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Menon J. Refractive Corneal surgeries: A Review. KERALA JOURNAL OF OPHTHALMOLOGY 2022. [DOI: 10.4103/kjo.kjo_21_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Gao Y, Qi Y, Huang Y, Li X, Zhou L, Zhao S. Lipidomics Analysis of the Tears in the Patients Receiving LASIK, FS-LASIK, or SBK Surgery. Front Med (Lausanne) 2021; 8:731462. [PMID: 34778293 PMCID: PMC8579130 DOI: 10.3389/fmed.2021.731462] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 09/24/2021] [Indexed: 01/17/2023] Open
Abstract
Purpose: Tear film lipid layer (TFLL) plays a vital role in maintaining the tear film stability and, thus, the lipid composition of the tears could greatly affect the physiological function and biophysical integrity of the tear film. The objective of this study is to assess the tear lipid composition of the patients receiving laser-assisted in situ keratomileusis (LASIK), femtosecond LASIK (FS-LASIK), or sub-Bowman's keratomileusis (SBK) surgery preoperatively and postoperatively. Methods: Tear samples were collected from the left eye of the patient who receiving LASIK (n = 10), FS-LASIK (n = 10), or SBK (n = 10) surgery in week 0, week 1, week 4, and week 52. A rapid direct injection shotgun lipidomics workflow, MS/MSALL (<2 min/sample), was applied to examine the tear lipidome. Results: In week 52, the SBK group demonstrated a similar lipidome profile compared to week 0, while the FS-LASIK and LASIK groups shifted away from week 0. Two lipids, ganglioside (GD3) 27:4 and triacylglycerol (TAG) 59:3, were found to be associated with the lipidome changes preoperatively and postoperatively. No statistical significance was found in the overall lipid classes from the FS-LASIK group. The LASIK group showed significant alteration in the phospholipid and sphingolipid over time, while the SBK group demonstrated a significant difference in the (O-acyl)-ω-hydroxy fatty acid (OAHFA) and phospholipid. Conclusion: LASIK showed the greatest impact on the tear lipidome changes over time, while SBK demonstrated minimal impact among the three types of refractive surgeries after 1 year.
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Affiliation(s)
- Yan Gao
- Ocular Proteomics Platform, Singapore Eye Research Institute, Singapore, Singapore
| | - Yuanyuan Qi
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Yue Huang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Xiaorong Li
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Lei Zhou
- Ocular Proteomics Platform, Singapore Eye Research Institute, Singapore, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Ophthalmology and Visual Sciences Academia Clinical Program, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Shaozhen Zhao
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
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Jun I, Kang DSY, Roberts CJ, Lee H, Jean SK, Kim EK, Seo KY, Kim TI. Comparison of Clinical and Biomechanical Outcomes of Small Incision Lenticule Extraction With 120- and 140-µm Cap Thickness. Transl Vis Sci Technol 2021; 10:15. [PMID: 34259803 PMCID: PMC8288062 DOI: 10.1167/tvst.10.8.15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to compare the clinical outcomes and corneal biomechanical changes between 120-µm and 140-µm cap thickness after small incision lenticule extraction (SMILE). Methods This prospective study included 150 eyes (150 patients: 91 eyes in the 120-µm group, and 59 eyes in the 140-µm group) who underwent SMILE. Enhanced correction nomograms were applied for patients according to cap thickness. Clinical outcomes, including visual acuity, refraction, and corneal wavefront aberrations, were compared between the two groups. Corneal biomechanics were evaluated using the Corvis ST (Oculus, Wetzlar, Germany). Results The mean uncorrected-distance visual acuity, safety and efficacy indices, and refractive predictability were comparable in the 120-µm and 140-µm groups after SMILE. The postoperative total corneal root mean square higher-order aberrations (HOAs) and spherical aberrations was 0.48 ± 0.31 and 0.26 ± 0.10 in the 120-µm group, and 0.53 ± 0.16 and 0.34 ± 0.13 in the 140-µm group, which showed significant differences between the two groups (P = 0.027, and <0.001, respectively). Although corneal stiffness decreased after SMILE in both groups, the changes in the deformation amplitude ratio were significantly higher in the 140-µm group than in the 120-µm group (P = 0.022). Conclusions SMILE with 120-µm and 140-µm cap thickness provided excellent predictable outcomes according to our enhanced correction nomogram. The amount of tissue removal required to achieve the same amount of refractive correction was greater in the thicker cap group. The induction of corneal HOAs and weakening of corneal biomechanics were less pronounced in the thin-cap group, which may be associated with the thinner cap, lesser lenticule thickness, or thicker residual stromal bed. Translational Relevance Although SMILE with different cap thickness was effective, thicker lenticule thickness in the thick-cap group may be associated with induction of HOAs, and corneal stiffness changes.
