LASIK

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Full Text Available ... surgery, FDA’s current LASIK activities , and FDA-approved lasers for LASIK . LASIK stands for Laser-Assisted In Situ Keratomileusis and is a procedure ... the front of the eye, using an excimer laser. A mechanical microkeratome (a blade device) or a ...

Epithelial ingrowth following laser in situ keratomileusis (LASIK): prevalence, risk factors, management and visual outcomes.

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Ting, Darren Shu Jeng; Srinivasan, Sathish; Danjoux, Jean-Pierre

2018-01-01

The number of laser in situ keratomileusis (LASIK) procedures is continuing to rise. Since its first application for correcting simple refractive errors over 25 years ago, the role of LASIK has extended to treat other conditions, including postkeratoplasty astigmatism/ametropia, postcataract surgery refractive error and presbyopia, among others. The long-term effectiveness, predictability and safety have been well established by many large studies. However, due to the creation of a potential interface between the flap and the underlying stroma, interface complications such as infectious keratitis, diffuse lamellar keratitis and epithelial ingrowth may occur. Post-LASIK epithelial ingrowth (PLEI) is an uncommon complication that usually arises during the early postoperative period. The reported incidence of PLEI ranged from 0%-3.9% in primary treatment to 10%-20% in retreatment cases. It can cause a wide spectrum of clinical presentations, ranging from asymptomatic interface changes to severe visual impairment and flap melt requiring keratoplasty. PLEI can usually be treated with mechanical debridement of the affected interface; however, additional interventions, such as alcohol, mitomycin C, fibrin glue, ocular hydrogel sealant, neodymium:yttriumaluminum garnet laser and amniotic membrane graft, may be required for recurrent or refractory cases. The aims of this review are to determine the prevalence and risk factors of PLEI; to describe its pathogenesis and clinical features and to summarise the therapeutic armamentarium and the visual outcome of PLEI.

Photorefractive keratectomy (PRK) versus laser assisted in situ keratomileusis (LASIK) for hyperopia correction.

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Settas, George; Settas, Clare; Minos, Evangelos; Yeung, Ian Yl

2012-06-13

Hyperopia, or hypermetropia (also known as long-sightedness or far-sightedness), is the condition where the unaccommodating eye brings parallel light to a focus behind the retina instead of on it. Hyperopia can be corrected with both non-surgical and surgical methods, among them photorefractive keratectomy (PRK) and laser assisted In situ keratomileusis (LASIK). There is uncertainty as to whether hyperopic-PRK or hyperopic-LASIK is the better method. The objectives of this review were to determine whether PRK or LASIK leads to more reliable, stable and safe results when correcting a hyperopic refractive error. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 2), MEDLINE (January 1950 to February 2012), EMBASE (January 1980 to February 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to February 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 17 February 2012. When trials are included in the review we will search the reference lists of the studies included in the review for information about further trials. We will use the Science Citation Index to search for papers that cite any studies included in this review. We did not handsearch journals or conference proceedings specifically for this review. We planned to include only randomised controlled trials (RCTs) comparing PRK against LASIK for correction of hyperopia and then perform a sensitivity analysis of pre- and post-millennial trials since this is the mid-point in the history of both PRK and LASIK. We did not identify any studies that met the inclusion criteria for this review. As no studies met the

Laser-assisted in-situ keratomileusis (LASIK) versus photorefractive keratectomy (PRK) for myopia.

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Shortt, Alex J; Allan, Bruce D S; Evans, Jennifer R

2013-01-31

Myopia (also known as short-sightedness or near-sightedness) is an ocular condition in which the refractive power of the eye is greater than is required, resulting in light from distant objects being focused in front of the retina instead of directly on it. The two most commonly used surgical techniques to permanently correct myopia are photorefractive keratectomy (PRK) and laser-assisted in-situ keratomileusis (LASIK). To compare the effectiveness and safety of LASIK and PRK for correction of myopia by examining post-treatment uncorrected visual acuity, refractive outcome, loss of best spectacle-corrected visual acuity, pain scores, flap complications in LASIK, subepithelial haze, adverse events, quality of life indices and higher order aberrations. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 11), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to November 2012), EMBASE (January 1980 to November 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to November 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 15 November 2012. We also searched the reference lists of the studies and the Science Citation Index. We included randomised controlled trials comparing LASIK and PRK for the correction of any degree of myopia. Two authors independently assessed trial quality and extracted data. We summarised data using the odds ratio and mean difference. We combined odds ratios using a random-effects model after testing for heterogeneity. We included 13 trials (1135 participants, 1923 eyes

Variation of contrast sensitivity after femtosecond laser in situ keratomileusis in changes environments

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Jing Zhou

2015-01-01

Full Text Available AIM: To evaluate the difference of contrast sensitivity(CSin photopic and scotopic environments in eyes with myopia and myopic astigmatism operated with femtosecond laser in situ keratomileusis(femto-LASIKand laser in situ keratomileusis(LASIK.METHODS: In a prospective study 160 myopia and myopic astigmatism patients' eyes were involved, which accepted femto-LASIK or LASIK in our hospital from January 2010 to February 2012. The myopia degree was -1.50～-10.00D, the astigmatism degree ≤-6.0D. Eighty eyes were treated with femto-LASIK in group A, and 80 eyes were treated with LASIK in group B, All patients in the treatment group completed the final 6mo of follow-up. The uncorrected visual acuity(UCVAand the best spectacle-corrected visual acuity(BSCVA, objective and manifest refractions, results of slit-lamp examination, the side effects, intraocular pressure, corneal topography, CS in photopic and scotopic environments were noted.RESULTS: All of operations on 160 cases were successful without severe complication after 6 mo follow-up. CS of femto-LASIK group(group Aat each spatial frequency environment were higher than that of LASIK group(group B. In group A, after 1mo the photopic CS, after 3mo of scotopic CS recovered to the preoperative level, 6mo after surgery improved than before the operation. In group B, after 3mo photopic CS to the preoperative level, scotopic CS at 6mo after operation was still not recovered to the preoperative level.CONCLUSION:Femto-LASIK for correction of myopia and myopic astigmatism, in improving the postoperative contrast sensitivity under shade environment has more advantages than LASIK.

Bilateral Simultaneous Rhegmatogenous Retinal Detachment following Laser in situ Keratomileusis

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Erhan Yumusak

2016-06-01

Full Text Available A 21-year-old woman developed simultaneous rhegmatogenous retinal detachment after laser in situ keratomileusis (LASIK in both eyes. She underwent pars plana vitrectomy surgery combined with endolaser photocoagulation and silicone oil tamponade in the right eye. A week later, pneumatic retinopexy was done in the left eye. As the retinal tear did not seal, 360° scleral buckling surgery was performed and retina was attached. Bilateral simultaneous rhegmatogenous retinal detachment after LASIK for correction of myopia can be a serious complication. Patients should be informed about the possibility of this complication.

Reactivation of presumed adenoviral keratitis after laser in situ keratomileusis.

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Safak, Nilgün; Bilgihan, Kamil; Gürelik, Gökhan; Ozdek, Sengül; Hasanreisoğlu, Berati

2002-04-01

We report a patient with reactivation of presumed adenoviral keratoconjunctivitis after laser in situ keratomileusis (LASIK) to correct high myopia. The preoperative refraction was -13.00 diopters (D) in the right eye and -14.00 D in the left eye, and the best corrected visual acuity was 20/20 in both eyes. On the first postoperative day, mild conjunctival hyperemia and multiple subepithelial infiltrations localized in the flap zone consistent with adenoviral keratoconjunctivitis were seen. After prompt treatment, the lesions resolved. As a consequence, LASIK successfully corrected the high myopia. Adenoviral keratoconjunctivitis can be reactivated after LASIK, unlike after photorefractive keratectomy, despite the absence of symptomatic and clinical findings before the procedure.

One year follow-up of contrast sensitivity following conventional laser in situ keratomileusis and laser epithelial keratomileusis.

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Townley, Deirdre; Kirwan, Caitriona; O'Keefe, Michael

2012-02-01

To determine the effect of conventional laser in situ keratomileusis (LASIK) and laser epithelial keratomileusis (LASEK) for myopia on contrast sensitivity (CS) using the Pelli-Robson and Vector Vision CSV-1000E CS tests. A prospective, comparative study was conducted on 36 eyes of 36 patients with myopia undergoing LASIK (18 eyes) and LASEK (18 eyes). Surgery was performed using the Technolas 217z laser (Bausch & Lomb). CS was recorded preoperatively and at 3, 6 and 12 months postoperatively. No statistically significant difference was found in LogMAR uncorrected visual acuity post-LASIK (-0.02 ± 0.16) and LASEK (-0.04 ± 0.14). Using the Pelli-Robson, CS was significantly lower in the LASIK group 3 and 6 months postoperatively. No significant postoperative reduction in CS was observed in either treatment group. Using the CSV-1000E test, CS was significantly reduced post-LASIK at 3 (p = 0.05) and 6 (p = 0.05) cycles/degree under photopic conditions. No significant postoperative change occurred in the LASEK group under photopic or scotopic conditions. There was no significant difference in postoperative CS between the LASIK and LASEK groups at 3, 6, 12 or 18 cycles/degree using the CSV-1000E test. One year postoperatively, there was no difference in CS between both treatment groups using the Pelli-Robson and CSV-1000E tests. CS was reduced postoperatively in the LASIK group at the lower spatial frequencies under photopic conditions. No postoperative change was detected in CS following LASIK or LASEK using the Pelli-Robson test. © 2010 The Authors. Journal compilation © 2010 Acta Ophthalmol.

Straylight measurements in laser in situ keratomileusis and laser-assisted subepithelial keratectomy for myopia

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Lapid-Gortzak, Ruth; van der Linden, Jan Willem; van der Meulen, Ivanka; Nieuwendaal, Carla; van den Berg, Tom

2010-01-01

PURPOSE: To compare straylight values before and 3 months after laser in situ keratomileusis (LASIK) and laser-assisted subepithelial keratectomy (LASEK) and to analyze the causes of any change. SETTING: Private refractive surgery clinic, Driebergen, The Netherlands. METHODS: Straylight was measured

Functional outcomes and patient satisfaction after laser in situ keratomileusis for correction of myopia.

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Tahzib, N.G.; Bootsma, S.J.; Eggink, F.A.G.J.; Nabar, V.A.; Nuijts, R.M.

2005-01-01

PURPOSE: To determine subjective patient satisfaction and self-perceived quality of vision after laser in situ keratomileusis (LASIK) to correct myopia and myopic astigmatism. SETTING: Department of Ophthalmology, Academic Hospital Maastricht, Maastricht, The Netherlands. METHODS: A validated

Confocal comparison of corneal reinnervation after small incision lenticule extraction (SMILE and femtosecond laser in situ keratomileusis (FS-LASIK.

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Meiyan Li

Full Text Available PURPOSE: To evaluate corneal reinnervation, and the corresponding corneal sensitivity and keratocyte density after small incision lenticule extraction (SMILE and femtosecond laser in situ keratomileusis (FS-LASIK. METHODS: In this prospective, non-randomized observational study, 18 patients (32 eyes received SMILE surgery, and 22 patients (42 eyes received FS-LASIK surgery to correct myopia. The corneal subbasal nerve density and microscopic morphological changes in corneal architecture were evaluated by confocal microscopy prior to surgery and at 1 week, 1 month, 3 months, and 6 months after surgery. A correlation analysis was performed between subbasal corneal nerve density and the corresponding keratocyte density and corneal sensitivity. RESULTS: The decrease in subbasal nerve density was less severe in SMILE-treated eyes than in FS-LASIK-treated eyes at 1 week (P = 0.0147, 1 month (P = 0.0243, and 3 months (P = 0.0498, but no difference was detected at the 6-month visit (P = 0.5277. The subbasal nerve density correlated positively with central corneal sensitivity in both groups (r = 0.416, P<0.0001, and r = 0.2567, P = 0.0038 for SMILE group and FS-LASIK group, respectively. The SMILE-treated eyes have a lower risk of developing peripheral empty space with epithelial cells filling in (P = 0.0005. CONCLUSIONS: The decrease in subbasal nerve fiber density was less severe in the SMILE group than the FS-LASIK group in the first 3 months following the surgeries. The subbasal nerve density was correlated with central corneal sensitivity.

Straylight before and after hyperopic laser in situ keratomileusis or laser-assisted subepithelial keratectomy

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Lapid-Gortzak, Ruth; van der Linden, Jan Willem; van der Meulen, Ivanka J. E.; Nieuwendaal, Carla P.; Mourits, Maarten P.; van den Berg, Thomas J. T. P.

2010-01-01

PURPOSE To compare straylight values before and 3 months after hyperopic laser in situ keratomileusis (LASIK) or laser-assisted subepithelial keratectomy (LASEK) and determine the cause of any change SETTING Private refractive surgery clinic, Driebergen, The Netherlands DESIGN Comparative case

Comparative study of Epi-LASIK and LASIK for myopic astigmatism

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Jiao Chen

2013-11-01

Full Text Available AIM: To analyze the effects of epipolis laser in situ keratomileusis(Epi-LASIKand laser in situ keratomileusis(LASIKfor treatment of myopic astigmatism. METHODS: For treatment of myopic astigmatism, 32 patients(64 eyestreated by Epi-LASIK and 63 patients(126 eyesreceived LASIK. By their degree of astigmatism, the eyes were divided into Group Ⅰ(-0.25～-2.75DC and Group Ⅱ(-3.0～-5.0DC. During the 6-month follow-up, the early effects of the two operations were observed and compared in terms of uncorrected visual acuity(UCVA, best corrected visual acuity(BCVA, residual astigmatism, corneal healing, intraocular pressure(IOP, corneal topography. RESULTS: In Group Ⅱ, UCVA better than 20/20 was achieved in 87.5% of the eyes subjected to Epi-LASIK and in 63.3% of the eyes subjected to LASIK, with significant difference between them(χ2=4.055, Pt=2.672, Pt=2.234, PCONCLUSION: For treatment of high astigmatism(≥-3.00D, Epi-LASIK is more effective and predictive than LASIK.

Corneal biomechanical properties after laser-assisted in situ keratomileusis and photorefractive keratectomy

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Hwang ES

2017-10-01

Full Text Available Eileen S Hwang,1 Brian C Stagg,1 Russell Swan,1 Carlton R Fenzl,1 Molly McFadden,2 Valliammai Muthappan,1 Luis Santiago-Caban,1 Mark D Mifflin,1 Majid Moshirfar1,3 1Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, 2Department of Internal Medicine, University of Utah, Salt Lake City, 3HDR Research Center, Hoopes Vision, Draper, UT, USA Background: The purpose of this study was to evaluate the effects of laser-assisted in situ keratomileusis (LASIK and photorefractive keratectomy (PRK on corneal biomechanical properties.Methods: We used the ocular response analyzer to measure corneal hysteresis (CH and corneal resistance factor (CRF before and after refractive surgery.Results: In all, 230 eyes underwent LASIK and 115 eyes underwent PRK without mitomycin C (MMC. Both procedures decreased CH and CRF from baseline. When MMC was used after PRK in 20 eyes, it resulted in lower corneal biomechanical properties at 3 months when compared to the other procedures, but all three procedures had similar values at 12 months.Conclusion: Significant but similar decreases in corneal biomechanical properties after LASIK, PRK without MMC, and PRK with MMC were noted. Keywords: corneal biomechanics, photorefractive keratectomy, laser-assisted in situ keratomileusis, corneal hysteresis, corneal resistance factor, mitomycin C

Confocal comparison of corneal reinnervation after small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK).

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Li, Meiyan; Niu, Lingling; Qin, Bing; Zhou, Zimei; Ni, Katherine; Le, Qihua; Xiang, Jun; Wei, Anji; Ma, Weiping; Zhou, Xingtao

2013-01-01

To evaluate corneal reinnervation, and the corresponding corneal sensitivity and keratocyte density after small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK). In this prospective, non-randomized observational study, 18 patients (32 eyes) received SMILE surgery, and 22 patients (42 eyes) received FS-LASIK surgery to correct myopia. The corneal subbasal nerve density and microscopic morphological changes in corneal architecture were evaluated by confocal microscopy prior to surgery and at 1 week, 1 month, 3 months, and 6 months after surgery. A correlation analysis was performed between subbasal corneal nerve density and the corresponding keratocyte density and corneal sensitivity. The decrease in subbasal nerve density was less severe in SMILE-treated eyes than in FS-LASIK-treated eyes at 1 week (P = 0.0147), 1 month (P = 0.0243), and 3 months (P = 0.0498), but no difference was detected at the 6-month visit (P = 0.5277). The subbasal nerve density correlated positively with central corneal sensitivity in both groups (r = 0.416, PLASIK group, respectively). The SMILE-treated eyes have a lower risk of developing peripheral empty space with epithelial cells filling in (P = 0.0005). The decrease in subbasal nerve fiber density was less severe in the SMILE group than the FS-LASIK group in the first 3 months following the surgeries. The subbasal nerve density was correlated with central corneal sensitivity.

[Hyperopic Laser-in-situ-Keratomileusis after trifocal intraocular lens implantation : Aberration-free femto-Laser-in-situ-Keratomileusis treatment after implantation of a diffractive, multifocal, toric intraocular lens-case analysis].

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Hemkeppler, E; Böhm, M; Kohnen, T

2018-05-29

A 52-year-old highly myopic female patient was implanted with a multifocal, diffractive, toric intraocular lens because of the wish to be independent of eyeglasses. Despite high-quality, extensive preoperative examinations, a hyperopic refractive error remained postoperatively, which led to the patient's dissatisfaction. This error was treated with Laser-in-situ-Keratomileusis (LASIK). After corneal LASIK treatment and implantation of a diffractive toric multifocal intraocular lens the patient showed a good postoperative visual result without optical phenomena.

SMILE and Wavefront-Guided LASIK Out-Compete Other Refractive Surgeries in Ameliorating the Induction of High-Order Aberrations in Anterior Corneal Surface

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Ye, Min-jie; Liu, Cai-yuan; Liao, Rong-feng; Gu, Zheng-yu; Zhao, Bing-ying; Liao, Yi

2016-01-01

Purpose. To compare the change of anterior corneal higher-order aberrations (HOAs) after laser in situ keratomileusis (LASIK), wavefront-guided LASIK with iris registration (WF-LASIK), femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK), and small incision lenticule extraction (SMILE). Methods. In a prospective study, 82 eyes underwent LASIK, 119 eyes underwent WF-LASIK, 88 eyes underwent FS-LASIK, and 170 eyes underwent SMILE surgery. HOAs were measured with Pentacam device pr...

Safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK) with a 1000-Hz scanning spot excimer laser.

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Khoramnia, Ramin; Salgado, Josefina P; Wuellner, Christian; Donitzky, Christof; Lohmann, Chris P; Winkler von Mohrenfels, Christoph

2012-09-01

To evaluate the safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK) with a 1000-Hz scanning spot excimer laser (Concept System 1000; WaveLight GmbH, Erlangen, Germany). LASIK was performed on twenty eyes with myopia or myopic astigmatism (mean spherical equivalent refraction: -3.97±1.72 dioptres (D); mean cylinder: -0.84±0.77 D) using a microkeratome for flap creation and the Concept System 1000 for photoablation. Patients were examined preoperatively as well as 1, 3 and 6 months after the treatment. Manifest sphere and cylinder, uncorrected (UCDVA) and best corrected (BCDVA) distance visual acuity, corneal topography and pachymetry were analysed. We observed no adverse events that might have been associated with the use of a repetition rate of 1000 Hz. All eyes maintained or had improved BCDVA at 6 months after treatment when compared to preoperative values. Six months after LASIK, UCDVA was 20/20 or better in 85% and 20/25 or better in 100% of the eyes. The spherical equivalent refraction was within ±0.50 D in 95% of the eyes at 6 months after surgery. The refraction stayed stable over time; 95% of the eyes changedLASIK with the prototype 1000-Hz excimer laser was safe, efficient and predictable. The postoperative refraction was stable over time. There were no specific clinical side-effects that might be associated with the use of such a high repetition rate. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.

[Incidence of vitreoretinal pathologic conditions in myopic eyes after laser in situ keratomileusis].

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Lin, Jijian; Xie, Xin; Du, Xinhua; Yang, Yabo; Yao, Ke

2002-09-01

To determine the incidence of vitreoretinal pathologic conditions in myopic eyes after laser in situ keratomileusis. Vitreoretinal pathologic conditions of 1981 consecutive eyes (995 patients) having undergone laser-assisted in situ keratomileusis for the correction of myopia were studied. Preoperative and postoperative basic examinations included visual acuity, manifest and cycloplegic refraction, slit-lamp microscope examination, applanation tonometry and a fundus examination after pupil dilatation by indirect ophthalmoscopy and biomicroscopy with spherical lens of + 90 diopters. Before laser in situ keratomileusis, preventive treatment was carried out for predisposing lesion of retinal detachment in 8 eyes: 6 eyes for lattice degeneration and 2 eyes for atrophic holes. Postoperative examinations were conducted at 1, 3 and 12 months and once a year thereafter. All eyes were followed up for >/= 12 months. Eyes were followed for a mean of (18.40 +/- 4.50) months (range 12 - 28) after the surgery. Sixteen eyes of 13 patients (0.81%) developed vitreoretinopathy after LASIK, including 6 eyes with lattice degeneration (0.30%) in which one of them had previous laser treatment, 2 with posterior vitreous detachment (0.10%), 2 with macular hemorrhage (0.10%), 4 with rhegmatogenous retinal detachment (0.20%), and 2 with retinal tear without retinal detachment (0.10%) in which one of them had previous laser treatment for lattice degeneration. Five patients were males (5 eyes involved). Others were females. Mean age of the group with vitreoretinal pathologic conditions was 31.80 +/- 5.85 years (range 22 to 43). The interval between refractive surgery and development of vitreoretinal complication was (10.38 +/- 6.20) months (range 1 to 24). The eyes that developed vitreoretinopathy had myopia -4.75 to -15.00 diopters (mean -9.45 +/- 2.61 D) before LASIK. The comparison of incidences of vitreoretinopathy after LASIK between the group of >/= -6.00 D and lattice degeneration and

Dry Eye Post-Laser-Assisted In Situ Keratomileusis: Major Review and Latest Updates

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Spierer, Oriel

2018-01-01

Dry eye is one of the most common complications occurring after laser-assisted in situ keratomileusis (LASIK), with virtually all patients experiencing some degree of postoperative dry eye symptoms. Enhanced understanding of the pathophysiology and mechanism of dry eye development in addition to preoperative screening of patients who are prone to dry eye is essential for better patient satisfaction and for improving short-term visual outcome postoperatively. This article reviews the latest studies published on LASIK-associated dry eye, including epidemiology, pathophysiology, risk factors, preoperative assessment, and management. PMID:29619255

Lamina Cribrosa Changes after Laser In Situ Keratomileusis in Myopic Eyes.

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Lee, Soomin; Choi, Da Ye Diana; Lim, Dong Hui; Chung, Tae Young; Han, Jong Chul; Kee, Changwon

2018-04-01

To determine deep optic nerve head structure changes after transient intraocular pressure elevation during laser in situ keratomileusis (LASIK) for myopia. Enhanced depth imaging-optical coherence tomography was performed in each myopic eye that underwent LASIK surgery. Enhanced depth imaging-optical coherence tomography images were created at postoperative 1 day, 1 week, 2 weeks, and 1 month. Lamina cribrosa (LC) thickness, LC depth and prelaminar thickness at the superior, middle and inferior portions of the optic nerve head were measured by two investigators. Forty eyes in 40 patients were included in the present study. During follow-up, there were no significant differences in prelaminar thickness or LC depth. The LC demonstrated increased thickness at postoperative 1 day at all three locations (superior, middle, and inferior) (p LASIK surgery. However, the thickness will gradually return to baseline morphology. Temporary intraocular pressure increase during LASIK does not appear to induce irreversible LC thickness changes. © 2018 The Korean Ophthalmological Society.

Small incision lenticule extraction (SMILE) versus laser in-situ keratomileusis (LASIK): study protocol for a randomized, non-inferiority trial.

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Ang, Marcus; Tan, Donald; Mehta, Jodhbir S

2012-05-31

Small incision lenticule extraction or SMILE is a novel form of 'flapless' corneal refractive surgery that was adapted from refractive lenticule extraction (ReLEx). SMILE uses only one femtosecond laser to complete the refractive surgery, potentially reducing surgical time, side effects, and cost. If successful, SMILE could potentially replace the current, widely practiced laser in-situ keratomileusis or LASIK. The aim of this study is to evaluate whether SMILE is non-inferior to LASIK in terms of refractive outcomes at 3 months post-operatively. Single tertiary center, parallel group, single-masked, paired-eye design, non-inferiority, randomized controlled trial. Participants who are eligible for LASIK will be enrolled for study after informed consent. Each participant will be randomized to receive SMILE and LASIK in each eye. Our primary hypothesis (stated as null) in this non-inferiority trial would be that SMILE differs from LASIK in adults (>21 years old) with myopia (> -3.00 diopter (D)) at a tertiary eye center in terms of refractive predictability at 3 months post-operatively. Our secondary hypothesis (stated as null) in this non-inferiority trial would be that SMILE differs from LASIK in adults (>21 years old) with myopia (> -3.00 D) at a tertiary eye center in terms of other refractive outcomes (efficacy, safety, higher-order aberrations) at 3 months post-operatively. Our primary outcome is refractive predictability, which is one of several standard refractive outcomes, defined as the proportion of eyes achieving a postoperative spherical equivalent (SE) within ±0.50 D of the intended target. Randomization will be performed using random allocation sequence generated by a computer with no blocks or restrictions, and implemented by concealing the number-coded surgery within sealed envelopes until just before the procedure. In this single-masked trial, subjects and their caregivers will be masked to the assigned treatment in each eye. This novel

Keratectasia following laser in situ keratomileusis in a low-risk patient with benign joint hypermobility syndrome

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Gustavo Galperin

2014-04-01

Full Text Available Here we present the case of a 27-year-old woman with benign joint hypermobility (BJHS syndrome who developed keratectasia after laser in situ keratomileusis (LASIK in both eyes. Both eyes had identical low Randleman risk factor scores. To our knowledge, this is the first report of such a complication in a patient with BJHS. It highlights our incomplete knowledge of the risk factors for keratectasia following LASIK and suggests that BJHS should be considered as a risk factor for keratectasia.

