such as diffuse lamellar keratitis and transient light-sensitivity syndrome. Newer femtosecond models allow for much lower energy delivery to cut the flap, to the point the overall inflammatory response is not significantly different from the microkeratome. The incidence of complications such as epithelial defect and flap dislocations is higher with microkeratome flaps. SUMMARY This review examines the accuracy and complications of flaps created with femtosecond and microkeratome. Both femtosecond and microkeratome are able to create accurate LASIK flaps. Femtosecond LASIK flaps represent significant improvement in morphology and predictability with implications for safety.
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Wu D, Wang Y, Zhang L, Wei S, Tang X. Corneal biomechanical effects: small-incision lenticule extraction versus femtosecond laser-assisted laser in situ keratomileusis. J Cataract Refract Surg 2014; 40:954-62. [PMID: 24751146 DOI: 10.1016/j.jcrs.2013.07.056] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 07/23/2013] [Accepted: 07/26/2013] [Indexed: 10/25/2022]
Abstract
PURPOSE To compare the biomechanical properties of the cornea after small-incision lenticule extraction (lenticule extraction group) with those after femtosecond laser-assisted laser in situ keratomileusis (femtosecond LASIK group). SETTING Tianjin Eye Hospital & Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Medical University, Tianjin, China. DESIGN Prospective comparative case series. METHODS Corneal hysteresis (CH), the corneal resistance factor (CRF), and 37 other biomechanical waveform parameters were quantitatively assessed with the Ocular Response Analyzer preoperatively and 1 week and 1, 3, and 6 months postoperatively. RESULTS Each group comprised 40 eyes. The decrease in CH and the CRF was statistically significant 1 week postoperatively compared with preoperatively in both groups (P<.0001). However, the CH and CRF values in the lenticule extraction group were significantly higher than those in the femtosecond LASIK group 3 months and 6 months postoperatively (P<.032). The residual stromal thickness index versus the CRF and CH and the planned lenticule thickness versus the change in central corneal thickness were statistically significant in the lenticule extraction group (r = 0.388 to 0.950, P<.018); no significant correlation was found in the femtosecond LASIK group. In the waveform analysis of the lenticule extraction group, 28 of the 37 biomechanical waveform parameters differed significantly between preoperative values and postoperative values (P<.035). CONCLUSIONS Both small-incision lenticule extraction and femtosecond laser-assisted LASIK can cause biomechanical changes in the cornea. However, changes in the cornea's viscoelastic properties were less after lenticule extraction than after LASIK. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Di Wu
- From Tianjin Eye Hospital & Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Medical University, Tianjin, China
| | - Yan Wang
- From Tianjin Eye Hospital & Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Medical University, Tianjin, China.
| | - Lin Zhang
- From Tianjin Eye Hospital & Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Medical University, Tianjin, China
| | - Shengsheng Wei
- From Tianjin Eye Hospital & Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Medical University, Tianjin, China
| | - Xin Tang
- From Tianjin Eye Hospital & Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Medical University, Tianjin, China
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Kymionis GD, Kontadakis GA, Naoumidi I, Kankariya VP, Panagopoulou S, Manousaki A, Grentzelos MA, Pallikaris IG. Comparative study of stromal bed of LASIK flaps created with femtosecond lasers (IntraLase FS150, WaveLight FS200) and mechanical microkeratome. Br J Ophthalmol 2013; 98:133-7. [DOI: 10.1136/bjophthalmol-2013-304023] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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37
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Rosman M, Hall RC, Chan C, Ang A, Koh J, Htoon HM, Tan DT, Mehta JS. Comparison of efficacy and safety of laser in situ keratomileusis using 2 femtosecond laser platforms in contralateral eyes. J Cataract Refract Surg 2013; 39:1066-73. [DOI: 10.1016/j.jcrs.2013.02.038] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Revised: 02/15/2013] [Accepted: 02/18/2013] [Indexed: 10/26/2022]
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Sutton G, Lawless M, Hodge C. Laser in situ keratomileusis in 2012: a review. Clin Exp Optom 2013; 97:18-29. [PMID: 23786377 DOI: 10.1111/cxo.12075] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Revised: 11/08/2012] [Accepted: 12/14/2012] [Indexed: 11/25/2022] Open
Abstract
Laser in situ keratomileusis (LASIK) is a safe and effective treatment for refractive error. A combination of technological advances and increasing surgeon experience has served to further refine refractive outcomes and reduce complication rates. In this article, we review LASIK as it stands in late 2012: the procedure, indications, technology, complications and refractive outcomes.