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Affiliation(s)
- Ikhyun Jun
- The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea.,Corneal Dystrophy Research Institute, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | | | - Cynthia J Roberts
- Department of Ophthalmology & Visual Sciences and Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | - Hun Lee
- Department of Ophthalmology, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | | | - Eung Kweon Kim
- Corneal Dystrophy Research Institute, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea.,Saevit Eye Hospital, Goyang-Si, Gyeonggi-Do, Republic of Korea
| | - Kyoung Yul Seo
- The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Tae-Im Kim
- The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea.,Corneal Dystrophy Research Institute, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea
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Bages-Rousselon Y, Pinkus D, Rivas M, Butron K, Robledo N, Chayet A. Eighty-micron flap femtosecond-assisted LASIK for the correction of myopia and myopic astigmatism. J Cataract Refract Surg 2021; 47:445-449. [PMID: 33196573 DOI: 10.1097/j.jcrs.0000000000000484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/29/2020] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the safety and efficacy of 80-μm flap femtosecond laser-assisted LASIK and the early clinical and refractive outcomes in the correction of myopia and myopic astigmatism. SETTING Private practice, outpatient. DESIGN Prospective study. METHODS Patients who underwent femtosecond-assisted LASIK between February and April 2018 were included. Inclusion criteria were myopia from -1.00 to -8.00 diopters (D) and astigmatism up to -3.00 D and no previous surgeries. All patients were tested preoperatively and on day 1 and month 3 for uncorrected distance visual acuity (UDVA), manifest refraction, corrected distance visual acuity (CDVA), intraocular pressure (IOP), slitlamp and dilated fundus examination, Schirmer I test with anesthesia, and ocular surface disease index questionnaire. The FEMTO LDV Z8 was used for flap construction and the Wavelight Allegretto 400 excimer for refractive treatment. Flap thickness was measured at week 1 with anterior segment optical coherence tomography (AS-OCT). RESULTS Eighty-two eyes were included. Logarithm of the minimum angle of resolution UDVA was 1.28 ± 0.53 preoperatively, 0.02 ± 0.05 at day 1, and 0.14 ± 0.127 at month 3. There was no loss of CDVA lines. The mean flap thickness measured at 1 week with AS-OCT was 73 ± 6.7 µm. CONCLUSIONS The use of ultrathin flaps, just below Bowman's layer, with the Ziemer LDV Z8 femtosecond laser was possible, safe, reliable, and reproducible. Eighty-micron flaps allowed for excellent vision on 1 day post-LASIK and might be a good alternative to maintain an appropriate percentage of tissue altered, especially when attempting greater corrections or larger treatment zones.
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Beer SMC, Werner L, Nakano EM, Santos RT, Hirai F, Nitschke EJ, Francesconi Benicio C, Campos MSQ. A 3-year follow-up study of a new corneal inlay: clinical results and outcomes. Br J Ophthalmol 2019; 104:723-728. [PMID: 31446390 DOI: 10.1136/bjophthalmol-2019-314314] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 07/28/2019] [Accepted: 08/07/2019] [Indexed: 11/04/2022]
Abstract
PURPOSE Here, we report the results of a 3-year follow-up analysis of the outcomes of the Flexivue Microlens corneal inlay. PATIENTS Non-dominant eyes (n=31) of emmetropic presbyopic patients (spherical equivalent: -0.5 to 1.00 dioptre). METHODS A Flexivue Microlens corneal inlay was implanted after the creation of a 300 μm deep stromal pocket using a femtosecond laser. Patients were followed up according to a clinical protocol involving refraction, anterior segment imaging analysis (Oculyser), optical quality analysis (OPD-Scan), monocular binocular uncorrected and corrected visual acuity tests, contrast sensitivity measurements (photopic and mesopic), satisfaction questionnaire results and adverse event reporting. RESULTS Thirty patients were examined at the 3-year follow-up in this ongoing study. The mean uncorrected near visual acuity improved to Jaeger 1 in 76.9% of eyes treated with the inlays (vs 87.1% at the 1-year follow-up). All eyes improved four lines in all visits, except for four patients for whom the inlay was explanted. Patients reported that their near vision was good or excellent in 73.3% of cases (vs 90.3% in the first year). The UDVA remained stable over time. Three patients were explanted due to blurred vision for near-point and far-point distances. One patient developed a superficial corneal ulcer after 20 months. Two patients underwent cataract removal. Four patients underwent inlay exchange to increase near power correction. CONCLUSIONS The Presbia Flexivue Microlens provided presbyopia treatment by improving near vision. Manageable complications may occur over the long term. CLINICAL TRIAL REGISTRATION NUMBER U1111-1185-5684 and 0310451200000550.
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Affiliation(s)
| | - Liliana Werner
- Department of Ophthalmology and Visual Sciencies, University of Utah, Salt Lake City, Utah, USA
| | - Eliane Mayumi Nakano
- Department of Refractive Surgery, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
| | - Rodrigo T Santos
- Department of Refractive Surgery, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
| | - Flavio Hirai
- Department of Ophthalmology, Universidade Federal de Sao Paulo Escola Paulista de Medicina, Sao Paulo, Brazil
| | - Enrico J Nitschke
- Department of Ophthalmology, Universidade Federal de Sao Paulo Escola Paulista de Medicina, Sao Paulo, Brazil
| | | | - Mauro S Q Campos
- Department of Refractive Surgery, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
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Abstract
PURPOSE To report the results of a 1-year follow-up analysis of the safety and efficacy of the Flexivue Microlens corneal inlay. METHODS The Flexivue Microlens corneal inlay was implanted in the nondominant eye of patients with emmetropic presbyopia (a spherical equivalent of -0.5 to 1.00 diopter) after the creation of a 300-μm deep stromal pocket, using a femtosecond laser. The patients were followed up according to a clinical protocol involving refraction, anterior segment imaging analysis (Oculyzer), and optical quality analysis (OPD-Scan). RESULTS Thirty-one patients were enrolled in this ongoing study. The mean age was 50.7 years (range 45-60 yrs), and 70% of the patients were female. The mean uncorrected near visual acuity improved to Jaeger 1 in 87.1% of the eyes treated with the inlays. All eyes improved 4 lines at all visits. The binocular uncorrected distance visual acuity was 20/20 in all patients. Ninety percent of the patients reported that their near vision was good or excellent. Some of the patients (16.1%) lost more than 3 lines of corrected distance visual acuity. At the latest follow-up, induction of a corneal spherical aberration to improve near visual acuity was statistically significant. No other intraoperative or postoperative complication was noted. CONCLUSIONS The Flexivue Microlens provided patients with improved near vision, as a result of a negative spherical aberration. A significant loss of corrected distance visual acuity in the operated eyes was observed. Overall, this intracorneal inlay was an effective alternative to other procedures for the correction of presbyopia.
