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Löffler F, Böhm M, Herzog M, Petermann K, Kohnen T. Tomographic Analysis of Anterior and Posterior and Total Corneal Refractive Power Changes After Femtosecond Laser-Assisted Keratotomy. Am J Ophthalmol 2017; 180:102-109. [PMID: 28549845 DOI: 10.1016/j.ajo.2017.05.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 05/12/2017] [Accepted: 05/15/2017] [Indexed: 11/30/2022]
Abstract
PURPOSE To analyze the effect of penetrating femtosecond laser-assisted keratotomy (pFLAK) during laser lens surgery on anterior and posterior corneal astigmatism and total corneal refractive power (TCRP) astigmatism (CAant, CApost, CATCRP) measured with Scheimpflug tomography. DESIGN Prospective, interventional case series. METHODS This institutional study included 27 eyes of 23 patients (aged 65 ± 8 years) with low-to-moderate CATCRP determined with Scheimpflug tomography (Pentacam HR; Oculus, Wetzlar, Germany) after penetrating femtosecond laser-assisted keratotomy (pFLAK) and laser lens surgery. The CAant, CApost, and CATCRP were determined before and 1 and 3 months after surgery. Vector analysis according to the Alpins method was used to calculate surgically induced astigmatism (SIA). RESULTS The mean preoperative CAant (0.97 ± 0.30 diopter [D]) was significantly reduced to 0.63 ± 0.34 D (P < .001). SIAant was 0.71 ± 0.37 D. The CApost showed no significant change, from preoperative 0.26 ± 0.12 D to 0.26 ± 0.10 D postoperatively (P = .625). In line with this finding, SIApost was low (0.12 ± 0.07 D). The CATCRP showed similar results as CAant. CONCLUSION pFLAKs planned according to Scheimpflug-based CATCRP result in a significant reduction of the CAant and CATCRP, but do not affect the posterior corneal curvature significantly, as measured by Scheimpflug tomography. Further research is required to develop a new valid nomogram for laser-assisted lens surgery.
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Affiliation(s)
- Franziska Löffler
- Department of Ophthalmology, Goethe-University Frankfurt am Main, Frankfurt am Main, Germany
| | - Myriam Böhm
- Department of Ophthalmology, Goethe-University Frankfurt am Main, Frankfurt am Main, Germany
| | - Michael Herzog
- Department of Ophthalmology, Goethe-University Frankfurt am Main, Frankfurt am Main, Germany
| | - Kerstin Petermann
- Department of Ophthalmology, Goethe-University Frankfurt am Main, Frankfurt am Main, Germany
| | - Thomas Kohnen
- Department of Ophthalmology, Goethe-University Frankfurt am Main, Frankfurt am Main, Germany.
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Hammer T, Höche T, Heichel J. [Scanning electron microscopic investigations of cutting edge quality in lamellar keratotomy using the Wavelight femtosecond laser (FS-200) : What influence do spot distance and an additional tunnel have?]. Ophthalmologe 2017; 115:47-54. [PMID: 28741162 DOI: 10.1007/s00347-017-0544-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Femtosecond lasers (fs-lasers) are established cutting instruments for the creation of LASIK flaps. Previous studies often showed even rougher surfaces after application of fs-laser systems compared to lamellar keratotomy with mechanical microkeratomes. When cutting the cornea with fs-lasers, an intrastromal gas development occurs, which has a potentially negative influence on the cutting quality if the gas cannot be dissipated; therefore, manufacturers have chosen the way of gas assimilation in so-called pockets. The investigated system creates a tunnel which opens under the conjunctiva. The aim of this study was to investigate the effects of a tunnel as well as the influence of different spot distances on the quality of cut surfaces and edges. MATERIAL AND METHODS In this experimental study on freshly enucleated porcine eyes (n = 15), the following cuts were carried out with the FS-200 (Wavelight, Erlangen, Germany): 1. standard setting (spot and line separation 8 µm), 2. with tunnel for gas drainage, 3. without gas-conducting tunnel, 4. with increased spot spacing (spot and line separation 9 μm instead of 8 μm) and 5. with reduced spot spacing (spot and line separation 7 μm instead of 8 μm). Subsequently, scanning electron microscopy (FEI Quanta 650, Hillsboro, OR) of the cut edges and surfaces as well as the gas drain tunnel were performed. The evaluation was based on an established score. RESULTS The current fs-laser system (200 Hz) is able to create smooth cutting surfaces and sharp edges. The changed density of laser pulses compared to the standard settings with a reduced or increased distance between the pulses, did not achieve any further improvement in the surface quality. The gas-conducting tunnel could be detected by scanning electron microscope. In the case of cutting without a tunnel, roughened surfaces and irregularities on the cutting edges were found. CONCLUSION When the FS-200 fs-laser is used, LASIK cuts with very smooth cut surfaces and sharp cutting edges are achieved. This is only valid as long as an additional tunnel with the fs-laser is placed under the conjunctiva. It can be assumed that the resulting gas is effectively drained through this tunnel. The installation of the tunnel represents a new possibility to replace previous techniques of gas assimilation in deeper lying cutting areas.
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Affiliation(s)
- T Hammer
- Augenzentrum "Frohe Zukunft", Dessauer Str. 194, 06118, Halle (Saale), Deutschland.
- Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Halle (Saale), Halle (Saale), Deutschland.
| | - T Höche
- Fraunhofer Institut für Mikrostruktur von Werkstoffen und Systemen, Halle (Saale), Deutschland
| | - J Heichel
- Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Halle (Saale), Halle (Saale), Deutschland
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Visumax femtolasik versus Moria M2 microkeratome in mild to moderate myopia: efficacy, safety, predictability, aberrometric changes and flap thickness predictability. BMC Ophthalmol 2017; 17:125. [PMID: 28716114 PMCID: PMC5512974 DOI: 10.1186/s12886-017-0520-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 07/10/2017] [Indexed: 12/03/2022] Open
Abstract
Introduction This is an interventional prospective clinical study which was conducted to evaluate the efficacy, safety, predictability, ocular aberrations, and flap thickness predictability of Visumax femtosecond laser (FSL) compared to Moria M2 microkeratome (MK) in mild to moderate myopia. Methods This study included 60 eyes who were divided into two groups. Thirty eyes in group (I) in which the flap was created with Visumax FSL, while in group II (30 eyes) the Moria M2 MK was used. Keratometric, refractive, and aberrometric measurements were compared preoperatively and 3 months postoperatively. The intraoperative subtraction pachymetry (the SP 100 Handy pachymeter (Tomey, Nagoya, Japan) was used for preoperative pachymetry and flap thickness measurement. Results No significant difference was found between the two groups in regards to postoperative manifest sphere, spherical equivalent, astigmatism, safety indices nor ocular aberrations. Twenty six eyes (86.6%) in group I and 23 eyes in group II (76.6%) were within ±0.5D of the intended correction and 23 eyes (76.6%) in group I and 15 eyes in group II (50%) were within ±0.25D of the intended correction. In group I, the mean postoperative actual flap thickness was 100.12 ± 16.1 μm (81 to 122 μm), while in group II, it was 104.6 ± 20.1 μm (62 to 155 μm). The difference was statistically significant (p = 0.001). Conclusions Both Visumax and Moria M2 MK are safe and effective in treating myopia with no statistically significant difference in induction of ocular aberrations but with potential advantage for Visumax regarding predictability. More accurate flap thickness is achieved with Visumax femtolasik. Trial registration This study was retrospectively registered on 19/6/2017. Trial registration number NCT03193411, clinicalTrials.gov.
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Ortega-Usobiaga J, Llovet-Osuna F, Katz T, Djodeyre MR, Druchkiv V, Bilbao-Calabuig R, Baviera J. Comparison of 5468 retreatments after laser in situ keratomileusis by lifting the flap or performing photorefractive keratectomy on the flap. ACTA ACUST UNITED AC 2017; 93:60-68. [PMID: 28651810 DOI: 10.1016/j.oftal.2017.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 05/22/2017] [Accepted: 05/23/2017] [Indexed: 11/25/2022]
Abstract
PURPOSE To assess visual outcomes of retreatment after laser in situ keratomileusis (LASIK) by lifting the flap or performing photorefractive keratectomy (PRK) on the flap, as well as to establish whether there was an increased risk of epithelial ingrowth (EIG) when LASIK and lifting of the flap are separated by a long time interval and to determine the incidence of corneal haze after PRK. METHODS Retrospective study of 4077 patients (5468 eyes) who underwent LASIK and subsequent retreatment were reviewed in order to study their visual results and identify cases of EIG and corneal haze. RESULTS Enhancements included 5196 eyes from 3876 patients that were retreated by lifting the flap, and 272 eyes from 201 patients that were retreated by PRK on the flap. No statistically significant differences were found between the retreatments in terms of predictability, efficacy, and safety. A total of 704 cases of EIG were found after lifting the flap, for which surgical cleansing was necessary in 70. Surgical cleansing decreased the efficacy index when compared with patients with EIG who did not need cleansing (P=.01). Differences in terms of safety and predictability were not statistically significant. The incidence of corneal haze after ablation of the surface of the previous flap was 14.34%, although none of these cases were clinically relevant. CONCLUSIONS Visual outcomes were similar between patients who were retreated by lifting the flap and those who underwent PRK. The incidence of EIG when the flap was lifted was 13.55%. The incidence of EIG increases with the time elapsed between the primary procedure and retreatment.