Láser in situ keratomileusis en la corrección de miopía y astigmatismo residual posqueratotomía radial en casos seleccionados Laser in situ keratomileusis to correct myopia and residual astigmatism after radial keratotomy in selected cases

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Eneida Pérez Candelaria

2010-01-01

Full Text Available OBJETIVO: Evaluar la seguridad y la eficacia del tratamiento con láser in situ keratomileusis en pacientes con defectos residuales posqueratotomía radial. MÉTODOS: Se realizó un estudio descriptivo de tipo prospectivo longitudinal a 55 ojos de 31 pacientes con miopía y/o astigmatismo residuales posqueratotomía radial reoperados con láser in situ keratomileusis en el Servicio de Cirugía Refractiva del Instituto Cubano de Oftalmología "Ramón Pando Ferrer" desde enero a junio del 2007. En la selección de los pacientes, se utilizaron estrictos criterios de inclusión y exclusión utilizándose las variables: error refractivo residual en equivalente esférico medio, la agudeza visual sin corrección y la mejor agudeza visual corregida preLASIK y posLASIK, así como las complicaciones transoperatorias y postoperatorias. El seguimiento promedio de los pacientes fue de 12 ± 3 meses. RESULTADOS: El equivalente esférico posLASIK disminuyó notablemente en el primer día del posoperatorio y se mantuvo estable en la última consulta. La agudeza visual sin corrección posLASIK fue 1,0 (20/20 en 22 ojos (40 % y > 0,5 (20/40 en 44 ojos (80 %. En 11 ojos (20 %, la mejor agudeza visual corregida mejoró 1 línea en la cartilla de Snellen. Se presentócomo complicación intraoperatoria un ojo con perforación central del flap corneal y dentro de las complicaciones postoperatorias se reportaron detritus y restos hemáticos en la interfase en 2 ojos, pliegues finos del colgajo en un solo ojo y epitelización de la interfase fuera del eje visual igualmente, en un solo ojo. CONCLUSIONES: El Láser in situ keratomileusis puede ser usado exitosamente en la corrección de la miopía y el astigmatismo posqueratotomía radial en casos debidamente seleccionados.OBJECTIVE: To evaluate the safety and the efficacy of the Laser in Situ Keratomileusis treatment in patients with residual defects after radial keratotomy. METHODS: A prospective, longitudinal and

Nerve growth factor concentration and implications in photorefractive keratectomy vs laser in situ keratomileusis.

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Lee, Hyung Keun; Lee, Kyung Sub; Kim, Hyeon Chang; Lee, Sung Ho; Kim, Eung Kweon

2005-06-01

To determine whether tear nerve growth factor (NGF) concentration correlates with corneal sensation and ocular surface dryness after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). Prospective, nonrandomized comparative clinical trial. Seventy eyes of 35 patients and 76 eyes of 38 patients underwent PRK and LASIK procedures to correct myopia and myopic astigmatism, respectively. Total tear protein level, tear NGF concentration, tear film breakup time (BUT) and Schirmer values were measured before and 1 day, 1 week, 1 month, 3 months, and 6 months after surgery. The postoperative mean tear NGF/total tear protein (NGF/tP) ratio increased in both PRK and LASIK patients compared with preoperative levels (P PRK than in LASIK subjects (P LASIK in the ablated zone was lower than the preoperative sensation (P PRK subjects. Mean BUT and Schirmer values were significantly lower in LASIK-treated eyes compared with PRK-treated eyes up to 6 months postoperatively (P PRK-treated and LASIK-treated eyes might be related to the difference in the early postoperative levels of NGF, which is a potent nerve growth stimulator.

Corneal ectasia after myopic laser in situ keratomileusis: a long-term study

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Spadea L

2012-11-01

Full Text Available Leopoldo Spadea,1 Emilia Cantera,2 Magdalena Cortes,2 Nicole Evangelista Conocchia,1 Charles WM Stewart11University of L’Aquila, Department of Biotechnological and Applied Clinical Sciences, Eye Clinic, L’Aquila, 2Villa Stuart Clinic, Department of Ophthalmic Sciences, Rome, ItalyBackground: The purpose of this study was to evaluate the long-term postoperative incidence of and key factors in the genesis of corneal ectasia after myopic laser-assisted in situ keratomileusis (LASIK in a large number of cases.Methods: A retrospective review of one surgeon's myopic LASIK database was performed. Patients were stratified into two groups based on date of surgery, ie, group 1 (1313 eyes from 1999 to 2001 and group 2 (2714 eyes from 2001 to 2003. Visual acuity, refraction, pachymetry, and corneal topography data were available for each patient from examinations performed both before and after the refractive procedures.Results: Of the 4027 surgically treated eyes, 23 (0.57% developed keratectasia during the follow-up period, which was a minimum seven years; nine eyes (0.69% were from group 1 and 14 eyes (0.51% were from group 2. The onset of corneal ectasia was at 2.57 ± 1.04 (range 1–4 years and 2.64 ± 1.29 (range 0.5–5 years, respectively, for groups 1 and 2. The most important preoperative risk factors using the Randleman Ectasia Risk Score System were manifest refractive spherical error in group 1 and a thin residual stromal bed in group 2. Each of the cases that developed corneal ectasia had risk factors that were identified.Conclusion: Ectasia was an uncommon outcome after an otherwise uncomplicated laser in situ keratomileusis procedure. The variables present in eyes developing postoperative LASIK ectasia can be better understood using the Randleman Ectasia Risk Score System.Keywords: corneal topography, Ectasia Risk Score System, keratectasia, myopia, LASIK

Bilateral Iris Atrophy after the Femtosecond Assisted Laser In Situ Keratomileusis Surgery

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Kenan Olcay

2015-01-01

Full Text Available Purpose. To report an unknown complication of laser in situ keratomileusis (LASIK surgery. Case Presentation. A 28-year-old female presented with photophobia and glare to our eye service. She stated in her medical history that she had undergone femtosecond assisted LASIK surgery in both eyes 15 months ago and her symptoms started just after this surgery. On admission, her best-corrected visual acuity was 10/10 in both eyes. She had mydriatic pupils with no direct light reflex. Examination of the anterior segment revealed bilateral iris atrophy projecting within the LASIK ablation zone and a transillumination defect was remarkable on the slit lamp examination. Conclusion. We hypothesized that this condition may have been caused by the abnormally increased IOP that resulted in ischemia in the iris vascular plexus during the suction process of surgery.

Effects of laser in situ keratomileusis on mental health-related quality of life

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Tounaka-Fujii K

2016-09-01

Full Text Available Kaoru Tounaka-Fujii,1 Kenya Yuki,2 Kazuno Negishi,2 Ikuko Toda,3 Takayuki Abe,4 Keisuke Kouyama,4 Kazuo Tsubota2 1Health Center, Keio University, 2Department of Ophthalmology, Keio University School of Medicine, 3Minamiaoyama Eye Clinic, 4Center for Clinical Research, Keio University School of Medicine, Tokyo, Japan Purpose: The aims of our study were to investigate whether laser in situ keratomileusis (LASIK improves health-related quality of life (HRQoL and to identify factors that affect postoperative HRQoL. Materials and methods: A total of 213 Japanese patients who underwent primary LASIK were analyzed in this study. The average age of patients was 35.0±9.4 years. The subjects were asked to answer questions regarding subjective quality of vision, satisfaction, and quality of life (using the Japanese version of 36-Item Short Form Health Survey Version 2 at three time points: before LASIK, 1 month after LASIK, and 6 months after LASIK. Longitudinal changes over 6 months in the outputs of mental component summary (MCS score and the physical component summary (PCS score from the 36-Item Short Form Health Survey Version 2 questionnaire were compared between time points using a linear mixed-effects model. Delta MCS and PCS were calculated by subtracting the postoperative score (1 month after LASIK from the preoperative score. Preoperative and postoperative factors associated with a change in the MCS score or PCS score were evaluated via a linear regression model. Results: The preoperative MCS score was 51.0±9.4 and increased to 52.0±9.8 and 51.5±9.6 at 1 month and 6 months after LASIK, respectively, and the trend for the change from baseline in MCS through 6 months was significant (P=0.03. PCS score did not change following LASIK. Delta MCS was significantly negatively associated with preoperative spherical equivalent, axial length, and postoperative quality of vision, after adjusting for potential confounding factors. Conclusion

Laser in situ keratomileusis in patients with collagen vascular disease: a review of the literature

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Simpson RG

2012-11-01

Full Text Available Rachel G Simpson,1 Majid Moshirfar,2 Jason N Edmonds,2 Steven M Christiansen,2 Nicholas Behunin21The University of Arizona College of Medicine, Phoenix, AZ, USA; 2John A Moran Eye Center, The University of Utah School of Medicine, Salt Lake City, UT, USAPurpose: To evaluate the current United States Food and Drug Administration (FDA recommendations regarding laser in situ keratomileusis (LASIK surgery in patients with collagen vascular diseases (CVD and assess whether these patients make appropriate candidates for laser vision correction, and offer treatment recommendations based on identified clinical data.Methods: A literature search was conducted using PubMed, Medline, and Ovid to identify all existing studies of LASIK in patients with collagen vascular diseases. The search was conducted without date limitations. Keywords used for the search included MeSH terms: laser in situ keratomileusis, LASIK, refractive surgery, ocular surgery, and cataract surgery connected by "and" with the following MeSH and natural-language terms: collagen vascular disease, rheumatic disease, systemic disease, rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome, seronegative spondyloarthropathy, HLA B27, ankylosing spondylitis, reactive arthritis, psoriatic arthritis. The abstracts for all studies meeting initial search criteria were reviewed; relevant studies were included. No prospective studies were found; however, four retrospective case studies were identified that examined LASIK surgery in patients with CVD. Several case reports were also identified in similar fashion.Results: The FDA considers CVD a relative contraindication to LASIK surgery, due largely to the ocular complications associated with disease in the CVD spectrum. However, recent studies of LASIK in patients with CVD indicate LASIK may be safe for patients with very well-controlled systemic disease, minimal ocular manifestations, and no clinical signs or history of dry

INTACS before or after laser in situ keratomileusis: correction of thin corneas with moderately high myopia.

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Ito, Mitsutoshi; Arai, Hiroyuki; Fukumoto, Teruki; Toda, Ikuko; Tsubota, Kazuo

2004-01-01

Intrastromal corneal ring segments (INTACS Micro-Thin Prescription Inserts by Addition Technologies, Fremont, Calif) were inserted as a combined surgery with laser in situ keratomileusis (LASIK) in six eyes with thin corneas to correct moderately high myopia. INTACS were implanted before LASIK (INTACS-LASIK) in three eyes and after LASIK (LASIK-INTACS) in three eyes. Mean preoperative manifest spherical equivalent refraction was -7.88 diopters. Mean follow-up was 306 days. No intraoperative complications occurred. The LASIK-INTACS eyes were slightly more overcorrected than the INTACS-LASIK eyes because of the enhanced performance of INTACS in the thinned corneal tissue. Induced astigmatism by INTACS per se was less in the LASIK-INTACS eyes than in the INTACS-LASIK eyes. At last examination, uncorrected visual acuity was better than 20/25 in all eyes. Best spectacle-corrected visual acuity was within 1 line of the preoperative value in all eyes. Both methods resulted in significant improvement in visual acuity and refraction. Based on our limited experience, however, LASIK followed by INTACS is preferred for reasons of safety, convenience, and lower induced cylinder.

Evaluation of Biomechanical Changes in Myopia Patients with Unsatisfactory Corneas After Femto Second-Laser In Situ Keratomileusis (FS-LASIK) Concurrent with Accelerated Corneal Collagen Cross-Linking Using Corvis-ST: Two-Year Follow-Up Results.

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Xu, Weiwei; Tao, Ye; Wang, Liqiang; Huang, Yifei

2017-07-27

BACKGROUND Some myopia patients with unsatisfactory corneas consider corneal refractive surgery for different reasons. Accelerated corneal collagen crosslinking (ACXL) is an effective method to enhance the resistance of the cornea. The present investigation was designed to evaluate the changes of biomechanical properties in patients with myopia and thin corneas after femtosecond-laser in situ keratomileusis (FS-LASIK) concurrent with ACXL. MATERIAL AND METHODS A prospective study was designed. A total of 22 eyes of 11 myopia astigmatism patients with unsatisfactory corneas were enrolled. The patients were assigned to femtosecond-laser in situ keratomileusis concurrent with accelerated corneal collagen crosslinking (FS-LASIK-ACXL). The follow-up duration was 24 months. Manifest refraction, uncorrected (UDVA), and corrected distance visual acuity (CDVA), ultra-high-speed camera (Corvis-ST), corneal topography, anterior segment OCT (AS-OCT), Pentacam, and endothelial cell density (ECD) were examined before and after the operation. The corneal biomechanical and refractive data was analyzed using SAS9.3. Data were analyzed through normal distribution test and variance of analysis. The difference was considered as statistically significant when pLASIK-ACXL operation. The values of first applanation length (A1L), the second applanation length (A2L), the first applanation velocity (A1V), the second applanation velocity (A2V), deformation amplitude (DA), highest concavity peak distance (PD), and radius of curvature at the time of highest concavity (HCR) did not show significant difference after the operation. CONCLUSIONS FS-LASIK-ACXL is an effective and safe surgery for improving visual acuity for myopic patients with thin corneas, and it does not increase the risk of iatrogenic keratectasia.

Superficial corneal crosslinking during laser in situ keratomileusis.

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Seiler, Theo G; Fischinger, Isaak; Koller, Tobias; Derhartunian, Viktor; Seiler, Theo

2015-10-01

To determine the safety of superficial corneal crosslinking after laser in situ keratomileusis (LASIK). Institut für Refraktive und Ophthalmo-Chirurgie, Zurich, Switzerland. Prospective study. Eyes with an ectasia risk score of 2 or higher were treated with standard LASIK (90 μm flap) for myopia correction, after which a rapid corneal crosslinking was performed in the interface (riboflavin 0.5% for 2 minutes, 9 mW/cm(2) for 5 minutes) (Group 1). The follow-up was up to 1 year. The prevalence of complications was statistically compared with that in a group of eyes matched regarding age, sex, and attempted refractive correction that were treated with standard LASIK only (Group 2). One month postoperatively, 5 eyes in Group 1 lost 1 line of corrected distance visual acuity (CDVA) compared with 1 eye in Group 2 (P rate of less than 5%. The refractive success was identical in both groups. Early postoperative complications such as erosions (16%), diffuse lamellar keratitis (DLK) stage 1 (38%), and DLK stage 2 (5%) were statistically significantly more frequent after superficial corneal crosslinking, leading to a statistically significantly reduced uncorrected distance visual acuity at 1 month (P interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Wavefront-guided laser in situ keratomileusis (Lasik) versus wavefront-guided photorefractive keratectomy (Prk): a prospective randomized eye-to-eye comparison (an American Ophthalmological Society thesis).

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Manche, Edward E; Haw, Weldon W

2011-12-01

To compare the safety and efficacy of wavefront-guided laser in situ keratomileusis (LASIK) vs photorefractive keratectomy (PRK) in a prospective randomized clinical trial. A cohort of 68 eyes of 34 patients with -0.75 to -8.13 diopters (D) of myopia (spherical equivalent) were randomized to receive either wavefront-guided PRK or LASIK in the fellow eye using the VISX CustomVue laser. Patients were evaluated at 1 day, 1 week, and months 1, 3, 6, and 12. At 1 month, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), 5% and 25% contrast sensitivity, induction of higher-order aberrations (HOAs), and subjective symptoms of vision clarity, vision fluctuation, ghosting, and overall self-assessment of vision were worse (PPRK group. By 3 months, these differences had resolved (P>0.05). At 1 year, mean spherical equivalent was reduced 94% to -0.27 ± 0.31 D in the LASIK group and reduced 96% to -0.17 ± 0.41 D in the PRK group. At 1 year, 91% of eyes were within ±0.50 D and 97 % were within ±1.0 D in the PRK group. At 1 year, 88% of eyes were within ±0.50 D and 97% were within ±1.0 D in the LASIK group. At 1 year, 97% of eyes in the PRK group and 94% of eyes in the LASIK group achieved an UCVA of 20/20 or better (P=0.72). Refractive stability was achieved in both PRK and LASIK groups after 1 month. There were no intraoperative or postoperative flap complications in the LASIK group. There were no instances of corneal haze in the PRK group. Wavefront-guided LASIK and PRK are safe and effective at reducing myopia. At 1 month postoperatively, LASIK demonstrates an advantage over PRK in UCVA, BSCVA, low-contrast acuity, induction of total HOAs, and several subjective symptoms. At postoperative month 3, these differences between PRK and LASIK results had resolved.

Post-LASIK dry eye

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Shtein, Roni M

2011-01-01

Laser-assisted in situ keratomileusis (LASIK) is a frequently performed corneal refractive surgery with excellent refractive outcomes. The most common complication of LASIK is dry eyes, with virtually all patients developing some degree of dryness in the immediate postoperative period. Identifying preoperative dry eyes, and conscientious attention and treatment in the perioperative time period, can lead to enhanced patient satisfaction and more accurate visual outcomes. Improved understanding...

Outcomes of laser in situ keratomileusis and photorefractive keratectomy in patients taking isotretinoin.

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Ortega-Usobiaga, Julio; Llovet-Osuna, Fernando; Djodeyre, Mohammad Reza; Bilbao-Calabuig, Rafael; González-López, Félix; Llovet-Rausell, Andrea; Druchkiv, Vasyl

2018-05-14

To determine the functional outcomes of laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) in patients taking isotretinoin, which is contraindicated for these procedures. Multicentre, retrospective, interventional case series METHODS: All patients taking isotretinoin who underwent LASIK or PRK from January 2003 to September 2017 were included (group 1). Patients were compared with those undergoing LASIK or PRK who had taken isotretinoin previously but not in the previous 6 months (group 2). Patients were included consecutively. A total of 113 patients (219 eyes) were included. No significant intraoperative or postoperative complications were found. There were no significant differences between the groups in terms of visual acuity, postoperative spherical equivalent, efficacy index, predictability, or safety index. When only PRK patients were taken into account, the efficacy index (p: 0.017), postoperative sphere (p: 0.041), and postoperative astigmatism (pLASIK and PRK can be performed effectively and safely in selected patients taking isotretinoin. The absolute exclusion of certain systemic medications should be reconsidered. Copyright © 2018 Elsevier Inc. All rights reserved.

Post-LASIK dry eye

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Shtein, Roni M

2011-01-01

Laser-assisted in situ keratomileusis (LASIK) is a frequently performed corneal refractive surgery with excellent refractive outcomes. The most common complication of LASIK is dry eyes, with virtually all patients developing some degree of dryness in the immediate postoperative period. Identifying preoperative dry eyes, and conscientious attention and treatment in the perioperative time period, can lead to enhanced patient satisfaction and more accurate visual outcomes. Improved understanding of the development of dry eyes after LASIK will advance our understanding of the complex pathophysiology of dry eye disease. PMID:22174730

[Two cases of retinal detachment following laser in Situ keratomileusis repaired by scleral buckling surgery].

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Onguchi, Tatsuya; Eshita, Tadahiko; Mita, Shinji; Ishida, Susumu; Shinoda, Kei; Kitamura, Shizuaki; Kawashima, Shinichi; Inoue, Makoto; Oguchi, Yoshihisa; Toda, Ikuko; Kato, Naoko

2002-02-01

As laser in situ keratomileusis (LASIK) becomes the treatment of choice in the field of refractive surgery, postoperative rhegmatogenous retinal detachment has also begun to occur. However, since it has not been reported yet here in Japan, we report two cases of retinal detachment following LASIK with suggestions based on our experience. A 34-year-old male(Case 1) and a 26-year-old male(Case 2) suffered from retinal detachment one month and eight months after LASIK, respectively. Contributing retinal breaks were a horseshoe tear in Case 1 and atrophic holes in the lattice degeneration in Case 2. Each patient underwent partial scleral buckling with no intraoperative complication, resulting in successful retinal reattachment. Postoperatively, myopic changes developed and persisted one month in Case 1 and several months in Case 2. Great attention should be paid to the possibility of postoperative myopia after a repair of retinal detachment following LASIK. Thus, we stress the necessity of close cooperation between LASIK surgeons and vitreoretinal surgeons to settle the matter.

Wavefront-guided versus wavefront-optimized laser in situ keratomileusis: contralateral comparative study.

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Padmanabhan, Prema; Mrochen, Michael; Basuthkar, Subam; Viswanathan, Deepa; Joseph, Roy

2008-03-01

To compare the outcomes of wavefront-guided and wavefront-optimized treatment in fellow eyes of patients having laser in situ keratomileusis (LASIK) for myopia. Medical and Vision Research Foundation, Tamil Nadu, India. This prospective comparative study comprised 27 patients who had wavefront-guided LASIK in 1 eye and wavefront-optimized LASIK in the fellow eye. The Hansatome (Bausch & Lomb) was used to create a superior-hinged flap and the Allegretto laser (WaveLight Laser Technologie AG), for photoablation. The Allegretto wave analyzer was used to measure ocular wavefront aberrations and the Functional Acuity Contrast Test chart, to measure contrast sensitivity before and 1 month after LASIK. The refractive and visual outcomes and the changes in aberrations and contrast sensitivity were compared between the 2 treatment modalities. One month postoperatively, 92% of eyes in the wavefront-guided group and 85% in the wavefront-optimized group had uncorrected visual acuity of 20/20 or better; 93% and 89%, respectively, had a postoperative spherical equivalent refraction of +/-0.50 diopter. The differences between groups were not statistically significant. Wavefront-guided LASIK induced less change in 18 of 22 higher-order Zernike terms than wavefront-optimized LASIK, with the change in positive spherical aberration the only statistically significant one (P= .01). Contrast sensitivity improved at the low and middle spatial frequencies (not statistically significant) and worsened significantly at high spatial frequencies after wavefront-guided LASIK; there was a statistically significant worsening at all spatial frequencies after wavefront-optimized LASIK. Although both wavefront-guided and wavefront-optimized LASIK gave excellent refractive correction results, the former induced less higher-order aberrations and was associated with better contrast sensitivity.

Retinal peripheral changes after LASIK

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Nassaralla Junior,João Jorge; Santos,Regina Cândido Ribeiro dos; Nassaralla,Belquiz Amaral

2008-01-01

PURPOSE: To better define the effect of laser in situ keratomileusis (LASIK) on myopic eyes and the risk and incidence of retinal complications after surgery. METHODS: In a prospective study, 200 eyes of 100 patients, 49 male and 51 female, with a mean age of 29.7 years, had a complete posterior pole examination before and at 1 week, 1, 3 and 12 months after bilateral simultaneous LASIK for the correction of myopia. Mean spherical equivalent was 7.75D (range 1.00 to -17.25D). Before LASIK, pr...

Contralateral eye comparison on changes in visual field following laser in situ keratomileusis vs photorefractive keratectomy for myopia: a randomized clinical trial.

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Mostafaei, A; Sedgipour, M R; Sadeghi-Bazargani, H

2009-12-01

Study purpose was to compare the changes of Visual Field (VF) during laser in situ Keratomileusis (LASIK) VS photorefractive keratectomy (PRK). This randomized, double blind, study involved 54 eyes of 27 Myopia patients who underwent LASIK or PRK procedures for contralateral eyes in each patient. Using Humphrey 30-2 SITA standard, the Mean Defect (MD) and Pattern Standard Deviation (PSD) were evaluated preoperatively and three months after surgery. At the same examination optical zone size, papillary and corneal diameters were also evaluated. There was no clinically significant difference in PSD and MD measurements between treated eyes with LASIK or PRK in any zone pre and postoperatively. VF may not be affected by corneal changes induced by LASIK or PRK three months after surgery.

Corneal Densitometry as a Tool to Measure Epithelial Ingrowth After Laser In Situ Keratomileusis.

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Adran, Daniel; Vaillancourt, Louis; Harissi-Dagher, Mona; Kruh, Jonathan N; Syed, Zeba A; Robinson, Steven; Melki, Samir

2017-04-01

This study evaluates the correlation between corneal densitometry and epithelial ingrowth (EI) after laser in situ keratomileusis (LASIK). Corneal densitometry of 3 patients who developed EI after LASIK was measured with the Oculus Pentacam. Corneal densitometry readings of each patient were obtained preoperatively and postoperatively after ingrowth was discovered. Densitometry was recorded at the central nest of opacity and at the leading edges of EI. For all patients, the most severe stages of EI observed on slit-lamp photographs correlated with the highest densitometry readings, with peak densitometry ranging from 73.3 to 95.1. These values were much higher than preoperative densitometry readings, which ranged from 21.8 to 27.2. In 2 cases, the Pentacam densitometry map revealed progression of EI toward the visual axis that was only faintly detectable or not detectable at all on the corresponding slit-lamp photographs. Corneal densitometry seems to be an objective measure of the severity and progression of EI after LASIK.

Evaluation of the effectiveness of laser in situ keratomileusis and photorefractive keratectomy for myopia : A meta-analysis

OpenAIRE

Yang, Xin-Jun; Yan, Hong-Tao; Nakahori, Yutaka

2003-01-01

Objective: To evaluate the effectiveness of laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) for correcting myopia. Methods : Study selection, data extraction, and quality assessment were performed by two of authors independently. Summary odds ratios and 95% confidence intervals were calculated by DerSimonian amp Laird random-effects model and Mantel-Haenszel (fixed-effects) model. All calculations were based on an intention-to-treat and per protocol analysis. Result...

