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Ex-vivo study on the surface quality of corneal lenticule and stroma after low energy femtosecond laser lenticule extraction. Sci Rep 2022; 12:10034. [PMID: 35705567 PMCID: PMC9200215 DOI: 10.1038/s41598-022-13468-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 05/24/2022] [Indexed: 11/26/2022] Open
Abstract
This study aimed to assess the surface quality of cap, stroma and lenticular surfaces created using low-energy femtosecond laser lenticule extraction (Ziemer FEMTO LDV Z8). Twenty-four porcine eyes were divided into four groups (n = 6 each): two with optimal laser power (32%) with posterior curvature equivalent to a spherical correction of -2D and -5D, respectively and the other two with high power (64%) with spherical correction of -2D and -5D respectively. Samples were analysed using scanning electron microscopy (SEM). Surface morphology was evaluated using a standard scoring system; surface relief, surface regularity, extent and position of irregularities were graded by four independent clinicians. Eyes with 32% power and -2D correction had significantly less size of the irregular area than those with -5D; however, no significant difference was found between the two groups with 64% power. When comparing eyes with -2D correction, the size of the irregular area was lesser with 32% power. Surface relief was lesser with -5D correction with 32% power than 64% power. Low-energy femtosecond laser lenticule extraction (Ziemer FEMTO LDV Z8) produces good surface quality results. There is a tendency for smoother surface stromal quality with lower power settings than a higher power.
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Liang C, Zhang Y, He Y, Wang S. Research Progress on Morphological Changes and Surgery-related Parameters of Corneal Cap in Small Incision Lenticule Extraction. Ophthalmic Res 2021; 65:4-13. [PMID: 34670218 DOI: 10.1159/000520241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 10/10/2021] [Indexed: 11/19/2022]
Abstract
Small incision lenticule extraction (SMILE) is an "all-in-one" surgical method for refractive correction. An advantage of the SMILE over traditional surgery is that it depends on the corneal cap's design. This review discusses the morphological evaluation of the corneal cap, selection of the corneal cap with different thickness and diameters, influence of the corneal cap design on retreatment, and management of corneal cap-related complications. The following points should be recognized to define the correct morphology and design of the operation-related parameters of the corneal cap during SMILE: (1) the thickness and diameter of the corneal cap are predictable and influence postoperative visual quality, (2) the change in anterior surface curvature of the corneal cap should be considered in the design of nomogram value, (3) for patients with moderate myopic correction, early visual quality is better with a 6.9-mm than with a 7.5-mm diameter corneal cap, (4) there is no significant difference in visual quality or biomechanics among corneal caps with different thickness; (5) primary corneal cap thickness plays an important role in the SMILE retreatment, (6) a 7.78-mm diameter corneal cap has a greater risk of suction loss than a 7.60-mm diameter corneal cap, (6) if suction loss occurs when lenticular scanning exceeds 10%, then SMILE can be continued by changing corneal cap thickness, (7) preventive collagen cross-linking with SMILE caps are 90-120 μm thick and 7-7.8 mm in diameter, and (8) properly treating SMILE-related complications ensures better postoperative results. The data presented herein shall deepen the understanding of the importance of the corneal cap during SMILE and provide diversified analysis for personalized operational design of corneal cap parameters.
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Affiliation(s)
- Chen Liang
- Corneal Refraction Department, The Second Hospital of Jilin University, Changchun, China,
| | - Yan Zhang
- Corneal Refraction Department, The Second Hospital of Jilin University, Changchun, China
| | - Yuxi He
- Corneal Refraction Department, The Second Hospital of Jilin University, Changchun, China
| | - Shurong Wang
- Corneal Refraction Department, The Second Hospital of Jilin University, Changchun, China
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Yin Y, Hu T, Xiang A, Fu Y, Zhao Y, Wu X, Wu X, Wen D. A microscopic study of the corneal stromal lenticules extracted during femtosecond laser-assisted small incision lenticule extraction. Exp Ther Med 2021; 22:681. [PMID: 33986846 DOI: 10.3892/etm.2021.10113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 11/20/2020] [Indexed: 11/06/2022] Open
Abstract
The aim of the present study was to investigate the histological and morphological characteristics of corneal stromal lenticules extracted during femtosecond laser-assisted small incision lenticule extraction (SMILE) surgery by light and electron microscopy. A total of 20 human corneal stromal lenticules extracted during SMILE surgery were sent for microscopic examination immediately after surgery. Of these, six were observed under a light microscope and 14 were observed under an electron microscope. The smoothness of the front and rear surface of the lenticules observed under an electron microscope was rated on a scale of 0 to 4 according to unified evaluation criteria and the scores were statistically compared. Under the light microscope, the edge of the cross section of the corneal stromal lenticules was deeply stained and certain burrs and broken collagen fibers were observed. The swollen corneal stromal fibers were distributed irregularly, with a few bubbles of different sizes. Under the electron microscope, the surface of the lenticules ablated using a femtosecond laser was not perfectly smooth and the front surface was smoother than the rear surface. The side edge of the lenticules ablated using a femtosecond laser was not as regular as the edge cut using microscissors. Necrosis and dissolution of collagen fibers were observed near the surface of the lenticules. In conclusion, the surface quality of corneal stromal lenticules ablated using a femtosecond laser was not optimal when observed under a microscope. Increased attention should be paid to the histology and morphology of the corneal surface following laser ablation.