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Affiliation(s)
- J Ortega-Usobiaga
- Departamento de Catarata y Cirugía Refractiva, Clínica Baviera, Bilbao, España.
| | - F Llovet-Osuna
- Departamento de Catarata y Cirugía Refractiva, Clínica Baviera, Madrid, España
| | - T Katz
- Departamento de Catarata y Cirugía Refractiva, Care Vision, Hamburgo, Alemania; Departamento de Oftalmología, Universitätsklinikum Hamburg-Eppendorf (UKE), Hamburgo, Alemania
| | - M R Djodeyre
- Departamento de Catarata y Cirugía Refractiva, Clínica Baviera, Zaragoza, España
| | - V Druchkiv
- Departamento de Investigación y Desarrollo, Clínica Baviera, Valencia, España
| | - R Bilbao-Calabuig
- Departamento de Catarata y Cirugía Refractiva, Clínica Baviera, Madrid, España
| | - J Baviera
- Departamento de Catarata y Cirugía Refractiva, Clínica Baviera, Valencia, España
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Chang JSM, Law AKP, Ng JCM, Cheng MSY. Femtosecond Laser in situ Keratomileusis Flap Creation in Narrow Palpebral Fissure Eyes without Suction. Case Rep Ophthalmol 2017; 8:341-348. [PMID: 28690535 PMCID: PMC5498974 DOI: 10.1159/000477201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/02/2017] [Indexed: 11/19/2022] Open
Abstract
PURPOSE To evaluate a surgical technique used in eyes with narrow palpebral fissure undergoing femtosecond laser flap creation without suction during laser in situ keratomileusis (LASIK). METHODS All data of 2 patient groups were collected through chart review. Group 1 consisted of 6 eyes with narrow palpebral fissure in which the suction ring was manually fixated and femtosecond laser was applied accordingly. Thirty comparison cases were randomly drawn from among eyes that underwent a standard LASIK procedure matched for age and preoperative refraction (group 2). Only 1 eye of each patient was selected to compare the refractive and visual outcomes between groups. RESULTS In all group 1 eyes, the flaps were created successfully with manual fixation of the suction ring without suction. No eyes lost 2 or more lines of vision. No significant difference was found in the safety and refractive outcomes between groups. CONCLUSION Manual fixation of the suction ring in eyes with narrow palpebral fissure without suction was feasible for flap creation during LASIK.
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Affiliation(s)
- John S M Chang
- Department of Ophthalmology, Hong Kong Sanatorium and Hospital, Hong Kong, Hong Kong
| | - Antony K P Law
- Department of Ophthalmology, Hong Kong Sanatorium and Hospital, Hong Kong, Hong Kong
| | - Jack C M Ng
- Department of Ophthalmology, Hong Kong Sanatorium and Hospital, Hong Kong, Hong Kong
| | - May S Y Cheng
- Department of Ophthalmology, Hong Kong Sanatorium and Hospital, Hong Kong, Hong Kong
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Kohnen T, Steinwender G. Laser-in-situ-Keratomileusis mit Mikrokeratom oder Femtosekundenlaser. Ophthalmologe 2017; 114:661-665. [DOI: 10.1007/s00347-017-0517-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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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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Nerve regeneration by human corneal stromal keratocytes and stromal fibroblasts. Sci Rep 2017; 7:45396. [PMID: 28349952 PMCID: PMC5369053 DOI: 10.1038/srep45396] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 02/23/2017] [Indexed: 01/12/2023] Open
Abstract
Laser refractive surgeries reshape corneal stroma to correct refractive errors, but unavoidably affect corneal nerves. Slow nerve regeneration and atypical neurite morphology cause desensitization and neuro-epitheliopathy. Following injury, surviving corneal stromal keratocytes (CSKs) are activated to stromal fibroblasts (SFs). How these two different cell types influence nerve regeneration is elusive. Our study evaluated the neuro-regulatory effects of human SFs versus CSKs derived from the same corneal stroma using an in vitro chick dorsal root ganglion model. The neurite growth was assessed by a validated concentric circle intersection count method. Serum-free conditioned media (CM) from SFs promoted neurite growth dose-dependently, compared to that from CSKs. We detected neurotrophic and pro-inflammatory factors (interleukin-8, interleukin-15, monocyte chemoattractant protein-1, eotaxin, RANTES) in SFCM by Bio-Plex Human Cytokine assay. More than 130 proteins in SFCM and 49 in CSKCM were identified by nanoLC-MS/MS. Proteins uniquely present in SFCM had reported neuro-regulatory activities and were predicted to regulate neurogenesis, focal adhesion and wound healing. Conclusively, this was the first study showing a physiological relationship between nerve growth and the metabolically active SFs versus quiescent CSKs from the same cornea source. The dose-dependent effect on neurite growth indicated that nerve regeneration could be influenced by SF density.
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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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Konstantopoulos A, Liu YC, Teo EPW, Lwin NC, Yam GHF, Mehta JS. Early wound healing and refractive response of different pocket configurations following presbyopic inlay implantation. PLoS One 2017; 12:e0172014. [PMID: 28235010 PMCID: PMC5325226 DOI: 10.1371/journal.pone.0172014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 01/29/2017] [Indexed: 11/25/2022] Open
Abstract
Background Presbyopic inlays have mostly been implanted under a corneal flap. Implantation in a pocket has advantages including less postoperative dry eye and neurotrophic effect, and better biomechanical corneal stability. This study investigated the effect of different pocket and flocket dimensions on corneal stability and refractive power after Raindrop™ implantation, and the associated wound healing response. Methodology Ten New Zealand White rabbits had bilateral pocket Raindrop™ implantation. Eyes were allocated to 4 groups: pockets with 4mm, 6mm, and 8mm diameters, and 8mm flocket. They were examined pre-operatively, at day 1, weeks 1, 2, 3 and 4 post-surgery with anterior segment optical coherence tomography, corneal topography and in-vivo confocal microscopy. After euthanasia (week 4), CD11b, heat shock protein (HSP) 47 and fibronectin corneal immunohistochemistry was performed. Results Corneal thickness (mean±SD) increased from 360.0±16.2μm pre-operatively to 383.9±32.5, 409.4±79.3, 393.6±35.2, 396.4±50.7 and 405±20.3μm on day 1, weeks 1,2,3 and 4 respectively (p<0.008, all time-points). Corneal refractive power increased by 11.1±5.5, 7.5±2.5, 7.5±3.1, 7.0±3.6 and 6.3±2.9D (p<0.001). Corneal astigmatism increased from 1.1±0.3D to 2.3±1.6, 1.7±0.7, 1.8±1.0, 1.6±0.9 and 1.6±0.9D respectively (p = 0.033). CT, refractive power change and astigmatism were not different between groups. The 8mm pocket and 8mm flocket groups had the least stromal keratocyte reflectivity. CD11b, fibronectin or HSP47 weren’t detected. Conclusions Anatomical and refractive stability was achieved by 1 week; the outcomes were not affected by pocket or flocket configuration. No scarring or inflammation was identified. The 8mm pocket and flocket showed the least keratocyte activation, suggesting they might be the preferred configuration.
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Affiliation(s)
- Aris Konstantopoulos
- Singapore Eye Research Institute, Singapore, Singapore
- Singapore National Eye Centre, Singapore, Singapore
- University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
| | - Yu-Chi Liu
- Singapore Eye Research Institute, Singapore, Singapore
- Singapore National Eye Centre, Singapore, Singapore
| | | | | | | | - Jodhbir S. Mehta
- Singapore Eye Research Institute, Singapore, Singapore
- Singapore National Eye Centre, Singapore, Singapore
- Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore, Singapore
- Nanyang Technological University, Singapore, Singapore
- * E-mail:
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Abstract
FS-assisted LASIK has become the preferred method for LASIK flap creation due to the precision, accuracy, and reproducibility of the flap creation. Thinner, planar flaps may help prevent cases of post-LASIK ectasia and may have a superior refractive outcome. However, FS flap creation has several unique complications that require early recognition and optimal timely management for the best visual outcomes.