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Precision, Morphology, and Histology of Corneal Flap Cuts Using a 200-kHz Femtosecond Laser. Eur J Ophthalmol 2018; 22:161-7. [PMID: 21623593 DOI: 10.5301/ejo.2011.8376] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2011] [Indexed: 11/20/2022]
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Althomali TA. Comparison of microkeratome assisted sub-Bowman keratomileusis with photorefractive keratectomy. Saudi J Ophthalmol 2017; 31:19-24. [PMID: 28337058 PMCID: PMC5352945 DOI: 10.1016/j.sjopt.2017.01.004] [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] [Received: 01/24/2016] [Revised: 01/17/2017] [Accepted: 01/18/2017] [Indexed: 11/30/2022] Open
Abstract
Purpose To compare the outcomes of photorefractive keratectomy (PRK) and thin-flap Laser-Assisted in Situ Keratomileusis/sub-Bowman keratomileusis (SBK) with intended flap thicknesses of 100 μm using the One Use-Plus SBK microkeratome. Methods Ninety-eight eyes of 52 subjects with myopic manifest refraction spherical equivalent (MRSE) of up to −5 diopters (D), a stable refraction for 1 year and a corrected distance visual acuity (CDVA) of at least 20/20 in each eye which had undergone SBK or PRK were reviewed retrospectively. Primary outcome measures were MRSE, uncorrected distance visual acuity (UDVA), CDVA, pachymetry and higher order aberrations (HOA). All patients were seen at 1 and 3 days, 1 week, and 1, 3, and 6 months after surgery. Results Both MRSE and UDVA showed a statistically significant improvement at postoperative 1, 3 and 6 months from baseline in both SBK and PRK groups. At postoperative 6 months, 100% of eyes were within ±0.50 D of attempted correction in both groups. However, SBK group demonstrated better outcomes with 81% of eyes within ±0.13 D, compared to 70% eyes in the PRK group. Both SBK and PRK group demonstrated similar refractive astigmatism accuracy at postoperative 6 months, with 88% of eyes having cylindrical error ⩽0.25 D. None of eyes lost any lines of CDVA in the PRK, and 2% eyes lost one line of CDVA in SBK group at postoperative 6 months. Conclusion The visual and refractive outcomes after both PRK and microkeratome assisted SBK are comparable, albeit with a higher complication rate in the SBK group.
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Zhao W, Wu T, Dong ZH, Feng J, Ren YF, Wang YS. Comparison of visual acuity of the patients on the first day after sub-Bowman keratomileusis or laser in situ keratomileusis. Int J Ophthalmol 2016; 9:448-52. [PMID: 27158619 DOI: 10.18240/ijo.2016.03.22] [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: 02/13/2015] [Accepted: 06/08/2015] [Indexed: 11/23/2022] Open
Abstract
AIM To compare recovery of the visual acuity in patients one day after sub-Bowman keratomileusis (SBK) or laser in situ keratomileusis (LASIK). METHODS Data from 5923 eyes in 2968 patients that received LASIK (2755 eyes) or SBK (3168 eyes) were retrospectively analyzed. The eyes were divided into 4 groups according to preoperative spherical equivalent: between -12.00 to -9.00 D, extremely high myopia (n=396, including 192 and 204 in SBK and LASIK groups, respectively); -9.00 to -6.00 D, high myopia (n=1822, including 991 and 831 in SBK and LASIK groups, respectively), -6.00 to -3.00 D, moderate myopia (n=3071, including 1658 and 1413 in SBK and LASIK groups, respectively), and -3.00 to 0.00 D, low myopia (n=634, including 327 and 307 in SBK and LASIK groups, respectively). Uncorrected logMAR visual acuity values of patients were assessed under standard natural light. Analysis of variance was used for comparisons among different groups. RESULTS Uncorrected visual acuity values were 0.0115±0.1051 and 0.0466±0.1477 at day 1 after operation for patients receiving SBK and LASIK, respectively (P<0.01); visual acuity values of 0.1854±0.1842, 0.0615±0.1326, -0.0033±0.0978, and -0.0164±0.0972 were obtained for patients in the extremely high, high, moderate, and low myopia groups, respectively (P<0.01). In addition, significant differences in visual acuity at day 1 after operation were found between patients receiving SBK and LASIK in each myopia subgroup. CONCLUSION Compared with LASIK, SBK is safer and more effective, with faster recovery. Therefore, SBK is more likely to be accepted by patients than LASIK for better uncorrected visual acuity the day following operation.
