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Refractive Effect of Epithelial Remodelling in Myopia after Transepithelial Photorefractive Keratectomy. VISION (BASEL, SWITZERLAND) 2022; 6:vision6040074. [PMID: 36548936 PMCID: PMC9781313 DOI: 10.3390/vision6040074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 11/15/2022] [Accepted: 12/08/2022] [Indexed: 12/15/2022]
Abstract
(1) Introduction: We analysed epithelial changes after the treatment of moderate myopia with transepithelial photorefractive keratectomy. (2) Materials and Methods: We used optical coherence tomography data and analysed changes in the stroma and epithelium after ablation. We aimed to ascertain how much epithelium hyperplasia occurred after TransPRK; for this, we used data from 50 eyes treated with TransPRK with the AMARIS 1050 Hz, with a minimum follow-up of 4 months. (3) Results: The measured epithelial changes corresponded to a less than 0.1 ± 0.2D of spherical effect, less than 0.2 ± 0.2D of astigmatic effect, and less than 0.5 ± 0.2D of comatic effect. (4) Conclusions: The changes in epithelial thickness after aberration-neutral transepithelial photorefractive keratectomy for moderate myopia were very small, indicating a low level of epithelial hyperplasia without resembling a regression-inducing lentoid.
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Zhang KP, Fang X, Zhang Y, Chao M. Comparison of Q-value-guided laser-assisted in situ keratomileusis and standard laser in situ keratomileusis for myopia: A meta-analysis. Medicine (Baltimore) 2020; 99:e21563. [PMID: 33157908 PMCID: PMC7647622 DOI: 10.1097/md.0000000000021563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Previous studies examining the safety and efficacy of Q-value-guided laser-assisted in situ keratomileusis (LASIK) for treating myopia have yielded inconsistent results. We, therefore, performed a meta-analysis to clarify this issue METHODS:: Various databases were conducted up to November 21, 2018. All randomized controlled trials and cohorts that compared Q-value-guided LASIK with standard LASIK were selected. Mean differences (MDs) or odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the strength of the correlations. Additionally, different subgroup analyses and publication bias tests were performed. Data were extracted including the number of postoperative uncorrected visual acuity (UCVA) of 20/20 or better, postoperative UCVA, preoperative and postoperative Q-value, postoperative refractive spherical equivalent (SE), the number of postoperative SE within ±0.5D, higher order aberration (HOA), coma-like aberration and spherical-like aberration. RESULTS A total of seventeen studies with 2640 patients and 3,358 eyes were included. It has been shown that postoperative Q-value (MD = -0.42; 95% CI: -0.64, -0.21; P < .001), HOA (MD = -0.14; 95% CI: -0.23, -0.06; P = .001), spherical-like aberration (MD = -0.19; 95% CI: -0.32, -0.06; P = .004) rather than postoperative UCVA (MD = 0.04; 95% CI: 0.01, 0.07; P = .012) were significantly better in the Q-value-guided LASIK than standard LASIK. However, the pooled results revealed that no significant differences were found between the 2 paired groups of postoperative UCVA of 20/20 or better (OR = 1.09; 95% CI: 0.62, 1.92; P = .763), preoperative Q-value (MD = -0.00; 95% CI: -0.02, 0.02; P = .922), postoperative refractive SE (MD = 0.08; 95% CI: -0.09, 0.25; P = .336), coma-like aberration (horizontal: MD = -0.00; 95% CI: -0.03, 0.03; P = .966; vertical: MD = -0.01; 95% CI: -0.03, 0.01; P = .263) and postoperative SE within ±0.5 D (OR = 1.06; 95% CI: 0.48, 2.33; P = .886). Likewise, similar results were detected in some corresponding subgroups. CONCLUSION Q-value-guided LASIK is a safe, effective and predictable surgical option for treating myopia, especially showing superiority over standard LASIK in postoperative Q-value, HOA and spherical-like aberration. However, more detailed studies are required to confirm our conclusions in advanced researches.
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Jun I, Kang DSY, Tan J, Choi JY, Heo W, Kim JY, Lee MG, Kim EK, Seo KY, Kim TI. Comparison of clinical outcomes between wavefront-optimized versus corneal wavefront-guided transepithelial photorefractive keratectomy for myopic astigmatism. J Cataract Refract Surg 2019; 43:174-182. [PMID: 28366363 DOI: 10.1016/j.jcrs.2016.11.045] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 11/21/2016] [Accepted: 11/22/2016] [Indexed: 10/19/2022]
Abstract
PURPOSE To evaluate and compare the clinical outcomes, including visual acuity, refractive errors, and aberrations, between aberration-free transepithelial photorefractive keratectomy (PRK) and corneal wavefront-guided transepithelial PRK in eyes with myopic astigmatism. SETTING Yonsei University College of Medicine and Eyereum Eye Clinic, Seoul, South Korea. DESIGN Retrospective comparative case series. METHODS Patients with myopic astigmatism were treated with aberration-free transepithelial PRK or corneal wavefront-guided transepithelial PRK using a 1050 Hz high-repetition excimer laser. The safety, efficacy, predictability, and corneal aberrations were compared preoperatively and 1, 2, 3, and 6 months postoperatively. RESULTS The study comprised 188 patients (188 eyes); 91 eyes had aberration-free transepithelial PRK and 97 eyes corneal wavefront-guided transepithelial PRK. Six month after surgery, the mean uncorrected distance visual acuity was comparable (-0.06 logMAR ± 0.07 [SD] aberration-free group; -0.06 ± 0.06 logMAR wavefront-guided group). The safety, efficacy, and predictability of refractive and visual outcomes were also comparable between groups. Corneal total root-mean-square (RMS) higher-order aberrations (HOAs) increased after treatment in both groups, although fewer RMS HOAs were induced in the corneal wavefront-guided group than in the aberration-free group. Spherical aberration increased similarly after treatment in both groups. However, coma and trefoil increased only in the aberration-free group. CONCLUSIONS Aberration-free transepithelial PRK and corneal wavefront-guided transepithelial PRK were safe and effective for correction of myopic astigmatism without difference in visual acuity and refractive outcomes. However, the corneal wavefront-guided profile induced fewer corneal aberrations than the aberration-free profile.