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Errors in Treatment of Lower-order Aberrations and Induction of Higher-order Aberrations in Laser Refractive Surgery. Int Ophthalmol Clin 2016; 56:19-45. [PMID: 26938336 DOI: 10.1097/iio.0000000000000113] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ağca A, Demirok A, Yıldırım Y, Demircan A, Yaşa D, Yeşilkaya C, Perente İ, Taşkapılı M. Refractive lenticule extraction (ReLEx) through a small incision (SMILE) for correction of myopia and myopic astigmatism: current perspectives. Clin Ophthalmol 2016; 10:1905-1912. [PMID: 27757010 PMCID: PMC5055042 DOI: 10.2147/opth.s80412] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Small-incision lenticule extraction (SMILE) is an alternative to laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) for the correction of myopia and myopic astigmatism. SMILE can be performed for the treatment of myopia ≤−12 D and astigmatism ≤5 D. The technology is currently only available in the VisuMax femtosecond laser platform. It offers several advantages over LASIK and PRK; however, hyperopia treatment, topography-guided treatment, and cyclotorsion control are not available in the current platform. The working principles, potential advantages, and disadvantages are discussed in this review.
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Affiliation(s)
- Alper Ağca
- Beyoğlu Eye Research and Training Hospital
| | - Ahmet Demirok
- Department of Ophthalmology, Istanbul Medeniyet University, Istanbul, Turkey
| | | | | | - Dilek Yaşa
- Beyoğlu Eye Research and Training Hospital
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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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Shen Z, Shi K, Yu Y, Yu X, Lin Y, Yao K. Small Incision Lenticule Extraction (SMILE) versus Femtosecond Laser-Assisted In Situ Keratomileusis (FS-LASIK) for Myopia: A Systematic Review and Meta-Analysis. PLoS One 2016; 11:e0158176. [PMID: 27367803 PMCID: PMC4930219 DOI: 10.1371/journal.pone.0158176] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 06/11/2016] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The goal of this study was to compare small incision lenticule extraction (SMILE) with femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for treating myopia. METHODS The CENTRAL, EMBASE, PubMed databases and a Chinese database (SinoMed) were searched in May of 2016. Twelve studies with 1,076 eyes, which included three randomized controlled trials (RCTs) and nine cohorts, met our inclusion criteria. The overall quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group framework. Data were extracted and analysed at three to six months postoperatively. Primary outcome measures included a loss of one or more lines of best spectacle corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA) of 20/20 or better, mean logMAR UCVA, postoperative mean spherical equivalent (SE) and postoperative refraction within ±1.0 D of the target refraction. Secondary outcome measures included ocular surface disease index (OSDI), tear breakup time (TBUT) and Schirmer's 1 test (S1T) as dry eye parameters, along with corneal sensitivity. RESULTS The overall quality of evidence was considered to be low to very low. Pooled results revealed no significant differences between the two groups with regard to a loss of one or more lines in the BSCVA (OR 1.71; 95% CI: 0.81, 3.63; P = 0.16), UCVA of 20/20 or better (OR 0.71; 95% CI: 0.44, 1.15; P = 0.16), logMAR UCVA (MD 0.00; 95% CI: -0.03, 0.04; P = 0.87), postoperative refractive SE (MD -0.00; 95% CI: -0.05, 0.05; P = 0.97) or postoperative refraction within ±1.0 D of the target refraction (OR 0.78; 95% CI: 0.22, 2.77; P = 0.70) within six months postoperatively. The pooled analysis also indicated that the FS-LASIK group suffered more severely from dry eye symptoms (OSDI; MD -6.68; 95% CI: -11.76, -2.00; P = 0.006) and lower corneal sensitivity (MD 12.40; 95% CI: 10.23, 14.56; P < 0.00001) at six months postoperatively. CONCLUSIONS In conclusion, both FS-LASIK and SMILE are safe, effective and predictable surgical options for treating myopia. However, dry eye symptoms and loss of corneal sensitivity may occur less frequently after SMILE than after FS-LASIK.
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Affiliation(s)
- Zeren Shen
- Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Keda Shi
- Department of Gastroenterology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yinhui Yu
- Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiaoning Yu
- Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yuchen Lin
- Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Ke Yao
- Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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Antonios R, Arba Mosquera S, Awwad ST. Hyperopic laser in situ keratomileusis: comparison of femtosecond laser and mechanical microkeratome flap creation. J Cataract Refract Surg 2016; 41:1602-9. [PMID: 26432116 DOI: 10.1016/j.jcrs.2014.11.049] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 11/08/2014] [Accepted: 11/28/2014] [Indexed: 10/23/2022]
Abstract
PURPOSE To evaluate and compare the refractive predictability and stability of laser in situ keratomileusis (LASIK) flap creation performed with a femtosecond laser and with a mechanical microkeratome to correct mild to moderate hyperopia. SETTING American University of Beirut Medical Center, Beirut, Lebanon. DESIGN Retrospective case series. METHODS Patients who had hyperopic LASIK treatment using the Amaris excimer laser were included. Eyes in which the LDV femtosecond laser was used for flap creation were compared with eyes in which the Moria M2 microkeratome was used. RESULTS The microkeratome group comprised 53 eyes and the femtosecond laser group, 72 eyes. Baseline characteristics were similar between groups (P > .05). The mean spherical equivalent (SE) deviation from target 1 week postoperatively was -0.08 diopter (D) ± 0.58 (SD) in the femtosecond laser group and -0.06 ± 0.87 D in the microkeratome group (P = .92). Thereafter, the mean SE deviation from target increased gradually and by 6 months postoperatively was +0.30 ± 0.50 D and +0.70 ± 0.71 D, respectively (P = .001). The correlation between the achieved and the attempted SE refraction was better in the femtosecond laser group (R(2) = 0.806) than the microkeratome group (R(2) = 0.671). CONCLUSIONS Using the same nomogram, the short-term refractive outcomes of hyperopic LASIK with flap creation performed with the femtosecond laser were comparable to those for the microkeratome; however, the femtosecond group showed significantly better stability over the 6-month follow-up and better predictability, as reflected by a lower standard deviation and stronger Pearson correlation. FINANCIAL DISCLOSURE Dr. Arba Mosquera is an employee of Schwind eye-tech-solutions GmbH and Co. KG. No other author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Rafic Antonios
- From the Department of Ophthalmology (Antonios, Awwad), American University of Beirut, Beirut, Lebanon; the Department of Research and Development (Arba Mosquera), Schwind eye-tech-solutions GmbH and Co. KG, Kleinostheim, Germany; the Recognized Research Group in Optical Diagnostic Techniques (Arba Mosquera), University of Valladolid, Valladolid, and the Department of Ophthalmology and Sciences of Vision (Arba Mosquera), University of Oviedo, Oviedo, Spain
| | - Samuel Arba Mosquera
- From the Department of Ophthalmology (Antonios, Awwad), American University of Beirut, Beirut, Lebanon; the Department of Research and Development (Arba Mosquera), Schwind eye-tech-solutions GmbH and Co. KG, Kleinostheim, Germany; the Recognized Research Group in Optical Diagnostic Techniques (Arba Mosquera), University of Valladolid, Valladolid, and the Department of Ophthalmology and Sciences of Vision (Arba Mosquera), University of Oviedo, Oviedo, Spain
| | - Shady T Awwad
- From the Department of Ophthalmology (Antonios, Awwad), American University of Beirut, Beirut, Lebanon; the Department of Research and Development (Arba Mosquera), Schwind eye-tech-solutions GmbH and Co. KG, Kleinostheim, Germany; the Recognized Research Group in Optical Diagnostic Techniques (Arba Mosquera), University of Valladolid, Valladolid, and the Department of Ophthalmology and Sciences of Vision (Arba Mosquera), University of Oviedo, Oviedo, Spain.
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Callou TP, Garcia R, Mukai A, Giacomin NT, de Souza RG, Bechara SJ. Advances in femtosecond laser technology. Clin Ophthalmol 2016; 10:697-703. [PMID: 27143847 PMCID: PMC4844446 DOI: 10.2147/opth.s99741] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Femtosecond laser technology has become widely adopted by ophthalmic surgeons. The purpose of this study is to discuss applications and advantages of femtosecond lasers over traditional manual techniques, and related unique complications in cataract surgery and corneal refractive surgical procedures, including: LASIK flap creation, intracorneal ring segment implantation, presbyopic treatments, keratoplasty, astigmatic keratotomy, and intrastromal lenticule procedures.