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Affiliation(s)
- Yewei Yin
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.,Hunan Key Laboratory of Ophthalmology, College of Basic Medicine, Central South University, Changsha, Hunan 410008, P.R. China
| | - Tu Hu
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.,Hunan Key Laboratory of Ophthalmology, College of Basic Medicine, Central South University, Changsha, Hunan 410008, P.R. China
| | - Aiqun Xiang
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Yanyan Fu
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Yang Zhao
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Xiaoying Wu
- Department of Pathology, College of Basic Medicine, Central South University, Changsha, Hunan 410008, P.R. China
| | - Xiaoying Wu
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.,Hunan Key Laboratory of Ophthalmology, College of Basic Medicine, Central South University, Changsha, Hunan 410008, P.R. China
| | - Dan Wen
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.,Hunan Key Laboratory of Ophthalmology, College of Basic Medicine, Central South University, Changsha, Hunan 410008, P.R. China
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Wu Y, Wang Y, Zhang Z, Yu X, Zhao X. Quantitative Analysis of Human Corneal Lenticule Surface Microstructure Irregularity with 3D Optical Profiler Using White Light Interferometry. Curr Eye Res 2020; 46:461-469. [PMID: 32847425 DOI: 10.1080/02713683.2020.1809000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To quantitatively evaluate the cutting quality of small incision lenticule extraction (SMILE) by measuring human corneal lenticule surface roughness in different areas with white light interferometer. METHOD A white light interferometer was used to quantitatively measure the corneal lenticule surface roughness in different areas. Sixty-three myopic patients (102 eyes) who underwent SMILE surgery were recruited. The surface roughness of the central, pericentral, and peripheral parts of the corneal lenticule surface was measured in both the anterior and posterior planes. Differences in corneal lenticule surface roughness were analyzed between different myopic groups. RESULTS The surface roughness of the anterior plane of the corneal lenticule was lower than the posterior plane in various areas (central, pericentral, and peripheral parts) (P < .01). Surface roughness gradually increased from the center to the periphery, in both the anterior and posterior planes (P < .01). There were no significant differences in the surface roughness of the central part in both the anterior and posterior planes between the low and high myopic groups. The surface roughness of the high myopic group was higher than that of the low myopic group in the peripheral part (P < .01). There were no significant differences among the three cylinder-specific groups. There was no significant correlation between two paired eyes. A positive correlation between posterior central surface roughness and the percentage tissue altered score (PTA) was found (r = 0.248, P = .012). CONCLUSIONS The cutting surface of the corneal lenticule performed by femtosecond laser was evaluated with a white light interferometer and displayed inhomogeneity. Deeper cutting with higher myopia and some intraoperative complications, such as suction loss, may result in larger irregularities.
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Affiliation(s)
- Yanan Wu
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.,Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin, China
| | - Yan Wang
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.,Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin, China
| | - Zimiao Zhang
- Tianjin Key Laboratory of High Speed Cutting & Precision Machining, Tianjin University of Technology and Education, Tianjin, China
| | - Xingchen Yu
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.,Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin, China
| | - Xinheng Zhao
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.,Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin, China
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Zhao Y, Zhao F, Han T, Zhao J, Zhou X. A pilot study: lenticule quality of hyperopic small incision lenticule extraction (SMILE) in rabbits. BMC Ophthalmol 2020; 20:158. [PMID: 32306923 PMCID: PMC7169024 DOI: 10.1186/s12886-020-01432-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 04/13/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To evaluate lenticule surface characteristics of small incision lenticule extraction (SMILE) for hyperopia correction in rabbits. METHODS The left and right eyes of 8 rabbits were divided into two groups. The right eyes were assigned to a myopia group, and the left eyes to a hyperopia group. The rabbits received SMILE procedures with + 3.00 D and - 3.00 D correction for the hyperopia and myopia groups, respectively. Extracted lenticules were examined via scanning electron microscopy. Lenticules from odd-numbered rabbits were accessed with the anterior surface, and lenticules from even-numbered rabbits were observed with the posterior surface. A previously established scoring system was used to evaluate lenticule surface characteristics. Statistical analysis was conducted to compare the scores between the two groups. RESULTS All procedures were performed successfully, and the lenticules were extracted smoothly. One myopia lenticule that was facing downward was handled failed in preparation for imaging, thus 15 lenticules were ultimately graded. Twelve lenticules exhibited smooth surfaces, and regularly arranged tissue bridges were observed in almost all regions. Three lenticules exhibited a partially rough surface and irregularities affecting more than 10% of the lenticules (2 in the hyperopia group and 1 in the myopia group). Rough lenticules occurred in twice as many lenticules in the hyperopia group compared to the myopia group. CONCLUSIONS Scan quality of lenticules after SMILE for hyperopia correction is comparable to that of myopia lenticules. The shape of hyperopic lenticule may increase the difficulty of surgical manipulation and result in surface roughness.