Antiglaucoma drugs for achieving monovision after laser in situ keratomileusis

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Kazutaka Kamiya

2009-02-01

Full Text Available Kazutaka Kamiya, Kimiya ShimizuDepartment of Ophthalmology, University of Kitasato School of Medicine, JapanAbstract: We report on a patient in whom the use of antiglaucoma drugs has been beneficial for the attainment of monovision after laser in situ keratomileusis (LASIK. A 57-year-old woman undergoing LASIK complained of blurred vision in the right eye. After a successful trial of monovision with contact lenses, antiglaucoma drugs (2.5% nipradilol were administered topically to the right eye twice a day to establish monovision. In the right eye, the manifest refraction was changed from −4.0, −1.0 × 80, with an uncorrected visual acuity (UCVA of 0.3 for near vision before treatment, to −2.5, −1.0 × 80, with an UCVA of 0.9 for near vision after treatment, while, in the left eye, it was 0, −1.0 × 100, with an UCVA of 0.9 for far vision. Binocular UCVA was improved from 0.3 for near and 0.9 for distance vision before treatment, to 0.9 for near and 1.0 for distance vision after treatment. No complications were observed and the manifest refraction remained stable during the 6-month follow-up period. The use of antiglaucoma drugs may be helpful for the achievement of monovision by reduction of myopic regression after LASIK.Keywords: antiglaucoma drugs, regression, monovision, LASIK

Resultados refractivos en pacientes operados por LASIK versus LASEK con mitomicina C Refractive results in patients operated by LASIK versus LASEK with Mitomycin C

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Abel Cabrera Martínez

2009-06-01

Full Text Available OBJETIVO: Evaluar comparativamente los resultados refractivos obtenidos en ojos operados con el uso de la keratomileusis in situ asistida con láser (LASIK contra la keratomileusis subepitelial asistida con láser combinándosele a esta última el uso de la mitomicina C (LASEK+MC. MÉTODOS: Se realizó un estudio prospectivo, experimental, comparativo en un total de 210 ojos de pacientes que acudieron a consulta para ser operados por algún defecto refractivo. Un total de 104 ojos fueron intervenidos por LASIK y 106 por LASEK+MC. Para comparar los resultados del estudio se realizaron varios exámenes antes y después de operados los pacientes. RESULTADOS: Los defectos refractivos fueron superiores con significación estadística (pOBJECTIVE: Evaluating comparatively the refractive results obtained in eyes operated by keratomileusis in situ assisted with laser (LASIK versus keratomileusis subepithelial assisted with laser plus Mitomycin C (LASEK + MC. METHODS: A prospective, experimental and comparative study was performed in 210 eyes of patients who went to see the specialist to be operated from some refractive defect. A total of 104 eyes were operated by LASIK and 106 by LASEK + MC. In order to compare the results of study, several tests were made before and after surgery. RESULTS: The refractive defects were greater with statistical significance (p< 0,05, for Student's t for the eyes operated by LASEK + MC. The visual result of the LASEK with MC surgery was better than that of LASIK. Haze was a problem resolved for the LASEK when included Mitomycin C in patients with high myopia, in addition to improvement of quality of life of the patients. CONCLUSIONS: The corneal surgery with laser through the LASEK technique plus use of Mitomycin C demonstrated being as reliable as that with LASIK for ametropy correction, since it provides additional advantages that increases the quality of life of patient, with less postoperative risks.

Nd:YAG laser for epithelial ingrowth after laser in situ keratomileusis.

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Mohammed, Osama Ali; Mounir, Amr; Hassan, Amin Aboali; Alsmman, Alahmady Hamad; Mostafa, Engy Mohamed

2018-05-04

To evaluate the efficacy of neodymium:yttrium-aluminum-garnet (Nd:YAG) laser for treatment of epithelial ingrowth after laser in situ keratomileusis (LASIK). Fifty-eight patients with epithelial ingrowth presented to Sohag refractive center, Sohag, Egypt, between January 2015 and March 2017. Only 41 patients (18 females and 23 males, mean age: 33.4 years) involving 41 eyes were indicated for treatment by Nd:YAG laser as the rest of the eyes were only under observation. Patients with epithelial ingrowth were recognized at a mean of 6 months after primary LASIK procedure (range: 2-16 months). Four eyes had undergone previous LASIK enhancements. Four eyes had the epithelial ingrowth removed by flap lift and scrapping. The mean intensity of the spots used was 0.8 mJ with variable number of shots depending on the size and density of the epithelial ingrowth area. Twenty-eight eyes showed complete regression after one session, while the rest necessitated 2-3 sessions for complete resolution. Mean follow-up period was 8 months (range 5-12 months). Epithelial ingrowth was treated successfully in all 41 eyes. The uncorrected visual acuities were 20/20, and there was no evidence of recurrent epithelial ingrowth after 6 months with no complications reported. YAG laser is a simple, effective outpatient procedure for the management of epithelial ingrowth after LASIK.

Management of the ocular surface and tear film before, during, and after laser in situ keratomileusis.

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Albietz, Julie M; Lenton, Lee M

2004-01-01

To identify evidence-based, best practice strategies for managing the ocular surface and tear film before, during, and after laser in situ keratomileusis (LASIK). After a comprehensive review of relevant published literature, evidence-based recommendations for best practice management strategies are presented. Symptoms of ocular irritation and signs of dysfunction of the integrated lacrimal gland/ocular surface functional gland unit are common before and after LASIK. The status of the ocular surface and tear film before LASIK can impact surgical outcomes in terms of potential complications during and after surgery, refractive outcome, optical quality, patient satisfaction, and the severity and duration of dry eye after LASIK. Before LASIK, the health of the ocular surface should be optimized and patients selected appropriately. Dry eye before surgery and female gender are risk factors for developing chronic dry eye after LASIK. Management of the ocular surface during LASIK can minimize ocular surface damage and the risk of adverse outcomes. Long-term management of the tear film and ocular surface after LASIK can reduce the severity and duration of dry eye symptoms and signs. Strategies to manage the integrated ocular surface/lacrimal gland functional unit before, during, and after LASIK can optimize outcomes. As problems with the ocular surface and tear film are relatively common, attention should focus on the use and improvement of evidence-based management strategies.

Laser in situ keratomileusis for residual hyperopic astigmatism after conductive keratoplasty.

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Kymionis, George D; Aslanides, Ioannis M; Khoury, Aghlab N; Markomanolakis, Marinos M; Naoumidi, Tatiana; Pallikaris, loannis G

2004-01-01

To report a case of laser in situ keratomileusis (LASIK) in a patient with previous conductive keratoplasty. A 48-year-old man underwent conductive keratoplasty for low hyperopic astigmatism (manifest refraction OD: +2.25 -0.50 x 77 degrees; OS: +2.50 -0.50 x 105 degrees). Three months postoperatively, UCVA was 20/25 and BSCVA was 20/20 in both eyes; manifest refraction OD: -0.25 -0.75 x 110 degrees; OS: +0.75 -0.75 x 50 degrees. Sixteen months after the operation, regression of refractive outcome was (manifest) OD: +1.75 -1.25 x 90 degrees; OS: +2.50 -0.50 x 85 degrees; UCVA was 20/40 in the right eye and 20/63 in the left eye and BSCVA was 20/20 in both eyes. LASIK was performed for hyperopic regression in the left eye using an automated microkeratome (Alcon SKBM, 130-microm plate; Aesculap-Meditec MEL 70 excimer laser). LASIK was uneventful and no intraoperative or postoperative complications related to the previous conductive keratoplasty procedure or LASIK were observed. Three months after LASIK and 19 months after the initial conductive keratoplasty, the patient's left eye was emmetropic; UCVA was 20/20(-2), BSCVA was 20/20 and manifest refraction was +0.25 -0.25 x 35 degrees. There was a uniform increase in topographical steepening. Visual acuity, refraction and topographic findings remained unchanged at 6 months. Even though our experience is limited, treatment of hyperopia with LASIK in an eye with refractive regression following previous conductive keratoplasty resulted in a predicted refractive outcome, with no complications, and improvement in visual acuity at 6 months follow-up.

Laser-assisted subepithelial keratectomy (LASEK) versus laser-assisted in-situ keratomileusis (LASIK) for correcting myopia.

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Kuryan, Jocelyn; Cheema, Anjum; Chuck, Roy S

2017-02-15

Near-sightedness, or myopia, is a condition in which light rays entering the eye along the visual axis focus in front of the retina, resulting in blurred vision. Myopia can be treated with spectacles, contact lenses, or refractive surgery. Options for refractive surgery include laser-assisted subepithelial keratectomy (LASEK) and laser-assisted in-situ keratomileusis (LASIK). Both procedures utilize a laser to shape the corneal tissue (front of the eye) to correct refractive error, and both create flaps before laser treatment of corneal stromal tissue. Whereas the flap in LASEK is more superficial and epithelial, in LASIK it is thicker and also includes some anterior stromal tissue. LASEK is considered a surface ablation procedure, much like its predecessor, photorefractive keratectomy (PRK). LASEK was developed as an alternative to PRK to address the issue of pain associated with epithelial debridement used for PRK. Assessing the relative benefits and risks/side effects of LASEK and LASIK warrants a systematic review. To assess the effects of LASEK versus LASIK for correcting myopia. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register (2016, Issue 10); MEDLINE Ovid (1946 to 24 October 2016); Embase.com (1947 to 24 October 2016); PubMed (1948 to 24 October 2016); LILACS (Latin American and Caribbean Health Sciences Literature Database; 1982 to 24 October 2016); the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), last searched 20 June 2014; ClinicalTrials.gov (www.clinicaltrials.gov); searched 24 October 2016; and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 24 October 2016. We did not use any date or language restrictions in the electronic searches for trials. We considered only randomized controlled trials (RCTs) for the purposes of this review. Eligible RCTs were those in which myopic participants were

Ascorbic acid levels in human tears after photorefractive keratectomy, transepithelial photorefractive keratectomy, and laser in situ keratomileusis.

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Bilgihan, A; Bilgihan, K; Toklu, Y; Konuk, O; Yis, O; Hasanreisoğlu, B

2001-04-01

To investigate the level of ascorbic acid in human tear fluid after photorefractive keratectomy (PRK), transepithelial PRK, and laser in situ keratomileusis (LASIK). Departments of Ophthalmology and Biochemistry, School of Medicine, Gazi University, Ankara, Turkey. Twenty patients (7 women and 13 men) were included in this study. Traditional PRK with epithelial scraping by a blunt spatula followed by surface ablation (7 eyes), transepithelial PRK (7 eyes), or LASIK (6 eyes) was performed. Tears were collected preoperatively and 1 and 5 days postoperatively. Ascorbic acid levels were measured using 2-4 dinitrophenylhydrazine. Ascorbic acid levels in the tear fluid were decreased significantly 1 day after PRK, transepithelial PRK, and LASIK (P <.05). On the fifth day, the ascorbic acid levels were significantly lower than preoperatively in all groups. After PRK, transepithelial PRK, and LASIK, the ascorbic acid levels of the tear fluid decreased significantly. Because ascorbic acid is the major scavenger of superoxide radicals in tears, topical ascorbic acid therapy may help eliminate the harmful effect of free radicals from excimer laser surgery.

Retinal peripheral changes after laser in situ keratomileusis in patients with high myopia.

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Suzuki, Cássia R; Farah, Michel E

2004-02-01

Retinal detachment has been reported after laser in situ keratomileusis (LASIK) in myopic eyes. This complication may be related to the risk from myopia before surgery or may be induced by LASIK surgery itself. We performed a study to evaluate retinal peripheral changes after LASIK in patients with high myopia and to correlate symptoms on presentation and vitreoretinal anatomic changes. The study was carried out at a university-affiliated hospital in São Paulo between November 1997 and February 1999. Patients scheduled to undergo LASIK were included if their spherical equivalent was greater than 6.00 dioptres. The exclusion criteria were previous retinal treatment and myopic macular degenerations. We performed binocular indirect ophthalmoscopy with scleral indentation and fundus biomicroscopy with Goldmann lens before LASIK and 1, 3 and 6 months after surgery. We examined 198 eyes preoperatively. Of the 198, 50 did not undergo LASIK surgery owing to refractive criteria, and 79 were lost to follow-up. We thus studied 69 eyes. The mean spherical equivalent preoperatively was -8.00 D (standard deviation 1.95 D). Twenty-four eyes had normal retinal periphery preoperatively; all 24 remained without alterations after LASIK. Forty-five eyes had peripheral alterations: 17 (24.6%) had cystic degeneration, 14 (20.3%) had lattice degeneration, 11 (15.9%) had white-without-pressure, 5 (7.2%) had cystic tufts, 3 (4.3%) had pavingstone degeneration, 2 (2.9%) had pigmentary alteration, 1 (1.4%) had holes with free operculum, and 1 (1.4%) had punctiform holes. The only alteration after surgery was almost punctiform holes around the previous cystic tuft 1 month after surgery in one patient. Retinal detachment did not develop in any of the eyes. In this group of patients it appears that LASIK did not lead to progressive peripheral retinal lesions in asymptomatic patients during the period studied.

Long-term safety and efficacy follow-up of prophylactic higher fluence collagen cross-linking in high myopic laser-assisted in situ keratomileusis

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Kanellopoulos AJ

2012-07-01

Full Text Available Anastasios John KanellopoulosLaservision.gr Institute, Athens, Greece, and New York University Medical School, New York, NY, USABackground: The purpose of this study was to evaluate the safety and efficacy of ultraviolet A irradiation cross-linking on completion for cases of high myopic laser-assisted in situ keratomileusis (LASIK.Methods: Forty-three consecutive LASIK cases treated with femtosecond laser flap and the WaveLight excimer platform were evaluated perioperatively for uncorrected visual acuity, best corrected spectacle visual acuity, refraction, keratometry, topography, total and flap pachymetry, corneal optical coherence tomography, and endothelial cell count. All eyes at the completion of LASIK had cross-linking through the repositioned flap, with higher fluence (10 mW/cm2 ultraviolet light of an average 370 µm wavelength and 10 mW/cm2 fluence applied for 3 minutes following an earlier single instillation of 0.1% riboflavin within the flap interface. Mean follow-up duration was 3.5 (range 1.0–4.5 years.Results: Mean uncorrected visual acuity changed from 0.2 to 1.2, best corrected spectacle visual acuity from 1.1 to 1.2, spherical equivalent from -7.5 diopters (D to -0.2 D, keratometry from 44.5 D to 38 D, flap pachymetry from 105 µm to, total pachymetry from 525 to 405, and endothelial cell count from 2750 to 2800. None of the cases developed signs of ectasia or significant regression during follow-up.Conclusion: Prophylactic collagen cross-linking for high-risk LASIK cases appears to be a safe and effective adjunctive treatment for refractive regression and potential ectasia. This application may be viewed as prophylactic customization of the biomechanical behavior of corneal collagen.Keywords: prophylactic collagen cross-linking, laser-assisted in situ keratomileusis, high-risk, post-LASIK ectasia

Retinal Nerve Fibre Layer Injury after Laser in situ Keratomileusis (LASIK)

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Saif, S.E.H.; Bahgat, M.; El emary, A.T.; Naguib, N.I; Lotfy, A.A.

2006-01-01

The number of LASIK procedures performed is growing rapidly; this growth trend is fuelled by aggressive marketing of the procedure and a public that is becoming increasingly informed and demanding of the procedure. Furthermore, the fact that LASIK is a quick relatively pain-free procedure with almost instantaneous visual improvement. 45 patients were subjected to LASIK followed by optic coherence tomography (OCT) and visual field (VF) in this study in the research institute of ophthalmology. Clinical assessment will be achieved by using visual perimetry, while anatomical of the structural changes of the RNFL will be achieved by OCT. there was a highly significant reduction in the inferior and superior quadrants. there was a highly significant reduction in myopic patients >-7 D. LASIK has a deleterious effect of 7% as a whole on RNFLT, especially on the inferior and the superior quadrants and on patients with myopia >-7 D

Retinal Nerve Fibre Layer Injury after Laser in situ Keratomileusis (LASIK)

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Saif, S E.H.; Bahgat, M [Ophthalmology Dept, Cairo (Egypt); El emary, A T [Research Institute of Ophthalmology (Egypt); Naguib, N I; Lotfy, A A [National Centre for Radiation Research and Technology (NCRRT), Atomic Energy Authority (AEA), Cairo (Egypt)

2006-05-15

The number of LASIK procedures performed is growing rapidly; this growth trend is fuelled by aggressive marketing of the procedure and a public that is becoming increasingly informed and demanding of the procedure. Furthermore, the fact that LASIK is a quick relatively pain-free procedure with almost instantaneous visual improvement. 45 patients were subjected to LASIK followed by optic coherence tomography (OCT) and visual field (VF) in this study in the research institute of ophthalmology. Clinical assessment will be achieved by using visual perimetry, while anatomical of the structural changes of the RNFL will be achieved by OCT. there was a highly significant reduction in the inferior and superior quadrants. there was a highly significant reduction in myopic patients >-7 D. LASIK has a deleterious effect of 7% as a whole on RNFLT, especially on the inferior and the superior quadrants and on patients with myopia >-7 D.

Early rhegmatogenous retinal detachment following laser in situ keratomileusis for high myopia.

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Farah, M E; Höfling-Lima, A L; Nascimento, E

2000-01-01

Four eyes had early rhegmatogenous retinal detachment within 3 months of laser in situ keratomileusis (LASIK) for correction of high myopia using the microkeratome, Clear Corneal Molder. In two eyes, retinal detachment resulted from horseshoe tears, one occurring in an otherwise normal region of the retina and the other at the margin of an area of lattice degeneration detected during preoperative examination. The first eye was treated with retinopexy using a 287 encircling scleral exoplant, drainage of subretinal fluid, and laser photocoagulation by indirect ophthalmoscopy. The other eye was treated with pneumatic retinopexy and cryotherapy. In the other eyes, retinal detachment was the result of giant tears with no evidence of prior retinal degeneration. These eyes were treated with pars plana vitrectomy, fluid-gas exchange with 15% perfluoropropane (C3F8), endolaser photocoagulation, and a 42 encircling scleral exoplant. After treatment, the first two eyes achieved spectacle-corrected visual acuity of 20/40. In the last two eyes, final spectacle-corrected visual acuity was 20/400 in one eye and light perception in the other. Although no cause-effect relationship between LASIK and retinal detachment can be stated, these cases suggest that LASIK may be associated with retinal detachment, particularly in highly myopic eyes. Further studies are necessary to determine high-risk patient characteristics.

SMILE and Wavefront-Guided LASIK Out-Compete Other Refractive Surgeries in Ameliorating the Induction of High-Order Aberrations in Anterior Corneal Surface

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2016-01-01

Purpose. To compare the change of anterior corneal higher-order aberrations (HOAs) after laser in situ keratomileusis (LASIK), wavefront-guided LASIK with iris registration (WF-LASIK), femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK), and small incision lenticule extraction (SMILE). Methods. In a prospective study, 82 eyes underwent LASIK, 119 eyes underwent WF-LASIK, 88 eyes underwent FS-LASIK, and 170 eyes underwent SMILE surgery. HOAs were measured with Pentacam device preoperatively and 6 months after surgery. The aberrations were described as Zernike polynomials, and analysis focused on total HOAs, spherical aberration (SA), horizontal coma, and vertical coma over 6 mm diameter central corneal zone. Results. Six months postoperatively, all procedures result in increase of anterior corneal total HOAs and SA. There were no significant differences in the induced HOAs between LASIK and FS-LASIK, while SMILE induced fewer total HOAs and SA compared with LASIK and FS-LASIK. Similarly, WF-LASIK also induced less total HOAs than LASIK and FS-LASIK, but only fewer SA than FS-LASIK (P LASIK, whereas SMILE induced more horizontal coma and vertical coma compared with WF-LASIK (P LASIK and LASIK induced comparable anterior corneal HOAs. Compared to LASIK and FS-LASIK, both SMILE and WF-LASIK showed advantages in inducing less total HOAs. In addition, SMILE also possesses better ability to reduce the induction of SA in comparison with LASIK and FS-LASIK. However, SMILE induced more horizontal coma and vertical coma compared with WF-LASIK, indicating that the centration of SMILE procedure is probably less precise than WF-LASIK. PMID:27818792

Clinical benefit, complication patterns and cost effectiveness of laser in situ keratomileusis (LASIK) in moderate myopia: results of independent meta analyses on clinical outcome and postoperative complication profiles.

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Lamparter, J; Dick, H B; Krummenauer, Frank

2005-09-12

Laser in situ keratomileusis (LASIK) means a patient investment of 2426 Euro per eye, which usually cannot be funded by European health care insurers. In the context of recent resource allocation discussions, however, the cost effectiveness of LASIK could become an important indication of allocation decisions. Therefore an evidence based estimation of its incremental cost effectiveness was intended. Three independent meta analyses were implemented to estimate the refractive gain (dpt) due to conventional LASIK procedures as well as the predictability of the latter (%) (fraction of eyes achieving a postoperative refraction with maximum deviation of +/- 0.5 dpt from the target refraction). Study reports of 1995 - 2004 (English or German language) were screened for appropriate key words. Meta effects in refractive gain and predictability were estimated by means and standard deviations of reported effect measures. Cost data were estimated by German DRG rates and individual clinical pathway calculations; cost effectiveness was then computed in terms of the incremental cost effectiveness ratio (ICER) for both clinical benefit endpoints. A sensitivity analysis comprised cost variations of +/- 10 % and utility variations alongside the meta effects' 95% confidence intervals. Total direct costs from the patients' perspective were estimated at 2426 Euro per eye, associated with a refractive meta benefit of 5.93 dpt (95% meta confidence interval 5.32 - 6.54 dpt) and a meta predictability of 67% (43% - 91%). In terms of incremental costs, the unilateral LASIK implied a patient investion of 409 Euro (sensitivity range 351 - 473 Euro) per gained refractive unit or 36 Euro (27 - 56 Euro) per gained percentage point in predictability. When LASIK associated complication patterns were considered, the total direct costs amounted up to 3075 Euro, resulting in incremental costs of 519 Euro / dpt (sensitivity range 445 - 600 Euro / dpt) or 46 Euro / % (34 - 72 Euro / %). Most frequently

Delayed onset Mycobacterium intracellulare keratitis after laser in situ keratomileusis: A case report and literature review.

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Ko, JaeSang; Kim, Se Kyung; Yong, Dong Eun; Kim, Tae-Im; Kim, Eung Kweon

2017-12-01

Infectious keratitis is a relatively uncommon but potentially sight-threatening complication of laser in situ keratomileusis (LASIK). Mycobacterial keratitis is usually regarded as late onset keratitis among post-LASIK keratitis. There has been no documented case of Mycobacterium intracellulare post-LASIK keratitis of a long-latent period. A 36-year-old man was referred to our out-patient clinic, for persistent corneal epithelial defect with intrastromal infiltration. He had undergone uneventful bilateral LASIK procedure 4 years before. He complained decreased vision, accompanied by ocular pain, photophobia, and redness in his left eye for 7 months. Lamellar keratectomy was taken using femtosecond laser. Bacterial culture with sequenced bacterial 16s ribosomal DNA confirmed the organism to be M intracellulare. After 3 months of administration of topical clarithromycin, amikacin, and moxifloxacin, the corneal epithelial defect was resolved and the infiltration was much improved. However, newly developed diffuse haziness with surrounding granular infiltration in the central cornea was noted. Drug toxicity was suspected and topical moxifloxacin was discontinued, resulting in resolution of the diffuse haze with infiltration. The patient was followed up regularly without medication thereafter and recurrence was not found for 7 years. This case presents the first case of M intracellulare keratitis after LASIK. LASIK surgeons should aware that post-LASIK keratitis can develop long after the operation and careful suspicion of infectious disease with meticulous diagnostic test is needed. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Diplopia after laser in situ keratomileusis (LASIK) in a patient with a history of strabismus.

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Heinmiller, Laura J; Wasserman, Barry N

2013-02-01

In patients with a history of strabismus, refractive surgery can result in decompensation of ocular alignment, with subsequent diplopia. Refractive surgery in the management of strabismus has been described, although it remains controversial. We present a young adult with past history of strabismus surgery and new-onset diplopia after refractive surgery. Binocular diplopia was treated surgically with laser in situ keratomileusis. Copyright © 2013 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

Chronic dry eye in photorefractive keratectomy and laser in situ keratomileusis: Manifestations, incidence, and predictive factors.

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Bower, Kraig S; Sia, Rose K; Ryan, Denise S; Mines, Michael J; Dartt, Darlene A

2015-12-01

To evaluate dry-eye manifestations after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) and determine the incidence and predictive factors of chronic dry eye using a set of dry-eye criteria. Walter Reed Army Medical Center, Washington, DC, USA. Prospective, non-randomized clinical study. Dry-eye evaluation was performed before and after surgery. Main outcome measures included dry-eye manifestations, incidence, and predictive factors of chronic dry eye. This study comprised 143 active-duty U.S. Army personnel, ages 29.9 ± 5.2 years, with myopia or myopic astigmatism (manifest spherical equivalent -3.83 ± 1.96 diopters) having PRK or LASIK. Schirmer scores, corneal sensitivity, ocular surface staining, surface regularity index, and responses to dry-eye questionnaire significantly changed over time after PRK. After LASIK, significant changes were observed in tear breakup time, corneal sensitivity, ocular surface staining, and responses to questionnaire. Twelve months postoperatively, 5.0% of PRK and 0.8% of LASIK participants developed chronic dry eye. Regression analysis showed that pre-operatively lower Schirmer score will significantly influence development of chronic dry eye after PRK, whereas preoperatively, lower Schirmer score or higher ocular surface staining score will significantly influence the occurrence of chronic dry eye after LASIK. Chronic dry eye was uncommon after PRK and LASIK. Ocular surface and tear-film characteristics during pre-operative examination might help to predict chronic dry-eye development in PRK and LASIK. The authors have no financial interest in any product, drug, instrument, or equipment discussed in this manuscript. Copyright © 2015 ASCRS and ESCRS. All rights reserved.