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Affiliation(s)
| | - Renato Garcia
- Department of Ophthalmology, University of Sao Paulo, Sao Paulo, Brazil
| | - Adriana Mukai
- Department of Ophthalmology, University of Sao Paulo, Sao Paulo, Brazil
| | | | | | - Samir J Bechara
- Department of Ophthalmology, University of Sao Paulo, Sao Paulo, Brazil
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Courtin R, Saad A, Guilbert E, Grise-Dulac A, Gatinel D. Opaque Bubble Layer Risk Factors in Femtosecond Laser-assisted LASIK. J Refract Surg 2016; 31:608-12. [PMID: 26352566 DOI: 10.3928/1081597x-20150820-06] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To determine the characteristics and risk factors for occurrence of opaque bubble layer (OBL) during femtosecond laser-assisted flap creation for LASIK. METHODS One hundred ninety-eight eyes of 102 consecutive patients who underwent LASIK flap creation performed with the Alcon WaveLight FS200 laser (Alcon Laboratories, Inc., Fort Worth, TX) were retrospectively analyzed in a cohort study. Preoperative manifest refraction, corneal keratometry, central corneal thickness, white-to-white corneal diameter, corneal hysteresis, corneal resistance factor, and programmed flaps parameters were collected. Digital images automatically recorded after flap creation were analyzed to measure OBL areas. Correlation tests were performed between preoperative corneal parameters and OBL areas. RESULTS The incidence rate of OBL was 48% (103 eyes). The mean OBL area as a percentage of the corneal flap area in the OBL group was 4.25% ± 7.16% (range: 0% to 32.9%). The central corneal thickness, corneal resistance factor, and corneal hysteresis were significantly positively correlated with the OBL area (r = 0.242, P = .001; r = 0.254, P = .028; and r = 0.351, P < .0001, respectively). Corneal hysteresis and OBL area were positively correlated, independently of the central corneal thickness and other confounder factors with standardized coefficient (r = 0.353 ± 0.227, P = .002). CONCLUSIONS This study confirms the already known OBL risk factors with a larger cohort and suggests for the first time that an elevated corneal hysteresis is an independent predictive risk for OBL occurrence.
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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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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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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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Abstract
Techniques available for corneal lamellar refractive surgery are laser-assisted in situ keratomileusis (LASIK) using a microkeratome or femtosecond laser incision followed by excimer laser corneal ablation, and femtosecond laser-assisted refractive lenticule extraction (ReLEx). These treatments are nowadays considered to be safe and effective standard procedures for surgical correction of mild to moderate ametropia. Possible complications include too small or decentered optical zones, intraoperative flap cutting errors and postoperative inflammation (e.g. diffuse lamellar keratitis, DLK), epithelial or flap folds, epithelial ingrowths or iatrogenic ectasia. The occurrence of complications may be significantly reduced by compliance to corresponding standards of indication and treatment that are based on current scientific knowledge.
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Affiliation(s)
- T Kohnen
- Klinik für Augenheilkunde, Goethe-Universität Frankfurt am Main, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Deutschland.
| | - M Remy
- Klinik für Augenheilkunde, Goethe-Universität Frankfurt am Main, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Deutschland
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Xia LK, Yu J, Chai GR, Wang D, Li Y. Comparison of the femtosecond laser and mechanical microkeratome for flap cutting in LASIK. Int J Ophthalmol 2015; 8:784-90. [PMID: 26309880 DOI: 10.3980/j.issn.2222-3959.2015.04.25] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 07/04/2014] [Indexed: 11/02/2022] Open
Abstract
AIM To compare refractive results, higher-order aberrations (HOAs), contrast sensitivity and dry eye after laser in situ keratomileusis (LASIK) performed with a femtosecond laser versus a mechanical microkeratome for myopia and astigmatism. METHODS In this prospective, non-randomized study, 120 eyes with myopia received a LASIK surgery with the VisuMax femtosecond laser for flap cutting, and 120 eyes received a conventional LASIK surgery with a mechanical microkeratome. Flap thickness, visual acuity, manifest refraction, contrast sensitivity function (CSF) curves, HOAs and dry-eye were measured at 1wk; 1, 3, 6mo after surgery. RESULTS At 6mo postoperatively, the mean central flap thickness in femtosecond laser procedure was 113.05±5.89 µm (attempted thickness 110 µm), and 148.36±21.24 µm (attempted thickness 140 µm) in mechanical microkeratome procedure. An uncorrected distance visual acuity (UDVA) of 4.9 or better was obtained in more than 98% of eyes treated by both methods, a gain in logMAR lines of corrected distance visual acuity (CDVA) occurred in more than 70% of eyes treated by both methods, and no eye lost ≥1 lines of CDVA in both groups. The difference of the mean UDVA and CDVA between two groups at any time post-surgery were not statistically significant (P>0.05). The postoperative changes of spherical equivalent occurred markedly during the first month in both groups. The total root mean square values of HOAs and spherical aberrations in the femtosecond treated eyes were markedly less than those in the microkeratome treated eyes during 6mo visit after surgery (P<0.01). The CSF values of the femtosecond treated eyes were also higher than those of the microkeratome treated eyes at all space frequency (P<0.01). The mean ocular surface disease index scores in both groups were increased at 1wk, and recovered to preoperative level at 1mo after surgery. The mean tear breakup time (TBUT) of the femtosecond treated eyes were markedly longer than those of the microkeratome treated eyes at postoperative 1, 3mo (P<0.01). CONCLUSION Both the femtosecond laser and the mechanical microkeratome for LASIK flap cutting are safe and effective to correct myopia, with no statistically significant difference in the UDVA, CDVA during 6mo follow-up. Refractive results remained stable after 1mo post-operation for both groups. The femtosecond laser may have advantages over the microkeratome in the flap thickness predictability, fewer induced HOAs, better CSF, and longer TBUT.
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Affiliation(s)
- Li-Kun Xia
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
| | - Jie Yu
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
| | - Guang-Rui Chai
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
| | - Dang Wang
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
| | - Yang Li
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
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Malhotra C, Jain AK, Veluswami J, Ram J, Gupta R, Kumar P. Higher Order Aberrations and Visual Outcomes in Wavefront-Optimized Sub-Bowman Keratomileusis: Flap Creation Using Femtosecond Laser Versus Mechanical Microkeratome. Asia Pac J Ophthalmol (Phila) 2015; 4:197-203. [PMID: 26225777 DOI: 10.1097/apo.0000000000000081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE The aim of this study was to compare the outcomes of wavefront-optimized sub-Bowman keratomileusis (SBK) performed using the 150 KHz IntraLase femtosecond (IFS) laser (Abbot Medical Optics) with those using the Moria Evo 3 One Use-Plus SBK mechanical microkeratome (Moria SA). DESIGN A prospective comparative clinical trial. METHODS Fifty patients had bilateral wavefront-optimized SBK performed for myopia or myopic astigmatism. In 25 patients, the flap was created with the 150 KHz IFS laser (group 1) and in the other 25 with the Moria One Use-Plus SBK mechanical microkeratome (group 2). All other treatment parameters were the same. Results were reported for 1 eye per patient in each group (ie, 25 eyes in each group). RESULTS Efficacy, refractive stability, predictability, and safety profiles were comparable between the 2 groups. Although higher order aberrations (HOAs) increased significantly in both groups after laser in situ keratomileusis, intergroup comparison revealed that group 1 was associated with a significantly higher induction of both total HOAs [mean root mean square (RMS), 0.63 ± 0.20 in group 1 vs 0.52 ± 0.14 in group 2; P = 0.031] and spherical aberrations (RMS, 0.37 ± 0.17 in group 1 vs 0.22 ± 0.09 in group 2; P < 0.001) as compared with group 2. CONCLUSIONS Flaps created using the Moria Evo 3 One Use-Plus SBK mechanical microkeratome were associated with significantly lower induction of total HOAs and spherical aberrations as compared with 150 KHz IFS flaps at the end of 3 months follow-up.
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Affiliation(s)
- Chintan Malhotra
- From the Advanced Eye Center, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Laser-Assisted Cataract Surgery: Soft Lens Assisted Interface (SoftFit) versus Direct Contact Interface. Eur J Ophthalmol 2015; 26:242-7. [DOI: 10.5301/ejo.5000684] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2015] [Indexed: 11/20/2022]
Abstract
Purpose To determine the safety of the Laser SoftFit™ patient interface by comparing intraoperative results with the contact interface of the LenSx® femtosecond laser platform (FSL). Methods In this nonrandomized, consecutive case series, 50 eyes underwent femtosecond laser-assisted cataract surgery (FLACS) using the LenSx® laser platform (group 1); FLACS was performed in another 50 eyes, using the Laser SoftFit™ patient interface (group 2). Intraoperative complications (corneal folds) and surgical results (incomplete and free capsulotomies, incomplete phacofragmentation, and unopened incisions) were compared. Results Corneal folds and incomplete capsulotomies were less common (p = 0.0001 for both) and free-floating capsulotomies were more frequent (p = 0.0001) with the Laser SoftFit™ patient interface. Incomplete phacofragmentation and unopened incision exhibited similar rates in both groups (p = 0.436 and 0.204, respectively). Conclusions Using the Laser SoftFit™ patient interface decreased the incidence of corneal folds, resulting in better capsulotomy outcomes during FLACS.