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Affiliation(s)
- Yu Zhao
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, PR China.,NHC Key Laboratory of Myopia (Fudan University); Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Feng Zhao
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, PR China.,NHC Key Laboratory of Myopia (Fudan University); Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.,Department of Ophthalmology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Tian Han
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, PR China.,NHC Key Laboratory of Myopia (Fudan University); Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Jing Zhao
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, PR China.,NHC Key Laboratory of Myopia (Fudan University); Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xingtao Zhou
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, PR China. .,NHC Key Laboratory of Myopia (Fudan University); Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China. .,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.
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Weng S, Xiang D, Lin L, Lin H, Liu F, Liu Q. Optimal Parameters of Scanning Mode in Small Incision Lenticule Extraction (SMILE): Clinical Results and Ultrastructural Analysis. J Refract Surg 2020; 36:34-41. [DOI: 10.3928/1081597x-20191114-02] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 11/14/2019] [Indexed: 11/20/2022]
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Hammer CM, Kunert KS, Zhang Y, Lörner J, Wüllner C, Rothuber EL, Paulsen F, Seiler T. Interface morphology and gas production by a refractive 347 nm ultraviolet femtosecond laser: Comparison with established laser systems. J Cataract Refract Surg 2018; 44:1371-1377. [DOI: 10.1016/j.jcrs.2018.05.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 03/13/2018] [Accepted: 05/25/2018] [Indexed: 10/28/2022]
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Luft N, Schumann RG, Dirisamer M, Kook D, Siedlecki J, Wertheimer C, Priglinger SG, Mayer WJ. Wound Healing, Inflammation, and Corneal Ultrastructure After SMILE and Femtosecond Laser-Assisted LASIK: A Human Ex Vivo Study. J Refract Surg 2018; 34:393-399. [PMID: 29889292 DOI: 10.3928/1081597x-20180425-02] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 04/20/2018] [Indexed: 01/30/2023]
Abstract
PURPOSE To assess the wound healing, inflammation, and tissue ultrastructure in the human corneal stroma after small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK (FS-LASIK). METHODS Sixteen corneoscleral discs of 16 human donors unsuitable for corneal transplantation were obtained from an eye bank. Eight eyes underwent SMILE with -5.00 diopters (D) of myopic correction; in 3 of them the lenticule was not extracted. Further 5 donor corneas were subjected to FS-LASIK with -5.00 D ablation, and 3 eyes served as the control group without surgical intervention. Postoperatively, specimens were incubated in organ culture medium for 72 hours before being subjected to immunofluorescence staining for CD11b, Ki67, fibronectin, terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay, and high-magnification scanning electron microscopy. RESULTS Keratocyte apoptosis, keratocyte proliferation, and infiltration of immune cells were generally mild and comparable between FS-LASIK and SMILE (irrespective of surgical lenticule extraction). By staining for fibronectin, we observed a trend toward milder fibrotic response in the corneal stroma after SMILE than after FS-LASIK. On the contrary, scanning electron microscopy analysis revealed a smoother, more regular ultrastructural appearance of the residual corneal bed after FS-LASIK. CONCLUSIONS Corneal stromal wound healing after SMILE and FS-LASIK was virtually identical with respect to keratocyte proliferation and apoptosis in the human donor eye model. Although reactive fibrosis adjacent to the laser application site appeared less marked after SMILE, the stromal bed after LASIK exhibited a smoother surface texture. [J Refract Surg. 2018;34(6):393-399.].
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Weng S, Yang X, Liu F, Lin H, Liu M, Liu Q. Development of a liquid dissection technique for small-incision lenticule extraction: Clinical results and ultrastructural evaluation. J Cataract Refract Surg 2018; 44:1080-1089. [PMID: 30060900 DOI: 10.1016/j.jcrs.2018.06.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Accepted: 06/04/2018] [Indexed: 11/16/2022]
Abstract
PURPOSE To determine the effect of a liquid dissection technique on clinical outcomes with ultrastructural analysis of the lenticule surface in small-incision lenticule extraction (SMILE). SETTING Zhongshan Ophthalmic Center, Guangzhou, China. DESIGN Prospective case series. METHODS Consecutive patients with myopia scheduled for small-incision lenticule extraction were included. The liquid dissection technique was performed in 1 eye and the traditional dissection technique was performed in the other eye by randomized assignment. Ophthalmic examinations were evaluated preoperatively and at different timepoint follow-ups after small-incision lenticule extraction. Ten human corneal lenticules were analyzed using scanning electron microscopy. RESULTS The study comprised 29 patients (58 eyes). Uncorrected distance visual acuity (logarithm of the minimum angle of resolution) postoperative measurements at 2 and 4 hours were significantly better in the liquid dissection group than in the traditional dissection group (P < .001 and P = .001, respectively); however, there were no significant differences between the 2 groups at 1 day, 1 week, and 1 month postoperatively. Compared with the traditional dissection technique, the liquid dissection technique induced significantly fewer corneal aberrations at 2 hours and 1 month after the procedures (P = .031 and P = .016, respectively), the postoperative contrast sensitivity in the liquid dissection group was significantly higher after 1 day (P = .01). The liquid dissection samples showed smoother lenticule surfaces compared with the traditional dissection samples qualitatively and quantitatively (P = .004 and P < .001, respectively). CONCLUSION The liquid dissection technique was helpful in facilitating better visual acuity recovery and produced smooth cuts in the early postoperative period.