Analysis on personality traits in patients undergoing LASIK

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Yong Wang

2014-07-01

Full Text Available AIM: To analyze personality traits in preoperative patients who undergolaser in situ keratomileusis(LASIKand to provide psychological basis for the selection of refractive surgery.METHODS: Eligible patientswere seeking customized LASIK(group A n=53, conventional LASIK(group B n=75and non-operation patients with ametropia(group C n=71, who completed 16 personality factor questionnaires(16PF. Statistical analyses were performed with one-way ANOVA by SPSS11.0 software package.RESULTS: Compared to group C, patients in group A scored high on dominance and tension levels, and low on emotional stability level(PPPCONCLUSION: The data indicates that personality profiles of LASIK patients with refractive error influence their decision for correction. Patients need suitable psychological assessment before surgery who actively chose customized LASIK seem to be more assertive and suspicious.

Corneal Collagen Crosslinking Combined with Phototherapeutic Keratectomy and Photorefractive Keratectomy for Corneal Ectasia after Laser in situ Keratomileusis.

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Zhu, Wei; Han, Yunfei; Cui, Changxia; Xu, Wenwen; Wang, Xuan; Dou, Xiaoxiao; Xu, Linlin; Xu, Yanyun; Mu, Guoying

2018-01-01

The aim of this study was to analyze the effects of corneal crosslinking (CXL) combined with phototherapeutic keratectomy (PTK) and photorefractive keratectomy (PRK) in halting the progression and improving the visual function of corneal ectasia after laser in situ keratomileusis (LASIK). PTK-PRK-CXL was performed on 14 eyes of 14 patients who developed corneal ectasia after LASIK. The visual acuity, spherical refraction and cylinder, corneal topography indices, thinnest corneal thickness (TCT), and endothelial cell count were evaluated at baseline and at 1, 3, 6, and 12 months postoperatively. The mean uncorrected visual acuity improved significantly from 0.64 ± 0.36 logMAR preoperatively to 0.19 ± 0.12 logMAR at 12 months of follow-up (p 0.05) beyond 6 months after treatment. PTK-PRK-CXL is a promising procedure to halt the progression of post-LASIK keratectasia with significant visual quality improvement. © 2018 S. Karger AG, Basel.

Healthcare and a holiday: the risks of LASIK tourism.

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Lockington, David; Johnson, Richard; Patel, Dipika V; McGhee, Charles N J

2014-07-01

Medical tourism is the practice of travelling overseas for surgery. We describe a patient with low myopia who underwent laser in situ keratomileusis (LASIK) while on holiday in India. She presented to local hospital eye services six weeks post-LASIK with discomfort and reduced vision. She reported three previous LASIK flap lifts in the right eye. Clinical assessment, optical coherence tomography and confocal microscopy demonstrated moderate epithelial ingrowth and reduced visual acuity. Epithelial ingrowth after LASIK may be associated with visual impairment and management is determined by location, magnitude and effect on vision. LASIK tourism may mean patients are less well-informed of risks and lose continuity of professional care. © 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.

Effect of laser in situ keratomileusis with corneal flap created by femtosecond laser on tear film detected by Keratograph in different age groups

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Yu-Xia Zhang

2016-03-01

Full Text Available AIM:To explore the changes of tear film detected by Keratograph in the patients after laser in situ keratomileusis(LASIKwith corneal flap created by femtosecond laser. METHODS: Totally 75 myopic patients(150 eyeswere enrolled who underwent femtosecond laser LASIK from July 2014 to June 2015, including patientsRESULTS: Before surgeries, the dry eye symptoms score of three groups had no significant difference(P>0.05. After surgeries, there were significant difference at each follow-up time among the three groups on symptoms score(PPCONCLUSION: LASIK can affect the dry eye symptoms and the stability of tear film, which decreased by postoperative time. And the index recovered to preoperative levels earlier in younger patients.

Small Incision Lenticule Extraction (SMILE versus Femtosecond Laser-Assisted In Situ Keratomileusis (FS-LASIK for Myopia: A Systematic Review and Meta-Analysis.

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Zeren Shen

Full Text Available The goal of this study was to compare small incision lenticule extraction (SMILE with femtosecond laser-assisted in situ keratomileusis (FS-LASIK for treating myopia.The CENTRAL, EMBASE, PubMed databases and a Chinese database (SinoMed were searched in May of 2016. Twelve studies with 1,076 eyes, which included three randomized controlled trials (RCTs and nine cohorts, met our inclusion criteria. The overall quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE working group framework. Data were extracted and analysed at three to six months postoperatively. Primary outcome measures included a loss of one or more lines of best spectacle corrected visual acuity (BSCVA, uncorrected visual acuity (UCVA of 20/20 or better, mean logMAR UCVA, postoperative mean spherical equivalent (SE and postoperative refraction within ±1.0 D of the target refraction. Secondary outcome measures included ocular surface disease index (OSDI, tear breakup time (TBUT and Schirmer's 1 test (S1T as dry eye parameters, along with corneal sensitivity.The overall quality of evidence was considered to be low to very low. Pooled results revealed no significant differences between the two groups with regard to a loss of one or more lines in the BSCVA (OR 1.71; 95% CI: 0.81, 3.63; P = 0.16, UCVA of 20/20 or better (OR 0.71; 95% CI: 0.44, 1.15; P = 0.16, logMAR UCVA (MD 0.00; 95% CI: -0.03, 0.04; P = 0.87, postoperative refractive SE (MD -0.00; 95% CI: -0.05, 0.05; P = 0.97 or postoperative refraction within ±1.0 D of the target refraction (OR 0.78; 95% CI: 0.22, 2.77; P = 0.70 within six months postoperatively. The pooled analysis also indicated that the FS-LASIK group suffered more severely from dry eye symptoms (OSDI; MD -6.68; 95% CI: -11.76, -2.00; P = 0.006 and lower corneal sensitivity (MD 12.40; 95% CI: 10.23, 14.56; P < 0.00001 at six months postoperatively.In conclusion, both FS-LASIK and SMILE are safe

Small Incision Lenticule Extraction (SMILE) versus Femtosecond Laser-Assisted In Situ Keratomileusis (FS-LASIK) for Myopia: A Systematic Review and Meta-Analysis

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Shen, Zeren; Shi, Keda; Yu, Yinhui; Yu, Xiaoning; Lin, Yuchen; Yao, Ke

2016-01-01

Purpose The goal of this study was to compare small incision lenticule extraction (SMILE) with femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for treating myopia. Methods The CENTRAL, EMBASE, PubMed databases and a Chinese database (SinoMed) were searched in May of 2016. Twelve studies with 1,076 eyes, which included three randomized controlled trials (RCTs) and nine cohorts, met our inclusion criteria. The overall quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group framework. Data were extracted and analysed at three to six months postoperatively. Primary outcome measures included a loss of one or more lines of best spectacle corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA) of 20/20 or better, mean logMAR UCVA, postoperative mean spherical equivalent (SE) and postoperative refraction within ±1.0 D of the target refraction. Secondary outcome measures included ocular surface disease index (OSDI), tear breakup time (TBUT) and Schirmer’s 1 test (S1T) as dry eye parameters, along with corneal sensitivity. Results The overall quality of evidence was considered to be low to very low. Pooled results revealed no significant differences between the two groups with regard to a loss of one or more lines in the BSCVA (OR 1.71; 95% CI: 0.81, 3.63; P = 0.16), UCVA of 20/20 or better (OR 0.71; 95% CI: 0.44, 1.15; P = 0.16), logMAR UCVA (MD 0.00; 95% CI: -0.03, 0.04; P = 0.87), postoperative refractive SE (MD -0.00; 95% CI: -0.05, 0.05; P = 0.97) or postoperative refraction within ±1.0 D of the target refraction (OR 0.78; 95% CI: 0.22, 2.77; P = 0.70) within six months postoperatively. The pooled analysis also indicated that the FS-LASIK group suffered more severely from dry eye symptoms (OSDI; MD -6.68; 95% CI: -11.76, -2.00; P = 0.006) and lower corneal sensitivity (MD 12.40; 95% CI: 10.23, 14.56; P LASIK and SMILE are safe, effective and predictable surgical

The outcome of the first 1000 cases of LASIK performed at the king Hussein Medical Center

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Abdallat, W [King Hussein Medical Centre, Amman (Jordan). Dept. of Ophthalmology

2011-07-01

The current study evaluates the refractive and visual outcome of patients who had laser in situ keratomileusis (LASIK) performed at the refractive center at King Hussein Medical centre in Jordan. The predictability of LASIK surgery in terms of refractive and visual outcome results is very good with mild regression in refraction over time. (author).

The outcome of the first 1000 cases of LASIK performed at the king Hussein Medical Center

International Nuclear Information System (INIS)

Abdallat, W

2011-01-01

The current study evaluates the refractive and visual outcome of patients who had laser in situ keratomileusis (LASIK) performed at the refractive center at King Hussein Medical centre in Jordan. The predictability of LASIK surgery in terms of refractive and visual outcome results is very good with mild regression in refraction over time. (author).

Combined application of prophylactic corneal cross-linking and laser in-situ keratomileusis - a review of literature.

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Chan, Tommy C Y; Ng, Alex L K; Chan, Karen K W; Cheng, George P M; Wong, Ian Y H; Jhanji, Vishal

2017-11-01

Laser in-situ keratomileusis (LASIK) is safe and effective laser refractive procedures in treating refractive errors. However, regression of treatment and iatrogenic keratectasia remain to be a major concern, especially in treating thin cornea with high ametropia. Collagen cross-linking (CXL) is an effective method in stopping keratoconus progression through increasing the biomechanical strength of the cornea. Adjuvant cross-linking to refractive procedures can theoretically help prevent regression and reduce the risk of keratectasia development by increasing the mechanical stability of cornea. During the procedure, riboflavin is directly applied to the corneal stroma, thereby reducing the need of de-epithelialization as in the conventional protocol for keratoconus. Currently, there is still no consensus regarding the indication of CXL during refractive procedure, nor any standardized treatment protocol. This article aims to summarize the current evidence regarding the use of adjuvant CXL in LASIK. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Comparison of optical quality after implantable collamer lens implantation and wavefront-guided laser in situ keratomileusis.

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Liu, Hong-Ting; Zhou, Zhou; Luo, Wu-Qiang; He, Wen-Jing; Agbedia, Owhofasa; Wang, Jiang-Xia; Huang, Jian-Zhong; Gao, Xin; Kong, Min; Li, Min; Li, Li

2018-01-01

To compare the optical quality after implantation of implantable collamer lens (ICL) and wavefront-guided laser in situ keratomileusis (WG-LASIK). The study included 40 eyes of 22 patients with myopia who accepted ICL implantation and 40 eyes of 20 patients with myopia who received WG-LASIK. Before surgery and three months after surgery, the objective scattering index (OSI), the values of modulation transfer function (MTF) cutoff frequency, Strehl ratio, and the Optical Quality Analysis System (OQAS) values (OVs) were accessed. The higher order aberrations (HOAs) data including coma, trefoil, spherical, 2 nd astigmatism and tetrafoil were also obtained. For patients with pupil size LASIK group, significant improvements in visual acuities were found postoperatively, with a significant reduction in spherical equivalent ( P LASIK group, the OSI significantly increased from 0.68±0.43 preoperatively to 0.91±0.53 postoperatively (Wilcoxon signed ranks test, P =0.000). None of the mean MTF cutoff frequency, Strehl ratio, OVs showed statistically significant changes in both ICL and WG-LASIK groups. In the ICL group, there were no statistical differences in the total HOAs for either 4 mm-pupil or 6 mm-pupil. In the WG-LASIK group, the HOA parameters increased significantly at 4 mm-pupil. The total ocular HOAs, coma, spherical and 2 nd astigmatism were 0.12±0.06, 0.06±0.03, 0.00±0.03, 0.02±0.01, respectively. After the operation, these values were increased into 0.16±0.07, 0.08±0.05, -0.04±0.04, 0.03±0.01 respectively (Wilcoxon signed ranks test, all P LASIK group. ICL implantation has a less disturbance to optical quality than WG-LASIK. The OQAS is a valuable complementary measurement to the wavefront aberrometers in evaluating the optical quality.

Wavefront aberrometry and refractive outcomes of flap amputation after LASIK

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Al Saady, Rana L.; van der Meulen, Ivanka J.; Nieuwendaal, Carla P.; Engelbrecht, Leonore A.; Mourits, Maarten P.; Lapid-Gortzak, Ruth

2014-01-01

Laser in situ keratomileusis flap amputation was performed in 3 eyes of 2 patients because of flap melt and surface irregularity. In the first patient, a 34-year-old man, flaps were excised after a photorefractive keratectomy retreatment procedure on a previous LASIK flap had been done, secondary to

Late-onset traumatic dislocation of laser in situ keratomileusis corneal flaps: a case series with many clinical lessons.

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Ting, Darren Shu Jeng; Danjoux, Jean-Pierre

2018-05-12

To report three cases of late-onset (7-14 years postoperative) traumatic dislocation of laser in situ keratomileusis (LASIK) flaps with epithelial ingrowth that all had delayed surgical intervention. A retrospective, interventional case series of three patients who underwent flap repositioning and mechanical debridement of epithelial ingrowth, all after an initial delayed diagnosis/treatment of dislocated LASIK flap. Visual improvement was noted in all three cases following LASIK flap repositioning and debridement of epithelial ingrowth; patient 1 improved from 20/800 corrected-distance-visual-acuity (CDVA) to 20/20 uncorrected-distance-visual-acuity (UDVA) postoperative (14 years post-LASIK, 5-week interval between injury and surgery), patient 2 improved from 20/50 CDVA to 20/20 CDVA (10 years post-LASIK, 4-month interval between injury and surgery) and patient 3 improved from 20/80 CDVA to 20/60 CDVA (7 years post-LASIK, 14-month interval between injury and surgery). Flap dislocation was not suspected or diagnosed in two patients during the first ophthalmic visit. Postoperative visual outcome was not influenced by the presenting vision but might be negatively affected by the delay in surgical intervention, the presence of preoperative central epithelial ingrowth and postoperative striae. This case series reported one of the longest documented intervals between LASIK and traumatic dislocation of LASIK flap with secondary epithelial ingrowth. Delayed diagnosis and management of flap dislocation after corneal trauma may potentially increase the risk of epithelial ingrowth, recalcitrant flap striae and visual impairment. The presence of late-onset epithelial ingrowth in patients with previous LASIK mandates careful examination for occult flap displacement.

Alterações da retina periférica após LASIK

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Nassaralla Junior, João Jorge; Santos, Regina Cândido Ribeiro dos; Nassaralla, Belquiz Amaral

2008-01-01

PURPOSE: To better define the effect of laser in situ keratomileusis (LASIK) on myopic eyes and the risk and incidence of retinal complications after surgery. METHODS: In a prospective study, 200 eyes of 100 patients, 49 male and 51 female, with a mean age of 29.7 years, had a complete posterior pole examination before and at 1 week, 1, 3 and 12 months after bilateral simultaneous LASIK for the correction of myopia. Mean spherical equivalent was 7.75D (range 1.00 to -17.25D). Before LASIK, pr...

Analysis of corneal endothelial cell density and morphology after laser in situ keratomileusis using two types of femtosecond lasers

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Tomita M

2012-09-01

Full Text Available Minoru Tomita,1,2,* George O Waring IV,3,4 Miyuki Watabe,1,* 1Shinagawa LASIK Center, Chiyoda-ku, Tokyo, Japan; 2Department of Ophthalmology, Wenzhou Medical College, Wenzhou, China; 3Medical University of South Carolina, Storm Eye Institute, Charleston, SC, USA; 4Magill Laser Center, Charleston, SC, USA*These authors contributed equally to this studyPurpose: To compare two different femtosecond lasers used for flap creation during laser-assisted in situ keratomileusis (LASIK surgery in terms of their effects on the corneal endothelium.Methods: We performed LASIK surgery on 254 eyes of 131 patients using IntraLase FS60 (Abbott Medical Optics, Inc, Irvine, CA; IntraLase group and 254 eyes of 136 patients using Femto LDV (Ziemer Group AG, Port, Switzerland; LDV group for corneal flap creation. The mean cell density, coefficient of variation, and hexagonality of the corneal endothelial cells were determined and the results were statistically compared.Results: There were no statistically significant differences in the corneal morphology between pre and post LASIK results in each group, nor were there significant differences between the results of both groups at 3 months post LASIK.Conclusions: Both IntraLase FS60 and Ziemer Femto LDV are able to create flaps without significant adverse effects on the corneal endothelial morphology through 3 months after LASIK surgery.Keywords: LASIK, corneal endothelium, femtosecond laser, IntraLase FS60, Ziemer LDV

Ten years after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for moderate to high myopia (control-matched study).

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Alió, J L; Ortiz, D; Muftuoglu, O; Garcia, M J

2009-10-01

To compare the long-term outcomes of photorefractive keratectomy (PRK) and laser in situ keratomilesis (LASIK) for myopia between -6 and -10 D. A retrospective, control-matched study including 68 eyes, 34 which underwent PRK and 34 LASIK, with myopia between -6 and -10 D, operated using the VISX 20/20 excimer laser, was performed. Optical zones of 5.5 to 6 mm were used. All PRK-treated eyes were matched with LASIK-treated eyes of the same age, spherical equivalent within +/-1.25 D, sphere within +/-1.5 D and cylinder within +/-2.5 D. All patients were evaluated 3 months, 1 year, 2 years, 5 years and 10 years after surgery. The main outcomes measures were refractive predictability and stability, safety, efficacy and re-treatment rate. At 10 years, 20 (71%) and 23 (88%) were within +/-1.00 D after PRK and LASIK respectively. The re-treatment rate was 35% and 18% respectively. No eye lost more than two lines of BSCVA in both groups. The efficacy was 0.90 for PRK and 0.95 for LASIK. Both PRK and LASIK were safe for moderate myopia. LASIK demonstrated slightly better efficacy, predictability, and less rate of re-treatment after 10 years. The technical improvements should be taken into account when comparing these results with those obtained more recently.

Effects of Pentacam on the posterior corneal surface height changes after LASEK and LASIK operation

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Qing-Song Zhang

2014-05-01

Full Text Available AIM: To explore the application of Pentacam excimer laser epithelial keratomileusis(LASEKand excimer laser in situ keratomileusis(LASIKafter the changes of posterior corneal surface height.METHODS: Retrospective analysis of clinical data of 100 patients with myopia by using LASEK and LASIK for the treatment of the 50 patients(100 eyesin our hospital from January 2013 to June 2013, surface height changes after preoperative and postoperative 3 months were compared by measuring Pentacam corneal analysis system.RESULTS: Three months after operation, the LASEK posterior corneal surface height was 7.4±5.0mm, significantly higher than 5.6±3.4mm before operation, LASIK posterior corneal surface height was 7.5±5.1mm, significantly higher than 5.5±3.5mm before operation, the differences were statistically significant(PP>0.05.CONCLUSION: LASEK and LASIK on corneal posterior surface forward, LASIK is slightly obvious in early period.

Safety, efficacy, and predictability of laser in situ keratomileusis to correct myopia or myopic astigmatism with a 750 Hz scanning-spot laser system.

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Tomita, Minoru; Watabe, Miyuki; Yukawa, Satoshi; Nakamura, Nobuo; Nakamura, Tadayuki; Magnago, Thomas

2014-02-01

To evaluate the clinical outcomes of laser in situ keratomileusis (LASIK) to correct myopia or myopic astigmatism using the Amaris 750S 750 Hz excimer laser. Private LASIK center, Tokyo, Japan. Case series. Patients with myopia or myopic astigmatism (spherical equivalent -0.50 to -11.63 diopters [D]), a corrected distance visual acuity (CDVA) of 20/20 or better, and an estimated residual bed thickness of 300 μm or more had LASIK using the aspheric aberration-free ablation profile of the 750 Hz scanning-spot laser and the Femto LDV Crystal Line femtosecond laser for flap creation. Study parameters included uncorrected distance visual acuity (UDVA), CDVA, manifest refraction, astigmatism, and higher-order aberrations (HOAs). The study included 1280 eyes (685 patients). At 3 months, 96.6% of eyes had a UDVA of 20/20 or better and 99.1% had 20/32 or better; 94.1% of eyes were within ± 0.50 D of the intended correction and 98.9% were within ± 1.00 D; 89.7% of eyes had no residual cylinder and 96.0% had a postoperative astigmatism of less than 0.50 D. All eyes had a postoperative CDVA of 20/20 or better. The HOAs increased postoperatively (PLaser in situ keratomileusis with the 750 Hz scanning-spot laser was safe, effective, and predictable. No specific clinical side effects that might be associated with a high repetition rate occurred. Mr. Magnago is an employee of Schwind eye-tech-solutions GmbH. No other author has a financial or proprietary interest in any material or method mentioned. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

The effect of flap thickness on corneal biomechanics after myopic laser in situ keratomileusis using the M-2 microkeratome.

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Goussous, Iyad A; El-Agha, Mohamed-Sameh; Awadein, Ahmed; Hosny, Mohamed H; Ghaith, Alaa A; Khattab, Ahmed L

2017-01-01

The purpose of this study was to determine the effect of flap thickness on corneal biomechanics after myopic laser in situ keratomileusis (LASIK). This is a prospective controlled non-randomized, institutional study. Patients underwent either epi-LASIK with mitomycin (advanced surface ablation [ASA]), thin-flap LASIK (90 µm head), or thick-flap LASIK (130 µm head). In ASA, the Moria Epi-K hydroseparator was used. LASIK flaps were created using the Moria M-2 mechanical microkeratome. The corneal hysteresis (CH) and corneal resistance factor (CRF) were measured preoperatively and 3 months after surgery, using the Ocular Response Analyzer ® . Ten patients (19 eyes) underwent ASA, 11 patients (16 eyes) underwent thin-flap LASIK, and 11 patients (16 eyes) underwent thick-flap LASIK. The mean preoperative CH was 10.47±0.88, 10.52±1.4, and 11.28±1.4 mmHg ( p =0.043), respectively, decreasing after surgery by 1.75±1.02, 1.66±1.00, and 2.62±1.03 mmHg ( p =0.017). The mean reduction of CH per micron of central corneal ablation was 0.031, 0.023, and 0.049 mmHg/µm ( p =0.005). Mean preoperative CRF was 10.11±1.28, 10.34±1.87, and 10.62±1.76 mmHg ( p =0.66), decreasing after surgery by 2.33±1.35, 2.77±1.03, and 2.92±1.10 mmHg ( p =0.308). The mean reduction of CRF per micron of central corneal ablation was 0.039, 0.040, and 0.051 mmHg/µm ( p =0.112). Thick-flap LASIK caused a greater reduction of CH and CRF than thin-flap LASIK and ASA, although this was statistically significant only for CH. ASA and thin-flap LASIK were found to be biomechanically similar.

A prospective, randomized, fellow eye comparison of WaveLight® Allegretto Wave® Eye-Q versus VISX CustomVue™ STAR S4 IR™ in laser in situ keratomileusis (LASIK: analysis of visual outcomes and higher order aberrations

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Moshirfar M

2011-09-01

Full Text Available Majid Moshirfar1, Brent S Betts2, Daniel S Churgin3, Maylon Hsu1, Marcus Neuffer1, Shameema Sikder4, Dane Church5, Mark D Mifflin11John A Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, USA; 2Temple University School of Medicine, Philadelphia, PA, USA; 3University of Arizona College of Medicine – Phoenix, Phoenix, AZ, USA; 4Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA; 5Virginia Commonwealth University School of Medicine, Richmond, VA, USAPurpose: To compare outcomes in visual acuity, refractive error, higher-order aberrations (HOAs, contrast sensitivity, and dry eye in patients undergoing laser in situ keratomileusis (LASIK using wavefront (WF guided VISX CustomVue and WF optimized WaveLight Allegretto platforms.Methods: In this randomized, prospective, single-masked, fellow eye study, LASIK was performed on 44 eyes (22 patients, with one eye randomized to WaveLight Allegretto, and the fellow eye receiving VISX CustomVue. Postoperative outcome measures at 3 months included uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, refractive error, root-mean-square (RMS value of total and grouped HOAs, contrast sensitivity, and Schirmers testing.Results: Mean values for UDVA (logMAR were -0.067 ± 0.087 and -0.073 ± 0.092 in the WF optimized and WF guided groups, respectively (P = 0.909. UDVA of 20/20 or better was achieved in 91% of eyes undergoing LASIK with both lasers while UDVA of 20/15 or better was achieved in 64% of eyes using the Allegretto platform, and 59% of eyes using VISX CustomVue (P = 1.000. In the WF optimized group, total HOA increased 4% (P = 0.012, coma increased 11% (P = 0.065, and spherical aberration increased 19% (P = 0.214, while trefoil decreased 5% (P = 0.490. In the WF guided group, total HOA RMS decreased 9% (P = 0.126, coma decreased 18% (P = 0.144, spherical aberration decreased 27% (P = 0.713 and trefoil

Outcomes of presbyopia-correcting intraocular lenses after laser in situ keratomileusis.