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Affiliation(s)
- Ikhyun Jun
- From the Institute of Vision Research (Jun, E.K. Kim, Seo, T-i. Kim), the Corneal Dystrophy Research Institute (Jun, E.K. Kim, T-i. Kim), Department of Ophthalmology, the Department of Pharmacology (Jun, Heo, J.Y. Kim, Lee), Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, and the Eyereum Eye Clinic (Kang, Choi), Seoul, South Korea; the Jerry Tan Eye Surgery (Tan), Singapore
| | - David Sung Yong Kang
- From the Institute of Vision Research (Jun, E.K. Kim, Seo, T-i. Kim), the Corneal Dystrophy Research Institute (Jun, E.K. Kim, T-i. Kim), Department of Ophthalmology, the Department of Pharmacology (Jun, Heo, J.Y. Kim, Lee), Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, and the Eyereum Eye Clinic (Kang, Choi), Seoul, South Korea; the Jerry Tan Eye Surgery (Tan), Singapore
| | - Jerry Tan
- From the Institute of Vision Research (Jun, E.K. Kim, Seo, T-i. Kim), the Corneal Dystrophy Research Institute (Jun, E.K. Kim, T-i. Kim), Department of Ophthalmology, the Department of Pharmacology (Jun, Heo, J.Y. Kim, Lee), Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, and the Eyereum Eye Clinic (Kang, Choi), Seoul, South Korea; the Jerry Tan Eye Surgery (Tan), Singapore
| | - Jin Young Choi
- From the Institute of Vision Research (Jun, E.K. Kim, Seo, T-i. Kim), the Corneal Dystrophy Research Institute (Jun, E.K. Kim, T-i. Kim), Department of Ophthalmology, the Department of Pharmacology (Jun, Heo, J.Y. Kim, Lee), Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, and the Eyereum Eye Clinic (Kang, Choi), Seoul, South Korea; the Jerry Tan Eye Surgery (Tan), Singapore
| | - Woon Heo
- From the Institute of Vision Research (Jun, E.K. Kim, Seo, T-i. Kim), the Corneal Dystrophy Research Institute (Jun, E.K. Kim, T-i. Kim), Department of Ophthalmology, the Department of Pharmacology (Jun, Heo, J.Y. Kim, Lee), Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, and the Eyereum Eye Clinic (Kang, Choi), Seoul, South Korea; the Jerry Tan Eye Surgery (Tan), Singapore
| | - Joo Young Kim
- From the Institute of Vision Research (Jun, E.K. Kim, Seo, T-i. Kim), the Corneal Dystrophy Research Institute (Jun, E.K. Kim, T-i. Kim), Department of Ophthalmology, the Department of Pharmacology (Jun, Heo, J.Y. Kim, Lee), Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, and the Eyereum Eye Clinic (Kang, Choi), Seoul, South Korea; the Jerry Tan Eye Surgery (Tan), Singapore
| | - Min Goo Lee
- From the Institute of Vision Research (Jun, E.K. Kim, Seo, T-i. Kim), the Corneal Dystrophy Research Institute (Jun, E.K. Kim, T-i. Kim), Department of Ophthalmology, the Department of Pharmacology (Jun, Heo, J.Y. Kim, Lee), Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, and the Eyereum Eye Clinic (Kang, Choi), Seoul, South Korea; the Jerry Tan Eye Surgery (Tan), Singapore
| | - Eung Kweon Kim
- From the Institute of Vision Research (Jun, E.K. Kim, Seo, T-i. Kim), the Corneal Dystrophy Research Institute (Jun, E.K. Kim, T-i. Kim), Department of Ophthalmology, the Department of Pharmacology (Jun, Heo, J.Y. Kim, Lee), Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, and the Eyereum Eye Clinic (Kang, Choi), Seoul, South Korea; the Jerry Tan Eye Surgery (Tan), Singapore
| | - Kyoung Yul Seo
- From the Institute of Vision Research (Jun, E.K. Kim, Seo, T-i. Kim), the Corneal Dystrophy Research Institute (Jun, E.K. Kim, T-i. Kim), Department of Ophthalmology, the Department of Pharmacology (Jun, Heo, J.Y. Kim, Lee), Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, and the Eyereum Eye Clinic (Kang, Choi), Seoul, South Korea; the Jerry Tan Eye Surgery (Tan), Singapore
| | - Tae-Im Kim
- From the Institute of Vision Research (Jun, E.K. Kim, Seo, T-i. Kim), the Corneal Dystrophy Research Institute (Jun, E.K. Kim, T-i. Kim), Department of Ophthalmology, the Department of Pharmacology (Jun, Heo, J.Y. Kim, Lee), Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, and the Eyereum Eye Clinic (Kang, Choi), Seoul, South Korea; the Jerry Tan Eye Surgery (Tan), Singapore.
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Abstract
Introduction In the field of ophthalmology, laser technology is used in many basic and clinical disciplines and specialities. It has played an important role in promoting the development of ophthalmology. Aim This article is designed to review the evolution of laser technology in refractive surgeries in ophthalmology, mainly focusing on the characteristics of the excimer laser applied in corneal refractive surgery. Methods This article was performed based on a literature review and Internet search through scientific databases such as PubMed, Scopus, Web of Science and Google Scholar. Result The literature on excimer laser technology addresses the technical and physical aspects of excimer lasers including types, characteristics and commercially available lasers on the market. Conclusion The conclusion on this forum aims to help understand the benefits of excimer laser use in ophthalmology, with focus on correction of refractive errors.
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Affiliation(s)
- Ajla Pidro
- Eye Polyclinic Svjetlost, Sarajevo, Bosnia and Herzegovina
| | - Alma Biscevic
- Eye Polyclinic Svjetlost, Sarajevo, Bosnia and Herzegovina.,University Eye Hospital Svjetlost, School of Medicine University of Rijeka, Zagreb, Croatia
| | | | - Ivana Mravicic
- University Eye Hospital Svjetlost, School of Medicine University of Rijeka, Zagreb, Croatia
| | - Nita Bejdic
- Eye Polyclinic Svjetlost, Sarajevo, Bosnia and Herzegovina
| | - Maja Bohac
- University Eye Hospital Svjetlost, School of Medicine University of Rijeka, Zagreb, Croatia
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de Ortueta D, von Rüden D, Verma S, Magnago T, Arba-Mosquera S. Transepithelial Photorefractive Keratectomy in Moderate to High Astigmatism With a Non-wavefront-Guided Aberration-Neutral Ablation Profile. J Refract Surg 2018; 34:466-474. [PMID: 30001450 DOI: 10.3928/1081597x-20180402-04] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 04/02/2018] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate the outcomes of transepithelial photorefractive keratectomy (PRK) in moderate to high astigmatism with a non-wavefront-guided aberration-neutral ablation profile using SmartPulse allocation. METHODS In this retrospective study, myopic patients with a preoperative cylinder of 2.00 diopters (D) or greater were analyzed at 3 months of follow-up. Transepithelial PRK treatments were performed in each patient with the Amaris 1050RS laser (SCHWIND eye-tech-solutions, Kleinostheim, Germany) creating aspheric ablation profiles by applying a SmartPulse allocation. Standard examinations and wavefront analyses were included for low and high ocular residual astigmatism subgroups. RESULTS Fifty-eight eyes (44 patients) were included in the cohort. The eyes were divided into separate ocular residual astigmatism subgroups: 17 eyes presented with less than 0.50 D (low ocular residual astigmatism) and 24 eyes with greater than 0.75 D (high ocular residual astigmatism). The mean refractive cylinder in the entire cohort was 2.84 ± 0.86 D preoperatively and 0.40 ± 0.39 D postoperatively, with 81% of the eyes within 0.75 D of the target astigmatism. At 3 months of follow-up, significant improvement (P < .05) was seen in terms of sphere, cylinder, spherical equivalent, and uncorrected (UDVA) and corrected (CDVA) distance visual acuity. CDVA improved in 40% of eyes and 3% of eyes lost one line of CDVA. No clinically relevant changes were seen in higher order aberrations. The refractive changes showed an excellent match with the keratometric changes. The difference between the low and high ocular residual astigmatism subgroups was not significant except for the change of Snellen lines of CDVA (P < .05). CONCLUSIONS Transepithelial PRK using a non-wavefront-guided aberration-neutral ablation profile performed by applying SmartPulse allocation yielded excellent visual outcomes. The preoperative astigmatism was reduced to subclinical values. Both subgroups were effective in terms of UDVA, CDVA, spherical and astigmatic correction, and preserving higher order aberrations. However, the low ocular residual astigmatism subgroup was slightly more prone to gain lines of CDVA. [J Refract Surg. 2018;34(7):466-474.].