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Affiliation(s)
- Shengbei Weng
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre, Sun Yat-sen University, Guangzhou, China
| | - Xiaonan Yang
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre, Sun Yat-sen University, Guangzhou, China
| | - Fang Liu
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre, Sun Yat-sen University, Guangzhou, China
| | - Haiqin Lin
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre, Sun Yat-sen University, Guangzhou, China
| | - Manli Liu
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre, Sun Yat-sen University, Guangzhou, China
| | - Quan Liu
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre, Sun Yat-sen University, Guangzhou, China.
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Damgaard IB, Ang M, Farook M, Htoon HM, Mehta JS. Intraoperative Patient Experience and Postoperative Visual Quality After SMILE and LASIK in a Randomized, Paired-Eye, Controlled Study. J Refract Surg 2018; 34:92-99. [PMID: 29425387 DOI: 10.3928/1081597x-20171218-01] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Accepted: 12/08/2017] [Indexed: 11/20/2022]
Abstract
PURPOSE To compare intraoperative and postoperative subjective patient experience after small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK. METHODS In a prospective, randomized, paired-eye, single-masked clinical trial at Singapore National Eye Centre, 70 patients were randomly treated with SMILE and LASIK in each eye. The intraoperative questionnaire was completed immediately after surgery and included light perception and levels of anxiety, fear, and discomfort. The postoperative 1- and 3-month questionnaires evaluated severity of light sensitivity, eye discomfort, eye dryness, excessive tearing, gritty sensation, glare, halos, blurring, and fluctuations in vision. RESULTS Average discomfort scores were higher during tissue manipulation in SMILE (1.9 ± 0.9) than flap lifting in LASIK (1.59 ± 0.8) (P = .020) but comparable during docking and laser application (P > .249). Fear scores were lower in SMILE than LASIK during docking (2.6 ± 1.6 vs 3.4 ± 1.9, P = .024) but similar during occasional blackout, laser application, and lenticule/flap manipulation (P > .364). Fear scores were generally higher in patients with intraoperative suction loss (n = 3). For SMILE, light sensitivity, eye discomfort, blurring, and fluctuations in vision improved from 1 to 3 months (P < .039). For LASIK, improvements were reported for light sensitivity, eye discomfort, eye dryness, gritty sensation, and fluctuations in vision from 1 to 3 months (P < .046). At 1 month, patients experienced more blurring after SMILE than LASIK (2.1 ± 0.8 vs 1.8 ± 0.7, P = .025), but with no differences in any of the visual symptoms at 3 months. CONCLUSIONS Tissue manipulation may be more uncomfortable during SMILE than LASIK, but not more frightening. Subjective visual symptoms were comparable after 3 months. [J Refract Surg. 2018;34(2):92-99.].
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Vukich JA, Durrie DS, Pepose JS, Thompson V, van de Pol C, Lin L. Evaluation of the small-aperture intracorneal inlay: Three-year results from the cohort of the U.S. Food and Drug Administration clinical trial. J Cataract Refract Surg 2018; 44:541-556. [DOI: 10.1016/j.jcrs.2018.02.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 02/20/2018] [Accepted: 02/28/2018] [Indexed: 10/16/2022]
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Evaluation of Human Corneal Lenticule Quality After SMILE With Different Cap Thicknesses Using Scanning Electron Microscopy. Cornea 2018; 37:59-65. [PMID: 29053560 DOI: 10.1097/ico.0000000000001404] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the surface characteristics of lenticules created by small-incision lenticule extraction (SMILE) with different cap thicknesses. METHODS This prospective study included 20 consecutive patients who underwent bilateral SMILE. Surface regularity of the extracted corneal lenticule was analyzed using scanning electron microscopy (SEM) combined with 2 methods: qualitative and quantitative regularity. Qualitative regularity of SEM images was graded by masked observers using an established scoring system. Quantitative regularity of SEM images was assessed by counting the total number and areas of tissue bridges using Image-Pro Plus software. Four different cap thickness of 120, 130, 140, and 150 μm were compared. Refractive outcomes of patients were measured at baseline and 1 month after surgery. RESULTS As 10 specimens were not analyzable, only 30 eyes were included. Postoperatively, all eyes had postoperative uncorrected distance visual acuity of 20/20 or better; 43% had an unchanged corrected distance visual acuity; 43% gained 1 line; 10% lost 1 line. Ultrastructurally, surface irregularity was primarily caused by tissue bridges. The average surface regularity score obtained was 10.87 ± 2.40 for 120 μm, 10.78 ± 2.60 for 130 μm, 8.76 ± 2.16 for 140 μm, and 8.70 ± 2.66 for 150 μm (P < 0.001). The total number and areas of tissue bridges of 120 to 130 μm were significantly less than 140 to 150 μm (P < 0.05). Surface regularity decreased as cap thickness increased (P < 0.05). CONCLUSIONS There is smoother appearance of the lenticular surface as seen through SEM when a thin cap is created compared with a thick cap qualitatively and quantitatively.