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Nejima R, Terada Y, Mori Y, Ogata M, Minami K, Miyata K. Clinical utility of femtosecond laser-assisted astigmatic keratotomy after cataract surgery. Jpn J Ophthalmol 2015; 59:209-15. [PMID: 25990805 DOI: 10.1007/s10384-015-0383-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 04/10/2015] [Indexed: 10/23/2022]
Abstract
PURPOSE To examine the clinical utility of femtosecond laser-assisted astigmatic keratotomy (FSL-AK) for eyes after cataract surgery. METHODS Eight eyes of 6 patients with an intraocular lens and corneal astigmatism of 2.0 diopters (D) or more underwent FSL-AK. The mean preoperative manifest cylindrical refraction was 2.88 ± 0.64 D and the mean corneal astigmatism was 2.84 ± 0.83 D. Paired symmetrical arcuate incisions were created with the same settings, except for the incision depth. Uncorrected distance visual acuity (UDVA), manifest cylindrical power, and surgically induced astigmatism (SIA) were measured at 1 day, 1 week, and 1 month postoperatively. Fourier analysis of corneal topography and incision depths measured with anterior-segment optical coherence tomography were evaluated 1 month postoperatively. RESULTS In all eyes, the UDVA improved at 1 week and 1 month postoperatively, and the manifest cylinder also decreased postoperatively, while the SIA showed overcorrections in 6 eyes. Fourier analysis showed decreases in spherical and regular astigmatic components and increases in higher-order irregularity. The mean incision depth was measured as 60 µm deeper than the intended depth. CONCLUSION The FSL-AK effectively reduced corneal astigmatism and improved the UDVA, although it was demonstrated that the deeper incisions led to overcorrection.
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Affiliation(s)
- Ryohei Nejima
- Miyata Eye Hospital, 6-3 Kurahara-cho, Miyakonojo, Miyazaki, 885-0051, Japan,
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Robert MC, Khreim N, Todani A, Melki SA. Anterior chamber gas bubble emergence pattern during femtosecond LASIK-flap creation. Br J Ophthalmol 2015; 99:1201-5. [PMID: 25947557 DOI: 10.1136/bjophthalmol-2014-306307] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 02/04/2015] [Indexed: 11/04/2022]
Abstract
AIM To characterise the emergence pattern of cavitation bubbles into the anterior chamber (AC) following femtosecond laser-assisted in situ keratomileusis (LASIK)-flap creation METHODS Retrospective review of patients undergoing femtosecond LASIK surgery at Boston Laser, a private refractive surgery practice in Boston, Massachusetts, between December 2008 and February 2014. Patient charts were reviewed to identify all cases with gas bubble migration into the AC. Surgical videos were examined and the location of bubble entry was recorded separately for right and left eyes. RESULTS Five thousand one hundred and fifty-eight patients underwent femtosecond LASIK surgery. Air bubble migration into the AC, presumably via the Schlemm's canal and trabecular meshwork, occurred in 1% of cases. Patients with AC bubbles had an average age of 33±8 years with a measured LASIK flap thickness of 96±21 μm. The occurrence of gas bubbles impaired iris registration in 64% of cases. Gas bubbles appeared preferentially in the nasal or inferior quadrants for right (92% of cases) and left (100% of cases) eyes. This bubble emergence pattern is significantly different from that expected with a random distribution (p<0.0001) and did not seem associated with decentration of the femtosecond laser docking system. CONCLUSIONS The migration of gas bubbles into the AC is a rare occurrence during femtosecond laser flap creation. The preferential emergence of gas bubbles into the nasal and inferior quadrants of the AC may indicate a distinctive anatomy of the nasal Schlemm's canal.
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Affiliation(s)
- Marie-Claude Robert
- Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Boston, Massachusetts, USA
| | - Nour Khreim
- Boston Eye Group, Brookline, Massachusetts, USA
| | - Amit Todani
- Boston Eye Group, Brookline, Massachusetts, USA
| | - Samir A Melki
- Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Boston, Massachusetts, USA Boston Eye Group, Brookline, Massachusetts, USA
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Yvon C, Archer TJ, Gobbe M, Reinstein DZ. Comparison of Higher-Order Aberration Induction Between Manual Microkeratome and Femtosecond Laser Flap Creation. J Refract Surg 2015; 31:130-5. [DOI: 10.3928/1081597x-20150122-09] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 12/01/2014] [Indexed: 11/20/2022]
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Rescue of primary incomplete microkeratome flap with secondary femtosecond laser flap in LASIK. Case Rep Ophthalmol Med 2014; 2014:289354. [PMID: 25506449 PMCID: PMC4258920 DOI: 10.1155/2014/289354] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 11/14/2014] [Accepted: 11/14/2014] [Indexed: 11/17/2022] Open
Abstract
For laser-assisted in situ keratomileusis (LASIK) retreatments with a previous unsuccessful mechanical microkeratome-assisted surgery, some surgical protocols have been described as feasible, such as relifting of the flap or the creation of a new flap and even the change to a surface ablation procedure (photorefractive keratectomy (PRK)). This case shows the use of femtosecond technology for the creation of a secondary flap to perform LASIK in a cornea with a primary incomplete flap obtained with a mechanical microkeratome. As we were unable to characterize the interface of the first partial lamellar cut, a thick flap was planned and created using a femtosecond laser platform. As the primary cut was very thick in the nasal quadrant, a piece of loose corneal tissue appeared during flap lifting which was fitted in its position and not removed. Despite this condition and considering the regularity of the new femtosecond laser cut, the treatment was uneventful. This case report shows the relevance of a detailed corneal analysis with an advanced imaging technique before performing a secondary flap in a cornea with a primary incomplete flap. The femtosecond laser technology seems to be an excellent tool to manage such cases successfully.
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81
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Sinha Roy A, Dupps WJ, Roberts CJ. Comparison of biomechanical effects of small-incision lenticule extraction and laser in situ keratomileusis: finite-element analysis. J Cataract Refract Surg 2014; 40:971-80. [PMID: 24857440 DOI: 10.1016/j.jcrs.2013.08.065] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 07/12/2013] [Accepted: 08/14/2013] [Indexed: 11/18/2022]
Abstract
PURPOSE To theoretically compare the corneal stress distribution of laser in situ keratomileusis (LASIK) with the stress distribution of small-incision lenticule extraction. SETTING Cleveland Clinic Cole Institute, Cleveland, and The Ohio State University, Columbus, Ohio, USA. DESIGN Computational modeling study. METHODS A finite-element anisotropic collagen fiber-dependent model of myopic surgery using patient-specific corneal geometry was constructed for LASIK, small-incision lenticule extraction, and a geometry analog model with unaltered material properties from preoperative but with postoperative geometry including thickness. Surgical parameters, magnitude of myopic correction, LASIK flap thickness, and lenticule depth in small-incision lenticule extraction were varied. Two sets of models, 1 with uniform and 1 with depth-dependent material properties, were constructed. RESULTS Stress distribution between small-incision lenticule extraction simulations and the geometry analog model were similar. In contrast, LASIK consistently reduced stress in the flap and increased stress in the residual stromal bed (RSB) compared with the geometry analog model. An increase in flap thickness or lenticule depth resulted in a greater increase in RSB stress in the LASIK model than in the small-incision lenticule extraction model. CONCLUSIONS Small-incision lenticule extraction may present less biomechanical risk to the residual bed of susceptible corneas than comparable corrections involving LASIK flaps. Deeper corrections in the stroma may be possible in small-incision lenticule extraction without added risk for ectasia. FINANCIAL DISCLOSURES Proprietary or commercial disclosures are listed after the references.
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Affiliation(s)
- Abhijit Sinha Roy
- From the Cole Eye Institute (Sinha Roy, Dupps), Cleveland Clinic Foundation, the Department of Biomedical Engineering (Dupps), Lerner Research Institute, and the Department of Biomedical Engineering (Dupps), Case Western Reserve University, Cleveland, and the Departments of Ophthalmology and Biomedical Engineering (Roberts), The Ohio State University, Columbus, Ohio, USA
| | - William J Dupps
- From the Cole Eye Institute (Sinha Roy, Dupps), Cleveland Clinic Foundation, the Department of Biomedical Engineering (Dupps), Lerner Research Institute, and the Department of Biomedical Engineering (Dupps), Case Western Reserve University, Cleveland, and the Departments of Ophthalmology and Biomedical Engineering (Roberts), The Ohio State University, Columbus, Ohio, USA
| | - Cynthia J Roberts
- From the Cole Eye Institute (Sinha Roy, Dupps), Cleveland Clinic Foundation, the Department of Biomedical Engineering (Dupps), Lerner Research Institute, and the Department of Biomedical Engineering (Dupps), Case Western Reserve University, Cleveland, and the Departments of Ophthalmology and Biomedical Engineering (Roberts), The Ohio State University, Columbus, Ohio, USA.