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Affiliation(s)
- Wei Zhao
- Department of Ophthalmology, Xijing Hospital, the Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
| | - Ting Wu
- Out-patient Department, the Second Artillery Engineering University, Xi'an 710025, Shaanxi Province, China
| | - Ze-Hong Dong
- Department of Ophthalmology, Xijing Hospital, the Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
| | - Jie Feng
- Department of Ophthalmology, Xijing Hospital, the Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
| | - Yu-Feng Ren
- Department of Ophthalmology, Xijing Hospital, the Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
| | - Yu-Sheng Wang
- Department of Ophthalmology, Xijing Hospital, the Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
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Kasetsuwan N, Satitpitakul V, Puangsricharern V, Reinprayoon U, Pariyakanok L. Comparison of performances of femtosecond laser and microkeratome for thin-flap laser in situ keratomileusis. Lasers Surg Med 2016; 48:596-601. [PMID: 26996546 DOI: 10.1002/lsm.22511] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/08/2016] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To compare the clinical outcomes of femtosecond laser (FS) and microkeratome (MK) for thin-flap in situ keratomileusis (LASIK). MATERIALS AND METHODS Data from patients with moderate to high myopia (spherical equivalent, >-4 diopters [D]) who underwent thin-flap LASIK using FS (199 eyes/110 patients) and MK (157 eyes/86 patients) were analyzed in this retrospective study. Preoperative and postoperative data were recorded from day 1 and months 1 and 3, postoperatively. Visual and refractive outcomes were compared for efficacy, safety, predictability, stability, and the efficacy and safety indices. RESULTS Three months postoperatively, more eyes in the FS group had an uncorrected distance visual acuity (UCVA) of 20/40 or better compared to MK group (relative risk [RR] 1.01, 95% confidence interval [CI], 0.97-1.05, P = 0.58); significantly more eyes in FS group had an UCVA of 20/20 or better (RR, 1.26, 95%CI, 1.08-1.48, P = 0.003). Intraoperative bleeding occurred in 5% and 36.7%, respectively, of FS and MK groups. There were no significant differences in the refractive predictability within spherical equivalents of 0.5 D (FS, 72%; MK, 63%) and 1.0 D (FS, 90%; MK, 86%). Both groups showed good stability 3 months, postoperatively. The efficacy index in FS group was 113.4%; that in MK group was 102.5% at 3 months postoperatively (P < 0.05). The safety indices for FS and MK groups at 3 months postoperatively were 116.4% and 108.2%, respectively (P < 0.05). CONCLUSIONS Both methods of thin-flap created LASIK were effective, safe, predicable, and stable. FS group had significant improvements in efficacy and safety, confirmed by the efficacy and safety indices, compared to MK group. Lasers Surg. Med. 48:596-601, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Ngamjit Kasetsuwan
- Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Vannarut Satitpitakul
- Department of Ophthalmology, King Chulalongkorn Memorial Hospital, Bangkok, Thailand
| | - Vilavun Puangsricharern
- Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Usanee Reinprayoon
- Department of Ophthalmology, King Chulalongkorn Memorial Hospital, Bangkok, Thailand
| | - Lalida Pariyakanok
- Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
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Xu Z, Shen M, Hu L, Zhuang X, Peng M, Hu D, Liu J, Wang J, Qu J, Lu F. The Impact of Flap Creation Methods for Sub-Bowman's Keratomileusis (SBK) on the Central Thickness of Bowman's Layer. PLoS One 2015; 10:e0124996. [PMID: 25938492 PMCID: PMC4418749 DOI: 10.1371/journal.pone.0124996] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 03/19/2015] [Indexed: 11/20/2022] Open
Abstract
Purpose To determine the impact of flap creation methods for sub-Bowman’s keratomileusis (SBK) on central Bowman’s layer thickness. Methods SBK flaps were made by Moria microkeratome for 20 subjects and by femtosecond (FEMTO) laser for 21 subjects. Corneal sublayer thicknesses were measured by ultra-high resolution optical coherence tomography before SBK and at 1 day, 1 week, 2 weeks, and 1 month afterwards. Each subject was imaged twice on each visit. Thicknesses of central epithelium, Bowman’s layer, flap, and total cornea were calculated using a custom-made automated image processing algorithm. The repeatability of sublayer thickness measurements was tested by the intraclass correlation coefficient (ICC) and by the coefficient of repeatability (CoR) at 1 week post-SBK. Results ICCs of the Moria and FEMTO groups were ≥0.959 and ≥0.961 respectively for all sublayer measurements. The segmentation CoRs were less than 6.78% and 5.63% respectively. For both groups, microdistortions were present in the epithelium and Bowman’s layer after SKB. The flap thickness of the Moria group was 9.8 μm (95% confidence interval: 4.8 – 14.8μm) thinner than the FEMTO group one day after SBK (independent samples t-test, P < 0.05). Bowman’s layer became thicker by 1.6 ± 1.1 μm and 1.7 ± 1.6 μm one day post-SBK for the Moria and FEMTO groups (repeated ANOVA, P < 0.05) and then remained stable. Corneal and sublayer thickness were similar between the two groups. Conclusions Central Bowman’s layer thickness increased 1 day post-SBK. Flap creation by Moria microkeratome and femtosecond laser did not have significantly different impacts on Bowman’s layer thickness following SBK. Trial Registration Chinese Clinical Trial Registry (ChiCTR) NO: ChiCTR-OCH-14004525
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Affiliation(s)
- Zhe Xu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Meixiao Shen
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Liang Hu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiran Zhuang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Mei Peng
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Di Hu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jing Liu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jianhua Wang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States of America
| | - Jia Qu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Fan Lu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