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Kobashi H, Kamiya K, Igarashi A, Takahashi M, Shimizu K. Two-years results of small-incision lenticule extraction and wavefront-guided laser in situ keratomileusis for Myopia. Acta Ophthalmol 2018. [PMID: 28631305 DOI: 10.1111/aos.13470] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To compare the 2-years visual and refractive outcomes between small-incision lenticule extraction (SMILE) and wavefront-guided laser in situ keratomileusis (LASIK) in eyes with myopia and myopic astigmatism. METHODS Our retrospective case-control study examined 30 eyes of 30 patients with the manifest refraction spherical equivalent (MRSE) of -3.71 ± 1.83 dioptres (D) who underwent SMILE and 30 eyes of 30 patients with MRSE of -3.81 ± 1.40 D who underwent wavefront-guided LASIK. We assessed the 2-years clinical outcomes. RESULTS Logarithm of the minimal angle of resolution (LogMAR)-corrected distance visual acuity (CDVA) was -0.23 ± 0.07 in the SMILE group and -0.24 ± 0.07 in the wavefront-guided LASIK group 2 years postoperatively (p = 0.82). Logarithm of the minimal angle of resolution-uncorrected distance visual acuity (UDVA) was -0.18 ± 0.09 and -0.15 ± 0.11 (p = 0.30, respectively). In the SMILE and wavefront-guided LASIK groups 2 years postoperatively, 100% and 73% of eyes, respectively, were within 0.5 D of the prompted MRSE correction (p = 0.005). Changes in the MRSE of -0.10 ± 0.30 D and -0.23 ± 0.51 D occurred from 3 months to 2 years (p = 0.40, respectively). We found a significant correlation between myopic regression and the changes in the keratometric readings from 3 months to 2 years after wavefront-guided LASIK (r = -0.48, p = 0.002), but not after SMILE (r = -0.004, p = 0.90). CONCLUSION Small-incision lenticule extraction offers better refractive outcomes than wavefront-guided LASIK during a 2-years follow-up for the correction of myopia and myopic astigmatism.
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Affiliation(s)
- Hidenaga Kobashi
- Department of Ophthalmology; University of Kitasato School of Medicine; Kanagawa Japan
| | - Kazutaka Kamiya
- Department of Ophthalmology; University of Kitasato School of Medicine; Kanagawa Japan
| | - Akihito Igarashi
- Department of Ophthalmology; University of Kitasato School of Medicine; Kanagawa Japan
| | - Masahide Takahashi
- 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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14
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Effect of Cap-Lenticule Diameter Difference on the Visual Outcome and Higher-Order Aberrations in SMILE: 0.4 mm versus 1.0 mm. J Ophthalmol 2017; 2017:8259546. [PMID: 29270316 PMCID: PMC5705886 DOI: 10.1155/2017/8259546] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/29/2017] [Accepted: 10/12/2017] [Indexed: 11/17/2022] Open
Abstract
Purpose To evaluate the effect of cap-lenticule diameter difference (CLDD) on the visual outcome and higher-order aberrations (HOAs) of small-incision lenticule extraction (SMILE). Methods A total of 132 patients who had bilateral SMILE for myopia or myopic astigmatism were included. The CLDD was 0.4 mm in 54 patients (group 1) and 1.0 mm in 78 patients (group 2). The refractive parameters, uncorrected (UDVA) and corrected distance visual acuity (CDVA), and HOAs were determined preoperatively and during six months follow-up. Results Group 1 had better CDVA (in logMAR) compared to group 2 at day 1 (−0.07 ± 0.07 versus 0.04 ± 0.07, resp.; p < 0.001) and week 1 (−0.07 ± 0.07 versus –0.04 ± 0.07, resp.; p = 0.001). The visual acuity improved more in group 1 than in group 2. The UDVA (in logMAR) was 0.07 ± 0.07 and 0.29 ± 0.09 at day 1 (p < 0.001) and −0.08 ± 0.07 and −0.06 ± 0.06 at six months (p = 0.038) in group 1 and group 2, respectively. Group 1 was associated with significantly less induction of HOAs (0.24 ± 0.08 μm and 0.32 ± 0.26 μm, resp.; p = 0.002). Conclusions In SMILE, 0.4 mm CLDD is associated with better visual outcome and less induction of HOAs than 1.0 mm. Narrow CLDD should be considered in SMILE to increase the visual acuity particularly in the early postoperative period.