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82
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Sáles CS, Manche EE. One-year eye-to-eye comparison of wavefront-guided versus wavefront-optimized laser in situ keratomileusis in hyperopes. Clin Ophthalmol 2014; 8:2229-38. [PMID: 25419115 PMCID: PMC4235493 DOI: 10.2147/opth.s70145] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background To compare wavefront (WF)-guided and WF-optimized laser in situ keratomileusis (LASIK) in hyperopes with respect to the parameters of safety, efficacy, predictability, refractive error, uncorrected distance visual acuity, corrected distance visual acuity, contrast sensitivity, and higher order aberrations. Methods Twenty-two eyes of eleven participants with hyperopia with or without astigmatism were prospectively randomized to receive WF-guided LASIK with the VISX CustomVue S4 IR or WF-optimized LASIK with the WaveLight Allegretto Eye-Q 400 Hz. LASIK flaps were created using the 150-kHz IntraLase iFS. Evaluations included measurement of uncorrected distance visual acuity, corrected distance visual acuity, <5% and <25% contrast sensitivity, and WF aberrometry. Patients also completed a questionnaire detailing symptoms on a quantitative grading scale. Results There were no statistically significant differences between the groups for any of the variables studied after 12 months of follow-up (all P>0.05). Conclusion This comparative case series of 11 subjects with hyperopia showed that WF-guided and WF-optimized LASIK had similar clinical outcomes at 12 months.
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Affiliation(s)
- Christopher S Sáles
- Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Edward E Manche
- Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
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83
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Abouzeid H, Ferrini W. Femtosecond-laser assisted cataract surgery: a review. Acta Ophthalmol 2014; 92:597-603. [PMID: 24835818 DOI: 10.1111/aos.12416] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 03/12/2014] [Indexed: 02/06/2023]
Abstract
Introduced in 2008, the femtosecond laser is a promising new technological advance which plays an ever increasing role in cataract surgery where it automates the three main surgical steps: corneal incision, capsulotomy and lens fragmentation. The proven advantages over manual surgery are: a better quality of incision with reduced induced astigmatism; increased reliability and reproducibility of the capsulotomy with increased stability of the implanted lens; a reduction in the use of ultrasound. Regarding refractive results or safety, however, no prospective randomized study to date has shown significant superiority compared with standard manual technique. The significant extra cost generated by this laser, undertaken by the patient, is a limiting factor for both its use and study. This review outlines the potential benefits of femtosecond-laser-assisted cataract surgery due to the automation of key steps and the safety of this new technology.
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Affiliation(s)
- Hana Abouzeid
- Cataract Unit; Department of ophthalmology; University of Lausanne; Lausanne Switzerland
- Jules-Gonin Eye Hospital; Lausanne Switzerland
- Fondation Asile des Aveugles; Lausanne Switzerland
- IRO-Institute for Research in Ophthalmology; Sion Switzerland
| | - Walter Ferrini
- Cataract Unit; Department of ophthalmology; University of Lausanne; Lausanne Switzerland
- Jules-Gonin Eye Hospital; Lausanne Switzerland
- Fondation Asile des Aveugles; Lausanne Switzerland
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84
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Pajic B, Vastardis I, Pajic-Eggspuehler B, Gatzioufas Z, Hafezi F. Femtosecond laser versus mechanical microkeratome-assisted flap creation for LASIK: a prospective, randomized, paired-eye study. Clin Ophthalmol 2014; 8:1883-9. [PMID: 25284975 PMCID: PMC4181739 DOI: 10.2147/opth.s68124] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To compare a femtosecond laser with a microkeratome for flap creation during laser in situ keratomileusis (LASIK) in terms of flap thickness predictability and visual outcomes. Patients and methods This was a prospective, randomized, masked, paired-eye study. Forty-four patients (34 females) who received bilateral LASIK were included. Patients were stratified by ocular dominance, and they then underwent randomization of flap creation using the femtosecond laser on one eye and undergoing the microkeratome procedure on the other one. The visual outcome differences between the corrected distance visual acuity (CDVA) at baseline and the uncorrected distance visual acuity (UDVA) on the first day postoperatively were set as the efficiency index for both groups. All visual acuity outcome results and the deviation of flap thickness were evaluated. P-values <0.05 were considered statistically significant. Results The index of efficiency regarding the postoperative visual outcomes in the microkeratome group was lower (P<0.0001). This result was correlated with the difference between intended and achieved flap thickness (P=0.038; r=0.28), and a negative relationship in the regression analysis was confirmed (P<0.04; R2=0.1428). The UDVA in the microkeratome group improved significantly by the end of the first month (P<0.0271) in comparison to the baseline CDVA. The deviation between intended and postoperative flap thickness using either optical coherence pachymetry or Heidelberg Retinal Tomography II confocal microscopy was statistically significant (paired t-test; P<0.001) between the groups. The flap thickness deviation in the microkeratome group was higher. In the femtosecond laser group, the efficiency index was stable postoperatively (P=0.64) The UDVA improved significantly by the end of the first postoperative week (P=0.0043) in comparison to the baseline CDVA. Six months after surgery, improvement in the UDVA was significant in both groups (all P<0.001; one way analysis of variance). Conclusion Femtosecond laser was superior to microkeratome-assisted LASIK in terms of flap thickness predictability and the speed of visual acuity recovery. A negative relationship in the regression analysis between increasing flap thickness deviation and visual acuity recovery was confirmed.
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Affiliation(s)
- Bojan Pajic
- Swiss Eye Research Foundation, Eye Clinic ORASIS, Reinach, Switzerland ; Division of Ophthalmology, Department of Clinical Neurosciences, University Hospital of Geneva, Geneva, Switzerland ; Eye Hospital VIDAR-ORASIS Swiss, University of Novi Sad, Faculty of Physics, Novi Sad, Serbia ; Military Medical Academy, University of Defense, Belgrade, Serbia
| | - Iraklis Vastardis
- Swiss Eye Research Foundation, Eye Clinic ORASIS, Reinach, Switzerland ; Eye Hospital VIDAR-ORASIS Swiss, University of Novi Sad, Faculty of Physics, Novi Sad, Serbia
| | | | - Zisis Gatzioufas
- Division of Ophthalmology, Department of Clinical Neurosciences, University Hospital of Geneva, Geneva, Switzerland
| | - Farhad Hafezi
- Division of Ophthalmology, Department of Clinical Neurosciences, University Hospital of Geneva, Geneva, Switzerland ; Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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85
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Teus MA, Garcia-Gonzalez M. Comparison of the Visual Results After Small Incision Lenticule Extraction and Femtosecond Laser-Assisted LASIK for Myopia. J Refract Surg 2014. [DOI: 10.3928/1081597x-20140814-05] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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86
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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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87
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Kobashi H, Kamiya K, Hoshi K, Igarashi A, Shimizu K. Wavefront-guided versus non-wavefront-guided photorefractive keratectomy for myopia: meta-analysis of randomized controlled trials. PLoS One 2014; 9:e103605. [PMID: 25072409 PMCID: PMC4114780 DOI: 10.1371/journal.pone.0103605] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 07/01/2014] [Indexed: 11/23/2022] Open
Abstract
Purpose To compare the efficacy, predictability, safety, and induced higher-order aberrations (HOAs) between wavefront-guided and non-wavefront-guided photorefractive keratectomy (PRK). Methods The Cochrane Central Register of Controlled Trials, PubMED, and EMBASE were searched for randomized controlled trials. Trials meeting the selection criteria were quality appraised, and data was extracted by 2 independent authors. Measures of association were pooled quantitatively using meta-analytical methods. Comparisons between wavefront-guided and non-wavefront-guided ablations were made as pooled odds ratios (ORs) or weighted mean differences. The pooled ORs and 95% confidence intervals (CIs) were computed for efficacy, safety, and predictability. The weighted mean differences and 95% CIs were used to compare induced HOAs. Results The study covered five trials involving 298 eyes. After wavefront-guided PRK, the pooled OR of achieving an uncorrected distance visual acuity of 20/20 (efficacy) was 1.18 (95% CI, 0.53–2.60; p = 0.69), the pooled OR of achieving a result within ±0.50 diopter of the intended target (predictability) was 0.86 (95% CI, 0.40–1.84; p = 0.70). No study reported a loss of 2 or more lines of Snellen acuity (safety) with either modality. In eyes with wavefront-guided PRK, the postoperative trefoil aberrations (mean difference −0.02; 95% CI, −0.03 to −0.00; p = 0.03) were significantly lower. There were no significant differences between the two groups in the postoperative total HOAs (mean difference −0.04; 95% CI, −0.23 to 0.14; p = 0.63), spherical (mean difference 0.00; 95% CI, −0.08 to 0.09; p = 0.93), and coma (mean difference −0.06; 95% CI, −0.14 to 0.03; p = 0.20) aberrations. Conclusions According to the meta-analysis, wavefront-guided PRK offered no advantage in efficacy, predictability, or safety measures over non-wavefront-guided PRK, although it may have induced fewer trefoil aberrations.