- * E-mail:
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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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Zhang J, Zhang SS, Yu Q, Wu JX, Lian JC. Comparison of corneal flap thickness using a FS200 femtosecond laser and a moria SBK microkeratome. Int J Ophthalmol 2014; 7:273-7. [PMID: 24790869 DOI: 10.3980/j.issn.2222-3959.2014.02.14] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 07/24/2013] [Indexed: 11/02/2022] Open
Abstract
AIM To evaluate differences in flap thickness resulting from use of an Alcon Wavelight FS200 femtosecond laser and a MORIA SBK microkeratome when making a 110-µm-thick corneal flap and to identify the potential factors that affect corneal flap thickness. METHODS A prospective case study was performed on 120 eyes of 60 patients who were divided into two groups for LASIK, each group consisting of 60 eyes (30 patients). The corneal flaps were created using an Alcon Wavelight FS200 femtosecond laser or a MORIA SBK microkeratome. The central corneal flap thickness was calculated by subtraction pachymetry. Age, central corneal thickness (CCT), spherical equivalent refraction, mean keratometry, and corneal diameter were recorded preoperatively for analysis. RESULTS Cutting of all flaps was easily performed without intraoperative complications. In the Alcon Wavelight FS200 femtosecond laser group, the mean right and left corneal flap thicknesses were 114.0±6.6 µm (range: 98-126) and 111.4±7.6 µm (range: 98-122), respectively. The difference (2.6±9.1 µm) in the corneal flap thickness between the right and left eyes was not significant (t=1.59, P=0.12). Stepwise regression analysis indicated that the resulting corneal flap thickness was unrelated to the patient's age, preoperative CCT, spherical equivalent refraction, mean keratometry, or corneal diameter. In the MORIA SBK microkeratome group, the mean right and left corneal flap thicknesses were 110.6±7.4 µm (range: 97-125 µm) and 108.2±6.1 µm (range: 78-123 µm), respectively. The difference in the corneal flap thickness between the right and left eyes (2.4±6.5µm) was not significant (t=2.039, P=0.0506). The corneal flap thickness was positively correlated with the preoperative CCT through stepwise regression analysis (r=0.297, P=0.021). The corneal flap thickness was not related to age, spherical equivalent refraction, mean keratometry, or corneal diameter. The corneal flap thickness was estimated using the following equation: Tflap=67.77+0.076 CCT (F=5.63, P=0.021). CONCLUSION Both the Alcon Wavelight FS200 femtosecond laser and the MORIA SBK microkeratome produced 110-µm-thick corneal flaps. The central corneal flap thickness was positively correlated with the preoperative CCT in MORIA SBK microkeratome surgery.
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Affiliation(s)
- Jing Zhang
- New Vision Eye Clinic, Shanghai 200011, China
| | | | - Qing Yu
- New Vision Eye Clinic, Shanghai 200011, China
| | | | - Jing-Cai Lian
- New Vision Eye Clinic, Shanghai 200011, China ; Department of Ophthalmology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200025, China
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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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Shortt AJ, Allan BDS, Evans JR. Laser-assisted in-situ keratomileusis (LASIK) versus photorefractive keratectomy (PRK) for myopia. Cochrane Database Syst Rev 2013:CD005135. [PMID: 23440799 DOI: 10.1002/14651858.cd005135.pub3] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Myopia (also known as short-sightedness or near-sightedness) is an ocular condition in which the refractive power of the eye is greater than is required, resulting in light from distant objects being focused in front of the retina instead of directly on it. The two most commonly used surgical techniques to permanently correct myopia are photorefractive keratectomy (PRK) and laser-assisted in-situ keratomileusis (LASIK). OBJECTIVES To compare the effectiveness and safety of LASIK and PRK for correction of myopia by examining post-treatment uncorrected visual acuity, refractive outcome, loss of best spectacle-corrected visual acuity, pain scores, flap complications in LASIK, subepithelial haze, adverse events, quality of life indices and higher order aberrations. SEARCH METHODS We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 11), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to November 2012), EMBASE (January 1980 to November 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to November 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 15 November 2012. We also searched the reference lists of the studies and the Science Citation Index. SELECTION CRITERIA We included randomised controlled trials comparing LASIK and PRK for the correction of any degree of myopia. DATA COLLECTION AND ANALYSIS Two authors independently assessed trial quality and extracted data. We summarised data using the odds ratio and mean difference. We combined odds ratios using a random-effects model after testing for heterogeneity. MAIN RESULTS We included 13 trials (1135 participants, 1923 eyes) in this review. Nine of these trials randomised eyes to treatment, two trials randomised people to treatment and treated both eyes, and two trials randomised people to treatment and treated one eye. None of the paired trials reported an appropriate paired analysis. We considered the overall quality of evidence to be low for most outcomes because of the risk of bias in the included trials. There was evidence that LASIK gives a faster visual recovery than PRK and is a less painful technique. Results at one year after surgery were comparable: most analyses favoured LASIK but they were not statistically significant. AUTHORS' CONCLUSIONS LASIK gives a faster visual recovery and is a less painful technique than PRK. The two techniques appear to give similar outcomes one year after surgery. Further trials using contemporary techniques are required to determine whether LASIK and PRK as currently practised are equally safe. Randomising eyes to treatment is an efficient design, but only if analysed properly. In future trials, more efforts could be made to mask the assessment of outcome.