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Zheng Y, Zhou YH, Zhang J, Liu Q, Zhang L, Deng ZZ, Li SM. Comparison of Visual Outcomes After Femtosecond LASIK, Wave Front-Guided Femtosecond LASIK, and Femtosecond Lenticule Extraction. Cornea 2016; 35:1057-61. [PMID: 27348719 DOI: 10.1097/ico.0000000000000891] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To compare the mesopic contrast sensitivity (CS) and higher order aberrations (HOAs) at 3 months after femtosecond-laser in situ keratomileusis (LASIK) (FS-LASIK), wave front-guided femtosecond LASIK (WF-LASIK), and femtosecond lenticule extraction (FLEx) for the correction of myopia and myopic astigmatism. METHODS In this prospective nonrandomized study, 332 right eyes of 332 patients were treated with FS-LASIK, WF-LASIK, or FLEx. The HOAs and mesopic CS were evaluated preoperatively and at 3 months postoperatively. RESULTS At 3 months of follow-up, 98 eyes (96.1%) of the FS-LASIK group, 92 eyes (98.9%) of the WF-LASIK group, and 133 eyes (96.4%) of the FLEx group had an uncorrected distance visual acuity of 20/20 or better. The HOAs improved from 0.34 μm during preoperative examination to 0.56 μm of the end of the follow-up in the FS-LASIK group, from 0.31 to 0.41 μm in the WF-LASIK group, and from 0.32 to 0.54 μm in the FLEx group (all P < 0.01). At a spatial frequency of 12 cycles per degree, a better mesopic CS was observed in the WF-LASIK group (1.47) than in the FS-LASIK (1.36) and FLEx (1.33) groups (P < 0.01); a better mesopic CS with glare was also noted in the WF-LASIK group (1.37) than in the FS-LASIK (1.25) and FLEx (1.29) groups (P < 0.01). CONCLUSIONS The FS-LASIK, WF-LASIK, and FLEx procedures result in comparable refractive results at 3 months postoperatively. However, there is improvement in the mesopic CS and HOAs after WF-LASIK.
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Affiliation(s)
- Yan Zheng
- Beijing Tongren Eye Center, Beijing Key Laboratory of Ophthalmology and Visual Science, Beijing Tongren Hospital, Capital Medical University, Beijing, China
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Clinical Outcomes After SMILE and Femtosecond Laser-Assisted LASIK for Myopia and Myopic Astigmatism. Cornea 2016; 35:210-6. [DOI: 10.1097/ico.0000000000000707] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Zhao Y, Li M, Sun L, Zhao J, Chen Y, Zhou X. Lenticule Quality After Continuous Curvilinear Lenticulerrhexis in SMILE Evaluated With Scanning Electron Microscopy. J Refract Surg 2015; 31:732-5. [DOI: 10.3928/1081597x-20151029-01] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 08/18/2015] [Indexed: 12/31/2022]
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Abstract
Corneal photorefractive surgery is currently performed by ablation of corneal stroma under the stromal flap. A stromal flap is created using a femtosecond (FS) laser or mechanical microkeratome, although the FS laser procedure is considered safer and more accurate. This review assesses and compares the use of FS laser versus mechanical microkeratome ablation for corneal stromal characteristics mainly examined by histology and cellular biological responses. Supporting data from our studies, using corneas of enucleated porcine eye globes, are included in this review. Histological analysis and experimental studies of cellular/tissue responses to FS laser irradiation should be further investigated, and the equipment used to perform these techniques should be improved.
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Ziebarth NM, Lorenzo MA, Chow J, Cabot F, Spooner GJR, Dishler J, Hjortdal JØ, Yoo SH. Surface Quality of Human Corneal Lenticules After SMILE Assessed Using Environmental Scanning Electron Microscopy. J Refract Surg 2014; 30:388-93. [DOI: 10.3928/1081597x-20140513-01] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 03/04/2014] [Indexed: 11/20/2022]
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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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Ozulken K, Cabot F, Yoo SH. Applications of femtosecond lasers in ophthalmic surgery. Expert Rev Med Devices 2014; 10:115-24. [DOI: 10.1586/erd.12.59] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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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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Time course of optical quality and intraocular scattering after refractive lenticule extraction. PLoS One 2013; 8:e76738. [PMID: 24146917 PMCID: PMC3797688 DOI: 10.1371/journal.pone.0076738] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 08/28/2013] [Indexed: 11/19/2022] Open
Abstract
Purpose To assess the time course of optical quality and intraocular scattering in relation to visual acuity after femtosecond lenticule extraction (FLEx) for the correction of myopia. Methods This study evaluated 36 eyes of 36 patients with spherical equivalents of −4.38±1.53 D [mean ± standard deviation] who underwent FLEx. Before surgery, and 1 week and 1, 3 and 6 months after surgery, we assessed the modulation transfer function (MTF) cutoff frequency, Strehl ratio, objective scattering index (OSI), and OQAS values (OVs), using a double-pass instrument. We also investigated the relationship of the OSI with corrected distance visual acuity (CDVA) preoperatively and postoperatively. Results The mean changes in MTF cutoff frequency, Strehl ratio, OSI, OV100%, OV20%, and OV9% preoperatively and 6 months postoperatively were −5.51±15.01, −0.03±0.07, 0.35±0.83, −0.17±0.48, −0.14±0.38, and −0.09±0.22, respectively. We found no significant preoperative correlation between the OSI and logMAR CDVA (Spearman rank correlation coefficient r = 0.068, p = 0.69), and modest, but significant correlations 1 week and 1, 3, and 6 months postoperatively (r = 0.572, r = 0.562, r = 0.542, r = 0.540, p<0.001, respectively). Conclusions FLEx induced a transient decrease in optical quality in association with an increase in intraocular scattering in the early postoperative period, possibly due to mild interface haze formation, but gradually recovered with time. It is suggested that this transient degradation in optical quality related to an increase in the intraocular scattering may result in a slight delay of CDVA recovery in the early postoperative period.