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Affiliation(s)
- Hidenaga Kobashi
- Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan
- * E-mail:
| | - Kazutaka Kamiya
- Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan
| | - Keika Hoshi
- Department of Preventive Medicine, University of Kitasato School of Medicine, Kanagawa, Japan
| | - Akihito Igarashi
- Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan
| | - Kimiya Shimizu
- Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan
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88
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Kankariya VP, Diakonis VF, Kymionis GD, Yoo SH. Anterior Gas Breakthrough During Femtosecond Intrastromal Astigmatic Keratotomy (FISK). J Refract Surg 2014; 30:511-3. [DOI: 10.3928/1081597x-20140711-02] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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89
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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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90
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Corneal backscatter analysis by in vivo confocal microscopy: fellow eye comparison of small incision lenticule extraction and femtosecond laser-assisted LASIK. J Ophthalmol 2014; 2014:265012. [PMID: 24734168 PMCID: PMC3964686 DOI: 10.1155/2014/265012] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 01/13/2014] [Indexed: 11/17/2022] Open
Abstract
Purpose. To evaluate and compare corneal backscatter from anterior stroma between small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK (femto-LASIK). Methods. A cohort of 60 eyes of 30 patients was randomized to receive SMILE in one eye and femto-LASIK in the fellow eye. In vivo confocal microscopy was performed at 1 week and 1, 3, and 6 months after surgery. The main outcome measurements were maximum backscattered intensity and the depth from which it was measured, the backscattered light intensity 30 μ m below Bowman's membrane at the flap interface and 150 μ m below the superficial epithelium, and the number of refractive particles at the flap interface. Results. The mean backscattered light intensity (LI) at all measured depths and the maximum backscattered LI were higher in the SMILE group than the femto-LASIK group at all postoperative visits. LI differences at 1 week and 1- and 3-month visits were statistically significant (P < 0,05). LI differences at 6 months were not statistically significant. There was no difference in the number of refractive particles at the flap interface between the groups at any visit. Conclusions. SMILE results in increased backscattered LI in the anterior stroma when compared with femto-LASIK were evaluated.
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Heichel J, Wilhelm F, Kunert KS, Schlueter R, Stuhltraeger U, Hammer T. Influence of microkeratome parameters on the stromal bed and flap edge quality in laser in situ keratomileusis. Clin Ophthalmol 2013; 8:61-9. [PMID: 24368878 PMCID: PMC3869919 DOI: 10.2147/opth.s51200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose Femtosecond lasers have become the standard for laser-assisted in situ keratomileusis (LASIK) flap creation, but advanced mechanical microkeratomes are still an alternative, more cost-effective way to create the flap. The SCHWIND Carriazo-Pendular microkeratome is one of the most commonly used microkeratomes. The influence of different cutting parameters (head-advance speeds, cutting heads) on morphology of LASIK cuts was investigated. Setting Experimental study performed at the University Eye Hospital of the Martin Luther University Halle/Wittenberg, Halle (Saale), Germany. Methods The Carriazo-Pendular microkeratome was used on freshly enucleated porcine eyes for lamellar keratotomy. After flap removal, the cutting edge and stromal bed were evaluated from scanning electron micrographs using an individualized scoring system. Four different settings of microkeratome parameters were compared. For each setting, eight cuts were evaluated (n=32). Results Different oscillation frequencies and head-advance speeds did not influence the cutting qualities. A higher oscillation/feed rate ratio seemed to be advantageous for a smoother interface. Concerning different cuttings heads, a deeper keratotomy led to sharper cutting edges. The thinner the flap, the more irregularities in the stromal bed appeared. Complications did not occur. Conclusion The Carriazo-Pendular microkeratome is a safe tool with which to create a LASIK flap and is a good alternative to a costly femtosecond laser. Deeper keratotomies, as well as the use of a higher oscillation/feed rate quotient, improve the cutting quality.
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Affiliation(s)
- Jens Heichel
- Department of Ophthalmology, University Hospital of Martin Luther University Halle/Wittenberg, Halle (Saale), Germany
| | | | - Kathleen S Kunert
- Department of Ophthalmology, Helios Klinikum Erfurt, Erfurt, Germany
| | - Rabea Schlueter
- Institute of Microbiology, Ernst-Moritz-Arndt-University, Greifswald, Germany
| | - Ute Stuhltraeger
- Department of Ophthalmology, University Hospital of Martin Luther University Halle/Wittenberg, Halle (Saale), Germany
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92
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Zhang YL, Liu L, Cui CX, Hu M, Li ZN, Cao LJ, Jing XH, Mu GY. Comparative study of visual acuity and aberrations after intralase femtosecond LASIK: small corneal flap versus big corneal flap. Int J Ophthalmol 2013; 6:641-5. [PMID: 24195040 DOI: 10.3980/j.issn.2222-3959.2013.05.16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 07/24/2013] [Indexed: 11/02/2022] Open
Abstract
AIM To study the effect of different flap sizes on visual acuity, refractive outcomes, and aberrations after femtosecond laser for laser in situ keratomileusis (LASIK). METHODS In each of the forty patients enrolled, 1 eye was randomly assigned to receive treatment with a 8.1mm diameter corneal flap, defined as the small flap, while the other eye was treated with a 8.6mm diameter corneal flap, defined as the big flap. Refractive errors, visual acuity, and higher-order aberrations were compared between the two groups at week 1, month 1 and 3 postoperatively. RESULTS The postoperative refractive errors and visual acuity all conformed to the intended goal. Postoperative higher-order aberrations were increased, especially in spherical aberration (Z12) and vertical coma (Z7). There were no statistically significant differences between the two groups in terms of postoperative refractive errors, visual acuity, root mean square of total HOAs (HO-RMS), trefoil 30° (Z6), vertical coma (Z7), horizontal coma (Z8), trefoil 0° (Z9), and spherical aberration (Z12) at any point during the postoperative follow-up. CONCLUSION Both the small and big flaps are safe and effective procedures to correct myopia, provided the exposure stroma meets the excimer laser ablations. The personalized size corneal flap is feasible, as we can design the size of corneal flap based on the principle that the corneal flap diameter should be equal to or greater than the sum of the maximum ablation diameter and apparatus error.
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Affiliation(s)
- Ya-Li Zhang
- Department of Ophthalmology, Shandong Provincial Hospital affiliated to Shandong University, No.324 Jingwuweiqi Road, Jinan 250021, Shandong Province, China ; Department of Ophthalmology, The Second People's Hospital of Jinan, 148 Jingyi Road, Jinan 250001, Shandong Province, 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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94
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Visual outcomes comparison of 2 femtosecond laser platforms for laser in situ keratomileusis. J Cataract Refract Surg 2013; 39:1647-52. [DOI: 10.1016/j.jcrs.2013.04.044] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 04/17/2013] [Accepted: 04/18/2013] [Indexed: 11/22/2022]
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95
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Lim DH, Keum JE, Ju WK, Lee JH, Chung TY, Chung ES. Prospective contralateral eye study to compare 80- and 120-μm flap LASIK using the VisuMax femtosecond laser. J Refract Surg 2013; 29:462-8. [PMID: 23820228 DOI: 10.3928/1081597x-20130617-04] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 03/26/2013] [Indexed: 11/20/2022]
Abstract
PURPOSE To compare visual outcomes and flap stability of LASIK with ultrathin 80- and 120-μm flaps created with a VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) for moderate to high myopia and to evaluate the effect of corneal flap thickness on outcomes. METHODS In a prospective contralateral eye study, 36 consecutive patients (72 eyes) underwent bilateral LASIK for myopia ranging from -2.00 to -10.00 diopters using the VisuMax femtosecond laser and MEL-80 excimer laser (Carl Zeiss Meditec). One eye of each patient was randomized to have the 80-μm flap and the other to the 120-μm flap created with 200-kHz VisuMax femtosecond laser. Preoperative and postoperative tests included visual acuity, manifest refraction, contrast sensitivity, and flap thickness measured by anterior segment optical coherence tomography. Main outcomes and complications were checked at postoperative 1 week and 1, 3, and 6 months. RESULTS There were no differences in visual outcome, residual refractive error, or contrast sensitivity between groups during follow-up, except for better uncorrected visual acuity at postoperative 1 day in the 120-μm group. Mean standard deviations of measured flap thickness during follow-up ranged from 3.16 to 3.80 μm in both groups. Opaque bubble layer, a unique complication in femtosecond LASIK, was more frequent in the 80-μm group (7 of 36: 19%) than in the 120-μm flap group (3 of 36: 8%) without a statistically significant difference (P = .301) and was related to thicker central cornea and steeper keratometric value, although it did not influence clinical results. Comparison of the intended versus achieved correction showed no significant differences between groups. CONCLUSIONS LASIK using the VisuMax femtosecond laser supplied good clinical results and flap reproducibility in both the 80- and 120-μm flap groups. Patients with relatively thin cornea may benefit from 80-μm flap LASIK.