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Chow, Sharon S W; Chan, Tommy C Y; Ng, Alex L K; Kwok, Alvin K H

2018-03-28

Laser in situ keratomileusis (LASIK) is the most common refractive surgery in young patients, which aims at providing a clear distance vision without the use of spectacles. With time, these patients develop symptomatic cataract, which affects activities of daily living, and to improve visual acuity, intraocular lens (IOL) implantation can be considered. In post-myopic LASIK patients, to allow continuation of spectacle independence, the implantation of presbyopia-correcting IOLs is a suitable option. The purpose of this retrospective case series is to report the visual outcome and quality in post-myopic LASIK eyes after the implantation of AT LISA tri839MP IOL. Twenty eyes of 13 patients with history of myopic LASIK within 20 years underwent phacoemulsification by one single surgeon. All eyes were implanted with AT LISA tri839PMP IOL, and their outcomes were evaluated at 6 months postoperation. The mean postoperative uncorrected distance visual acuity (VA) is 0.28 ± 0.29, while the corrected distance VA is 0.06 ± 0.14. The mean postoperative uncorrected near VA is 0.02 ± 0.05, while the corrected near VA is 0.01 ± 0.02. The mean postoperative manifest refraction spherical equivalent (SE) is - 0.92 ± 0.76D. There is a statistically significant difference between the preoperative and postoperative refraction (p = 0.02), which shows a postoperative myopic shift. There is also a statistically significant difference between the mean targeted SE and postoperative manifest refraction SE (p = 0.00). Only one out of 20 eyes (5%) reported halo and glare symptoms. Ten out of 20 eyes (50%) are able to achieve spectacles independence. In conclusion, in post-myopic LASIK eyes, AT LISA tri839MP provides a good visual outcome at both near and distance, but is more predictable at near than at distance. There is a myopic shift in the postoperative SE. Visual quality is satisfactory and has not been exacerbated. Most patients can remain to be

Expression of matrix metrallproteinase-2 in human tears fluid after LASIK

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Ai-Wei Chen

2014-12-01

Full Text Available AIM: To monitor long-term changes of matrix metalloproteinase-2(MMP-2in human tears fluid after laser in situ keratomileusis(LASIK. METHODS: Thirty-two myopia cases(64 eyesunderwent uneventful LASIK were enrolled in the study. Tear fluid were collected and MMP-2 expression was analyzed by Western-bolt assay preoperatively and postoperatively on 15d, at 1, 3mo, and 1a. RESULTS: LASIK increased the concentration of MMP-2 in human tear fluid. At 15d postoperatively, the magnitude of MMP-2 was 1.4 times that of preoperative, thereafter subsided, but didn't return to preoperative level by 3mo(PP>0.05. CONCLUSION: MMP-2 is significantly expressed in human tear fluid after LASIK, then subsided with time, but didn't return to preoperative level by 3mo and almost recovered up to 1a, indicating wound healing of LASIK would continue up at least 3mo after surgery and almost recovered 1a postoperatively.

Clinical outcomes of wavefront-guided laser in situ keratomileusis: 6-month follow-up.

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Aizawa, Daisuke; Shimizu, Kimiya; Komatsu, Mari; Ito, Misae; Suzuki, Masanobu; Ohno, Koji; Uozato, Hiroshi

2003-08-01

To evaluate the clinical outcomes 6 months after wavefront-guided laser in situ keratomileusis (LASIK) for myopia in Japan. Department of Ophthalmology, Sanno Hospital, Tokyo, Japan. This prospective study comprised 22 eyes of 12 patients treated with wavefront-guided LASIK who were available for evaluation at 6 months. The mean patient age was 31.2 years +/- 8.4 (SD) (range 23 to 50 years), and the mean preoperative spherical equivalent refraction was -7.30 +/- 2.72 diopters (D) (range -2.75 to -11.88 D). In all cases, preoperative wavefront analysis was performed with a Hartmann-Shack aberrometer and the Technolas 217z flying-spot excimer laser system (Bausch & Lomb) was used with 1.0 mm and 2.0 mm spot sizes and an active eye tracker with a 120 Hz tracking rate. The clinical outcomes of wavefront-guided LASIK were evaluated in terms of safety, efficacy, predictability, stability, complications, and preoperative and postoperative aberrations. At 6 months, 10 eyes had no change in best spectacle-correct visual acuity and 10 gained 1 or more lines. The safety index was 1.11 and the efficacy index, 0.82. Slight undercorrections were observed in highly myopic eyes. In all eyes, the postoperative refraction tended slightly toward myopia for 3 months and stabilized after that. No complication such as epithelial ingrowth, diffuse lamellar keratitis, or infection was observed. Comparison of the preoperative and postoperative aberrations showed that 2nd-order aberrations decreased and higher-order aberrations increased. In the 3rd order, aberrations increased in the high-myopia group (-6.0 D or worse) and decreased in the low to moderate-myopia group (better than -6.0 D). Wavefront-guided LASIK was a good option for refractive surgery, although a longer follow-up in a larger study is required.

Patient-reported outcomes 5 years after laser in situ keratomileusis.

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Schallhorn, Steven C; Venter, Jan A; Teenan, David; Hannan, Stephen J; Hettinger, Keith A; Pelouskova, Martina; Schallhorn, Julie M

2016-06-01

To assess vision-related, quality-of-life outcomes 5 years after laser in situ keratomileusis (LASIK) and determine factors predictive of patient satisfaction. Optical Express, Glasgow, Scotland. Retrospective case series. Data from patients who had attended a clinical examination 5 years after LASIK were analyzed. All treatments were performed using the Visx Star S4 IR excimer laser. Patient-reported satisfaction, the effect of eyesight on various activities, visual phenomena, and ocular discomfort were evaluated 5 years postoperatively. Multivariate regression analysis was performed to determine factors affecting patient satisfaction. The study comprised 2530 patients (4937 eyes) who had LASIK. The mean age at the time of surgery was 42.4 years ± 12.5 (SD), and the preoperative manifest spherical equivalent ranged from -11.0 diopters (D) to +4.88 D. Five years postoperatively, 79.3% of eyes were within ±0.50 D of emmetropia and 77.7% of eyes achieved monocular uncorrected distance visual acuity (UDVA) and 90.6% of eyes achieved binocular UDVA of 20/20 or better. Of the patients, 91.0% said they were satisfied with their vision and 94.9% did not wear distance correction. Less than 2.0% of patients noticed visual phenomena, even with spectacle correction. Major predictors of patient satisfaction 5 years postoperatively were postoperative binocular UDVA (37.6% variance explained by regression model), visual phenomena (relative contribution of 15.0%), preoperative and postoperative sphere and their interactions (11.6%), and eyesight-related difficulties with various activities such as night driving, outdoor activities, and reading (10.2%). Patient-reported quality-of-life and satisfaction rates remained high 5 years after LASIK. Uncorrected vision was the strongest predictor of satisfaction. Dr. S.C. Schallhorn is a consultant to Abbott Medical Optics, Inc., Zeiss Meditec AG, and Autofocus Inc. and a global medical director for Optical Express. No other

Topographically supported customized ablation for the management of decentered laser in situ keratomileusis.

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Kymionis, George D; Panagopoulou, Sophia I; Aslanides, Ioannis M; Plainis, Sotiris; Astyrakakis, Nikolaos; Pallikaris, Ioannis G

2004-05-01

To evaluate the efficacy, predictability, and safety of topographically supported customized ablations (TOSCAs) for decentered ablations following laser in situ keratomileusis (LASIK). Prospective nonrandomized clinical trial. Nine patients (11 eyes) with LASIK-induced decentered ablations underwent TOSCA following flap lifting. Topographically supported customized ablation was performed using a corneal topographer to obtain a customized ablation profile, combined with a flying spot laser. Mean follow-up was 9.22 +/- 2.82 months (range 6-12 months). No intra- or postoperative complications were observed. Manifest refraction (spherical equivalent) did not change significantly (pre-TOSCA: -0.14 +/- 1.58 diopters [range, -1.75 to +3.00 diopters] to +0.46 +/- 1.02 diopters [range, -1.00 to +1.75 diopters]; P =.76), whereas there was a statistically significant reduction in the refractive astigmatism (pre-TOSCA: -1.55 +/- 0.60 diopters [range, -3.00 to -0.75 diopters] to -0.70 +/- 0.56 diopters [range, -2.00 to -0.25 diopters]; P =.003). Mean uncorrected visual acuity improved significantly (P <.001) from 0.45 +/- 0.16 (range, 0.2-0.7) to 0.76 +/- 0.29 (range, 0.2-1.2) at last follow-up. Mean best-corrected visual acuity improved from 0.74 +/- 0.22 (range, 0.4-1.0) to 0.95 +/- 0.20 (range, 0.6-1.2; P =.002). Eccentricity showed a statistically significant reduction after TOSCA treatment (pre-TOSCA: 1.59 +/- 0.46 mm [range, 0.88-2.23 mm]; post-TOSCA: 0.29 +/- 0.09 mm [range, 0.18-0.44 mm]; P <.001). In our small sample, enhancement LASIK procedures with TOSCA appear to improve uncorrected and best-corrected visual acuity as well as eccentricity in patients with LASIK-induced decentered ablation.

Evaluation of corneal changes after myopic LASIK using the Pentacam®

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Khairat YM

2013-09-01

Full Text Available Yehia M Khairat, Yasser H Mohamed, Ismail ANO Moftah, Narden N Fouad Department of Ophthalmology, Faculty of Medicine, El-Minya University, Egypt Background: In this study, we used a Pentacam® device to evaluate the corneal changes that occur after laser-assisted in situ keratomileusis (LASIK. Methods: Our study included 60 eyes of 32 patients. All patients were treated for myopia and myopic astigmatism using LASIK. The eyes were examined preoperatively and 3 months postoperatively using a Pentacam to assess corneal changes with regard to curvature, elevation, and asphericity of the cornea. Results: A statistically significant decrease in mean keratometric power of the anterior corneal surface (P = 0.001 compared with its pre-LASIK value was detected after 3 months, but there was no significant change in keratometric power of the posterior surface (P = 0.836. Asphericity (Q-value of the anterior and posterior surfaces increased significantly after LASIK (P = 0.001. A significant forward bulge of the anterior corneal surface 4 mm and 7 mm from the central zone was detected 3 months post-LASIK (P = 0.001 for both, but there was no significant increase in posterior elevation at 4 mm and 7 mm from the center (P = 0.637 and P = 0.26, respectively. No cases of post-LASIK ectasia were detected. Correlation between different parameters of the corneal surface revealed an indirect relation between changes in pachymetry and anterior corneal elevation at 4 mm and 7 mm from the central zone (r = −0.27, P = 0.13, and r = −0.37, P = 0.04, respectively, and a direct proportion between changes in pachymetry and mean keratometric power of the anterior and posterior corneal surfaces (r = 0.7, P = 0.001 and r = 0.4, P = 0.028, respectively. Conclusion: LASIK causes significant changes at the anterior corneal surface but the effect is subtle and insignificant at the posterior surface. Keywords: LASIK, laser-assisted in situ keratomileusis, Pentacam®, corneal

A PRELIMINARY STUDY FOR SIX SIGMA IMPLEMENTATION IN LASER IN SITU KERATOMILEUSIS (LASIK SURGERIES

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Mehmet Tolga Taner

2014-01-01

Full Text Available The purpose of this study is to show how a private eye care center in Turkey developed a Six Sigma infrastructure to investigate the root causes of complications occuring during LASIK surgeries. To analyze the collected data, main tools of Six Sigma’s Define-Measure-Analyze-Improve-Control(DMAIC improvement cycle such as SIPOC table, Fishbone Diagram and, Failure, Mode and Effect Analysis were implemented. Experience of the refractive surgeons, type of microkeratome and hygiene of microkeratome were identified to be Critical-to-Quality (CTQ factors for a successful LASIK surgery. The most frequent complications of LASIK surgeries were found to be dry eye syndrome, subconjunctival haemorrhage and flap edge melt. The process sigma level was found to be 3.7135.

LASIK em pacientes adultos com alta anisometropia: relato de casos LASIK for high anisometropia in adults: case report

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Patrícia Ioschpe Gus

2006-04-01

Full Text Available OBJETIVO: Avaliar a eficácia da técnica laser in situ keratomileusis (LASIK na redução de anisometropia em adultos, para os quais os tratamentos convencionais não tiveram sucesso. MÉTODOS: Série de casos de três olhos de três pacientes adultos, dois do sexo feminino e um do sexo masculino, com idade entre 28 e 49 anos (média de 38,3 anos, os quais foram submetidos à técnica de LASIK. Dois pacientes foram acompanhados por dezoito meses e um por seis meses após a cirurgia. RESULTADOS: Comparando a acuidade visual corrigida do pré-operatório com a acuidade visual não corrigida do pós-operatório, um olho ganhou duas linhas de visão, um olho manteve-se igual e um olho perdeu uma linha de visão. Todos os olhos se mantiveram sem ametropia esférica, e o astigmatismo não excedeu -0,75 D no pós-operatório. CONCLUSÃO: A técnica LASIK mostrou-se eficaz na correção de alta anisometropia em adultos, melhorando a acuidade visual e as queixas astenopéicas, e diminuindo a anisometropia.PURPOSE: To evaluate the efficacy of the laser in situ keratomileusis (LASIK technique in the reduction of anisometropy in adults, for whom conventional treatment was not successful. METHODS: A sequence of cases of three eyes of three adult patients, two females and one male, age ranging from 28 and 49 years (average 38.3 years, who underwent LASIK. Two patients were followed up for eighteen months and one for six months. RESULTS: Comparing the corrected visual acuity before surgery with the non-corrected visual acuity after surgery, one eye gained two lines of vision, one eye remained the same and one eye lost one line of vision. All eyes remained without spheric refraction, and astigmatism did not exceed - 0.75 D after surgery. There has been an improvement in the symptoms of asthenopia in the three patients. CONCLUSION: The LASIK technique proved to be efficient in the correction of anisometropy in adults, improving visual accuity and asthenopia

Change in the accommodative convergence per unit of accommodation ratio after bilateral laser in situ keratomileusis for myopia in orthotropic patients: prospective evaluation.

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Prakash, Gaurav; Choudhary, Vandana; Sharma, Namrata; Titiyal, Jeewan S

2007-12-01

To analyze the effect of bilateral laser in situ keratomileusis (LASIK) on the accommodative convergence per unit of accommodation (AC/A) ratio in otherwise normal orthotropic myopic patients. Cornea and refractive services of a tertiary-care ophthalmic center. This prospective clinical trial consisted of 61 myopic patients who had bilateral LASIK. Those with manifest tropia, previous squint surgery, amblyopia, or absent or impaired binocularity or those in whom monovision was planned were excluded. The preoperative examination included visual acuity, cycloplegic refraction, assessment of binocularity, a prism cover test, and evaluation of the stimulus AC/A ratio by the gradient method. All patients had LASIK using the Zyoptix platform (Bausch & Lomb). Postoperative evaluation included uncorrected and best corrected visual acuities, residual refraction, and the AC/A ratio. All patients had a follow-up of 9 months. There was significant decrease in the mean AC/A ratio at the 1-week and 1-month follow-ups. The AC/A progressively recovered to near preoperative values between 3 months and 9 months after surgery (analysis of variance test). There was a significant reduction in the number of symptomatic patients from the first month onward (chi square = 89.23; Paccommodation-convergence relationship after LASIK occurs in the first 3 months.

Evaluation of the tear film stability after laser in situ keratomileusis using the tear film stability analysis system.

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Goto, Tomoko; Zheng, Xiaodong; Klyce, Stephen D; Kataoka, Hisashi; Uno, Toshihiko; Yamaguchi, Masahiko; Karon, Mike; Hirano, Sumie; Okamoto, Shigeki; Ohashi, Yuichi

2004-01-01

To evaluate the tear film stability of patients before and after laser in situ keratomileusis (LASIK) using the tear film stability analysis system (TSAS). Prospective observational case series. New videokeratography software for a topographic modeling system (TMS-2N) was developed that can automatically capture consecutive corneal surface images every second for 10 seconds. Thirty-four subjects (64 eyes) who underwent myopia LASIK were enrolled in this study. All subjects were examined with the new system before LASIK and at 1 week, 1 month, 3 months, and 6 months after the surgery. Corneal topographs were analyzed for tear breakup time (TMS breakup time) and breakup area (TMS breakup area). Based on pre-LASIK TSAS analysis, subjects were separated into normal and abnormal TSAS value groups. The criteria for the normal group were either TMS breakup time more than 5 seconds or TMS breakup area less than 0.2. The percentage of the occurrence of superficial punctuate keratitis was compared between the two groups with regard to subject's dry eye signs and symptoms. Tear film stability decreased significantly during the early period after LASIK, as indexed by decreased TMS breakup time and increased TMS breakup area. Tear film instability resolved at 6 months after surgery. Before LASIK, 22 subjects (43 eyes) had normal TSAS evaluation and 12 subjects (21 eyes) were abnormal. After LASIK, among normal TSAS value eyes, 8 of 43 (18.6%) eyes developed superficial punctuate keratitis. In sharp contrast, 14 of 21 (66.7%) eyes in the abnormal group displayed superficial punctuate keratitis, correlating well with the patients' dry eye symptoms. The difference in the presence of superficial punctuate keratitis after LASIK between normal and abnormal TSAS value groups was statistically significant (P <.001). Subjects with abnormal TSAS evaluation also displayed resistance to dry eye treatment and had extended period of recovery. Tear film stability analysis can be a useful

Oral Omega-3 Fatty Acid Supplementation for Laser In Situ Keratomileusis-Associated Dry Eye.

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Goyal, Parul; Jain, Arun K; Malhotra, Chintan

2017-02-01

To determine the effect of oral omega-3 fatty acid (ω3FA) supplementation in laser in situ keratomileusis (LASIK)-associated dry eye. In this prospective, open-label study, patients undergoing LASIK were randomized to receive either 1.2 g/d of a triglyceride formulation of oral ω3FA (treatment group) or 400 mg/d vitamin E (control group) for 1 week before and continued for 12 weeks after surgery. Ocular surface disease index, tear breakup time, ocular surface staining, and Schirmer scores were evaluated and compared preoperatively and at 3 months after LASIK. The study included 30 patients in each group. All parameters were comparable at baseline. Ocular surface disease index scores increased comparably in both groups (1.9 ± 0.6 increase in the treatment group; 2.8 ± 0.5 in the control group) (P = 0.267). Compared with baseline levels, tear breakup time decreased significantly (P treatment (-2.3 ± 0.4 seconds decrease) and control (-3.5 ± 0.7 seconds decrease) groups (P = 0.105). More eyes in the control group (43.4%) had conjunctival staining with Lissamine green at 3 months compared with the treatment group (14%) (P = 0.009). The Schirmer score at 3 months was higher (P = 0.003) in the treatment group (30.5 ± 0.90 mm) than in the control group (25.7 ± 1.3 mm) with a increase of 5.9 ± 1.3 mm from baseline in the treatment group and a decrease of 1.5 ± 1.2 mm in the control group. Supplementation with ω3FA in patients undergoing LASIK had a positive influence on tear secretion, whereas tear film stability remained unaffected when compared with the control group.

Efficacy of punctal occlusion in management of dry eyes after laser in situ keratomileusis for myopia.

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Alfawaz, Abdullah M; Algehedan, Saeed; Jastaneiah, Sabah S; Al-Mansouri, Samir; Mousa, Ahmed; Al-Assiri, Abdullah

2014-03-01

To evaluate the effect of punctal plug use in preventing dry eye after laser in situ keratomileusis (LASIK). A randomized clinical trial at a tertiary eye care center, Riyadh, Saudi Arabia. Participants underwent LASIK for myopia in both eyes and a lower punctal occlusion in one eye only while the other eye served as control. Both eyes received the same postoperative medications except for lubricant duration (subject eye: four times per day for one week; control eye: four times per day for 6 months). Participants were evaluated at 1 week, 2, and 6 months after surgery for signs and symptoms of dry eye. The main outcome measures were visual acuity; ocular surface parameters; and Ocular Surface Disease Index questionnaire. Seventy-eight eyes of 39 patients were included in this study. The Ocular Surface Disease Index scores of eyes with punctal plugs were better at all follow-up visits, and the differences between both eyes were statistically significant (1 week, p eyes was higher in eyes with punctal plugs for all ocular surface parameters (Schirmer 1 test, 94.9%; tear breakup time, 77.8%; punctate epithelial keratitis score, 71.8%) compared to eyes without occlusion (Schirmer 1 test, 92.3%; tear breakup time, 58.3%; punctate epithelial keratitis score, 53.8%); however, such differences were not statistically significant. Punctal plug insertion after LASIK surgeries may minimize the need for frequent lubricant application and hence improve patient satisfaction.

Increased preference of surface ablation over laser in situ keratomileusis between 2008–2011 is correlated to risk of ecatasia

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Moisseiev E

2013-01-01

Full Text Available Elad Moisseiev,1,3 Tzahi Sela,2 Liza Minkev,2 David Varssano1,31Department of Ophthalmology, Tel-Aviv Medical Center, Tel-Aviv, Israel; 2Care Vision, Tel Aviv, Israel; 3Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, IsraelPurpose: To evaluate the trends in corneal refractive procedure selection for the correction of myopia, focusing on the relative proportions of laser in situ keratomileusis (LASIK and surface ablation procedures.Methods: Only eyes that underwent LASIK or surface ablation for the correction of myopia between 2008–2011 were included in this retrospective study. Additional recorded parameters included patient age, preoperative manifest refraction, corneal thickness, and calculated residual corneal bed thickness. A risk score was given to each eye, based on these parameters, according to the Ectasia Risk Factor Score System (ERFSS, without the preoperative corneal topography.Results: This study included 16,163 eyes, of which 38.4% underwent LASIK and 61.6% underwent surface ablation. The risk score correlated with procedure selection, with LASIK being preferred in eyes with a score of 0 and surface ablation in eyes with a score of 2 or higher. When controlling for age, preoperative manifest refraction, corneal thickness, and all parameters, the relative proportion of surface ablation compared with LASIK was found to have grown significantly during the study period.Conclusions: Our results indicate that with time, surface ablation tended to be performed more often than LASIK for the correction of myopia in our cohort. Increased awareness of risk factors and preoperative risk assessment tools, such as the ERFSS, have shifted the current practice of refractive surgery from LASIK towards surface ablation despite the former's advantages, especially in cases in which the risk for ectasia is more than minimal (risk score 2 and higher.Keywords: surface ablation, LASIK, PRK, myopia correction, ectasia

Evaluation of the effectiveness of laser in situ keratomileusis and photorefractive keratectomy for myopia: a meta-analysis.

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Yang, Xin-Jun; Yan, Hong-Tao; Nakahori, Yutaka

2003-08-01

To evaluate the effectiveness of laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) for correcting myopia. Study selection, data extraction, and quality assessment were performed by two of authors independently. Summary odds ratios and 95% confidence intervals were calculated by DerSimonian & Laird random-effects model and Mantel-Haenszel (fixed-effects) model. All calculations were based on an intention-to-treat and per protocol analysis. Five hundred and eighty eyes (476 patients) from 5 randomized controlled trials were included in this study. At > or = 6 months follow-up, by random-effects model, the pooled odds ratios (OR, for LASIK vs. PRK) of postoperative uncorrected visual acuity (UCVA) of 20/20 or better for all trials were 1.31 (95% CI=0.77-2.22) by per protocol analysis and 1.18 (95% CI=0.74-1.88) by intention-to-treat analysis. In the refractive outcome, the pooled OR of the postoperative spherical equivalent refraction within +/-0.5 diopter (D) of emmetropia did not show any statistical significance, for which the OR were 0.75 (95% CI=0.48-1.18) by per protocol analysis and 0.70 (95% CI=0.47-1.04) by intention-to-treat analysis. LASIK and PRK were found to be similarly effective for the correction of myopia from -1.5 to -15.0 D in a greater than 6 month follow-up.

Identification of the Infection Source of an Outbreak of Mycobacterium Chelonae Keratitis After Laser in Situ Keratomileusis.

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Nascimento, Heloisa; Viana-Niero, Cristina; Nogueira, Christiane Lourenço; Martins Bispo, Paulo José; Pinto, Fernando; de Paula Pereira Uzam, Camila; Matsumoto, Cristianne Kayoko; Oliveira Machado, Antônia Maria; Leão, Sylvia Cardoso; Höfling-Lima, Ana Luisa; de Freitas, Denise

2018-01-01

Nontuberculous mycobacteria keratitis is a rare but challenging complication of laser in situ keratomileusis (LASIK). This study was conducted to determine the source(s) of infection in a cluster of cases of keratitis after LASIK and to describe this outbreak and patients' outcomes. In this retrospective, case series, single-center study, 86 patients were included who underwent LASIK or photorefractive keratectomy between December 2011 and February 2012. Corneal scrapes from the affected eyes, samples of tap and distilled water, water from the reservoir of the distilling equipment, steamer, and autoclave cassette; antiseptic and anesthetic solutions and surgical instrument imprints were cultivated in liquid and on solid media. Gram-negative bacteria and yeasts were identified using automated systems and mycobacteria by polymerase chain reaction-restriction enzyme analysis of the hsp65 gene (PRA-hsp65) and DNA sequencing. Mycobacterial isolates were typed by pulsed-field gel electrophoresis. The cases and outcomes are described. The main outcome measure was identification of the source(s) of the mycobacterial infections. Eight (15 eyes) of 86 patients (172 eyes) who underwent LASIK developed infections postoperatively; no patients who underwent photorefractive keratectomy developed infections. Mycobacterium chelonae was isolated from 4 eyes. The distilled water collected in the surgical facility contained the same M. chelonae strain isolated from the patients' eyes. Different gram-negative bacteria and yeasts were isolated from samples collected at the clinic but not from the patients' eyes. Tap water distilled locally in surgical facilities may be a source of infection after ocular surgery and its use should be avoided.

Adjuvant corneal crosslinking to prevent hyperopic LASIK regression.

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Aslanides, Ioannis M; Mukherjee, Achyut N

2013-01-01

To report the long term outcomes, safety, stability, and efficacy in a pilot series of simultaneous hyperopic laser assisted in situ keratomileusis (LASIK) and corneal crosslinking (CXL). A small cohort series of five eyes, with clinically suboptimal topography and/or thickness, underwent LASIK surgery with immediate riboflavin application under the flap, followed by UV light irradiation. Postoperative assessment was performed at 1, 3, 6, and 12 months, with late follow up at 4 years, and results were compared with a matched cohort that received LASIK only. The average age of the LASIK-CXL group was 39 years (26-46), and the average spherical equivalent hyperopic refractive error was +3.45 diopters (standard deviation 0.76; range 2.5 to 4.5). All eyes maintained refractive stability over the 4 years. There were no complications related to CXL, and topographic and clinical outcomes were as expected for standard LASIK. This limited series suggests that simultaneous LASIK and CXL for hyperopia is safe. Outcomes of the small cohort suggest that this technique may be promising for ameliorating hyperopic regression, presumed to be biomechanical in origin, and may also address ectasia risk.