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The morphology of corneal cap and its relation to refractive outcomes in femtosecond laser small incision lenticule extraction (SMILE) with anterior segment optical coherence tomography observation. PLoS One 2013; 8:e70208. [PMID: 23940547 PMCID: PMC3734027 DOI: 10.1371/journal.pone.0070208] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 06/17/2013] [Indexed: 11/22/2022] Open
Abstract
Purpose To investigate the morphology of corneal caps in femtosecond laser small incision lenticule extraction (SMILE) and its relation to the refractive outcomes. Methods A prospective study of fifty-four corneal caps created with VisuMax femtosecond laser were examined using an Fourier-domain optical coherence tomography at 1 day, 1 week, 1 month and 6 months after SMILE. The cap thickness at nine points on each of the four meridians (0°, 45°, 90°, 135°) and the diameter were measured. Cap morphology, changes over time and its correlation with refractive outcomes were assessed. Results The mean achieved central cap thickness were (108.74±5.06) µm at 6 months and (107.32±4.81 ) µm at 1 month postoperatively, significantly thinner than that at 1 day (110.81±7.95) µm and 1 week (109.58±7.48 ) µm (P<0.05). The mean diameter on 0° meridian was (7.61±0.07) mm, significantly larger than that on 90° meridian (7.57±0.06) mm (P = 0.001). Cap morphology showed good regularity, except that the differences of points in two pairs were significant at 1 day postoperatively. The uniformity was consistent over time and the central cap thickness was thinner than those in the paracentral and peripheral areas. The refractive outcomes stabilized within 1 month. Uncorrected distance visual acuity (UDVA) was correlated to the central cap thickness at 1 day and 1 week (both rs = 0.33, p<0.05). The uniformity index was correlated with UDVA (rs = 0.34, p<0.05) and corrected distance visual acuity (rs = 0.32, p<0.05) at 1 week postoperatively. Conclusions Corneal caps of SMILE are predictable with good reproducibility, regularity and uniformity. Cap morphology might have a mild effect on refractive outcomes in the early stage. Further study should focus on the impact on the visual quality.
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Vestergaard A, Ivarsen A, Asp S, Hjortdal JØ. Femtosecond (FS) laser vision correction procedure for moderate to high myopia: a prospective study of ReLEx(®) flex and comparison with a retrospective study of FS-laser in situ keratomileusis. Acta Ophthalmol 2013; 91:355-62. [PMID: 22512839 DOI: 10.1111/j.1755-3768.2012.02406.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To present our initial clinical experience with ReLEx(®) flex (ReLEx) for moderate to high myopia. We compare efficacy, safety and corneal higher-order aberrations after ReLEx with femtosecond laser in situ keratomileusis (FS-LASIK). METHODS Prospective study of ReLEx compared with a retrospective study of FS-LASIK. ReLEx is a new keratorefractive procedure, where a stromal lenticule is cut by a femtosecond laser and manually extracted. Forty patients were treated with ReLEx on both eyes. A comparable group of 41 FS-LASIK patients were retrospectively identified. Visual acuity, spherical equivalent (SE) and corneal tomography were measured before and 3 months after surgery. RESULTS Preoperative SE averaged -7.50 ± 1.16 D (ReLEx) and -7.32 ± 1.09 D (FS-LASIK). For all eyes, mean corrected distance visual acuity remained unchanged in both groups. For eyes with emmetropia as target refraction, 41% of ReLEx and 61% of FS-LASIK eyes had an uncorrected distance visual acuity of logMAR ≤ 0.10 at day 1 after surgery, increasing to, respectively, 88% and 69% at 3 months. Mean SE was -0.06 ± 0.35 D 3 months after ReLEx and -0.53 ± 0.60 D after FS-LASIK. The proportion of eyes within ±1.00 D after 3 months was 100% (ReLEx) and 85% (FS-LASIK). For a 6.0-mm pupil, corneal spherical aberrations increased significantly less in ReLEx than FS-LASIK eyes. CONCLUSIONS ReLEx is an all-in-one femtosecond laser refractive procedure, and in this study, results were comparable to FS-LASIK. Refractive predictability and corneal aberrations at 3 months seemed better than or equal to FS-LASIK, whereas visual recovery after ReLEx was slower.
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Affiliation(s)
- Anders Vestergaard
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark.