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Comparison between Wavefront-optimized and corneal Wavefront-guided Transepithelial photorefractive keratectomy in moderate to high astigmatism. BMC Ophthalmol 2018; 18:154. [PMID: 29940974 PMCID: PMC6020237 DOI: 10.1186/s12886-018-0827-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 06/14/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To compare the clinical outcomes of wavefront-optimized (WFO) transepithelial photorefractive keratectomy (trans-PRK) and corneal wavefront-guided (CWFG) trans-PRK for myopic eyes with moderate to high astigmatism. METHODS One hundred ninety-six eyes (196 patients) with moderate to high astigmatism (≥ 1.75 D) treated with WFO or CWFG trans-PRK (101 and 95 eyes, respectively) were retrospectively registered. Safety, efficacy, predictability, vector analysis, and corneal aberrations were compared between groups preoperatively and at 6 months postoperatively. RESULTS At postoperative 6 months, the mean logMAR uncorrected distance visual acuity was similar in the WFO (- 0.07 ± 0.08) and CWFG (- 0.07 ± 0.07) groups. Safety, efficacy, and predictability of refractive and visual outcomes were also similar. The correction indices were 1.02 ± 0.14 and 1.03 ± 0.13 in the WFO and CWFG groups, respectively, with no significant difference. The absolute values of the angle of error were significantly higher in the WFO group (2.28 ± 2.44 vs. 1.40 ± 1.40; P = 0.002). Corneal total root mean square higher-order aberrations and corneal spherical aberrations increased postoperatively in both groups; however, the change was smaller in the CWFG group. Corneal coma showed a significant increase postoperatively only in the WFO group. CONCLUSIONS WFO and CWFG trans-PRK are safe and effective for correcting moderate to high astigmatism. However, CWFG trans-PRK provides a more predictable astigmatism correction axis and fewer induced corneal aberrations.
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Comparing aspheric ablation profile with standard corneal ablation for correction of myopia and myopic astigmatism, a contralateral eye study. Lasers Med Sci 2017; 32:2129-2138. [PMID: 29063473 DOI: 10.1007/s10103-017-2357-9] [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: 09/11/2015] [Accepted: 10/10/2017] [Indexed: 10/18/2022]
Abstract
The purpose of this study is to compare visual outcomes of myopic refractive surgery, using tissue saving (TS), a standard ablation profile by a Technolas 217z100, and aberration smart ablation (ASA), an aspheric algorithm by a MEL 80 excimer laser in two eyes of one patient. In this prospective interventional paired-eye controlled study, a total of 100 eyes of 50 participants with myopia with or without astigmatism underwent thin-flap Femto-LASIK, using a Femto LDV femtosecond laser (Ziemer Ophthalmic Systems AG, Port, Switzerland). For each patient, one eye was randomly treated with tissue-saving algorithm (TS group) by the Technolas 217z100 excimer laser and the other eye was treated with optimized smart ablation profile (ASA group) by the MEL 80 excimer laser. Outcome measures were uncorrected distance visual acuities (UDVAs), corrected distance visual acuities (CDVAs), manifest refraction, higher-order aberrations (HOAs), contrast sensitivity, and patient satisfaction 12 months after surgery. At 12 months postoperative, "45 subjects returned with mean" UDVA was - 0.02 ± 0.08 Logarithm of mean angle of resolution (LogMAR) for TS group and - 0.02 ± 0.09 LogMAR for ASA group (P = 0.91). Of the TS eyes, 42/45 (93.3%) and 32/45 (71.1%) were within ± 0.5 D and ± 0.25 D of target refraction, respectively, and of the ASA eyes, 41/45 (91.1%) and 30/45 (66.6%) were within ± 0.5 D and ± 0.25 D of target refraction, respectively. No statistically significant differences were observed between groups in HOAs changes and contrast sensitivity function. Aspheric and non-aspheric LASIKs using the two different excimer lasers provide similar results in myopic and myopic astigmatism patients.
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Reinstein DZ, Pradhan KR, Carp GI, Archer TJ, Gobbe M, Sekundo W, Khan R, Citron K, Dhungana P. Small Incision Lenticule Extraction (SMILE) for Hyperopia: Optical Zone Centration. J Refract Surg 2017; 33:150-156. [PMID: 28264128 DOI: 10.3928/1081597x-20161220-01] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 11/16/2016] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate optical zone centration of hyperopic small incision lenticule extraction (SMILE). METHODS This prospective study of 60 consecutive hyperopic SMILE procedures used the VisuMax femtosecond laser and matched LASIK procedures with the VisuMax and MEL 80 excimer lasers (Carl Zeiss Meditec AG, Jena, Germany). Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D) and astigmatism up to 6.00 D. For SMILE, the optical zone was between 6.3 and 6.7 mm, with a 2-mm transition zone. Two LASIK control groups (6.5- and 7-mm optical zone) were generated matched for spherical equivalent treated. In SMILE, the corneal vertex of the coaxially fixating eye was aligned with the vertex of the curved contact glass. In LASIK, the treatment was centered on the coaxially sighted corneal light reflex (first Purkinje image) with the contralateral eye (Seiler method). A tangential (instantaneous) curvature preoperative to 3 months postoperative difference map was generated for each eye. A fixed grid and set of concentric circles were superimposed on the difference map to measure the offset between the optical zone center and corneal vertex (0,0), and vector analysis was used for comparative analysis. RESULTS Mean attempted spherical equivalent was +5.61 ± 0.96 D (range: +3.20 to +6.50 D) and mean cylinder was -0.96 ± 0.62 D (range: 0.00 to -2.75 D) in the SMILE group. Mean age was 29 ± 7 years (range: 19 to 52 years) in the SMILE group. Mean centration offset was 0.23 ± 0.15 mm (range: 0 to 0.61 mm) for the SMILE group, 0.33 ± 0.14 mm (range: 0.14 to 0.85 mm) for the 6.5-mm LASIK group, and 0.31 ± 0.19 mm (range: 0.05 to 0.85 mm) for the 7-mm LASIK group. The mean centration offset for SMILE was less than that of both LASIK groups (P < .05). CONCLUSIONS Optical zone centration of hyperopic SMILE was found to be similar to eye-tracker-centered hyperopic LASIK with the MEL 80 laser. [J Refract Surg. 2017;33(3):150-156.].
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Jiménez JR, Alarcón A, Anera RG, Del Barco LJ. Hyperopic Q-optimized algorithms: a theoretical study on factors influencing optical quality. BIOMEDICAL OPTICS EXPRESS 2017; 8:1405-1414. [PMID: 28663837 PMCID: PMC5480552 DOI: 10.1364/boe.8.001405] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/02/2017] [Indexed: 06/07/2023]
Abstract
In this work, we analyze the way in which pupil size, optical zone, and initial hyperopic level influence optical quality for hyperopic Q-optimized corneal refractive surgery. Different Q-optimized algorithms and the Munnerlyn formula were tested to analyze the optical quality of the final retinal image for initial hyperopic errors from 1D to 5D. Three optical zones (5.5, 6, and 6.5 mm) and two pupil diameters (5 and 7 mm) were considered. To evaluate optical quality, we computed the modulation transfer function (MTF) and the area under MTF (MTFa). Q-optimized values at around Q = -0.18 were found to provide the best optical quality for most of the conditions tested. This optimum final asphericity for hyperopic ablation was not depending on the degree of hyperopia corrected, the optical zone or the pupil size being this information important for clinical practice.