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Affiliation(s)
- Gerard Sutton
- Vision Eye Institute, Chatswood, New South Wales, Australia; Save Sight Institute, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia.
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Shetty R, Malhotra C, D'Souza S, Wadia K. WaveLight FS200 vs Hansatome LASIK: intraoperative determination of flap characteristics and predictability by hand-held bioptigen spectral domain ophthalmic imaging system. J Refract Surg 2013; 28:S815-20. [PMID: 23447894 DOI: 10.3928/1081597x-20121005-01] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To intraoperatively determine and compare the characteristics and predictability of LASIK flaps made by the WaveLight FS200 femtosecond laser (Alcon Laboratories Inc) and Hansatome (Bausch & Lomb) microkeratome using a hand-held spectral domain ophthalmic imaging system (Bioptigen Inc). METHODS Sixty eyes from 30 patients undergoing bilateral LASIK were prospectively evaluated. Patients were divided into two equal groups to undergo flap creation with either 100-microm femtosecond laser flaps (FS flap group) or 120-microm microkeratome flaps (MK flap group). Flap thickness was measured intraoperatively after creation of the flap but prior to lifting using the hand-held probe of the spectral domain imaging system. Geometry of the flap edge and smoothness of the stromal bed after lifting the flap was also evaluated in all cases. RESULTS Mean difference between planned and achieved flap thickness in the paracentral region was 2.84 +/- 3.16 mm for the FS flap group and 11.33 +/- 10.27 mm for the MK flap group, whereas in the periphery, it was 5.72 +/- 3.26 mm in the FS flap group and 24.67 +/- 10.35 mm in the MK flap group. The differences between groups were statistically significant (P < 0.001, Kruskal-Wallis test). The edges of the flaps were vertical in the FS flap group and the stromal bed was smoother, whereas in the MK flap group, the edges were more sloping and the stromal bed more irregular. CONCLUSIONS The WaveLight FS200 femtosecond laser is able to produce planar flaps with a high degree of predictability between the desired and achieved flap thickness. The ability to study the flap characteristics intraoperatively (when flap edema and stromal bed hydration changes have not yet occurred) with the hand-held probe of the Bioptigen imaging system ensures greater accuracy than measurements done postoperatively using other anterior segment optical coherence tomography prototypes.
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Affiliation(s)
- Rohit Shetty
- Narayana Nethralaya Eye Hospital, Bangalore, India
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Ackermann R, Kammel R, Merker M, Kamm A, Tünnermann A, Nolte S. Optical side-effects of fs-laser treatment in refractive surgery investigated by means of a model eye. BIOMEDICAL OPTICS EXPRESS 2013; 4:220-9. [PMID: 23413236 PMCID: PMC3567709 DOI: 10.1364/boe.4.000220] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 11/29/2012] [Accepted: 11/30/2012] [Indexed: 05/25/2023]
Abstract
Optical side-effects of fs-laser treatment in refractive surgery are investigated by means of a model eye. We show that rainbow glare is the predominant perturbation, which can be avoided by randomly distributing laser spots within the lens. For corneal applications such as fs-LASIK, even a regular grid with spot-to-spot distances of ~3 µm is sufficient to minimize rainbow glare perception. Contrast sensitivity is affected, when the lens is treated with large 3D-patterns.