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Marian A, Nada O, Légaré F, Meunier J, Vidal F, Roy S, Brunette I, Costantino S. Smoothness assessment of corneal stromal surfaces. J Cataract Refract Surg 2012; 39:118-127. [PMID: 23128030 DOI: 10.1016/j.jcrs.2012.08.050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 08/10/2012] [Accepted: 08/12/2012] [Indexed: 11/24/2022]
Abstract
PURPOSE To assess the accuracy of the scanning electron microscopy (SEM) and present alternative approaches to quantify surface roughness based on numerical analysis. SETTING Department of Ophthalmology, Maisonneuve-Rosemont Hospital, University of Montreal, Montreal, Quebec, Canada. DESIGN Experimental study. METHODS Lamellar stromal cuts were performed on human corneas using a femtosecond laser or a microkeratome. The photodisrupted stromal surfaces were processed for SEM, and images were acquired at ×1000 magnification. First, images were evaluated by independent observers. Second, images were analyzed based on first-order and second-order statistics of gray-level intensities. Third, 3-dimensional (3-D) surface reconstructions were generated from pairs of SEM images acquired at 2 angles. RESULTS Results show that traditional assessment of roughness based on evaluating SEM images by independent observers can be replaced by computer-image texture analysis; an algorithm was developed to avoid subjective and time-consuming observations. The 3-D reconstructions allowed additional characterization of surface properties that was not possible with SEM images alone. Significant fluctuations in surface height were lost, although they could be retrieved using 3-D reconstructions. CONCLUSIONS Image texture analysis allowed objective and repeatable assessment of stromal surface roughness; however, full assessments of surface-height fluctuations required 3-D reconstruction. These complementary methodologies offer a more comprehensive assessment of corneal surface roughness in clinical applications.
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Affiliation(s)
- Anca Marian
- From the Maisonneuve-Rosemont Hospital Research Center (Marian, Nada, Brunette, Costantino), the Department of Mathematics and Statistics (Meunier, Roy), University of Montreal, and the Department of Ophthalmology (Meunier, Brunette, Costantino), University of Montreal, Montreal, Quebec, and the Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications (Marian, Légaré, Vidal), Varennes, Quebec, Canada
| | - Ossama Nada
- From the Maisonneuve-Rosemont Hospital Research Center (Marian, Nada, Brunette, Costantino), the Department of Mathematics and Statistics (Meunier, Roy), University of Montreal, and the Department of Ophthalmology (Meunier, Brunette, Costantino), University of Montreal, Montreal, Quebec, and the Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications (Marian, Légaré, Vidal), Varennes, Quebec, Canada; The Ophthalmology Department Ain Shams University, Cairo, Egypt
| | - François Légaré
- From the Maisonneuve-Rosemont Hospital Research Center (Marian, Nada, Brunette, Costantino), the Department of Mathematics and Statistics (Meunier, Roy), University of Montreal, and the Department of Ophthalmology (Meunier, Brunette, Costantino), University of Montreal, Montreal, Quebec, and the Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications (Marian, Légaré, Vidal), Varennes, Quebec, Canada
| | - Jean Meunier
- From the Maisonneuve-Rosemont Hospital Research Center (Marian, Nada, Brunette, Costantino), the Department of Mathematics and Statistics (Meunier, Roy), University of Montreal, and the Department of Ophthalmology (Meunier, Brunette, Costantino), University of Montreal, Montreal, Quebec, and the Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications (Marian, Légaré, Vidal), Varennes, Quebec, Canada
| | - François Vidal
- From the Maisonneuve-Rosemont Hospital Research Center (Marian, Nada, Brunette, Costantino), the Department of Mathematics and Statistics (Meunier, Roy), University of Montreal, and the Department of Ophthalmology (Meunier, Brunette, Costantino), University of Montreal, Montreal, Quebec, and the Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications (Marian, Légaré, Vidal), Varennes, Quebec, Canada
| | - Sébastien Roy
- From the Maisonneuve-Rosemont Hospital Research Center (Marian, Nada, Brunette, Costantino), the Department of Mathematics and Statistics (Meunier, Roy), University of Montreal, and the Department of Ophthalmology (Meunier, Brunette, Costantino), University of Montreal, Montreal, Quebec, and the Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications (Marian, Légaré, Vidal), Varennes, Quebec, Canada
| | - Isabelle Brunette
- From the Maisonneuve-Rosemont Hospital Research Center (Marian, Nada, Brunette, Costantino), the Department of Mathematics and Statistics (Meunier, Roy), University of Montreal, and the Department of Ophthalmology (Meunier, Brunette, Costantino), University of Montreal, Montreal, Quebec, and the Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications (Marian, Légaré, Vidal), Varennes, Quebec, Canada
| | - Santiago Costantino
- From the Maisonneuve-Rosemont Hospital Research Center (Marian, Nada, Brunette, Costantino), the Department of Mathematics and Statistics (Meunier, Roy), University of Montreal, and the Department of Ophthalmology (Meunier, Brunette, Costantino), University of Montreal, Montreal, Quebec, and the Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications (Marian, Légaré, Vidal), Varennes, Quebec, Canada.
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Reply to the letter by Zhang and Hoffman: Relationship between femtosecond laser parameters and quality of the corneal stromal bed surface. Graefes Arch Clin Exp Ophthalmol 2011; 251:399-400. [PMID: 22160506 DOI: 10.1007/s00417-011-1880-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 11/16/2011] [Indexed: 10/14/2022] Open
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Zhang ZY, Hoffman MR. Relationship between femtosecond laser parameters and quality of the corneal stromal bed surface. Graefes Arch Clin Exp Ophthalmol 2011; 251:397-8. [PMID: 22134714 DOI: 10.1007/s00417-011-1879-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 11/16/2011] [Indexed: 10/15/2022] Open
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