Vector analysis of high (≥3 diopters) astigmatism correction using small-incision lenticule extraction and laser in situ keratomileusis.

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Chan, Tommy C Y; Wang, Yan; Ng, Alex L K; Zhang, Jiamei; Yu, Marco C Y; Jhanji, Vishal; Cheng, George P M

2018-06-13

To compare the astigmatic correction in high myopic astigmatism between small-incision lenticule extraction and laser in situ keratomileusis (LASIK) using vector analysis. Hong Kong Laser Eye Center, Hong Kong. Retrospective case series. Patients who had correction of myopic astigmatism of 3.0 diopters (D) or more and had either small-incision lenticule extraction or femtosecond laser-assisted LASIK were included. Only the left eye was included for analysis. Visual and refractive results were presented and compared between groups. The study comprised 105 patients (40 eyes in the small-incision lenticule extraction group and 65 eyes in the femtosecond laser-assisted LASIK group.) The mean preoperative manifest cylinder was -3.42 D ± 0.55 (SD) in the small-incision lenticule extraction group and -3.47 ± 0.49 D in the LASIK group (P = .655). At 3 months, there was no significant between-group difference in uncorrected distance visual acuity (P = .915) and manifest spherical equivalent (P = .145). Ninety percent and 95.4% of eyes were within ± 0.5 D of the attempted cylindrical correction for the small-incision lenticule extraction and LASIK group, respectively (P = .423). Vector analysis showed comparable target-induced astigmatism (P = .709), surgically induced astigmatism vector (P = .449), difference vector (P = .335), and magnitude of error (P = .413) between groups. The absolute angle of error was 1.88 ± 2.25 degrees in the small-incision lenticule extraction group and 1.37 ± 1.58 degrees in the LASIK group (P = .217). Small-incision lenticule extraction offered astigmatic correction comparable to LASIK in eyes with high myopic astigmatism. Copyright © 2018 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

A prospective comparison of phakic collamer lenses and wavefront-optimized laser-assisted in situ keratomileusis for correction of myopia

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Parkhurst GD

2016-06-01

Full Text Available Gregory D Parkhurst1,2 1Refractive Surgery Center, Carl R Darnall Army Medical Center, Fort Hood, 2Parkhurst NuVision, San Antonio, TX, USA Purpose: The aim of this study was to evaluate and compare night vision and low-luminance contrast sensitivity (CS in patients undergoing implantation of phakic collamer lenses or wavefront-optimized laser-assisted in situ keratomileusis (LASIK.Patients and methods: This is a nonrandomized, prospective study, in which 48 military personnel were recruited. Rabin Super Vision Test was used to compare the visual acuity and CS of Visian implantable collamer lens (ICL and LASIK groups under normal and low light conditions, using a filter for simulated vision through night vision goggles.Results: Preoperative mean spherical equivalent was –6.10 D in the ICL group and –6.04 D in the LASIK group (P=0.863. Three months postoperatively, super vision acuity (SVa, super vision acuity with (low-luminance goggles (SVaG, super vision contrast (SVc, and super vision contrast with (low luminance goggles (SVcG significantly improved in the ICL and LASIK groups (P<0.001. Mean improvement in SVaG at 3 months postoperatively was statistically significantly greater in the ICL group than in the LASIK group (mean change [logarithm of the minimum angle of resolution, LogMAR]: ICL =-0.134, LASIK =-0.085; P=0.032. Mean improvements in SVc and SVcG were also statistically significantly greater in the ICL group than in the LASIK group (SVc mean change [logarithm of the CS, LogCS]: ICL =0.356, LASIK =0.209; P=0.018 and SVcG mean change [LogCS]: ICL =0.390, LASIK =0.259; P=0.024. Mean improvement in SVa at 3 months was comparable in both groups (P=0.154.Conclusion: Simulated night vision improved with both ICL implantation and wavefront-optimized LASIK, but improvements were significantly greater with ICLs. These differences may be important in a military setting and may also affect satisfaction with civilian vision correction

The effect of flap thickness on corneal biomechanics after myopic laser in situ keratomileusis using the M-2 microkeratome

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Goussous IA

2017-11-01

Full Text Available Iyad A Goussous,1 Mohamed-Sameh El-Agha,1 Ahmed Awadein,1 Mohamed H Hosny,1 Alaa A Ghaith,2 Ahmed L Khattab2 1Department of Ophthalmology, Faculty of Medicine, Cairo University, Cairo, 2Faculty of Medicine, Alexandria University, Alexandria, Egypt Purpose: The purpose of this study was to determine the effect of flap thickness on corneal biomechanics after myopic laser in situ keratomileusis (LASIK.Methods: This is a prospective controlled non-randomized, institutional study. Patients underwent either epi-LASIK with mitomycin (advanced surface ablation [ASA], thin-flap LASIK (90 µm head, or thick-flap LASIK (130 µm head. In ASA, the Moria Epi-K hydroseparator was used. LASIK flaps were created using the Moria M-2 mechanical microkeratome. The corneal hysteresis (CH and corneal resistance factor (CRF were measured preoperatively and 3 months after surgery, using the Ocular Response Analyzer®.Results: Ten patients (19 eyes underwent ASA, 11 patients (16 eyes underwent thin-flap LASIK, and 11 patients (16 eyes underwent thick-flap LASIK. The mean preoperative CH was 10.47±0.88, 10.52±1.4, and 11.28±1.4 mmHg (p=0.043, respectively, decreasing after surgery by 1.75±1.02, 1.66±1.00, and 2.62±1.03 mmHg (p=0.017. The mean reduction of CH per micron of central corneal ablation was 0.031, 0.023, and 0.049 mmHg/µm (p=0.005. Mean preoperative CRF was 10.11±1.28, 10.34±1.87, and 10.62±1.76 mmHg (p=0.66, decreasing after surgery by 2.33±1.35, 2.77±1.03, and 2.92±1.10 mmHg (p=0.308. The mean reduction of CRF per micron of central corneal ablation was 0.039, 0.040, and 0.051 mmHg/µm (p=0.112.Conclusion: Thick-flap LASIK caused a greater reduction of CH and CRF than thin-flap LASIK and ASA, although this was statistically significant only for CH. ASA and thin-flap LASIK were found to be biomechanically similar. Keywords: flap thickness ectasia, hysteresis, LASIK, surface ablation

The Correlation Analysis between Corneal Biomechanical Properties and the Surgically Induced Corneal High-Order Aberrations after Small Incision Lenticule Extraction and Femtosecond Laser In Situ Keratomileusis

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Wenjing Wu

2015-01-01

Full Text Available Background. To investigate the correlation between corneal biomechanics and the surgically induced corneal high-order aberrations (HOAs after small incision lenticule extraction (SMILE and femtosecond laser in situ keratomileusis (FS-LASIK. Methods. A total of 150 right myopic eyes that underwent SMILE or FS-LASIK surgery were included in this retrospective study, 75 eyes in each group. The corneal hysteresis (CH and the corneal resistance factor (CRF with the corneal HOAs of the anterior, posterior, and total cornea were assessed preoperatively and three months postoperatively. Multivariate linear regression was applied to determine the correlations. Results. The preoperative CRF was significantly correlated with the induced 3rd–6th-order HOAs and spherical aberration of the anterior surface and the total cornea after SMILE and FS-LASIK surgeries (P<0.05, postoperatively. The CRF was significantly correlated with the induced vertical coma of the anterior and posterior surfaces and the total cornea after SMILE surgery (P<0.05. There was a significant correlation between the CRF and the induced posterior corneal horizontal coma after FS-LASIK surgery (P=0.013. Conclusions. The corneal biomechanics affect the surgically induced corneal HOAs after SMILE and FS-LASIK surgery, which may be meaningful for screening the patients preoperatively and optimizing the visual qualities postoperatively.

Photorefractive keratectomy versus laser in situ keratomileusis for moderate to high myopia. A randomized prospective study.

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Hersh, P S; Brint, S F; Maloney, R K; Durrie, D S; Gordon, M; Michelson, M A; Thompson, V M; Berkeley, R B; Schein, O D; Steinert, R F

1998-08-01

This report presents the results of a randomized clinical trial of photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK). A randomized, prospective multicenter clinical trial. A total of 220 eyes of 220 patients entered the study cohort: 105 randomized to PRK and 115 to LASIK. The mean preoperative manifest refraction spherical equivalent was -9.23 diopters (D) in the PRK group and -9.30 D in the LASIK group. All patients received a one-pass, multizone excimer laser ablation as part of either a PRK or LASIK procedure using the Summit Apex excimer laser. Attempted corrections ranged from 6.00 to 15.00 D. Data on uncorrected and spectacle-corrected visual acuity, predictability,and stability of refraction, corneal haze, and flap complications were analyzed. Patients were observed for up to 6 months. One day after surgery, 0 (0.0%) and 3 (4.5%) eyes in the PRK group saw 20/20 and 20/40 or better uncorrected, respectively, while 7 (10%) and 48 (68.6%) eyes in the LASIK group saw 20/20 and 20/40 or better, respectively. At 6 months after PRK, 13 (19.1%) and 45 (66.2%) eyes saw 20/20 and 20/40 or better, respectively, while after LASIK, 16 (26.2%) and 34 (55.7%) eyes saw 20/20 and 20/40 or better, respectively (odds ratio = 0.56 for likelihood of uncorrected visual acuity PRK vs. LASIK, 95% confidence interval [CI] = 0.31-1.19). After PRK, 39 eyes (57.4%) were within 1.0 D of attempted correction compared with 24 eyes (40.7%) in the LASIK group (odds ratio = 0.50 for likelihood fo undercorrection 1.0 D for PRK vs. LASIK, 95% CI = 0.24-1.04); however, the standard deviation of the predictability was similar between groups: 1.01 D for PRK and 1.22 D for LASIK. From months 1 to 6, there was an average regression of 0.89 D in the PRK group and 0.55 D in the LASIK group. After PRK, eight eyes (11.8%) had a decrease in spectacle-corrected visual acuity of two Snellen lines or more; after LASIK, two eyes (3.2%) had a decrease of two lines or more

O impacto da cirurgia de ceratectomia fotorrefrativa (PRK e ceratomileuse assistida por excimer laser in situ (LASIK na qualidade visual e de vida em pacientes com ametropias The impact of photorefractive excimer laser keratectomy (PRK and laser in situ keratomileusis (LASIK on visual quality and life in patients with ametropias

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Ricardo Belfort

2008-02-01

significantemente para melhor em relação ao préoperatório, com redução substancial do estresse psicológico.PURPOSE: To evaluate the quality of life, vision and stress before and after refractive surgery. METHODS: This is a longitudinal, observational study, where 100 patients were evaluated; 54 espectacles wearers, 21 contact lens users before surgery and 25 controls wearers spectacles or contact lenses, who did not want to undergo refractive surgery during one year despite refractive error. The applied questionnaires were Self Reporting Questionnaires SRQ-20 of quality of life and vision and National Eye Institute Visual Function Questionnaire NEI VFQ-25 for the assessment of mental health. The intervention group answered the questionnaires before surgery, three, six and twelve months after follow-up and the control group answered the questionnaires at six and twelve months after the baseline. The questionnaires of the intervention group were applied by an independent person. RESULTS: In the intervention group (54 spectacle wearers, 39 were treated by photorefractive excimer laserkeratectomy (PRK and 15 by laser in situ keratomileusis (LASIK, of the 21 contact lens users: 12 received photorefractive excimer laser keratectomy and nine were treated by laser in situ keratomileusis (LASIK. The control group remained stable during the study. After three months of follow-up the intervention group showed improvement in quality of life, vision and reduction of stress. After one year of follow-up the assessments of quality of life and mental health were similar to the control group. After three months there was a significant reduction of psychiatric symptomatology in the intervention group. CONCLUSION: Patients operated for correction of ametropia showed a significant improvement in quality of life and mental health assessments.

Laser in situ keratomileusis enhancements with the Ziemer FEMTO LDV femtosecond laser following previous LASIK treatments.

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Pietilä, Juhani; Huhtala, Anne; Mäkinen, Petri; Uusitalo, Hannu

2013-02-01

The aim of this paper is to present the accuracy, predictability, and safety outcomes of LASIK enhancements performed with the FEMTO LDV femtosecond laser (Ziemer Ophthalmic Systems, Port, Switzerland) and the Allegretto Wave Concerto 500 Hz excimer laser (Wavelight AG, Erlangen, Germany), following previous LASIK treatments. FEMTO LDV was used for flap creation in 85 previously LASIK-treated eyes of 62 patients. The intended flap thickness was 90 μm in 81 eyes and 140 μm in 4 eyes. The size of the suction ring was 9.0 mm in 72 eyes and 9.5 mm in 13 eyes. Flap dimensions were measured and correlated to preoperative characteristics. With the intended flap thickness of 90 μm in previously LASIK-treated eyes, the actual flap thickness was 90.2 ± 6.6 μm (range 80-122), and the flap diameter was 9.2 ± 0.2 mm (range 8.7-9.9). The mean hinge length was 4.0 ± 0.2 mm (range 3.0-4.8). Flap thickness correlated positively with patient age and hinge length. Complications were reported in 12 eyes (14.1 %). Most of the complications were very mild, and none of them prevented further refractive laser treatment. One eye lost two Snellen lines of best spectacle-corrected visual acuity. Femtosecond LASIK enhancement is warranted only in rare cases. Surgical experience is needed and special caution must be practiced. For cases of a primary free cap, femtosecond LASIK is not recommended.

Rainbow glare after laser-assisted in situ keratomileusis: a review of literature

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Moshirfar M

2016-11-01

Full Text Available Majid Moshirfar,1,2 Jordan D Desautels,3 Tyler S Quist,4 David F Skanchy,5 Mark T Williams,6 Ryan T Wallace7 1Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT, 2HDR Research Center, Hoopes Vision, Draper, UT, 3Tufts University School of Medicine, Boston, MA, 4University of Utah School of Medicine, Salt Lake City, UT, 5McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 6University of California, San Francisco School of Medicine, San Francisco, CA, 7Brigham Young University, Provo, UT, USA Abstract: This article reviews the current literature pertaining to rainbow glare (RG, including incidence rate, clinical presentation, etiology, prognosis, and management. RG is a rare optical complication of femtosecond laser-assisted in situ keratomileusis that results in patients seeing an array of spectral bands surrounding point sources of light under mesopic and scotopic conditions. The mechanism is thought to be a consequence of the formation of a transmissive diffraction grating on the posterior surface of the corneal flap created by the FS laser. RG has a good prognosis and is usually self-limiting. Persistent RG with concomitant residual refractive error may warrant lifting the flap and photoablating the posterior surface of the flap. Patients with persistent RG and no residual refractive error should be considered candidates for phototherapeutic keratectomy on the posterior flap surface. Keywords: rainbow glare, femtosecond, LASIK, keratomileusis, phototherapeutic keratectomy

Comparison of optical quality after implantable collamer lens implantation and wavefront-guided laser in situ keratomileusis

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Hong-Ting Liu

2018-04-01

Full Text Available AIM: To compare the optical quality after implantation of implantable collamer lens (ICL and wavefront-guided laser in situ keratomileusis (WG-LASIK. METHODS: The study included 40 eyes of 22 patients with myopia who accepted ICL implantation and 40 eyes of 20 patients with myopia who received WG-LASIK. Before surgery and three months after surgery, the objective scattering index (OSI, the values of modulation transfer function (MTF cutoff frequency, Strehl ratio, and the Optical Quality Analysis System (OQAS values (OVs were accessed. The higher order aberrations (HOAs data including coma, trefoil, spherical, 2nd astigmatism and tetrafoil were also obtained. For patients with pupil size <6 mm, HOAs data were analyzed for 4 mm-pupil diameter. For patients with pupil size ≥6 mm, HOAs data were calculated for 6 mm-pupil diameter. Visual acuity, refraction, pupil size and intraocular pressures were also recorded. RESULTS: In both ICL and WG-LASIK group, significant improvements in visual acuities were found postoperatively, with a significant reduction in spherical equivalent (P< 0.001. After the ICL implantation, the OSI decreased slightly from 2.34±1.92 to 2.24±1.18 with no statistical significance (P=0.62. While in WG-LASIK group, the OSI significantly increased from 0.68±0.43 preoperatively to 0.91±0.53 postoperatively (Wilcoxon signed ranks test, P=0.000. None of the mean MTF cutoff frequency, Strehl ratio, OVs showed statistically significant changes in both ICL and WG-LASIK groups. In the ICL group, there were no statistical differences in the total HOAs for either 4 mm-pupil or 6 mm-pupil. In the WG-LASIK group, the HOA parameters increased significantly at 4 mm-pupil. The total ocular HOAs, coma, spherical and 2nd astigmatism were 0.12±0.06, 0.06±0.03, 0.00±0.03, 0.02±0.01, respectively. After the operation, these values were increased into 0.16±0.07, 0.08±0.05, -0.04±0.04, 0.03±0.01 respectively (Wilcoxon signed ranks test

Adjuvant corneal crosslinking to prevent hyperopic LASIK regression

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Aslanides IM

2013-03-01

Full Text Available Ioannis M Aslanides, Achyut N MukherjeeEmmetropia Mediterranean Eye Clinic, Heraklion, Crete, GreecePurpose: To report the long term outcomes, safety, stability, and efficacy in a pilot series of simultaneous hyperopic laser assisted in situ keratomileusis (LASIK and corneal crosslinking (CXL.Method: A small cohort series of five eyes, with clinically suboptimal topography and/or thickness, underwent LASIK surgery with immediate riboflavin application under the flap, followed by UV light irradiation. Postoperative assessment was performed at 1, 3, 6, and 12 months, with late follow up at 4 years, and results were compared with a matched cohort that received LASIK only.Results: The average age of the LASIK-CXL group was 39 years (26–46, and the average spherical equivalent hyperopic refractive error was +3.45 diopters (standard deviation 0.76; range 2.5 to 4.5. All eyes maintained refractive stability over the 4 years. There were no complications related to CXL, and topographic and clinical outcomes were as expected for standard LASIK.Conclusion: This limited series suggests that simultaneous LASIK and CXL for hyperopia is safe. Outcomes of the small cohort suggest that this technique may be promising for ameliorating hyperopic regression, presumed to be biomechanical in origin, and may also address ectasia risk.Keyword: CXL

Small Incision Lenticule Extraction (SMILE) vs. Femtosecond Laser in Situ Keratomileusis (FS-LASIK) for treatment of myopia

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Hansen, Rasmus Søgaard; Lyhne, Niels; Justesen, Birgitte

Purpose: - 67 ord LASIK has been the dominating corneal refractive procedure for almost two decades, but the new flap-free SMILE procedure has shown promising results. The aim of this study was to evaluate and compare refractive predictability, uncorrected and corrected distance visual acuity (UDVA...... and CDVA), and safety at 1 day, 1 week and 3 months after SMILE and FS-LASIK for all degrees of myopia, but in particular high myopia. Setting: Department of Ophthalmology, Odense University Hospital, Odense, Denmark Methods: - 157 ord Retrospective study of results after SMILE and FS-LASIK for all degrees...... having undergone re-treatment. The SMILE treatments and FS-LASIK flaps were performed with a VisuMax® femtosecond laser (Carl Zeiss-Meditec, Jena, Germany). The FS-LASIK photoablation was performed with a MEL-80 flying-spot excimer laser with eye-tracker (Carl Zeiss-Meditec, Jena, Germany). In SMILE...

Evaluation of iris recognition system for wavefront-guided laser in situ keratomileusis for myopic astigmatism.

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Ghosh, Sudipta; Couper, Terry A; Lamoureux, Ecosse; Jhanji, Vishal; Taylor, Hugh R; Vajpayee, Rasik B

2008-02-01

To evaluate the visual and refractive outcomes of wavefront-guided laser in situ keratomileusis (LASIK) using an iris recognition system for the correction of myopic astigmatism. Centre for Eye Research Australia, Melbourne Excimer Laser Research Group, and Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia. A comparative analysis of wavefront-guided LASIK was performed with an iris recognition system (iris recognition group) and without iris recognition (control group). The main parameters were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity, amount of residual cylinder, manifest spherical equivalent (SE), and the index of success using the Alpins method of astigmatism analysis 1 and 3 months postoperatively. A P value less than 0.05 was considered statistically significant. Preoperatively, the mean SE was -4.32 diopters (D) +/- 1.59 (SD) in the iris recognition group (100 eyes) and -4.55 +/- 1.87 D in the control group (98 eyes) (P = .84). At 3 months, the mean SE was -0.05 +/- 0.21 D and -0.20 +/- 0.40 D, respectively (P = .001), and an SE within +/-0.50 D of emmetropia was achieved in 92.0% and 85.7% of eyes, respectively (P = .07). At 3 months, the UCVA was 20/20 or better in 90.0% and 76.5% of eyes, respectively. A statistically significant difference in the amount of astigmatic correction was seen between the 2 groups (P = .00 and P = .01 at 1 and 3 months, respectively). The index of success was 98.0% in the iris recognition group and 81.6% in the control group (P = .03). Iris recognition software may achieve better visual and refractive outcomes in wavefront-guided LASIK for myopic astigmatism.

Two-years results of small-incision lenticule extraction and wavefront-guided laser in situ keratomileusis for Myopia.

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Kobashi, Hidenaga; Kamiya, Kazutaka; Igarashi, Akihito; Takahashi, Masahide; Shimizu, Kimiya

2018-03-01

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. 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. 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). 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. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Comparison of the corneal biomechanical effects after small-incision lenticule extraction and Q value guided femtosecond laser-assisted laser in situ keratomileusis

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Jun Zhang

2016-04-01

Full Text Available AIM:By comparing the changes of biomechanical properties of the cornea after small-incision lenticule extraction(SMILEand those after Q value guided femtosecond laser-assisted laser in situ keratomileusis(FSLASIK, to study the stability of biomechanical properties of the cornea after these two kinds of surgery and provide objective data for clinical operation.METHODS: Prospective comparative cases. One hundred and two cases(200 eyeswith myopia and myopic astigmatism were divided into 2 groups, 51 cases(100 eyesfor SMILE, and 51 cases(100 eyesfor Q value guided FS-LASIK. Corneal hysteresis(CHand the corneal resistance factor(CRFwere quantitatively assessed with the Ocular Response Analyzer(ORApreoperatively and 1d, 2wk, 1 and 3mo postoperatively.RESULTS: The decrease in CH and the CRF were statistically significant in both groups(PP>0.05. There were no statistically significant differences between the biomechanical changes in the two groups at any time(P>0.05.CONCLUSION: Both SMILE and Q value guided FS-LASIK can cause biomechanical decreases in the cornea. After 1d postoperatively, the decreases are nearly stable. There are no significant differences between the effect of SMILE and Q value guided FS-LASIK on the biomechanical properties of the cornea.

Seven-year changes in corneal power and aberrations after PRK or LASIK.

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Ivarsen, Anders; Hjortdal, Jesper

2012-09-06

To examine long-term changes in corneal power and aberrations in myopic patients randomized to photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK). Forty-five patients with myopia from -6 to -8 diopters (spherical equivalent refraction) were randomized to PRK (n = 20) or LASIK (n = 25). Patients were examined preoperatively and for up to 7 years after surgery. Measurements included refraction, topography (TMS-1), and ultrasound pachymetry. By 3 years, 16 PRK and 15 LASIK patients were examined and by 7 years, 9 PRK and 7 LASIK subjects were available. Only patients who had not been reoperated and attended the two late controls were included in data analyses. Optical analysis of topographic data was used to calculate corneal power and wavefront aberrations. PRK and LASIK caused a similar reduction in corneal power. During the first year after PRK, corneal power increased, but remained stable from 1 to 7 years. In contrast, corneal power continued to increase from 1 to 7 years after LASIK. Both PRK and LASIK caused an increase in coma-like and spherical aberrations that remained constant for 7 years. No significant changes in other higher-order aberrations were observed. The cornea may not be stable even 7 years after LASIK, as indicated by the continuing increase in corneal power. In contrast, PRK appears stable from 1 year post surgery. Coma-like and spherical aberrations are permanently increased after PRK and LASIK. (ClinicalTrials.gov number, NCT00404105.).

Nonarteritic ischemic optic neuropathy secondary to severe ocular hypertension masked by interface fluid in a post-LASIK eye.

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Pham, Mai T; Peck, Rachel E; Dobbins, Kendall R B

2013-06-01

We report a case of ischemic optic neuropathy arising from elevated intraocular pressure (IOP) masked by interface fluid in a post-laser in situ keratomileusis (LASIK) eye. A 51-year-old man, who had had LASIK 6 years prior to presentation, sustained blunt trauma to the left eye that resulted in a hyphema and ocular hypertension. Elevated IOP resulted in accumulation of fluid in the stromal bed-LASIK flap interface, leading to underestimation of IOP when measured centrally over the flap. After days of unrecognized ocular hypertension, ischemic optic neuropathy developed. To our knowledge, this is the first reported case of ischemic optic neuropathy resulting from underestimated IOP measurements in a post-LASIK patient. It highlights the inaccuracy of IOP measurements in post-LASIK eyes and a vision-threatening potential complication. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Factors Influencing Intraocular Pressure Changes after Laser In Situ Keratomileusis with Flaps Created by Femtosecond Laser or Mechanical Microkeratome.