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Affiliation(s)
- Roland Ackermann
- Institute of Applied Physics, Abbe Center of Photonics,
Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena,
Germany
| | - Robert Kammel
- Institute of Applied Physics, Abbe Center of Photonics,
Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena,
Germany
| | - Marina Merker
- Institute of Applied Physics, Abbe Center of Photonics,
Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena,
Germany
| | - Andreas Kamm
- Fraunhofer Institute for Applied Optics and Precision Engineering
(IOF), Albert-Einstein-Straße 7, 07745 Jena, Germany
| | - Andreas Tünnermann
- Institute of Applied Physics, Abbe Center of Photonics,
Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena,
Germany
- Fraunhofer Institute for Applied Optics and Precision Engineering
(IOF), Albert-Einstein-Straße 7, 07745 Jena, Germany
| | - Stefan Nolte
- Institute of Applied Physics, Abbe Center of Photonics,
Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena,
Germany
- Fraunhofer Institute for Applied Optics and Precision Engineering
(IOF), Albert-Einstein-Straße 7, 07745 Jena, Germany
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Christiansen SM, Mifflin MD, Edmonds JN, Simpson RG, Moshirfar M. Astigmatism induced by conventional spherical ablation after PRK and LASIK in myopia with astigmatism < 1.00 D. Clin Ophthalmol 2012; 6:2109-17. [PMID: 23277735 PMCID: PMC3532022 DOI: 10.2147/opth.s37489] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND The purpose of this study was to evaluate surgically-induced astigmatism after spherical ablation in photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK) for myopia with astigmatism < 1.00 D. METHODS The charts of patients undergoing spherical PRK or LASIK for the correction of myopia with minimal astigmatism of <1.00 D from 2002 to 2012 at the John A Moran Eye Center in Salt Lake City, UT, were retrospectively reviewed. Astigmatism was measured by manifest refraction. The final astigmatic refractive outcome at 6 months postoperatively was compared with the initial refraction by Alpins vector analysis. RESULTS For PRK, average cylinder increased from 0.39 ± 0.25 (0.00-0.75) preoperatively to 0.55 ± 0.48 (0.00-1.75) postoperatively (P = 0.014), compared with an increase in LASIK eyes from 0.40 ± 0.27 (0.00-0.75) preoperatively to 0.52 ± 0.45 (0.00-2.00) postoperatively (P = 0.041). PRK eyes experienced an absolute value change in cylinder of 0.41 ± 0.32 (0.00-1.50) and LASIK eyes experienced a change of 0.41 ± 0.31 (0.00-1.50, P = 0.955). Mean surgically-induced astigmatism was 0.59 ± 0.35 (0.00-1.70) in PRK eyes, with an increase in surgically-induced astigmatism of 0.44 D for each additional 1.00 D of preoperative cylinder; in LASIK eyes, mean surgically-induced astigmatism was 0.55 ± 0.32 (0.00-1.80, P = 0.482), with an increase in surgically-induced astigmatism of 0.29 D for each 1.00 D of preoperative cylinder. CONCLUSION Spherical ablation can induce substantial astigmatism even in eyes with less than one diopter of preoperative astigmatism in both PRK and LASIK. No significant difference in the magnitude of surgically-induced astigmatism was found between eyes treated with PRK and LASIK, although surgically-induced astigmatism was found to increase with greater levels of preoperative astigmatism in both PRK and LASIK.
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Khoramnia R, Salgado JP, Wuellner C, Donitzky C, Lohmann CP, Winkler von Mohrenfels C. Safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK) with a 1000-Hz scanning spot excimer laser. Acta Ophthalmol 2012; 90:508-13. [PMID: 21266022 DOI: 10.1111/j.1755-3768.2010.02052.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
PURPOSE To evaluate the safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK) with a 1000-Hz scanning spot excimer laser (Concept System 1000; WaveLight GmbH, Erlangen, Germany). METHODS LASIK was performed on twenty eyes with myopia or myopic astigmatism (mean spherical equivalent refraction: -3.97±1.72 dioptres (D); mean cylinder: -0.84±0.77 D) using a microkeratome for flap creation and the Concept System 1000 for photoablation. Patients were examined preoperatively as well as 1, 3 and 6 months after the treatment. Manifest sphere and cylinder, uncorrected (UCDVA) and best corrected (BCDVA) distance visual acuity, corneal topography and pachymetry were analysed. RESULTS We observed no adverse events that might have been associated with the use of a repetition rate of 1000 Hz. All eyes maintained or had improved BCDVA at 6 months after treatment when compared to preoperative values. Six months after LASIK, UCDVA was 20/20 or better in 85% and 20/25 or better in 100% of the eyes. The spherical equivalent refraction was within ±0.50 D in 95% of the eyes at 6 months after surgery. The refraction stayed stable over time; 95% of the eyes changed<0.5 D postoperatively. CONCLUSION LASIK with the prototype 1000-Hz excimer laser was safe, efficient and predictable. The postoperative refraction was stable over time. There were no specific clinical side-effects that might be associated with the use of such a high repetition rate.