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Affiliation(s)
- Alex J Shortt
- The Moorfields Eye Hospital/UCL Institute of Ophthalmology National Institute for Health Research Biomedical Research Centre,London, UK.
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Sun Y, Deng YP, Wang L, Huang YZ, Qiu LM. Comparisons of morphologic characteristics between thin-flap LASIK and SBK. Int J Ophthalmol 2012; 5:338-42. [PMID: 22773984 DOI: 10.3980/j.issn.2222-3959.2012.03.17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 04/13/2012] [Indexed: 11/02/2022] Open
Abstract
AIM To compare the morphologic characteristics between thin-flap laser in situ keratomileusis (LASIK) and Sub-Bowman keratomileusis (SBK), and to evaluate the uniformity of flap and to explore the correlative factors of corneal flap thickness. METHODS A prospective, randomized, comparative clinical study was performed in Department of Ophthalmology, West Hospital of China, Chengdu, Sichuan Province, China. Totally 59 patients 114 eyes underwent LASIK or SBK to correct myopia, 29 patients 57 eyes underwent SBK, 30 patients 57 eyes underwent LASIK. Anterior optical coherence tomography(OCT) was used to measure corneal flap thickness in all the patients 1 week after surgeries, 16 positions were set to be measured in each eye. Comparisons of flap thickness in each group and between 2 groups were evaluated. Correlative factors of flap thickness were evaluated. RESULTS Coefficient of variation (CV, s/×%) in SBK group were lesser than that in LASIK group, t test showed there was significant statistical difference between 2 groups(P=0.000). Comparisons of the difference of 2 paired positions(temporal-nasal; superior-inferior) showed there were no significant differences in each group, but between 2 groups, there were statistical significance of value of difference (D-value) of superior and inferior positions between SBK and LASIK group(P=0.036). Linear regression analysis of correlative factors of flap thickness showed there were no statistic significances related to central corneal thickness(CCT)(P=0.060, t=1.921) and corneal curvature(P=0.083, t=1.766). CONCLUSION SBK is better than LASIK in creating much uniform corneal flap. There was no evidence showing correlations between flap thickness and CCT or corneal curvature.
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Affiliation(s)
- Yi Sun
- Department of Ophthalmology, West Hospital of China, Chengdu 610041, Sichuan Province, China
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McAlinden C. Corneal refractive surgery: past to present. Clin Exp Optom 2012; 95:386-98. [PMID: 22672114 DOI: 10.1111/j.1444-0938.2012.00761.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 04/07/2012] [Accepted: 04/17/2012] [Indexed: 12/20/2022] Open
Abstract
There have been many historical corneal refractive techniques and procedures developed over the years. From early techniques of radial keratotomy to modern excimer laser techniques, the field of refractive surgery is one of the most rapidly developing in ophthalmology. This review details the historical aspects of the many early techniques up to current techniques used on millions of eyes around the world.
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Affiliation(s)
- Colm McAlinden
- University of Ulster, United Kingdom and Flinders Medical Centre and Flinders University, Adelaide, South Australia, Australia.
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Hatch BB, Moshirfar M, Ollerton AJ, Sikder S, Mifflin MD. A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function. Clin Ophthalmol 2011; 5:451-7. [PMID: 21573091 PMCID: PMC3090298 DOI: 10.2147/opth.s18967] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Indexed: 11/28/2022] Open
Abstract
Purpose: To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs) in eyes with stable myopia undergoing either photo-refractive keratectomy (PRK) or thin-flap laser in situ keratomileusis (LASIK) (intended flap thickness of 90 μm) using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively. Methods: In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and complications. Results: At 6 months, mean values for UDVA (logMAR) were −0.043 ± 0.668 and −0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466). UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600). Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156) or CDVA (P = 0.800) at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears. Conclusion: Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.
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Affiliation(s)
- Bryndon B Hatch
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
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Xu Y, Zhou X, Wang L, Xu H. A morphological study of corneal flap after thin-flap laser-assisted in situ keratomileusis by anterior segment optical coherence tomography. J Int Med Res 2011; 38:1952-60. [PMID: 21226998 DOI: 10.1177/147323001003800608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This prospective study assessed corneal flap morphology in 115 patients undergoing laser-assisted in situ keratomileusis (LASIK). Flaps were created using the Moria M2 90-μm or KM-5000D 110-μm microkeratomes. Flap thickness was measured using anterior segment optical coherence tomography at seven points in a 7-mm diameter zone 1 h, 1 day, 3 days, 1 week and 1 month after surgery. Flap accuracy, reproducibility, uniformity and changes over time were evaluated. The Moria M2 microkeratome created flaps with less accuracy in the centre than the KM-5000D microkeratome (114.06 ± 6.46 μm vs 128.39 ± 6.79 μm, respectively, at 1 week). For both microkeratomes, flap thickness varied between most of the peripheral areas and the central point. Both microkeratomes created flaps with good central predictability and reproducibility, but high variation and significant deviation from intended thickness were observed in peripheral flap thickness.