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Affiliation(s)
- Jose R. Jiménez
- Departamento de Óptica, Facultad de Ciencias, Edificio Mecenas, Universidad de Granada, Spain
| | - Aixa Alarcón
- Abbott Medical Optics, Groningen, The Netherlands
| | - Rosario G. Anera
- Departamento de Óptica, Facultad de Ciencias, Edificio Mecenas, Universidad de Granada, Spain
| | - L. Jiménez Del Barco
- Departamento de Óptica, Facultad de Ciencias, Edificio Mecenas, Universidad de Granada, Spain
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Arba Mosquera S, Verma S. Bilateral symmetry in vision and influence of ocular surgical procedures on binocular vision: A topical review. JOURNAL OF OPTOMETRY 2016; 9:219-30. [PMID: 26995709 PMCID: PMC5030319 DOI: 10.1016/j.optom.2016.01.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 01/15/2016] [Accepted: 01/18/2016] [Indexed: 06/05/2023]
Abstract
We analyze the role of bilateral symmetry in enhancing binocular visual ability in human eyes, and further explore how efficiently bilateral symmetry is preserved in different ocular surgical procedures. The inclusion criterion for this review was strict relevance to the clinical questions under research. Enantiomorphism has been reported in lower order aberrations, higher order aberrations and cone directionality. When contrast differs in the two eyes, binocular acuity is better than monocular acuity of the eye that receives higher contrast. Anisometropia has an uncommon occurrence in large populations. Anisometropia seen in infancy and childhood is transitory and of little consequence for the visual acuity. Binocular summation of contrast signals declines with age, independent of inter-ocular differences. The symmetric associations between the right and left eye could be explained by the symmetry in pupil offset and visual axis which is always nasal in both eyes. Binocular summation mitigates poor visual performance under low luminance conditions and strong inter-ocular disparity detrimentally affects binocular summation. Considerable symmetry of response exists in fellow eyes of patients undergoing myopic PRK and LASIK, however the method to determine whether or not symmetry is maintained consist of comparing individual terms in a variety of ad hoc ways both before and after the refractive surgery, ignoring the fact that retinal image quality for any individual is based on the sum of all terms. The analysis of bilateral symmetry should be related to the patients' binocular vision status. The role of aberrations in monocular and binocular vision needs further investigation.
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Affiliation(s)
| | - Shwetabh Verma
- Research and Development, SCHWIND eye-tech-solutions, Kleinostheim, Germany
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Yildirim Y, Olcucu O, Alagoz C, Basci A, Agca A, Yasa D, Ozgurhan EB, Demirok A. Visual and Refractive Outcomes of Photorefractive Keratectomy and Small Incision Lenticule Extraction (SMILE) for Myopia. J Refract Surg 2016; 32:604-10. [DOI: 10.3928/1081597x-20160602-02] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Accepted: 05/19/2016] [Indexed: 11/20/2022]
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Reinstein DZ, Gobbe M, Archer TJ, Carp GI. Mechanism for a Rare, Idiosyncratic Complication Following Hyperopic LASIK: Diurnal Shift in Refractive Error Due to Epithelial Thickness Profile Changes. J Refract Surg 2016; 32:364-71. [DOI: 10.3928/1081597x-20160428-05] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 02/04/2016] [Indexed: 11/20/2022]
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Improved lenticule shape for hyperopic femtosecond lenticule extraction (ReLEx FLEx): a pilot study. Lasers Med Sci 2016; 31:659-64. [PMID: 26868029 DOI: 10.1007/s10103-016-1902-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 02/02/2016] [Indexed: 10/22/2022]
Abstract
The aim of this study is to establish and to prove a new lenticule shape for the treatment of hyperopia using a 500 kHz femtosecond laser and the femtosecond lenticule extraction (ReLEx FLEx) technique. Improved lenticule shapes with a large transition zone of at least 2 mm adjusted to the 5.75 mm optical zone were designed. A prospective pilot study on nine eyes of five patients who underwent an uncomplicated FLEx using VisuMax femtosecond laser (Carl Zeiss Meditec AG) for spherical hyperopia was performed. Patients' mean age was 55.5 years, and the preoperative manifest spherical equivalent (SE) was +1.82 D (range +1.25 to +3.00 D). Because of the presbyopic age and in order to compensate for a possible regression, the treatment was aimed at low myopia (mean target SE was -0.88 D with a mean treatment refraction of +2.69 D). At the last follow-up, after 9 months, 33% were within ±0.50 D and 78% within ±1.00 D of intended correction. Thirty-three percent lost one line, and 11% gained one line corrected distance visual acuity (CDVA). On average, the centre of the optical zone was 0.34 ± 0.17 mm from the corneal vertex. No adverse effects were observed. This pilot study confirms that the improved lenticule's design with a large optical and transition zone can achieve good centration and acceptable results for spherical hyperopia using FLEx. The next steps are to extend the study to spherocylindrical hyperopic treatments and to increase the number of eyes for better assessment of refractive outcome.
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Arba-Mosquera S, de Ortueta D. LASIK for Hyperopia Using an Aberration-Neutral Profile With an Asymmetric Offset Centration. J Refract Surg 2016; 32:78-83. [DOI: 10.3928/1081597x-20151119-04] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 11/03/2015] [Indexed: 11/20/2022]
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Biscevic A, Bohac M, Koncarevic M, Anticic M, Dekaris I, Patel S. Vector analysis of astigmatism before and after LASIK: a comparison of two different platforms for treatment of high astigmatism. Graefes Arch Clin Exp Ophthalmol 2015; 253:2325-33. [PMID: 26400154 DOI: 10.1007/s00417-015-3177-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 08/17/2015] [Accepted: 09/08/2015] [Indexed: 10/23/2022] Open
Abstract
PURPOSE To compare the outcomes of astigmatic laser in-situ keratomileusis (LASIK) procedures between two different platforms using J0 and J45 vector analysis. METHODS Patients were divided into four groups, depending on the type of astigmatism and laser platform on which they were treated. Astigmatism was between 2 and 7 diopters (D). One hundred and thirty-five patients with myopic astigmatism (246 eyes) and 102 patients with mixed astigmatism (172 eyes) underwent unremarkable LASIK correction on Wavelight Allegretto Eye-Q 400Hz and Schwind Amaris 750S laser platform. The preoperative and postoperative sphere, negative cylinder [C] and axis (ø) of manifest refractions were subjected to vector analysis by calculations of the standard J0 (cos [4π(ø-90)/360]xC/2) and J45 (sin[4π(ø-90)/360]xC/2). RESULTS Reporting the key results, we found J0 significantly reduced after LASIK in both groups (p < 0.001) but not J45. There was no significant association between individual pairs of pre and postoperative J0 & J45 values. There was no significant difference between the outcomes of the two platforms. CONCLUSIONS Wavelight Allegretto 400Hz and Schwind Amaris 750S showed excellent results for treating patients with astigmatism, regardless whether it is mixed or myopic astigmatism. The J45 did not reduce significantly possibly because of the low number of eyes with oblique astigmatism. There was no genuine difference post-operatively between groups treated on two different laser platforms according to the vector analyses.