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Affiliation(s)
- Ramin Khoramnia
- Department of Ophthalmology, Technical University Munich, Munich, Germany.
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Paysse EA, Tychsen L, Stahl E. Pediatric refractive surgery: corneal and intraocular techniques and beyond. J AAPOS 2012; 16:291-7. [PMID: 22681949 DOI: 10.1016/j.jaapos.2012.01.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 12/01/2011] [Accepted: 01/29/2012] [Indexed: 11/16/2022]
Abstract
Refractive surgery has now been used successfully to treat severe anisometropia and isoametropia associated with amblyopia in children who cannot wear standard spectacles or contact lenses. Extraocular techniques include photorefractive keratectomy, laser-assisted subepithelial keratomileusis, and laser-assisted in situ keratomileusis. Intraocular techniques include refractive lensectomy and phakic intraocular lenses and are still being investigated in children for refractive errors outside the treatment dose capabilities of the excimer laser. This workshop discusses the various techniques, how and when to use each, and their risks and benefits. Newer techniques currently being used in adults that may someday be used in children are also introduced.
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Affiliation(s)
- Evelyn A Paysse
- Baylor College of Medicine, Texas Children's Hospital, Houston, Texas, USA.
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Cellular effects after laser in situ keratomileusis flap formation with femtosecond lasers: a review. Cornea 2012; 31:198-205. [PMID: 22157568 DOI: 10.1097/ico.0b013e3182068c42] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To provide an overview of the cellular effects of femtosecond laser in laser in situ keratomileusis flap formation. METHODS Literature review. RESULTS The IntraLase is the only femtosecond laser with sufficient histopathological and confocal studies to allow review of the cellular effects of laser application. Histopathological analyses have demonstrated that the energy per pulse and total energy delivered play important roles in the inflammatory reaction to the surgery. The IntraLase laser triggers cellular necrosis (death accompanied by the release of lysosomal enzymes and other components from membrane-bound intracellular compartments) in the corneal stroma surrounding the lamellar cut rather than apoptosis (gentler form of cell death in which most intracellular components remain confined to membrane-bound apoptotic bodies) that is predominant with the microkeratome. Necrosis is a more inflammatory form of cell death that attracts more inflammatory cells. This is likely why earlier femtosecond lasers, such as the 15-kHz IntraLase laser, which requires higher total energy delivery to cut a flap, are associated with more corneal inflammation and diffuse lamellar keratitis. The design of the 60-kHz IntraLase model allows for much lower energy delivery to cut the flap and, therefore, a substantial reduction in keratocyte necrosis to the point that the overall inflammatory response is not significantly different from the microkeratome. Histopathological analysis performed with the Femtec femtosecond laser noted little change in the corneal stromal structure. Confocal microcopy studies performed with the IntraLase laser showed keratocyte "activation" in the stroma and greater fibrotic scarring at the interface than that induced by a mechanical microkeratome. CONCLUSIONS The morphologic alterations in the corneal stroma produced by currently available models of the IntraLase laser are comparable to those produced by mechanical microkeratomes. Advances that have resulted in a reduction in the total amount of energy delivered by the laser when it cuts the flap have resulted in a decrease in the inflammatory response associated with femtosecond flap formation to the point that it is indistinguishable from the microkeratome at the cellular level. Further study of each of the femtosecond laser models, including the 150-kHz IntraLase laser, is needed to fully characterize the corneal response to these lasers.