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Meng-Yin Lin

Full Text Available The aim of this study is to describe factors that influence the measured intraocular pressure (IOP change and to develop a predictive model after myopic laser in situ keratomileusis (LASIK with a femtosecond (FS laser or a microkeratome (MK. We retrospectively reviewed preoperative, intraoperative, and 12-month postoperative medical records in 2485 eyes of 1309 patients who underwent LASIK with an FS laser or an MK for myopia and myopic astigmatism. Data were extracted, such as preoperative age, sex, IOP, manifest spherical equivalent (MSE, central corneal keratometry (CCK, central corneal thickness (CCT, and intended flap thickness and postoperative IOP (postIOP at 1, 6 and 12 months. Linear mixed model (LMM and multivariate linear regression (MLR method were used for data analysis. In both models, the preoperative CCT and ablation depth had significant effects on predicting IOP changes in the FS and MK groups. The intended flap thickness was a significant predictor only in the FS laser group (P < .0001 in both models. In the FS group, LMM and MLR could respectively explain 47.00% and 18.91% of the variation of postoperative IOP underestimation (R2 = 0.47 and R(2 = 0.1891. In the MK group, LMM and MLR could explain 37.79% and 19.13% of the variation of IOP underestimation (R(2 = 0.3779 and 0.1913 respectively. The best-fit model for prediction of IOP changes was the LMM in LASIK with an FS laser.

LASIK and PRK in hyperopic astigmatic eyes: is early retreatment advisable?

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Frings, Andreas; Richard, Gisbert; Steinberg, Johannes; Druchkiv, Vasyl; Linke, Stephan Johannes; Katz, Toam

2016-01-01

To analyze the refractive and keratometric stability in hyperopic astigmatic laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) during the first 6 months after surgery. This retrospective cross-sectional study included 97 hyperopic eyes; 55 were treated with LASIK and 42 with PRK. Excimer ablation for all eyes was performed using the ALLEGRETTO excimer laser platform using a mitomycin C for PRK and a mechanical microkeratome for LASIK. Keratometric and refractive data were analyzed during three consecutive follow-up intervals (6 weeks, 3 months, and 6 months). The corneal topography was obtained using Scheimpflug topography, and subjective refractions were acquired by expert optometrists according to a standardized protocol. After 3 months, mean keratometry and spherical equivalent were stable after LASIK, whereas PRK-treated eyes presented statistically significant (P1 D occurred. The optical zone diameter did not correlate with the development of regression. After corneal laser refractive surgery, keratometric changes are followed by refractive changes and they occur up to 6 months after LASIK and for at least 6 months after PRK, and therefore, caution should be applied when retreatment is planned during the 1st year after surgery because hyperopic refractive regression can lead to suboptimal visual outcome. Keratometric and refractive stability is earlier achieved after LASIK, and therefore, retreatment may be independent of late regression.

Bilateral Epithelial Defects after Laser in situ Keratomileusis. Clinical Features, Management and Outcome

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Rao Srinivas

2005-03-01

Full Text Available PURPOSE: To describe the preoperative characteristics, intraoperative details, management, and postoperative in patients with bilateral epithelial defects after laser in situ keratomileusis (LASIK. METHODS: Retrospective non-comparative case series. RESULTS: Six patients with bilateral epithelial defects after LAISK were part of a cohort of 605 patients undergoing bilateral LASIK at our center from December 2001 to April 2003. The mean age of the patients (5M:1F was 28.5 7.9 years, and the average pretreatment myopic spherical equivalent (SE refraction was 7.3 0.7 D (-4, -12.25D. An epithelial flap was present in 6 eyes and an epithelial defect with a mean diameter of 3 mm (2mm, 6mm was seen in 6 eyes. In four patients the epithelial disturbance was bilaterally similar. All defects occurred in the inferior cornea and the epithelial flaps had the hinge positioned superiorly. None of the patients had ocular or systemic risk factors that could have resulted in this complication. A bandage contact lens was used in 6 eyes. At last follow-up of 5.5 9.5 months (0.25, 21 months, unaided visual acuity was 6/9 or better in 10 eyes. Best spectacle-corrected visual acuity (BSCVA was maintained in 8 eyes, while 4 eyes lost one line of BSCVA. Recurrent corneal erosions were not reported in the follow-up period. CONCLUSIONS: These patients represent a hitherto unrecognised group of individuals who appear to have a subclinical weakness of adhesion of the corneal epithelium to the underlying structures, which is not evident on clinical examination. This results in bilateral epithelial disturbances after LASIK. Appropriate management results in satisfactory clinical outcomes. Other options for treatment of the fellow eye of such patients include the use of a different microkeratome, release of suction during the reverse pass of the Hansatome microkeratome, and photorefractive keratectomy if the refractive error is low.

Curative effect observation of n-flap and off-flap EPi-LASIK in ametropia

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Chao Liu

2015-11-01

Full Text Available AIM:To observe the clinical effect of on-flap and off-flap epipolis laser in situ keratomileusis(EPi-LASIKin ametropia.METHODS: Sixty-eight myopia patients(136 eyesreceiving surgical treatment were selected and divided into research group and control group according to different therapies. The patients in research group adopted off-flap EPi-LASIK and those in control group adopted on-flap EPi-LASIK. The index like uncorrected visual acuity, diopter and Haze of two groups before surgery, 1wk, 1 and 4mo after surgery was observed. RESULTS: One month after surgery, the uncorrected visual acuity of research group was 1.33±0.22 while that of control group was 1.22±0.19(PPPCONCLUSION:On-flap and off-flap EPi-LASIK are safe and effective surgery approaches in the clinical treatment of ametropia. The presence of corneal epithelial flap has a certain effect in the postoperative clinical outcome at early stage. The impact will be gradually reduced over time.

Comparison of photorefractive keratectomy and laser in situ keratomileusis for myopia of -6 D or less using the Nidek EC-5000 laser.

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Fernández, A P; Jaramillo, J; Jaramillo, M

2000-01-01

We compared the efficacy, predictability, and safety of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for the surgical correction of low and moderate myopia. A retrospective study was performed to evaluate uncorrected and spectacle-corrected visual acuity, and manifest refraction 1 year after PRK or LASIK. All procedures were done using an automatic microkeratome (Chiron Ophthalmic) and the Nidek EC-5000 excimer laser. PRK was performed in 75 eyes of 45 patients and LASIK in 133 eyes of 77 patients. Mean age for PRK patients was 32.8 years (range, 18 to 52 yr) and LASIK patients was 29.6 years (range, 18 to 49 yr). Mean preoperative spherical equivalent refraction for PRK patients was -3.28 D (range, -1.00 to -6.00 D) and LASIK, -3.86 D (range, -1.00 to -6.00 D). One year after surgery, mean spherical equivalent refraction for Group 1 (baseline, -1.00 to -3.00 D) PRK eyes was -0.18 +/- 0.61 D (range, -1.50 to +0.75 D) and for LASIK eyes, -0.08 +/- 0.61 D (range, -1.50 to +1.62 D), with no statistically significant difference. For Group 2 eyes (baseline, -3.25 to -6.00 D), mean spherical equivalent refraction for PRK eyes was -0.44 +/- 0.87 D (range, -2.00 to +2.12 D) and for LASIK eyes, -0.09 +/- 0.83 D (range, -1.50 to +1.75 D), with no statistically significant difference. The antilogarithm of the mean UCVA (antilogUCVA) in Group 1 for PRK was 0.79 +/- 0.21 (20/25) and for LASIK was 0.87 +/- 0.19 (20/23), with no statistically significant difference. The antilogUCVA in Group 2 for PRK eyes was 0.70 +/- 0.24 (20/28) and for LASIK eyes was 0.83 +/- 0.18 (20/24), with a statistically significant difference (0.7 vs. 0.83, P 20/40 in Group 1 for PRK was 91.5% (38 eyes) and for LASIK was 95% (50 eyes) (no statistically significant difference), and in Group 2 for PRK eyes, it was 82% (27 eyes) and 97.5% (78 eyes) for LASIK (statistically significant difference, P PRK and LASIK with the Nidek EC-5000 excimer laser are effective and safe for

LASIK vs LASEK vs PRK: advantages and indications.

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Ambrósio, Renato; Wilson, Steven

2003-03-01

The advent of the excimer laser as an instrument for use in reshaping the corneal stroma was a great step forward in refractive surgery. Laser energy can be delivered on the stromal surface in the photorefractive keratectomy (PRK) procedure or deeper on the corneal stroma by the means of a lamellar surgery in which a flap is created with the microkeratome in the laser in situ keratomileusis (LASIK) procedure. LASIK is currently the dominant procedure in refractive surgery. The main advantage of LASIK over PRK is related to maintaining the central corneal epithelium. This increases comfort during the early post-operative period, allows for rapid visual recovery, and reduces the wound healing response. Reduced wound healing correlates with less regression for high corrections and a lower rate of complications such as significant stromal opacity (haze). PRK, however, remains as an excellent option for mild to moderate corrections, particularly for cases associated with thin corneas, recurrent erosions, or a predisposition for trauma (Martial arts, military, etc.). Recently, a modification of PRK, laser subepithelial keratomileusis (LASEK), was introduced. In the LASEK procedure, an epithelial flap is created and replaced after the ablation. The benefits, if any, of the creation of an epithelial flap compared to traditional PRK are not fully appreciated. Advocates of LASEK suggest that there is less discomfort in the early postoperative period, faster visual recovery, and less haze compared to standard PRK for correction of similar levels of refractive error. Additional long-term clinical studies, along with laboratory research, will be crucial to validate these potential advantages of LASEK procedure.

A retrospective analysis of the postoperative use of loteprednol etabonate gel 0.5% following laser-assisted in situ keratomileusis or photorefractive keratectomy surgery.

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Salinger, Clifford L; Gordon, Michael; Jackson, Mitchell A; Perl, Theodore; Donnenfeld, Eric

2015-01-01

While loteprednol etabonate ophthalmic gel 0.5% (LE gel) is approved for treatment of postoperative ocular inflammation and pain, there have been no reported studies in patients undergoing laser-assisted in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK). This was a retrospective chart review conducted at five refractive surgical centers in the USA. Data were collected from primary LASIK or PRK surgery cases in which LE gel was used postoperatively as the clinician's routine standard of care and in which patients were followed-up for up to 6 months. Data extracted from charts included patient demographics, surgical details, LE gel dosing regimen, pre- and postsurgical refractive characteristics, intraocular pressure (IOP) measurements, and visual acuity. Primary outcomes included postoperative IOP elevations, adverse events, and early discontinuations. Data were collected on 189 LASIK eyes (96 patients) and 209 PRK eyes (108 patients). Mean (standard deviation [SD]) years of age at surgery was 36.0 (11.7) and 33.9 (11.3) in LASIK and PRK patients. LE gel was prescribed most often four times daily during the first postoperative week, regardless of procedure; the most common treatment duration was 7-14 days in LASIK and ≥30 days in PRK patients. No unusual corneal findings or healing abnormalities were reported. Mean postoperative uncorrected distance visual acuity was 20/24 in LASIK and 20/30 in PRK eyes. Mild/trace corneal haze was reported in 20% of PRK patients; two PRK patients with moderate/severe corneal haze were switched to another corticosteroid. Mean postoperative IOP did not increase over time in either LASIK or PRK eyes (P≥0.331); clinically significant elevations from baseline in IOP (≥10 mmHg) were noted in only three eyes of two PRK patients. LE gel appears to have a high level of safety and tolerability when used for the management of postoperative pain and inflammation following LASIK and PRK surgery.

Diffuse lamellar keratitis after laser in situ keratomileusis with the Moria LSK-One and Carriazo-Barraquer microkeratomes.

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Thammano, Pavika; Rana, Azhar N; Talamo, Jonathan H

2003-10-01

To assess risk factors for and incidence of diffuse lamellar keratitis (DLK) and to investigate whether microkeratome design is associated with the incidence of DLK. The Laser Eye Consultants of Boston, Boston and Waltham, Massachusetts, USA. In a retrospective nonrandomized comparative study, 1122 consecutive primary laser in situ keratomileusis (LASIK) treatments (584 patients) were analyzed to determine the incidence of DLK using 2 different microkeratome designs (Moria LSK-One [LSK] and Moria Carriazo-Barraquer [C-B]). The incidence of DLK was as determined by clinical signs. The overall incidence of DLK was 2.23%. The incidence in the LSK and C-B groups was 1.09% and 4.38%, respectively, with a statistically significant difference in incidence between the 2 groups (P<.01). Epithelial irregularities increased the risk for DLK. There was no significant statistical difference in sex, age, operating room location, type of laser, or time of day the surgery was performed between the 2 groups or between eyes that had DLK and eyes without DLK. The incidence of DLK using the C-B microkeratome fell significantly after May 2000, when new cleaning methods for this device were introduced. Different microkeratomes and how they are maintained may influence the incidence of DLK. Diffuse lamellar keratitis is more common after LASIK in a setting of epithelial irregularities, whether or not an actual epithelial defect is created.

Management of a Traumatic Flap Dislocation Seven Years after LASIK

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Majid Moshirfar

2011-01-01

Full Text Available Seven years after uneventful laser in situ keratomileusis (LASIK, a 48-year-old woman presented one week after being hit with an iron cord with blurry vision, pain, and irritation. The injury resulted in traumatic flap dislocation, epithelial ingrowth, and macrostriae. Following epithelial removal, the flap was refloated and repositioned. Nine interrupted sutures were used to secure the flap. Three-weeks after surgery with no sutures remaining, the epithelial ingrowth and macrostriae had resolved with a visual acuity of 20/20.

Fundus oculi pigmentation studies simulating the fs-LASIK process Fundus oculi pigmentation studies simulating the fs-LASIK process

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Sander, M.; Minet, O.; Zabarylo, U.; Müller, M.; Tetz, M. R.

2012-06-01

The femtosecond-laser in situ keratomileusis (fs-LASIK) technique has successfully entered the refractive surgery market to correct ametropia by cutting transparent corneal tissue with ultra-short laser pulses based on photodisruption. The laser pulses in the near infrared range (NIR) generate a laser-induced breakdown (LIOB) in the cornea. By propagating through the eye, a certain amount of the pulse is deposited in the cornea and the remaining energy interacts with the strong absorbing tissue behind. Due to the absorption by the retinal pigment epithelium and the transfer of the thermal energy to surrounding tissue, the transmitted energy can induce damage to the retina. The aim of this project was to find out the threshold influences concerning the tissue and the correlation between the results of the macroscopical appraisal and the fundus oculi pigmentation by simulating the fs-LASIK procedure with two various laser systems in the continuous wave (CW) and fs-regime. Therefore ex-vivo determinations were carried out macroscopically and histopathologically on porcine tissue.

Chronic dry eye in PRK and LASIK: manifestations, incidence and predictive factors

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Bower, Kraig S.; Sia, Rose K.; Ryan, Denise S.; Mines, Michael J.; Dartt, Darlene A.

2017-01-01

Purpose To evaluate dry eye manifestations following photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) and determine the incidence and predictive factors of chronic dry eye using a set of dry eye criteria. Setting Walter Reed Army Medical Center, Washington, DC, USA Methods This is a prospective non-randomized clinical study of 143 active duty U.S. Army personnel aged 29.9±5.2 years with myopia or myopic astigmatism (manifest spherical equivalent −3.83±1.96 diopters) undergoing either PRK or LASIK. Dry eye evaluation was performed pre- and postoperatively. Main outcome measures included dry eye manifestations, incidence, and predictive factors of chronic dry eye. Results Schirmer scores, corneal sensitivity, ocular surface staining, surface regularity index (SRI), and responses to dry eye questionnaire significantly changed over time after PRK. After LASIK, significant changes were observed in tear breakup time, corneal sensitivity, ocular surface staining, and responses to questionnaire. At twelve months postoperatively, 5.0% of PRK and 0.8% of LASIK participants developed chronic dry eye. Regression analysis showed preoperatively lower Schirmer score will significantly influence development of chronic dry eye after PRK whereas preoperatively lower Schirmer score or higher ocular surface staining score will significantly influence the occurrence of chronic dry eye after LASIK. Conclusions Chronic dry eye is uncommon after PRK and LASIK. Ocular surface and tear film characteristics during preoperative examination may help predict chronic dry eye development in PRK and LASIK. PMID:26796443

Astigmatism induced by conventional spherical ablation after PRK and LASIK in myopia with astigmatism < 1.00 D

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Christiansen SM

2012-12-01

Full Text Available Steven M Christiansen,1 Mark D Mifflin,1 Jason N Edmonds,1 Rachel G Simpson,2 Majid Moshirfar11John A Moran Eye Center, University of Utah, Salt Lake City, UT, 2The University of Arizona College of Medicine, Phoenix, AZ, USABackground: The purpose of this study was to evaluate surgically-induced astigmatism after spherical ablation in photorefractive keratectomy (PRK and laser-assisted in situ keratomileusis (LASIK for myopia with astigmatism < 1.00 D.Methods: The charts of patients undergoing spherical PRK or LASIK for the correction of myopia with minimal astigmatism of <1.00 D from 2002 to 2012 at the John A Moran Eye Center in Salt Lake City, UT, were retrospectively reviewed. Astigmatism was measured by manifest refraction. The final astigmatic refractive outcome at 6 months postoperatively was compared with the initial refraction by Alpins vector analysis.Results: For PRK, average cylinder increased from 0.39 ± 0.25 (0.00–0.75 preoperatively to 0.55 ± 0.48 (0.00–1.75 postoperatively (P = 0.014, compared with an increase in LASIK eyes from 0.40 ± 0.27 (0.00–0.75 preoperatively to 0.52 ± 0.45 (0.00–2.00 postoperatively (P = 0.041. PRK eyes experienced an absolute value change in cylinder of 0.41 ± 0.32 (0.00–1.50 and LASIK eyes experienced a change of 0.41 ± 0.31 (0.00–1.50, P = 0.955. Mean surgically-induced astigmatism was 0.59 ± 0.35 (0.00–1.70 in PRK eyes, with an increase in surgically-induced astigmatism of 0.44 D for each additional 1.00 D of preoperative cylinder; in LASIK eyes, mean surgically-induced astigmatism was 0.55 ± 0.32 (0.00–1.80, P = 0.482, with an increase in surgically-induced astigmatism of 0.29 D for each 1.00 D of preoperative cylinder.Conclusion: Spherical ablation can induce substantial astigmatism even in eyes with less than one diopter of preoperative astigmatism in both PRK and LASIK. No significant difference in the magnitude of surgically-induced astigmatism was found between eyes

One-year outcomes of a bilateral randomised prospective clinical trial comparing PRK with mitomycin C and LASIK.

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Wallau, A D; Campos, M

2009-12-01

To compare 1-year follow-up results of photorefractive keratectomy (PRK) with mitomycin C (MMC) and laser in situ keratomileusis (LASIK) for custom correction of myopia. Eighty-eight eyes of 44 patients with moderate myopia were randomised to PRK with 0.002% MMC for 1 min in one eye and LASIK in the fellow eye. The 1-year follow-up was evaluated. There were no differences between LASIK and MMC-PRK eyes preoperatively. Forty-two patients completed the 1-year follow-up. MMC-PRK eyes achieved better uncorrected visual acuity (p = 0.03) and better best-spectacle-corrected visual acuity (pPRK eyes postoperatively. Excellent vision was reported in 64% of LASIK and 74% of MMC-PRK eyes 1 year after surgery. The corneal resistance factor and corneal hysteresis (ORA, Reichert) were higher in LASIK than in MMC-PRK eyes (pPRK with 0.002% MMC was more effective than wavefront-guided LASIK for correction of moderate myopia. Further research is necessary to determine the optimal concentration, exposure time and long-term corneal side effect of MMC.

Dry Eye after Small Incision Lenticule Extraction (SMILE) versus Femtosecond Laser-Assisted in Situ Keratomileusis (FS-LASIK) for Myopia: A Meta-Analysis.

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Shen, Zeren; Zhu, Yanan; Song, Xiaohui; Yan, Jie; Yao, Ke

2016-01-01

To compare dry eye after small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK (FS-LASIK) for correcting myopia. CENTRAL, Embase and PubMed were searched in November 2016. All randomized controlled trials (RCTs) and prospective cohorts that compared dry eye after SMILE with FS-LASIK were selected. Five cohorts and one RCT were identified for comparing dry eye after SMILE (291 eyes) and FS-LASIK (277 eyes). The pooled results revealed that the SMILE and FS-LASIK groups did not differ significantly in terms of Schirmer's I test (SIT) and tear film osmolarity (TFO) at any postoperative visits. By contrast, tear break up time (TBUT; p = 0.04 for one month, p LASIK group than in the SMILE group at follow-up. At six months postoperatively, TBUT and TFO values in both the SMILE and FS-LASIK groups and OSDI scores in the SMILE group returned to preoperative levels, but SIT values in both groups (p = 0.02 for the SMILE group and p LASIK group) and OSDI in the FS-LASIK group (p LASIK usually occurs transiently. SMILE does not show obvious superiority over FS-LASIK by exhibiting similar and acceptable objective parameters, and SMILE may have milder subjective symptoms.

Small Incision Lenticule Extraction (SMILE) vs. Femtosecond Laser in Situ Keratomileusis (FS-LASIK) for treatment of myopia.

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Hansen, Rasmus Søgaard; Lyhne, Niels; Justesen, Birgitte; Grauslund, Jakob; Vestergaard, Anders Højslet

2014-01-01

Purpose: - 67 ord LASIK has been the dominating corneal refractive procedure for almost two decades, but the new flap-free SMILE procedure has shown promising results. The aim of this study was to evaluate and compare refractive predictability, uncorrected and corrected distance visual acuity (UDVA and CDVA), and safety at 1 day, 1 week and 3 months after SMILE and FS-LASIK for all degrees of myopia, but in particular high myopia. Setting: Department of Ophthalmology, Odense University Hospit...

Predictive factor analysis for successful performance of iris recognition-assisted dynamic rotational eye tracking during laser in situ keratomileusis.

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Prakash, Gaurav; Ashok Kumar, Dhivya; Agarwal, Amar; Jacob, Soosan; Sarvanan, Yoga; Agarwal, Athiya

2010-02-01

To analyze the predictive factors associated with success of iris recognition and dynamic rotational eye tracking on a laser in situ keratomileusis (LASIK) platform with active assessment and correction of intraoperative cyclotorsion. Interventional case series. Two hundred seventy-five eyes of 142 consecutive candidates underwent LASIK with attempted iris recognition and dynamic rotational tracking on the Technolas 217z100 platform (Techolas Perfect Vision, St Louis, Missouri, USA) at a tertiary care ophthalmic hospital. The main outcome measures were age, gender, flap creation method (femtosecond, microkeratome, epi-LASIK), success of static rotational tracking, ablation algorithm, pulses, and depth; preablation and intraablation rotational activity were analyzed and evaluated using regression models. Preablation static iris recognition was successful in 247 eyes, without difference in flap creation methods (P = .6). Age (partial correlation, -0.16; P = .014), amount of pulses (partial correlation, 0.39; P = 1.6 x 10(-8)), and gender (P = .02) were significant predictive factors for the amount of intraoperative cyclodeviation. Tracking difficulties leading to linking the ablation with a new intraoperatively acquired iris image were more with femtosecond-assisted flaps (P = 2.8 x 10(-7)) and the amount of intraoperative cyclotorsion (P = .02). However, the number of cases having nonresolvable failure of intraoperative rotational tracking was similar in the 3 flap creation methods (P = .22). Intraoperative cyclotorsional activity depends on the age, gender, and duration of ablation (pulses delivered). Femtosecond flaps do not seem to have a disadvantage over microkeratome flaps as far as iris recognition and success of intraoperative dynamic rotational tracking is concerned. Copyright (c) 2010 Elsevier Inc. All rights reserved.

A retrospective comparison of efficacy and safety of 680 consecutive lasik treatments for high myopia performed with two generations of flying-spot excimer lasers.

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Gazieva, Lola; Beer, Mette Hjuler; Nielsen, Kim; Hjortdal, Jesper

2011-12-01

To compare the visual refractive outcome and complication of laser in situ keratomileusis (LASIK) carried out with a Carl Zeiss-Meditec MEL-70 Excimer laser and a MEL-80 laser for treatment of high myopia. Journal records of 680 consecutive eyes that underwent LASIK with a Schwind Supratome microkeratome and a MEL-70 Excimer laser (Group A), or a Moria M2 microkeratome and a MEL-80 Excimer laser (Group B) were reviewed. Manifest refraction, uncorrected and best spectacle-corrected visual acuity (BSCVA), corneal topography and central corneal thickness (CCT) were recorded before and 3 months after treatment. Pre- and postoperative complications, visual and refractive outcome and frequency of retreatments were registered. Mean preoperative spherical equivalent refraction was -8.52 dioptres (-5.50- -18 dioptres), and the mean attempted laser correction was -8.02 dioptres (-5.50- -11 dioptres). Three months after LASIK, the average treatment error (difference between achieved and attempted correction) was 1.20 (SD=1.19) dioptres of under correction in Group A and 0.52 (SD=1.00) dioptres in Group B. Four eyes lost more than two lines of BSCVA (0.6%). In 110 eyes (16%), a re-LASIK procedure was performed to reduce remaining myopia after the primary procedure. Laser in situ keratomileusis treatment for high myopia can effectively reduce high degrees of myopia. Under correction was observed in both treatment groups but Group B has a slightly better predictability. Significant loss of BSCVA occurs infrequently after LASIK for even considerable grades of myopia (0.6% in each group). © 2010 The Authors. Journal compilation © 2010 Acta Ophthalmol.