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Affiliation(s)
- Alma Biscevic
- Specialty Eye Hospital "Svjetlost", Heinzelova 39, 10000, Zagreb, Croatia.
| | - Maja Bohac
- Specialty Eye Hospital "Svjetlost", Heinzelova 39, 10000, Zagreb, Croatia.
| | - Mateja Koncarevic
- Specialty Eye Hospital "Svjetlost", Heinzelova 39, 10000, Zagreb, Croatia.
| | - Marija Anticic
- Specialty Eye Hospital "Svjetlost", Heinzelova 39, 10000, Zagreb, Croatia.
| | - Iva Dekaris
- Specialty Eye Hospital "Svjetlost", Heinzelova 39, 10000, Zagreb, Croatia.
| | - Sudi Patel
- Specialty Eye Hospital "Svjetlost", Heinzelova 39, 10000, Zagreb, Croatia. .,NHS National Services Scotland, Edinburgh, UK.
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Abstract
PURPOSE To compare the change in aberrations produced by laser-assisted in situ keratomileusis (LASIK) measured by either front surface corneal aberrometry or Hartmann-Shack whole-eye aberrometry. METHODS This was a retrospective case series from consecutive patients treated with LASIK at the London Vision Clinic, London, UK. Corneal and ocular wavefront data were collected before and after LASIK for myopia and hyperopia. To control for centration of corneal and whole-eye aberration measurements, only patients with pupil offset (measured as the distance between the corneal vertex and the entrance pupil center) of 0.25 mm or less were recruited. Corneal front surface wavefront was obtained from a Placido-based corneal topography system (Atlas), and whole-eye wavefront was measured by Hartmann-Shack aberrometry (WASCA) before and at least 3 months after surgery. All aberrations were calculated up to the fourth order for the 6-mm pupil diameter. Change in HORMS (higher-order root mean square [RMS]) and all individual Zernike coefficients from the second to the fourth order were compared. RESULTS One hundred myopic eyes and 50 hyperopic eyes were included for analysis. For myopic LASIK, the change measured by corneal aberrometry or whole-eye aberrometry differed on average by 0.077 μm for HORMS, by 0.024 μm for secondary astigmatism, and by 0.065 μm for spherical aberration (p ≤ 0.003). For hyperopic LASIK, there was no statistically significant difference between the change measured by corneal aberrometry and whole-eye aberrometry for third- and fourth-order individual Zernike coefficients (p ≥ 0.034). However, the change in HORMS measured by whole-eye aberrometry was 0.095 μm greater than that measured by corneal aberrometry (p < 0.001). CONCLUSIONS This study demonstrated that when measuring the change in higher-order aberrations induced by LASIK, corneal front surface aberrometry measurement was not interchangeable with whole-eye ocular aberrometry.
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Bohac M, Biscevic A, Koncarevic M, Anticic M, Gabric N, Patel S. Comparison of Wavelight Allegretto Eye-Q and Schwind Amaris 750S excimer laser in treatment of high astigmatism. Graefes Arch Clin Exp Ophthalmol 2014; 252:1679-86. [PMID: 25150049 PMCID: PMC4181506 DOI: 10.1007/s00417-014-2776-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 05/17/2014] [Accepted: 08/07/2014] [Indexed: 11/26/2022] Open
Abstract
Purpose To compare functional outcomes of Wavelight Allegretto Eye-Q 400Hz and Schwind Amaris 750S excimer laser for astigmatism between 2 and 7 diopters(D). Methods Prospective comparative non-randomized case series of 480 eyes assigned in two laser groups and further divided into myopic and mixed astigmatism subgroups. All treatments were centered on corneal vertex. One-year results were compared between the groups. Statistical analysis was performed using z-test. Results Both Allegretto and Amaris postoperative uncorrected distance visual acuity (UDVA) improved in comparison to preoperative corrected distance visual acuity (CDVA). The difference was significant in the Allegretto group for myopic astigmatism (p = 0.017). There was no difference in postoperative UDVA between lasers. Average sphere decreased in all groups for both lasers (p < 0.001) without difference in effectiveness of spherical correction between lasers for both groups. In Allegretto, average cylinder decreased from −3.30D to −0.55D in myopic astigmatism (p < 0.001) and from −3.84D to −0.85D in mixed astigmatism (p < 0.001). In Amaris average cylinder decreased from −3.21D to −0.43D in myopic astigmatism (p < 0.001) and from −3.66D to −0.58D in mixed astigmatism (p < 0.001). Amaris group had less residual astigmatism (myopic astigmatism p = 0.023, mixed astigmatism p < 0.001). Mean spherical aberration shifted from positive to negative in mixed astigmatism for both lasers. Conclusion Both lasers are effective in terms of UDVA, CDVA, spherical correction, and preservation of high-order aberrations. However, Amaris was more effective in cylinder correction.
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Affiliation(s)
- Maja Bohac
- Specialty Eye Hospital „Svjetlost“, Heinzelova 39, 10000 Zagreb, Croatia
| | - Alma Biscevic
- Specialty Eye Hospital „Svjetlost“, Heinzelova 39, 10000 Zagreb, Croatia
| | - Mateja Koncarevic
- Specialty Eye Hospital „Svjetlost“, Heinzelova 39, 10000 Zagreb, Croatia
| | - Marija Anticic
- Specialty Eye Hospital „Svjetlost“, Heinzelova 39, 10000 Zagreb, Croatia
| | - Nikica Gabric
- Specialty Eye Hospital „Svjetlost“, Heinzelova 39, 10000 Zagreb, Croatia
| | - Sudi Patel
- Specialty Eye Hospital „Svjetlost“, Heinzelova 39, 10000 Zagreb, Croatia
- NHS National Services Scotland, Edinburgh, UK
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Ganesh S, Gupta R. Comparison of Visual and Refractive Outcomes Following Femtosecond Laser-Assisted LASIK With SMILE in Patients With Myopia or Myopic Astigmatism. J Refract Surg 2014; 30:590-6. [DOI: 10.3928/1081597x-20140814-02] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Piñero DP, Blanes-Mompó FJ, Ruiz-Fortes P, Pérez-Cambrodí RJ, Alzamora-Rodríguez A. Pilot study of hyperopic LASIK using the solid-state laser technology. Graefes Arch Clin Exp Ophthalmol 2012; 251:977-84. [PMID: 23052717 DOI: 10.1007/s00417-012-2166-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 09/17/2012] [Accepted: 09/20/2012] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND To evaluate and report the visual, refractive, and aberrometric outcomes of LASIK for the correction of low to moderate hyperopia in a pilot group using a commercially available solid-state laser METHODS Prospective pilot study including 11 consecutive eyes with low to moderate hyperopia of six patients undergoing LASIK surgery using the Pulzar Z1 solid-state laser (CustomVis Laser Pty Ltd., currently CV Laser). Visual, refractive, and aberrometric changes were evaluated. Potential complications were evaluated as well. Mean follow-up time was 6.6 months (range, 3 to 11 months). RESULTS A significant improvement in LogMAR uncorrected distance visual acuity (UDVA) was observed postoperatively (p = 0.01). No significant change was detected in LogMAR corrected distance visual acuity (CDVA) (p = 0.21). Postoperative LogMAR UDVA was 0.1 (about 20/25) or better in ten eyes (90.9 %). Mean overall efficacy and safety indices were 1.03 and 1.12. Postoperatively, no losses of lines of CDVA were observed. Postoperative spherical equivalent was within ± 1.00 D in ten eyes (90.9 %). With regard to aberrations, no statistically significant changes were found in higher order and primary coma RMS postoperatively (p ≥ 0.21), and only minimal but statistically significant negativization of primary spherical aberration (p = 0.02) was observed. No severe complications were observed. CONCLUSION LASIK surgery using the solid-state laser technology seems to be a useful procedure for the correction of low to moderate hyperopia, with minimal induction of higher order aberrations.