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Chen S, Feng Y, Stojanovic A, Jankov MR, Wang Q. IntraLase femtosecond laser vs mechanical microkeratomes in LASIK for myopia: a systematic review and meta-analysis. J Refract Surg 2012; 28:15-24. [PMID: 22233436 DOI: 10.3928/1081597x-20111228-02] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 10/13/2011] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate the safety, efficacy, and predictability of IntraLase (Abbott Medical Optics) femtosecond laser-assisted compared to microkeratome-assisted myopic LASIK. METHODS A comprehensive literature search of Cochrane Library, PubMed, and EMBASE was conducted to identify relevant trials comparing LASIK with IntraLase femtosecond laser to LASIK with microkeratomes for the correction of myopia. Meta-analyses were performed on the primary outcomes (loss of ≥2 lines of corrected distance visual acuity [CDVA], uncorrected distance visual acuity [UDVA] 20/20 or better, manifest refraction spherical equivalent [MRSE] within ±0.50 diopters [D], final refractive SE, and astigmatism), and secondary outcomes (flap thickness predictability, changes in higher order aberrations [HOAs], and complications). RESULTS Fifteen articles describing a total of 3679 eyes were identified. No significant differences were identified between the two groups in regards to a loss of ≥2 lines of CDVA (P=.44), patients achieving UDVA 20/20 or better (P=.24), final UDVA (P=.12), final mean refractive SE (P=.74), final astigmatism (P=.27), or changes in HOAs. The IntraLase group had more patients who were within ±0.50 D of target refraction (P=.05) compared to the microkeratome group, and flap thickness was more predictable in the IntraLase group (P<.0001). The microkeratome group had more epithelial defects (P=.04), whereas the IntraLase group had more cases of diffuse lamellar keratitis (P=.01). CONCLUSIONS According to the available data, LASIK with the IntraLase femtosecond laser offers no significant benefits over LASIK with microkeratomes in regards to safety and efficacy, but has potential advantages in predictability.
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Affiliation(s)
- Shihao Chen
- The Affiliated Eye Hospital, Wenzhou Medical College, Zhejiang, China
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Zhang ZH, Jin HY, Suo Y, Patel SV, Montés-Micó R, Manche EE, Xu X. Femtosecond laser versus mechanical microkeratome laser in situ keratomileusis for myopia: Metaanalysis of randomized controlled trials. J Cataract Refract Surg 2011; 37:2151-9. [DOI: 10.1016/j.jcrs.2011.05.043] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2010] [Revised: 05/18/2011] [Accepted: 05/23/2011] [Indexed: 10/15/2022]
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Xu L, Knox WH, DeMagistris M, Wang N, Huxlin KR. Noninvasive intratissue refractive index shaping (IRIS) of the cornea with blue femtosecond laser light. Invest Ophthalmol Vis Sci 2011; 52:8148-55. [PMID: 21931133 DOI: 10.1167/iovs.11-7323] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
PURPOSE To test the feasibility of intratissue refractive index shaping (IRIS) in living corneas by using 400-nm femtosecond (fs) laser pulses (blue-IRIS). To test the hypothesis that the intrinsic two-photon absorption of the cornea allows blue-IRIS to be performed with greater efficacy than when using 800-nm femtosecond laser pulses. METHODS Fresh cat corneas were obtained postmortem and cut into six wedges. Blue laser pulses at 400 nm, with 100-fs pulse duration at 80 MHz were used to micromachine phase gratings into each corneal wedge at scanning speeds from 1 to 15 mm/s. Grating lines were 1 μm wide, 5 μm apart, and 150 μm below the anterior corneal surface. Refractive index (RI) changes in micromachined regions were measured immediately by recording the diffraction efficiency of inscribed gratings. Six hours later, the corneas were processed for histology, and TUNEL staining was performed to assess whether blue-IRIS causes cell death. RESULTS Scanning at 1 and 2 mm/s caused overt corneal damage in the form of bubbles and burns. At faster scanning speeds (5, 10, and 15 mm/s), phase gratings were created in the corneal stroma, which were shown to be pure RI changes ranging from 0.037 to 0.021 in magnitude. The magnitude of RI change was inversely related to scanning speed. TUNEL staining showed cell death only around bubbles and burns. CONCLUSIONS Blue-IRIS can be performed safely and effectively in living cornea. Compared with near-infrared laser pulses, blue-IRIS enhances both achievable RI change and scanning speed without the need to dope the tissue with two-photon sensitizers, increasing the clinical applicability of this technique.