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Affiliation(s)
- Y Xu
- Department of Ophthalmology, Eye and ENT Hospital affiliated with Fudan University, Shanghai, China
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Flap thickness variation with 3 types of microkeratome heads. J Cataract Refract Surg 2011; 37:144-8. [DOI: 10.1016/j.jcrs.2010.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 07/22/2010] [Accepted: 07/23/2010] [Indexed: 11/18/2022]
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Medeiros FW, Sinha-Roy A, Alves MR, Dupps WJ. Biomechanical corneal changes induced by different flap thickness created by femtosecond laser. Clinics (Sao Paulo) 2011; 66:1067-71. [PMID: 21808877 PMCID: PMC3129968 DOI: 10.1590/s1807-59322011000600025] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Accepted: 03/04/2011] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE To evaluate the impact of the creation of corneal flaps at different thicknesses on the biomechanical properties of swine corneas. METHOD Twelve swine eyes were obtained to form two groups: 100 μm flap thickness and 300 μm flap thickness. Each eye was submitted to the following examinations: raster topography to investigate corneal curvature alterations, ocular response analyzer to investigate corneal hysteresis change, optical coherence tomography to measure central corneal and flap thickness and sonic wave propagation velocity as a measure of stiffness, before and immediately after flap creation. After flap amputation, surface wave velocity measurements were repeated. RESULTS Measured flap thicknesses were statistically different for thin and thick flap groups, with an average of 108.5 + 6.9 and 307.8 + 11.5 μm respectively. Hysteresis and corneal resistance factor did not change significantly after flap creation in the thin flap group. With thicker flaps, both parameters decreased significantly from 8.0 +1.0 to 5.1 +1.5 mmHg and from 8.2 + 1.6 to 4.1 +2.5 mmHg respectively. Simulated keratometry values increased in the thick flap group (from 39.5 + 1 D to 45.9+1.2 D) after flap creation but not in the thin flap group (from 40.6 + 0.6 D to 41.4+ 1.0 D). Regarding surface wave velocity analysis, the surgical procedures induced statistically lower results in some positions. CONCLUSION In the experimental conditions established by this model, thicker flaps presented a greater biomechanical impact on the cornea.
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Hafezi F, Seiler T. Persistent subepithelial haze in thin-flap LASIK. J Refract Surg 2010; 26:222-5. [PMID: 19810662 DOI: 10.3928/1081597x-20090930-02] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Accepted: 09/03/2009] [Indexed: 11/20/2022]
Abstract
PURPOSE To report persistent subepithelial haze in two patients following femtosecond LASIK associated with creation of a thin flap. METHODS Subepithelial haze was assessed by slit-lamp photography, high-resolution Scheimpflug imaging, and corneal confocal microscopy. RESULTS Two patients showed distinct subepithelial haze and reduced corrected distance visual acuity at 3 months after LASIK with a think-flap generated by a femtosecond laser. The extent of haze was documented, and the haze was treated topically with steroids up to 12 weeks. The haze was localized approximately 20 to 40 microm below Bowman's layer and dissolved slowly during the 2 months of treatment. At 6 months after surgery, uncorrected visual acuity was 20/20. CONCLUSIONS Subepithelial haze formation represents a new potential complication in the thin-flap LASIK.
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Affiliation(s)
- Farhad Hafezi
- Institute for Refractive and Opthalmic Surgery, Zurich, Switzerland.
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Prakash G, Agarwal A, Yadav A, Jacob S, Kumar DA, Agarwal A, Akhtar R. A Prospective Randomized Comparison of Four Femtosecond LASIK Flap Thicknesses. J Refract Surg 2010; 26:392-402. [DOI: 10.3928/1081597x-20090728-02] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Accepted: 06/09/2009] [Indexed: 01/29/2023]
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Chen HJ, Xia YJ, Zhong YY, Song XL, Chen YG. Anterior Segment Optical Coherence Tomography Measurement of Flap Thickness After Myopic LASIK Using the Moria One Use-Plus Microkeratome. J Refract Surg 2010; 26:403-10. [DOI: 10.3928/1081597x-20090710-04] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Accepted: 06/08/2009] [Indexed: 11/20/2022]
Affiliation(s)
- Hui-Jin Chen
- Peking University Third Hospital, Peking University Eye Center, Beijing, China
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Bansal AS, Doherty T, Randleman JB, Stulting RD. Influence of flap thickness on visual and refractive outcomes after laser in situ keratomileusis performed with a mechanical keratome. J Cataract Refract Surg 2010; 36:810-3. [PMID: 20457374 PMCID: PMC3783967 DOI: 10.1016/j.jcrs.2009.12.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 11/30/2009] [Accepted: 12/01/2009] [Indexed: 10/19/2022]
Abstract
PURPOSE To study the effect of flap thickness on visual acuity and refractive outcomes after laser in situ keratomileusis (LASIK) using 2 blade types with a mechanical microkeratome. SETTING Emory Vision, Atlanta, Georgia, USA. METHODS This retrospective analysis was of LASIK cases performed between January 2005 and June 2006 using an Amadeus I microkeratome and an ML7090 CLB blade (blade A) or a Surepass blade (blade B). Outcomes analyzed included flap thickness, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE), the enhancement rate, and surgical complications 3 months postoperatively. RESULTS Two hundred sixty-three eyes of 153 patients were analyzed; blade A was used in 158 eyes and blade B, in 105 eyes. The mean flap thickness was significantly thinner with blade A than with blade B (107 microm +/- 12 [SD] versus 130 +/- 20 microm) (P<.0001). There was no overall correlation with either blade between flap thickness and UDVA, CDVA, or MRSE (all r<0.2). At 3 months, there was no statistically significant difference in UDVA, CDVA, or MRSE between the 2 blade groups at 3 months (all P > .10), and there was no difference in the complication rates. CONCLUSION Flap thickness did not affect visual or refractive outcomes with a mechanical microkeratome with either blade type.