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Affiliation(s)
- David P Piñero
- Department of Ophthalmology, Oftalmar, Hospital Internacional Medimar, Avda. Denia 78, 03016 Alicante, Spain.
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Huang H, Yang J, Bao H, Chen S, Xia B, Zou J. Retrospective analysis of changes in the anterior corneal surface after Q value guided LASIK and LASEK in high myopic astigmatism for 3 years. BMC Ophthalmol 2012; 12:15. [PMID: 22708970 PMCID: PMC3407472 DOI: 10.1186/1471-2415-12-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 06/18/2012] [Indexed: 11/17/2022] Open
Abstract
Background To compare the corneal high-order aberrations (HOAs), asphericity and regularity after Q-value guided laser in situ keratomileusis (LASIK) and laser epithelial keratomileusis (LASEK) in high myopic astigmatism. Methods In this retrospectively comparative study, we measured the corneal HOAs, asphericity indices (Q values) and corneal regularity indices preoperatively and 36 months postoperatively in 70 eyes (35 patients) with Q-value guided surgeries. All the patients with high myopic astigmatism were divided into two groups which included 34 eyes underwent LASIK and 36 eyes underwent LASEK procedures. The main impact factors of the high-order aberrations were also analyzed. Results In the two groups, the efficacy index was more than 1.00 and safety index approached 1.00 at year 3 postoperatively. Statistically significant (P < 0.05) increased in Q values and main corneal HOAs (spherical aberrations and coma) following Q-value guided LASIK and LASEK procedures. Spherical aberrations increased more in the LASEK group and there was statistically difference compared to the LASIK group (P < 0.05). LASEK had better effects in correcting corneal astigmatism (P < 0.05). All the corneal regularity indices after surgeries increased and there was no significant difference (P = 0.707, P = 0.8 and P = 0.224, respectively) between the two groups. The main impact factors of spherical aberration included the optic zone size, changes of Q value, surgical procedure and the corrected refraction. Conclusions In high myopic astigmatism, Q-value guided ablation showed good safety, efficacy and predictability. Q value, regularity indices, spherical aberration and coma increased in both LASIK and LASEK procedures. Astigmatism could be corrected more effectively by LASEK but greater spherical aberration could be created. The difference might be related to the different healing mechanisms. Optic zone size and the corrected refraction might be the main influence factors on the anterior corneal high order aberrations.
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Affiliation(s)
- Hui Huang
- Department of Ophthalmology, Shanghai Sixth People's Hospital, Shanghai Jiaotong University, 600 Yishan Road, Shanghai, 200233, People's Republic of China
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Aslanides IM, Kolli S, Padron S, Arba Mosquera S. Stability of Therapeutic Retreatment of Corneal Wavefront Customized Ablation With the SCHWIND CAM: 4-year Data. J Refract Surg 2012; 28:347-52. [DOI: 10.3928/1081597x-20120410-01] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Accepted: 03/07/2012] [Indexed: 11/20/2022]
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Smadja D, Reggiani-Mello G, Santhiago MR, Krueger RR. Wavefront ablation profiles in refractive surgery: description, results, and limitations. J Refract Surg 2012; 28:224-32. [PMID: 22373035 DOI: 10.3928/1081597x-20120217-01] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2011] [Accepted: 12/06/2011] [Indexed: 11/20/2022]
Abstract
PURPOSE To provide an overview of the clinical results of different ablation profiles based on wavefront technology and discuss their characteristics and limitations. METHODS Literature review of studies reporting results of ablation profiles based on wavefront technology in virgin healthy eyes. RESULTS Over the past 10 years, a large number of studies comparing different treatment algorithms and newer excimer laser platforms have been published. Thirty-six clinical studies including 3637 eyes analyzing the clinical results obtained after wavefront-guided, wavefront-optimized, and Q-factor profiles have been reviewed. Although wavefront-driven profiles allowed reduction of the amount of induced optical aberrations with conventional ablations, thereby improving the quality of vision, it appears that no algorithm of treatment or excimer laser platform has demonstrated a clear superiority over another. Wound healing and unexpected biomechanical response to surgery affect the accuracy of customized treatments and produce variable results. In addition, it is difficult to rigorously analyze and compare findings among different studies because of the diverse variety in which the data are reported. CONCLUSIONS Despite several technological improvements over the years, wavefront ablation profiles have not consistently demonstrated superiority in terms of visual acuity and lower order aberrations compared to the standard procedure, although the induction of higher order aberrations has been reduced. The concept of an individualized eye model has emerged recently, based on the optical ray tracing algorithm, and could theoretically provide a higher level of customization, thus fulfilling the promise of "super vision."
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Affiliation(s)
- David Smadja
- Refractive Surgery Department, Cole Eye Institute, Cleveland Clinic Foundation, Ohio, USA.
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Smadja D, Reggiani-Mello G, Touboul D, Colin J. Les profils de photoablation cornéenne en chirurgie réfractive. Partie 1 : la quête de l’excellence. J Fr Ophtalmol 2012; 35:126-35. [DOI: 10.1016/j.jfo.2011.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 08/30/2011] [Accepted: 09/02/2011] [Indexed: 10/14/2022]
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de Ortueta D, Magnago T, Triefenbach N, Arba Mosquera S, Sauer U, Brunsmann U. In vivo measurements of thermal load during ablation in high-speed laser corneal refractive surgery. J Refract Surg 2011; 28:53-8. [PMID: 21913631 DOI: 10.3928/1081597x-20110906-01] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 07/18/2011] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate the thermal load of ablation in high-speed laser corneal refractive surgery with the AMARIS excimer laser (SCHWIND eye-tech-solutions). METHODS Thermal load from refractive corrections on human corneas using a 500-Hz laser system with a fluence of 500 mJ/cm(2) and aspheric ablation profiles was recorded with an infrared thermography camera. Each single in vivo measurement was analyzed and temperature values were evaluated. RESULTS Overall, the maximum temperature change of the ocular surface induced by the refractive ablations was ≤4°C. The increase in the peak temperature of the ocular surface never exceeded 35°C in any case. This low thermal load was independent of the amount of correction the eye achieved. CONCLUSIONS The thermal load of the ablation in high-speed laser corneal refractive surgery was minimized using a computer algorithm to control the peak temperature to avoid corneal collagen denaturation with minimal compromise on treatment duration.