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Affiliation(s)
- Lisen Xu
- The Institute of Optics, University of Rochester, Rochester, New York, USA
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Al-Mezaine HS, Al-Amro SA, Al-Fadda A, Al-Obeidan S. Outcomes of Retreatment after Aborted Laser In Situ Keratomileusis due to Flap Complications. Middle East Afr J Ophthalmol 2011; 18:232-7. [PMID: 21887080 PMCID: PMC3162737 DOI: 10.4103/0974-9233.84054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Purpose: To determine the refractive outcomes and complications of retreatment after aborted primary laser in situ keratomileusis (LASIK) due to flap complications. Materials and Methods: This retrospective study evaluated 50 retreated eyes that had flap complications during primary LASIK at the Eye Consultants Center in Riyadh, Saudi Arabia. Data were analyzed for patients with at least 3 months follow-up post retreatment. Results: Thirty-three eyes of 31 consecutive patients with 3 months follow-up or later post retreatment were included. The primary LASIK was aborted due to incomplete flaps in 22 eyes (66.7%), buttonhole flaps in 7 eyes (21.2%), free partial flaps in 3 eyes (9.1%), and a free complete flap in 1 eye (3.0%). Twenty-two eyes (66.7%) were retreated with LASIK, and 11 eyes (33.3%) were retreated with surface ablation. The mean spherical equivalent (SE) was –0.23 ± 0.72 D, the mean astigmatism was –0.65 ± 0.89 D, and the mean loss of the best corrected visual acuity (BCVA) was 0.78 lines at the final postoperative visit. At the last postoperative visit, 20/30 or better BCVA was achieved in 90.1% of eyes that underwent retreatment with LASIK and in 91% of eyes that were retreated with surface ablation. There was no statistical difference in postoperative SE between eyes retreated with LASIK and eyes retreated with surface ablation (P = 0.610). There was no statistical difference in postoperative BCVA between eyes retreated with LASIK and those retreated with surface ablation (P = 0.756). There were no intraoperative complications and no eyes required a second retreatment. Conclusion: Creation of a flap after a previous intraoperative flap complication was not associated with any complications. The refractive outcomes of retreatment with LASIK or surface ablation were comparable and reasonably favorable.
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Affiliation(s)
- Hani S Al-Mezaine
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia
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Abstract
PURPOSE OF REVIEW The corneal flap laser in-situ keratomileusis (LASIK) is among the most important determinants in the successful outcome of the surgery. Femtosecond lasers have evolved over the last decade to all but replace the mechanical microkeratome as the preferred method to create these flaps. With improvements in femtosecond laser technology, there has been a reduction in the time taken for the cut and the quality of the stromal bed has improved. Improved predictability has led surgeons to explore the possibility of thin flap LASIK. RECENT FINDINGS Corneal flaps created with the femtosecond laser have been shown to be more predictable in depth and have a more desirable planar morphology. Corneal flaps created by the femtosecond laser can be customized according to depth, profile, morphology, and side-cut configuration. Changes in the angulation of the side cut, to reduce the incidence of epithelial ingrowth, have not been corroborated by clinical evidence as yet. Thin flap LASIK, also referred to as sub-Bowman's keratomileusis, has the advantage of preserving more stroma and potentially reducing the incidence of corneal ectasia but seems to be associated with an increased incidence of interface haze. SUMMARY This review examines the advantages of creating a flap with the femtosecond laser and the various configurations of these flaps. It also explores the advantages of varying the thickness and profile of femtosecond flaps.
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Espandar L, Meyer J. Intraoperative and Postoperative Complications of Laser in situ Keratomileusis Flap Creation Using IntraLase Femtosecond Laser and Mechanical Microkeratomes. Middle East Afr J Ophthalmol 2011; 17:56-9. [PMID: 20543937 PMCID: PMC2880374 DOI: 10.4103/0974-9233.61217] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
An essential step of laser in situ keratomileusis surgery is corneal flap creation, Femtosecond (FS)-assisted or mechanical microkeratome. Each type has rare intraoperative and postoperative complication rates. Several recent studies have identified risk factors and guidelines to help manage these complications. Fortunately, studies have shown no loss of best-corrected visual acuity (BCVA) after the management of intraoperative and postoperative complications in IntraLase FS and mechanical microkeratome. Refractive surgeons need to be aware of the types of complications that can occur, how to avoid them and how to manage them to ensure the best possible outcomes.
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Affiliation(s)
- Ladan Espandar
- Department of Ophthalmology, Tulane University, New Orleans, LA, USA
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