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Affiliation(s)
- Dong Hui Lim
- Department of Ophthalmology, Samsung Medical Center Sungkyunkwan University School of Medicine, Seoul, Korea
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Abstract
Laser in situ keratomileusis (LASIK) is now considered to be a safe and effective standard procedure for surgical correction of low to medium ametropia. Nevertheless, as in any other surgical intervention complex courses may occur in single rare cases. Possible complications include, but are not limited to, optically effective errors, such as too small or decentered optical zones as well as intraoperative flap cutting errors and postoperative complications, such as inflammation (e.g. diffuse lamellar keratitis, DLK), epithelial or flap folds, epithelial ingrowths or iatrogenic ectasia. Compliance to standards for indications and treatment based on the current scientific knowledge can significantly reduce the occurrence of complications. These standards include adjustment of the optical zone to the mesopic pupil diameter, the application of state of the art eye trackers, careful performance of intraoperative and postoperative procedures by a surgeon experienced in the entire spectrum of ocular surgery, the possibility of treating complications directly on occurrence and, last but not least, conservative patient selection and choice of treatment.
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97
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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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98
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Cosar CB, Gonen T, Moray M, Sener AB. Comparison of visual acuity, refractive results and complications of femtosecond laser with mechanical microkeratome in LASIK. Int J Ophthalmol 2013; 6:350-5. [PMID: 23826532 DOI: 10.3980/j.issn.2222-3959.2013.03.18] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 05/17/2013] [Indexed: 01/28/2023] Open
Abstract
AIM To compare the outcomes of laser in situ keratomileusis (LASIK) performed with a femtosecond laser (Femtec, Technolas Perfect Vision GmbH, Germany) versus a mechanical microkeratome (Hansatome, Bausch and Lomb, USA) for the correction of myopia and astigmatism. METHODS In this retrospective study, patients who had undergone LASIK using the 80-kHz Femtec femtosecond laser were compared to age- and refraction-matched patients in whom the Hansatome microkeratome was used. Refractive and visual results 1 month and 3 months postoperatively, and complication rates were compared between the two groups. RESULTS A total of 280 eyes were analyzed (140 in each group). At 3 months postoperatively in the Femtec vs Hansatome group, spherical equivalent refraction was within ±1.00D of emmetropia in 140 vs 138 eyes (P=0.498), the cylinder was within ±0.50D in 137 vs 139 eyes (P=0.622), and the UDVA was 20/20 or better in 136 vs 137 eyes (P=0.724), respectively. There was no statistically significant difference in the complication rates between the two groups (P=0.099). CONCLUSION LASIK performed both with Femtec femtosecond laser and Hansatome microkeratome achieved satisfactory refractive and visual results at 3 months postoperatively, without significant differences in efficacy, safety, and complication rates between the two procedures.
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Affiliation(s)
- Cemile Banu Cosar
- Department of Ophthalmology, Acibadem University, Istanbul 34457, Turkey
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99
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Zhang Y, Chen YG, Xia YJ. Comparison of corneal flap morphology using AS-OCT in LASIK with the WaveLight FS200 femtosecond laser versus a mechanical microkeratome. J Refract Surg 2013; 29:320-4. [PMID: 23659230 DOI: 10.3928/1081597x-20130415-03] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 02/26/2013] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate and compare the thickness and the morphology of femtosecond and mechanical microkeratome LASIK flaps using anterior segment optical coherence tomography (AS-OCT). METHODS Bilateral LASIK was performed in 132 eyes from 61 myopic patients. Flaps were created in 72 eyes using the WaveLight FS200 femtosecond laser (Wave-Light GmbH, Erlangen, Germany) and in 50 eyes using the Moria microkeratome (Moria SA, Antony, France). AS-OCT was used 1 week postoperatively to evaluate the thickness of 17 points across each flap, which were 0, 2, and 3.5 mm to the corneal vertex on the horizontal, vertical, 45°, and 135° meridians. RESULTS The mean central flap thickness was 105.53 ± 5.86 μm in the WaveLight group and 132.96 ± 13.91 μm in the Moria group (P < .001). The difference between the achieved and the intended flap thickness (accuracy) was 6.17 ± 3.98 and 23.60 ± 12.64 μm, respectively (P < .001). The standard deviation within individual flap (uniformity) was smaller in the WaveLight group. The symmetry and regularity were also better in the WaveLight group. Flap morphology showed a more regular planar shape in the WaveLight group and a meniscus shape in the Moria group. CONCLUSIONS AS-OCT showed that the flaps created by the WaveLight femtosecond laser were more accurate, reproducible, and uniform than those created by the Moria microkeratome.
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Affiliation(s)
- Yu Zhang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
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100
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Sáles CS, Manche EE. One-year outcomes from a prospective, randomized, eye-to-eye comparison of wavefront-guided and wavefront-optimized LASIK in myopes. Ophthalmology 2013; 120:2396-2402. [PMID: 23778091 DOI: 10.1016/j.ophtha.2013.05.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 04/24/2013] [Accepted: 05/01/2013] [Indexed: 10/26/2022] Open
Abstract
OBJECTIVE To compare wavefront (WF)-guided and WF-optimized LASIK in myopes. DESIGN Prospective, randomized, eye-to-eye study. PARTICIPANTS A total of 72 eyes of 36 participants with myopia with or without astigmatism. METHODS Participants were randomized to receive WF-guided or WF-optimized LASIK with the WaveLight Allegretto Eye-Q 400-Hz excimer laser platform (Alcon, Inc., Hüenberg, Switzerland). LASIK flaps were created using the 150-kHz IntraLase iFS (Abbott Medical Optics, Santa Ana, CA). Evaluations included measurement of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), <5% and <25% contrast sensitivity, and WF aberrometry. Patients also completed a validated questionnaire detailing symptoms on a quantitative scale. MAIN OUTCOME MEASURES Safety, efficacy, predictability, refractive error, UDVA, CDVA, contrast sensitivity, and higher-order aberrations (HOAs). RESULTS The frequency with which the WF-guided and WF-optimized groups achieved postoperative UDVA of ≥ 20/16 or ≥ 20/20 and the frequency with which the groups lost 1 or 2 or more lines or maintained their preoperative CDVA were not statistically different from each other (all P > 0.05). The frequency with which the WF-guided group attained a refractive error within ± 0.25 diopters of emmetropia was higher than in the WF-optimized group (67.6%, 95% confidence interval [CI], 50.4-84.8 vs. 41.2%, 95% CI, 23.2-59.2; P = 0.03). The WF-guided group's mean UDVA was better than the WF-optimized group's UDVA by approximately 1 Early Treatment Diabetic Retinopathy Study line (-0.17 ± 0.11 logarithm of the minimum angle of resolution [logMAR], slightly <20/12 Snellen vs. -0.13 ± 0.12, slightly >20/16; P = 0.05). There were no statistically significant differences in contrast sensitivity, astigmatism, coma, or higher-order root mean square error between the groups (all P > 0.05), but the WF-guided group had less trefoil compared with the WF-optimized group (0.14 ± 0.07 vs. 0.20 ± 0.09; P < 0.01). There were no statistically significant differences in subjective parameters between the groups (all P > 0.05). CONCLUSIONS Wavefront-guided and WF-optimized LASIK using the Alcon WaveLight Allegretto Eye-Q 400-Hz excimer laser platform provide similar results in myopic patients; however, the WF-guided approach may yield small gains in visual acuity, predictability, and HOAs.
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Affiliation(s)
- Christopher S Sáles
- Byers Eye Institute, Stanford University School of Medicine, Palo Alto, California
| | - Edward E Manche
- Byers Eye Institute, Stanford University School of Medicine, Palo Alto, California.
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