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Camellin M, Arba Mosquera S. Aspheric Optical Zones in hyperopia with the SCHWIND AMARIS. JOURNAL OF OPTOMETRY 2011; 4:85-94. [PMCID: PMC3974388 DOI: 10.1016/s1888-4296(11)70047-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2011] [Accepted: 08/29/2011] [Indexed: 10/07/2023]
Abstract
Purpose To evaluate the corneal Functional Optical Zone (FOZ) and the Effective Optical Zone (EOZ) of the ablation, among eyes that underwent LASEK/Epi-LASEK treatments for hyperopic astigmatism. Methods Twenty LASEK/Epi-LASEK treatments with mean defocus +2.21 ± 1.28 D performed using the SCHWIND AMARIS were retrospectively evaluated at 6-month follow-up. In all cases pre-/post-operative Corneal-Wavefront analyses using the Keratron-Scout (OPTIKON2000) were performed. FOZ-values were evaluated from the Root-Mean-Square of High-Order Wave-Aberration (RMSho), whereas EOZ-values were evaluated from the changes of Root-Mean-Square of High-Order Wave-Aberration (ΔRMSho) and Root-Mean-Square of the change of High-Order Wave-Aberration (RMS(ΔHOAb)). Correlations of FOZ and EOZ with Planned Optical Zone (POZ) and Defocus correction (SEq) were analyzed using a bilinear function. Results At six-month, defocus was −0.04 ± 0.44 D, ninety percent eyes were within ± 0.50 D from emmetropia. Mean RMSho increased 0.18 ± 0.22 μm, SphAb −0.30 ± 0.18 μm, and Coma 0.07 ± 0.18 μm 6-month after treatment (6-mm diameter). Mean FOZPre was 7.40 ± 1.48 mm, mean POZ was 6.76 ± 0.22 mm, whereas mean FOZPost was 5.53 ± 1.18 mm (significantly smaller, p < 0.0001; bilinear correlation p < 0.005), mean EOZΔRMSho 6.47 ± 1.17 mm (bilinear correlation p < 0.005), EOZRMS(ΔHOAb) 5.67 ± 1.23 mm (significantly smaller, p < 0.0005; bilinear correlation p < 0.05). EOZ positively correlates with POZ and declines steadily with SEq. A treatment of +3 D in 6.50-mm POZ results in 5.75-mm EOZ (7.75-mm NPOZ), treatments in 7.00-mm POZ result in about 6.25-mm EOZ (8.25-mm nomogrammed POZ). Conclusions FOZPost was significantly smaller than FOZPre. EOZΔRMSho was similar to POZ, whereas EOZRMS(ΔHOAb) was significantly smaller. Differences were larger for smaller POZ or larger Defocus. SEq up to +2 D result in EOZ, at least, as large as POZ. For SEq higher than +2 D, a nomogram for OZ can be applied.
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Affiliation(s)
| | - Samuel Arba Mosquera
- Grupo de Investigación de Cirugía Refractiva y Calidad de Visión, Instituto de Oftalmobiología Aplicada, University of Valladolid, Valladolid, Spain
- SCHWIND eye-tech-solutions, Kleinostheim, Germany
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Arba Mosquera S, de Ortueta D. Optimized Zernike Term Selection in Customized Treatments for Laser Corneal Refractive Surgery: Case Report. J Refract Surg 2011; 27:148-152. [DOI: 10.3928/1081597x-20100224-01] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Accepted: 02/10/2009] [Indexed: 11/20/2022]
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Shah R, Shah S, Sengupta S. Results of small incision lenticule extraction: All-in-one femtosecond laser refractive surgery. J Cataract Refract Surg 2011; 37:127-37. [DOI: 10.1016/j.jcrs.2010.07.033] [Citation(s) in RCA: 362] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Revised: 07/08/2010] [Accepted: 07/14/2010] [Indexed: 10/18/2022]
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Einighammer J, Oltrup T, Bende T, Jean B. Real Ray Tracing Simulation Versus Clinical Outcomes of Corneal Excimer Laser Surface Ablations. J Refract Surg 2010; 26:625-37. [DOI: 10.3928/1081597x-20100319-01] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2009] [Accepted: 02/09/2010] [Indexed: 11/20/2022]
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Six-month clinical outcomes of customized treatments minimized for depth and time in laser corneal refractive surgery. Cornea 2010; 30:876-88. [PMID: 20802317 DOI: 10.1097/ico.0b013e3181d3d2ce] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Evaluating the application of 2 methods for minimizing the ablated tissue upon objective minimization of depth and time of Zernike-based customized ablations. SETTING Muscat Eye Laser Center, Muscat, Sultanate of Oman. METHODS Recently developed algorithms for selection of Zernike terms in customized treatments for refractive surgery were used. Clinical outcomes and tissue-saving attributes were evaluated on 2 groups [minimize depth (MD) and minimize volume (MV); 30 eyes each], plus a control group [corneal wavefront (CW); 30 eyes] with conventional customized approach. Clinical outcomes were evaluated in terms of predictability, safety, and contrast sensitivity and tissue-saving attributes in terms of saved depth and time for each condition (in micrometers, seconds, and percentage) and whether minimized depth or time were less than required for equivalent noncustomized treatments. RESULTS Ninety-three percent of treatments in the CW group, 93% in the MD group, and 100% in the MV group were within 0.50 diopters of spherical equivalent (SEq) postoperatively. Forty percent of treatments in the CW group, 34% in the MD group, and 47% in the MV group gained at least 1 line of best spectacle-corrected visual acuity postoperatively. Tissue-saving attributes showed an average saved depth of 8 μm (1-20 μm) and a saved time of 6 seconds (1-15 seconds) in the MD group and 6 μm (0-20 μm) and 8 seconds (2-26 seconds) in the MV group. Proposed corrections were always less deep and shorter than full wavefront corrections. In 43% of the MD cases, corrections were less deep, and in 40% of the MV cases, corrections were shorter than equivalent aberration-free treatments. CONCLUSION The minimization techniques compared here effectively reduced depth and time needed for ablation (up to a maximum of 50% and by 15% in average) without negatively affecting clinical outcomes postoperatively, yielding results equivalent to those of the full customization group.
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Arba-Mosquera S, Merayo-Lloves J, de Ortueta D. Asphericity analysis using corneal wavefront and topographic meridional fits. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:028003. [PMID: 20459293 DOI: 10.1117/1.3382910] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The calculation of corneal asphericity as a 3-D fit renders more accurate results when it is based on the corneal wavefront aberrations rather than on the corneal topography of the principal meridians. A more accurate prediction could be obtained for hyperopic treatments compared to myopic treatments. We evaluate a method to calculate corneal asphericity and asphericity changes after refractive surgery. Sixty eyes of 15 consecutive myopic patients and 15 consecutive hyperopic patients (n=30 each) are retrospectively evaluated. Preoperative and 3-month-postoperative topographic and corneal wavefront analyses are performed using corneal topography. Ablations are performed using a laser with an aberration-free profile. Topographic changes in asphericity and corneal aberrations are evaluated for a 6-mm corneal diameter. The induction of corneal spherical aberrations and asphericity changes correlates with the achieved defocus correction. Preoperatively as well as postoperatively, asphericity calculated from the topography meridians correlates with asphericity calculated from the corneal wavefront in myopic and hyperopic treatments. A stronger correlation between postoperative asphericity and the ideally expected/predicted asphericity is obtained based on aberration-free assumptions calculated from corneal wavefront values rather than from the meridians. In hyperopic treatments, a better correlation can be obtained compared to the correlation in myopic treatments. Corneal asphericity calculated from corneal wavefront aberrations represents a 3-D fit of the corneal surface; asphericity calculated from the main topographic meridians represents a 2-D fit of the principal corneal meridians. Postoperative corneal asphericity can be calculated from corneal wavefront aberrations with higher fidelity than from corneal topography of the principal meridians. Hyperopic treatments show a greater accuracy than myopic treatments.