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Affiliation(s)
- Alok S Bansal
- Emory Eye Center and Emory Vision, Atlanta, Georgia, USA
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Chan CCK, Hodge C, Sutton G. External analysis of the Randleman Ectasia Risk Factor Score System: a review of 36 cases of post LASIK ectasia. Clin Exp Ophthalmol 2010; 38:335-40. [DOI: 10.1111/j.1442-9071.2010.02251.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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de Benito-Llopis L, Teus MA, Gil-Cazorla R, Drake P. Comparison between femtosecond laser-assisted sub-Bowman keratomileusis vs laser subepithelial keratectomy to correct myopia. Am J Ophthalmol 2009; 148:830-6.e1. [PMID: 19781686 DOI: 10.1016/j.ajo.2009.07.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 07/06/2009] [Accepted: 07/10/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE To compare femtosecond laser sub-Bowman keratomileusis (FSBK) vs laser subepithelial keratectomy (LASEK) to correct myopia. DESIGN Retrospective, nonrandomized, interventional, comparative case series. METHODS Two thousand one hundred and eight eyes were included in the study. We compared 1,072 eyes treated with FSBK vs 1,036 eyes treated with LASEK with or without mitomycin C (MMC). Visual and refractive results were evaluated 1 day, 1 week, and 1 and 3 months postoperatively. RESULTS Preoperative mean sphere and best spectacle-corrected visual acuity (BSCVA) were -3.93 diopters (D) vs -3.87 D (P = .5) and 1.12 vs 1.12 (P = .8) in FSBK and LASEK, respectively. Uncorrected visual acuity (UCVA) was 0.92 vs 0.62, 0.98 vs 0.78, 0.96 vs 0.91, and 1.06 vs 1.03 in FSBK and LASEK, respectively, at 1 day, 1 week, and 1 and 3 months after surgery (P < .01 for all comparisons). Three months postoperatively, BSCVA was 1.13 and 1.10, respectively (P = .001). At that moment, 20 eyes (1.93%) in the LASEK group vs 9 eyes (0.84%) in the FSBK group had lost 2 or more lines of BSCVA. Ten eyes (0.96%) in the LASEK group gained 2 or more lines of BSCVA, whereas 3 eyes (0.28%) in the FSBK group gained 2 lines. Six months postoperatively, only 2 LASEK eyes (0.19%) showed loss of 2 or more lines of BSCVA, compared to 3 FSBK-treated eyes (0.28%). CONCLUSION Both FSBK and LASEK are safe and effective procedures to correct myopia. Slightly better visual and refractive results were observed in FSBK-treated eyes in a 3-month follow-up.
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Ruiz LA, Cepeda LM, Fuentes VC. Intrastromal correction of presbyopia using a femtosecond laser system. J Refract Surg 2009; 25:847-54. [PMID: 19835324 DOI: 10.3928/1081597x-20090917-05] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Accepted: 08/26/2009] [Indexed: 11/20/2022]
Abstract
PURPOSE To introduce a new, minimally invasive intrastromal correction for presbyopia (INTRACOR procedure) using the TECHNOLAS femtosecond laser system (Technolas Perfect Vision GmbH). METHODS The INTRACOR procedure was performed in 83 eyes of 45 patients aged 44 to 67 years. Follow-up was 6 to 12 months. Data recorded included age; pre- and postoperative refraction; uncorrected distance (UDVA), intermediate, and near visual acuity (UNVA); corrected distance visual acuity (CDVA); distance corrected near visual acuity; corneal hysteresis (CH), corneal resistance factor (CRF), and asphericity; pachymetry; endothelial cell density; contrast sensitivity; and ocular aberrations. RESULTS At 6 months postoperatively, all 83 (100%) eyes had improved UNVA, with minimal or no change in UDVA. Twenty-two eyes were available at 12 months; UNVA improved to J1 in these eyes with continued improvement in mean UDVA. At last follow-up, a mild myopic shift in refraction was noted with only 3 (3.6%) eyes showing a 2- or 3-line decrease of UDVA, and 74 (89.2%) eyes achieved both J2 and 20/25 or better. Mean CDVA and distance corrected near visual acuity continued to improve with time. Two (2.4%) eyes lost 2 lines of CDVA at 6 months, but this did not occur in the 22 eyes seen at 1 year. Overall stability was noted in CH, CRF, pachymetry, endothelial cell density, and contrast sensitivity. Primary spherical aberrations shifted toward negative values and secondary spherical aberration shifted toward positive values. No corneal structural complications were observed. CONCLUSIONS The INTRACOR intrastromal procedure using the TECHNOLAS femtosecond laser is a promising procedure for presbyopia correction. It preserves the corneal epithelium and anterior stromal fibers.
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Current world literature. Curr Opin Ophthalmol 2009; 20:333-41. [PMID: 19535964 DOI: 10.1097/icu.0b013e32832e478f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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