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Affiliation(s)
- Samuel Arba-Mosquera
- University of Valladolid, Instituto de Oftalmobiologia Aplicada, Refractive Surgery and Quality of Vision, Valladolid, E-47004 Spain.
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Arbelaez MC, Aslanides IM, Barraquer C, Carones F, Feuermannova A, Neuhann T, Rozsival P. LASIK for myopia and astigmatism using the SCHWIND AMARIS excimer laser: an international multicenter trial. J Refract Surg 2010; 26:88-98. [PMID: 20163073 DOI: 10.3928/1081597x-20100121-04] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Accepted: 02/10/2009] [Indexed: 11/20/2022]
Abstract
PURPOSE To assess the efficacy, predictability, and safety of LASIK for the surgical correction of low to moderate myopia with astigmatism using the SCHWIND AMARIS excimer laser. METHODS Six international study sites enrolled 358 eyes with a manifest refraction spherical equivalent (MRSE) from -0.50 to -7.38 diopters (D) (mean sphere: -3.13+/-1.58 D) with up to -5.00 D of astigmatism (mean: -0.69+/-0.67 D). All eyes underwent treatment with the nonwavefront-guided aspheric algorithm of the SCHWIND AMARIS excimer laser. All eyes were targeted for emmetropia. Refractive outcomes and corneal higher order aberrations were analyzed pre- and postoperatively. Visual quality was assessed using photopic and mesopic contrast sensitivity. Six-month postoperative outcomes are reported. RESULTS At 6 months postoperative, the MRSE for all eyes was -0.21+/-0.20 D, and 96% (343/358) of eyes had MRSE within +/-0.50 D. Uncorrected visual acuity was 20/20 or better in 98% (351/358) of eyes, and no eyes lost 2 or more lines of best spectacle-corrected visual acuity. The total corneal higher order aberrations root-mean-square increased by 0.09 microm, spherical aberration increased by 0.08 microm, and coma increased by 0.04 microm postoperatively. Photopic and mesopic contrast sensitivity did not change 6 months postoperatively. CONCLUSIONS Treatment of myopia with astigmatism using the SCHWIND AMARIS excimer laser is safe, efficacious, predictable, and maintains visual quality.
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Bühren J, Nagy L, Yoon G, MacRae S, Kohnen T, Huxlin KR. The effect of the asphericity of myopic laser ablation profiles on the induction of wavefront aberrations. Invest Ophthalmol Vis Sci 2010; 51:2805-12. [PMID: 20042646 DOI: 10.1167/iovs.09-4604] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To compare the effects of laser profile asphericity on the induction of wavefront aberrations, susceptibility to decentration, and depth of focus in a polymethylmethacrylate (PMMA) model. METHODS Four PMMA lenses received an excimer laser ablation of -6 D with a 6-mm optical zone and different amounts of primary spherical aberration (Z(4)(0)): 0, -0.346, -1.038, and -2.076 microm. The curvature of each lens was measured by using surface profilometry, and wavefront changes were computed from curvature differences. Changes in optical quality were compared by treatment simulation of 13 real myopic eyes. The influence of pupil diameter, ablation decentration, and defocus on retinal image quality was measured by using the optical transfer function-based visual Strehl ratio (VSOTF). RESULTS Aspheric ablation profiles induced significantly less primary but higher secondary spherical aberration (Z(6)(0)) than did the standard profile; however, Z(4)(0) compensation was incomplete. Simulated treatments with aspheric profiles resulted in significantly better retinal image quality and higher decentration tolerance than did the standard profile. Optical depth of focus was not affected with a 3-mm pupil, whereas with a 6-mm pupil, there was a small but statistically significant decrease in depth of focus. CONCLUSIONS Aspheric laser profiles showed theoretical optical benefits over standard ablation profiles for the treatment of myopia, including terms of decentration tolerance. However, there remained profound induction and thus, undercorrection of Z(4)(0), due to loss of laser ablation efficiency in the lens periphery.
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Affiliation(s)
- Jens Bühren
- University of Rochester Eye Institute, Rochester, New York, USA
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de Ortueta D, Arba Mosquera S, Baatz H. Aberration-neutral ablation pattern in hyperopic LASIK with the ESIRIS laser platform. J Refract Surg 2009; 25:175-84. [PMID: 19241768 DOI: 10.3928/1081597x-20090201-02] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To analyze refractive power changes, topographical changes, and aberrations induction after aberration-neutral (Aberration-Free") hyperopic LASIK using the SCHWIND ESIRIS laser platform. METHODS Thirty-three consecutive eyes of 19 patients were evaluated retrospectively. The outcomes were analyzed at 3 months. In all cases, standard examinations and pre- and postoperative topographical and corneal wavefront analysis with a Keratron topographer (OPTIKON 2000 SpA) were performed. The preoperative mean spherical equivalent refraction was +2.61 +/- 1.39 diopters (D) (range: +0.75 to +6.00 D) with a mean cylinder of 0.67 +/- 0.74 D (range: 0.00 to 4.00 D). Ablations were performed with the SCHWIND ESIRIS excimer laser system. Topographical changes of Maloney index, simulated keratometry (Sim-K), and K-readings at 5 and 7 mm were evaluated. RESULTS Corneal aberrations up to the seventh order (36 Zernike terms) were measured. Corneal spherical aberration was +0.197 +/- 0.144 microm preoperatively and -0.040 +/- 0.206 microm postoperatively at the 6-mm analysis diameter. At 3 months postoperatively, 88% of eyes were within +/-0.50 D manifest refraction. Changes in refraction, Maloney indices, and Sim-K indices postoperatively were correlated with the intended correction. Induction of negative corneal spherical aberrations and increased prolate asphericity were correlated with the achieved defocus correction. No other Zernike mode was significantly correlated. Topographically, a corneal multifocality of <0.25 D was also observed. CONCLUSIONS Analyzing the topographical maps, the corneal power change of the Maloney indices correlated with the intended correction. With the aberration-neutral (SCHWIND Aberration-Free) pattern, patients with hyperopia up to +5.00 D were treated safely and with good predictability. The induced corneal aberrations were less than those calculated with the classical profile and compared to the literature.
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Arbelaez MC, Vidal C, Jabri BA, Mosquera SA. LASIK for Myopia with Aspheric “Aberration Neutral” Ablations Using the ESIRIS Laser System. J Refract Surg 2009; 25:991-9. [DOI: 10.3928/1081597x-20091016-04] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Accepted: 10/24/2008] [Indexed: 11/20/2022]
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