Comparison of DLK incidence after laser in situ keratomileusis associated with two femtosecond lasers: Femto LDV and IntraLase FS60

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Tomita M

2013-07-01

Full Text Available Minoru Tomita,1–3 Yuko Sotoyama,1 Satoshi Yukawa,1 Tadayuki Nakamura1 1Shinagawa LASIK Center, Chiyoda-ku, Tokyo, Japan; 2Department of Ophthalmology, Wenzhou Medical College, Wenzhou, People’s Republic of China; 3Eye Can Cataract Surgery Center, Manila, Philippines Purpose: To compare the incidence of diffuse lamellar keratitis (DLK after laser in situ keratomileusis (LASIK with flap creation using the Femto LDV and IntraLase™ FS60 femtosecond lasers. Methods: A total of 818 consecutive myopic eyes had LASIK performed using either Femto LDV or IntraLase FS60 for flap creation. The same excimer laser, the Allegretto Wave® Eye-Q Laser, was used for correcting refractive errors for all patients. In the preoperative examination, uncorrected distance visual acuity, corrected distance visual acuity, and manifest refraction spherical equivalent were measured. At the postop examination, the same examinations were performed along with a slit-lamp biomicroscopic examination, and patients with DLK were classified into stages. For the statistical analysis of the DLK occurrence rate and the visual and refractive outcomes, the Mann-Whitney’s U-test was used. Results: In the Femto LDV group with 514 eyes, 42 (8.17% had DLK. In the IntraLase FS60 group with 304 eyes, 114 (37.5% had DLK. There was a statistically significant difference in the DLK incidence rate between these groups (P < 0.0001. Both groups had excellent visual and refractive outcomes. Although low levels of DLK were observed for both groups, they did not affect visual acuity. Conclusion: While there were significantly fewer incidences of low level DLK when using Femto LDV, neither femtosecond laser induced high levels of DLK, and any postoperative DLK cleared up within 1 week. Therefore, both lasers provide excellent results, with no clinical differences, and both excel at flap creation for LASIK. Keywords: LASIK, Ziemer, Femto LDV, DLK, IntraLase FS60, femtosecond laser

Induced Higher-order aberrations after Laser In Situ Keratomileusis (LASIK) Performed with Wavefront-Guided IntraLase Femtosecond Laser in moderate to high Astigmatism.

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Al-Zeraid, Ferial M; Osuagwu, Uchechukwu L

2016-03-22

Wavefront-guided Laser-assisted in situ keratomileusis (LASIK) is a widespread and effective surgical treatment for myopia and astigmatic correction but whether it induces higher-order aberrations remains controversial. The study was designed to evaluate the changes in higher-order aberrations after wavefront-guided ablation with IntraLase femtosecond laser in moderate to high astigmatism. Twenty-three eyes of 15 patients with moderate to high astigmatism (mean cylinder, -3.22 ± 0.59 dioptres) aged between 19 and 35 years (mean age, 25.6 ± 4.9 years) were included in this prospective study. Subjects with cylinder ≥ 1.5 and ≤2.75 D were classified as moderate astigmatism while high astigmatism was ≥3.00 D. All patients underwent a femtosecond laser-enabled (150-kHz IntraLase iFS; Abbott Medical Optics Inc) wavefront-guided ablation. Uncorrected (UDVA), corrected (CDVA) distance visual acuity in logMAR, keratometry, central corneal thickness (CCT) and higher-order aberrations (HOAs) over a 6 mm pupil, were assessed before and 6 months, postoperatively. The relationship between postoperative change in HOA and preoperative mean spherical equivalent refraction, mean astigmatism, and postoperative CCT were tested. At the last follow-up, the mean UDVA was increased (P < 0.0001) but CDVA remained unchanged (P = 0.48) and no eyes lost ≥2 lines of CDVA. Mean spherical equivalent refraction was reduced (P < 0.0001) and was within ±0.50 D range in 61% of eyes. The average corneal curvature was flatter by 4 D and CCT was reduced by 83 μm (P < 0.0001, for all), postoperatively. Coma aberrations remained unchanged (P = 0.07) while the change in trefoil (P = 0.047) postoperatively, was not clinically significant. The 4th order HOAs (spherical aberration and secondary astigmatism) and the HOA root mean square (RMS) increased from -0.18 ± 0.07 μm, 0.04 ± 0.03 μm and 0.47 ± 0.11 μm, preoperatively, to 0.33 ± 0

Retinal peripheral changes after LASIK Alterações da retina periférica após LASIK

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João Jorge Nassaralla Junior

2008-06-01

Full Text Available PURPOSE: To better define the effect of laser in situ keratomileusis (LASIK on myopic eyes and the risk and incidence of retinal complications after surgery. METHODS: In a prospective study, 200 eyes of 100 patients, 49 male and 51 female, with a mean age of 29.7 years, had a complete posterior pole examination before and at 1 week, 1, 3 and 12 months after bilateral simultaneous LASIK for the correction of myopia. Mean spherical equivalent was 7.75D (range 1.00 to -17.25D. Before LASIK, preventive treatment was carried out on predisposing lesions to retinal complications, with laser photocoagulation. RE: Before surgery, the ophthalmic features were: 86 eyes (43% presented no peripheral abnormalities; 49 eyes (24.5% had lattice degeneration; 18 eyes (9%, white without pressure; 5 eyes (2.5%, white with pressure; 33 (16.5%, oral chorioretinal degenerations; 6 (3%, paving stone; 45 (22.5%, posterior vitreous detachment; 20 (10%, retinal vitreous traction; and 12 (6%, round holes. Comparing the incidence of ophthalmic features before and at one year after surgery, there was not a statistical significant difference (P>0.05. CONCLUSION: Although retinal pathologic conditions have been described as complications after LASIK, our data did not reveal a cause-effect relationship between the refractive error corrective procedure and retinal complications. The retinal changes found after LASIK in this series of patients, appear to reflect the predisposition of myopes. Both patient and doctor should be aware that, even after the refractive error correction, the risk of complications related to the myopic eye would persist.OBJETIVO: Definir melhor o efeito da técnica laser in situ keratomileusis (LASIK em olhos míopes, o risco e a incidência de complicações retinianas após a cirurgia. Este estudo foi realizado no Instituto de Olhos de Goiânia. MÉTODOS: Em um estudo prospectivo, 200 olhos de 100 pacientes, 50 homens e 50 mulheres, com idade média de

Complicações per e pós-operatórias em 1000 olhos submetidos a LASIK An analysis of intraoperative and postoperative complications in 1000 laser in situ keratomileusis cases

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Telma Pereira

2001-11-01

Full Text Available Objetivo: Analisar a incidência, tipo, tratamento e evolução das complicações em LASIK. Métodos: Estudo retrospectivo de 1000 olhos submetidos a LASIK usando os microceratótomos Hansatome® ou Automated Corneal Shaper® e os aparelhos de Excimer Laser VISX 20/20B ou Chiron Technolas 217C. Complicações peroperatórias e pós-operatórias precoces e tardias foram analisadas. Resultados: A média do equivalente esférico pré-operatório foi de -4,29 ± 3,20D. A média do seguimento foi de 6,05 ± 6,69 meses. No período peroperatório foram encontradas cinco (0,5% complicações do disco relacionadas ao microceratótomo (3 discos finos, 1 disco com perfuração central e 1 disco pequeno. As complicações mais freqüentes no período pós-operatório precoce foram as dobras de disco (6,4%, seguidas de debris na interface (4,1%, ceratite não específica da interface (1,1%, "haze" (0,4%, crescimento epitelial da interface (0,4% e deslocamento de disco (0,3%. A maioria destes eventos foi prontamente tratada, alcançando-se bons resultados. Para as complicações tardias, relacionadas à refração, foram analisados 655 olhos que apresentavam seguimento mínimo de 3 meses. No último exame, a média do equivalente esférico neste grupo foi de -0,26±0,76D. Oito por cento dos olhos encontravam-se com hipocorreção superior a 1,00D; e 1,67% com hipercorreção > 1,00D. Retratamento foi necessário em 28 olhos (4,27%. Cinco casos (0,76% perderam de 2 ou mais linhas da melhor acuidade visual corrigida. Não foram observadas outras complicações visualmente importantes. Conclusão: LASIK é um procedimento refrativo seguro e com poucas complicações.Purpose: To analyze the incidence, type, management and evolution of complications in laser in situ keratomileusis (LASIK. Methods: Retrospective non-comparative case series. LASIK was performed in 1000 eyes using the Hansatome® or the Automated Corneal Shaper® microkeratomes, and the VISX 20/20B

Visual and flight performance recovery after PRK or LASIK in helicopter pilots.

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Van de Pol, Corina; Greig, Joanna L; Estrada, Art; Bissette, Gina M; Bower, Kraig S

2007-06-01

Refractive surgery, specifically photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK), is becoming more accepted in the military environment. Determination of the impact on visual performance in the more demanding aviation environment was the impetus for this study. A prospective evaluation of 20 Black Hawk pilots pre-surgically and at 1 wk, 1 mo, and 6 mo postsurgery was conducted to assess both PRK and LASIK visual and flight performance outcomes on the return of aviators to duty. Of 20 pilots, 19 returned to flight status at 1 mo after surgery; 1 PRK subject was delayed due to corneal haze and subjective visual symptoms. Improvements were seen under simulator night and night vision goggle flight after LASIK; no significant changes in flight performance were measured in the aircraft. Results indicated a significantly faster recovery of all visual performance outcomes 1 wk after LASIK vs. PRK, with no difference between procedures at 1 and 6 mo. Low contrast acuity and contrast sensitivity only weakly correlated to flight performance in the early post-operative period. Overall flight performance assessed in this study after PRK and LASIK was stable or improved from baseline, indicating a resilience of performance despite measured decrements in visual performance, especially in PRK. More visually demanding flight tasks may be impacted by subtle changes in visual performance. Contrast tests are more sensitive to the effects of refractive surgical intervention and may prove to be a better indicator of visual recovery for return to flight status.

Fundus oculi pigmentation studies simulating the fs-LASIK process

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Sander, M; Tetz, M R [Berlin Eye Research Institute, Alt Moabit 101b, 10559 Berlin (Germany); Minet, O; Zabarylo, U [Charite Centrum 6, Arbeitsgruppe Medizinische Physik/Optische Diagnostik, Fabeckstrasse 60–62, 14195 Berlin (Germany); Mueller, M [Augenklinik Ahaus, Am Schlossgraben 13, 48683 Ahaus (Germany)

2012-06-15

The femtosecond-laser in situ keratomileusis (fs-LASIK) technique has successfully entered the refractive surgery market to correct ametropia by cutting transparent corneal tissue with ultra-short laser pulses based on photodisruption. The laser pulses in the near infrared range (NIR) generate a laser-induced breakdown (LIOB) in the cornea. By propagating through the eye, a certain amount of the pulse is deposited in the cornea and the remaining energy interacts with the strong absorbing tissue behind. Due to the absorption by the retinal pigment epithelium and the transfer of the thermal energy to surrounding tissue, the transmitted energy can induce damage to the retina. The aim of this project was to find out the threshold influences concerning the tissue and the correlation between the results of the macroscopical appraisal and the fundus oculi pigmentation by simulating the fs-LASIK procedure with two various laser systems in the continuous wave (CW) and fs-regime. Therefore ex-vivo determinations were carried out macroscopically and histopathologically on porcine tissue.

Fundus oculi pigmentation studies simulating the fs-LASIK process

International Nuclear Information System (INIS)

Sander, M; Tetz, M R; Minet, O; Zabarylo, U; Mueller, M

2012-01-01

The femtosecond-laser in situ keratomileusis (fs-LASIK) technique has successfully entered the refractive surgery market to correct ametropia by cutting transparent corneal tissue with ultra-short laser pulses based on photodisruption. The laser pulses in the near infrared range (NIR) generate a laser-induced breakdown (LIOB) in the cornea. By propagating through the eye, a certain amount of the pulse is deposited in the cornea and the remaining energy interacts with the strong absorbing tissue behind. Due to the absorption by the retinal pigment epithelium and the transfer of the thermal energy to surrounding tissue, the transmitted energy can induce damage to the retina. The aim of this project was to find out the threshold influences concerning the tissue and the correlation between the results of the macroscopical appraisal and the fundus oculi pigmentation by simulating the fs-LASIK procedure with two various laser systems in the continuous wave (CW) and fs-regime. Therefore ex-vivo determinations were carried out macroscopically and histopathologically on porcine tissue

Corneal collagen cross-linking in the stabilization of PRK, LASIK, thermal keratoplasty, and orthokeratology.

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Nguyen, Michelle K; Chuck, Roy S

2013-07-01

To describe the use of corneal collagen cross-linking (CXL) and its efficacy in the stabilization of keratorefractive procedures, including PRK, laser in-situ keratomileusis (LASIK), thermal keratoplasty, and orthokeratology. Since its introduction, CXL has quickly gained interest in the treatment of ectactic disorders due to its ability to increase the biomechanical stability of the cornea. In its earliest use, it has shown to be effective in the treatment of both keratoconus and post-LASIK ectasia. More recent studies of CXL in combination with keratorefractive procedures have shown varying degrees of success. CXL with PRK has shown to be effective in slowing or halting the progression of keratoconus, pellucid marginal degeneration, and post-LASIK ectasia, in addition to potentially decreasing or delaying the need for penetrating keratoplasty. Several small case series have also demonstrated improved stability and efficacy of PRK and LASIK when combined with CXL, as well as a potentially decreased risk of postprocedure ectasia. In conjunction with thermokeratoplasty and orthokeratology, CXL has shown improved but only temporary results in the treatment of keratoconus. Future studies are needed to determine the efficacy and long-term stability of CXL in combination with keratorefractive procedures, as well as to address possible complications.

[LenSx® femto-LASIK, FEMTO LDV Z4® femto-LASIK, and PRK : Comparison of refractive results and an analysis of complications].

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Pahlitzsch, T; Pahlitzsch, M-L; Sumarni, U; Pahlitzsch, M

2017-10-30

The aim of this study is to evaluate three refractive procedures: LenSx® (Alcon, Fort Worth, TX, USA) femto-laser in situ keratomileusis (LASIK), FEMTO LDV Z4® (Ziemer, Port, Switzerland) femto-LASIK, and photorefractive keratectomy (PRK) in terms of refractive outcome, perioperative complications, pain, and patient satisfaction. Data of 168 eyes (myopic n = 84) were included in this retrospective study. Of these, 54 eyes (n = 27, 33.85 ± 7.64 years) were treated with LenSx® femto-LASIK, 60 eyes (n = 30, 35.03 ± 7.46 years) with FEMTO LDV Z4® femto-LASIK, and 54 eyes (n = 27, 33.24 ± 8.52 years) with PRK. Photoablation was induced by a MEL80 Excimerlaser (Zeiss, Oberkochen, Germany). The corrected (V sc ) and uncorrected (V cc ) distance subjective visual acuity, corneal topography (Pentacam® HR; Wetzlar, Germany), and objective astigmatism (ARK-760A Refractometer ; Nidek, Fremont, CA, USA) were measured preoperatively, and 1 day, 1 week, 1 month, and 3 months postoperatively. Subjective pain (verbal rating scale) and patient satisfaction were also recorded. Subjective V sc showed significantly better results in both femto-LASIK cohorts compared to PRK (p PRK cohorts (p = 0.072). LDV Z4® femto-LASIK showed the lowest pain score 1 day postoperatively (p PRK. There is no difference between the three techniques regarding refractive outcome after 3 months follow-up. LDV Z4® femto-LASIK can be recommended, if available, due to its low intraoperative complication rate and higher patient satisfaction compared to LenSx® femto-LASIK.

A retrospective analysis of the postoperative use of loteprednol etabonate gel 0.5% following laser-assisted in situ keratomileusis or photorefractive keratectomy surgery

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Salinger CL

2015-11-01

Full Text Available Clifford L Salinger,1 Michael Gordon,2 Mitchell A Jackson,3 Theodore Perl,4 Eric Donnenfeld5 1VIP Laser Eye Center, Palm Beach Gardens, FL, 2Gordon Weiss Schanzlin Vision Institute, San Diego, CA, 3Jacksoneye, Lake Villa, IL, 4Corneal Associates of New Jersey, Fairfield, NJ, 5Ophthalmic Consultants of Long Island, Garden City, NY, USA Background: While loteprednol etabonate ophthalmic gel 0.5% (LE gel is approved for treatment of postoperative ocular inflammation and pain, there have been no reported studies in patients undergoing laser-assisted in situ keratomileusis (LASIK or photorefractive keratectomy (PRK.Methods: This was a retrospective chart review conducted at five refractive surgical centers in the USA. Data were collected from primary LASIK or PRK surgery cases in which LE gel was used postoperatively as the clinician’s routine standard of care and in which patients were followed-up for up to 6 months. Data extracted from charts included patient demographics, surgical details, LE gel dosing regimen, pre- and postsurgical refractive characteristics, intraocular pressure (IOP measurements, and visual acuity. Primary outcomes included postoperative IOP elevations, adverse events, and early discontinuations.Results: Data were collected on 189 LASIK eyes (96 patients and 209 PRK eyes (108 patients. Mean (standard deviation [SD] years of age at surgery was 36.0 (11.7 and 33.9 (11.3 in LASIK and PRK patients. LE gel was prescribed most often four times daily during the first postoperative week, regardless of procedure; the most common treatment duration was 7–14 days in LASIK and ≥30 days in PRK patients. No unusual corneal findings or healing abnormalities were reported. Mean postoperative uncorrected distance visual acuity was 20/24 in LASIK and 20/30 in PRK eyes. Mild/trace corneal haze was reported in 20% of PRK patients; two PRK patients with moderate/severe corneal haze were switched to another corticosteroid. Mean postoperative

[Scattered light and glare sensitivity after wavefront-guided photorefractive keratectomy (WFG-PRK) and laser in situ keratomileusis (WFG-LASIK)].

Science.gov (United States)

Vignal, R; Tanzer, D; Brunstetter, T; Schallhorn, S

2008-05-01

To compare glare sensitivity measured by the intraocular scattered light between WFG-PRK and WFG-LASIK at 12 months follow-up and to assess its correlation to patients' complaints. Prospective and randomized study on 13 patients treated with WFG-LASIK, 13 patients with WFG-PRK and a control group of 35 patients. The intraocular stray light was measured by the Oculus C-Quant 12 months after surgery and before surgery for the control group. Photopic and mesopic contrast acuity and glare symptoms were reported pre- and postoperatively. Stray light values were normal in 79% of patients after WFG-LASIK and PRK and 86% in the control group, with mean values of 1.05 log, 1.03 log, and 0.99 log, respectively (p>0.05). All the patients with significant glare complaints had impaired stray light values versus 31.5% in the no-complaint group. Photopic and mesopic contrast acuity and glare symptoms were improved 1 year after surgery compared to preoperatively (no significant difference between groups). WFG-LASIK and PRK are safe and equivalent procedures regarding quality of vision. The measurement of stray light can be a discriminative test to assessing patients' glare complaints.

Comparison of Higher Order Aberrations after Wavefront-guided LASIK and PRK: One Year Follow-Up Results.

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Jahadi Hosseini, Seyed Hamid Reza; Abtahi, Seyed Mohammad Bagher; Khalili, Mohammad Reza

2016-01-01

To evaluate the changes and predictability of higher order aberrations (HOAs) after personalized laser in situ keratomileusis (LASIK) and personalized photorefractive keratectomy (PRK) for simple myopia and compound myopic astigmatism. In this prospective cross-sectional study, 100 eyes were included. A total of 50 eyes underwent personalized LASIK and 50 eyes underwent personalized PRK. Preoperative and postoperative wavefront data were compared between the two groups. The influential factors and predictability of HOAs were also assessed. Total HOA increased in the amount of 0.01 ± 0.14 μm for the 5 mm pupil ( P = 0.55) and 0.08 ± 0.22 μm for the 6 mm pupil ( P = 0.02) after PRK; however after LASIK the corresponding values for the 5 and 6 mm pupil sizes were 0.05 ± 0.12 and 0.15 ± 0.18 μm, respectively ( P PRK and LASIK groups for both 5 and 6 mm pupil sizes ( P = 0.21 and P = 0.13, respectively). Spherical aberration increased following LASIK more than following PRK ( P PRK and LASIK with no significant difference between the two groups. Change of the total HOA RMS was influenced by the preoperative values. The known influencing factors could predict nearly 50% of the changes in total HOA.

Three-year results of small incision lenticule extraction and wavefront-guided femtosecond laser-assisted laser in situ keratomileusis for correction of high myopia and myopic astigmatism.

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Xia, Li-Kun; Ma, Jing; Liu, He-Nan; Shi, Ce; Huang, Qing

2018-01-01

To compare and calculate the 3-year refractive results, higher-order aberrations (HOAs), contrast sensitivity (CS) and dry eye parameters after small incision lenticule extraction (SMILE) and wavefront-guided femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) for correction of high myopia and myopic astigmatism. In this prospective, non-randomized comparative study, 78 eyes with spherical equivalent (SE) of -8.11±1.09 diopters (D) received a SMILE surgery, and 65 eyes with SE of -8.05±1.12 D received a wavefront-guided FS-LASIK surgery with the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) for flap cutting. Visual acuity, manifest refraction, CS, HOAs, ocular surface disease index (OSDI) and tear break-up time (TBUT) were evaluated during a 3-year follow-up. The difference of uncorrected distance visual acuity (UDVA) postoperatively was achieved at 1mo and at 3mo, whereas the difference of the mean UDVA between two groups at 3y were not statistically significant ( t =-1.59, P =0.13). The postoperative change of SE was 0.89 D in the FS-LASIK group ( t =5.76, P =0.00), and 0.14 D in the SMILE group ( t =0.54, P =0.59) from 1mo to 3y after surgery. At 3-year postoperatively, both HOAs and spherical aberrations in the SMILE group were obviously less than those in the FS-LASIK group ( P =0.00), but the coma root mean square (RMS) was higher in the SMILE group (0.59±0.26) than in the FS-LASIK group (0.29±0.14, P =0.00). The mesopic CS values between two groups were not statistically significant at 3y postoperatively. Compared with the FS-LASIK group, lower OSDI scores and longer TBUT values were found in the SMILE group at 1mo and 3mo postoperatively. With regard to safety, no eye lost any line of CDVA in both groups at 3y after surgery. Both SMILE and wavefront-guided FS-LASIK procedures provide good visual outcomes. Both procedures are effective and safe, but SMILE surgery achieve more stable long-term refractive outcome and better

PRK versus LASIK para correção de miopia baixa e moderada PRK versus LASIK for correction of low and moderate myopia

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Adriana dos Santos Forseto

2000-08-01

Full Text Available Objetivo: Comparar, por meio de um estudo prospectivo e bilateral randomizado, a eficácia, segurança e previsibilidade das técnicas de ceratectomia fotorrefrativa (PRK e "excimer laser in situ keratomileusis" (LASIK para o tratamento da miopia baixa e moderada. Métodos: Foram incluídos dezessete pacientes (34 olhos com equivalente esférico (EE refracional entre -2,00 e -6,00 dioptrias (D. Cada paciente foi submetido a PRK em um olho e LASIK no outro. Ambos os olhos foram tratados no mesmo dia pelo mesmo cirurgião, com o excimer laser VISX 20/20B e o microceratótomo automatizado da Chiron. Resultados: No pré-operatório, a média do EE refracional foi semelhante nos dois grupos (-3,57±1,17D e -3,71±0,98D, para PRK e LASIK, respectivamente. Dor pós-operatória foi referida somente nos casos de PRK (8 olhos: 47,1%. O seguimento pós-operatório médio foi de 14±5 meses (6 a 24 para o grupo de PRK, e 14±6 meses (3 a 24 para o de LASIK. A média do erro refrativo residual foi semelhante nos dois grupos (-0,34±0,45D e -0,29±0,52D, para PRK e LASIK, respectivamente. No primeiro dia pós-tratamento, 15 olhos (100% do grupo de LASIK e 2 (13,3% de PRK apresentavam acuidade visual sem correção (AV s/c ³ 20/40 (n=15. Ao último exame, 15 olhos (88,2% de LASIK contra 11 (64,7% de PRK atingiram AV s/c ³ 20/20 (n=17. Não houve perda da melhor acuidade visual corrigida. Conclusão: Neste estudo, tanto o PRK quanto o LASIK mostraram-se ser tecnicamente seguros, eficazes e previsíveis para a correção da miopia baixa e moderada. A técnica de LASIK foi a preferida na análise subjetiva dos pacientes, pela recuperação visual mais precoce associada a menor dor no pós-operatório.Purpose: To compare, through a prospective, randomized and bilateral study, the effectiveness, safety and predic-tability of photorefractive keratectomy (PRK and excimer laser in situ keratomileusis (LASIK for correction of low and moderate myopia. Methods

Comparison of 5468 retreatments after laser in situ keratomileusis by lifting the flap or performing photorefractive keratectomy on the flap.

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Ortega-Usobiaga, J; Llovet-Osuna, F; Katz, T; Djodeyre, M R; Druchkiv, V; Bilbao-Calabuig, R; Baviera, J

2018-02-01

To assess visual outcomes of retreatment after laser in situ keratomileusis (LASIK) by lifting the flap or performing photorefractive keratectomy (PRK) on the flap, as well as to establish whether there was an increased risk of epithelial ingrowth (EIG) when LASIK and lifting of the flap are separated by a long time interval and to determine the incidence of corneal haze after PRK. Retrospective study of 4077 patients (5468 eyes) who underwent LASIK and subsequent retreatment were reviewed in order to study their visual results and identify cases of EIG and corneal haze. Enhancements included 5196 eyes from 3876 patients that were retreated by lifting the flap, and 272 eyes from 201 patients that were retreated by PRK on the flap. No statistically significant differences were found between the retreatments in terms of predictability, efficacy, and safety. A total of 704 cases of EIG were found after lifting the flap, for which surgical cleansing was necessary in 70. Surgical cleansing decreased the efficacy index when compared with patients with EIG who did not need cleansing (P=.01). Differences in terms of safety and predictability were not statistically significant. The incidence of corneal haze after ablation of the surface of the previous flap was 14.34%, although none of these cases were clinically relevant. Visual outcomes were similar between patients who were retreated by lifting the flap and those who underwent PRK. The incidence of EIG when the flap was lifted was 13.55%. The incidence of EIG increases with the time elapsed between the primary procedure and retreatment. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

Dry eyes and corneal sensation after laser in situ keratomileusis with femtosecond laser flap creation Effect of hinge position, hinge angle, and flap thickness.

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Mian, Shahzad I; Li, Amy Y; Dutta, Satavisha; Musch, David C; Shtein, Roni M

2009-12-01

To determine whether corneal sensation and dry-eye signs and symptoms after myopic laser in situ keratomileusis (LASIK) surgery with a femtosecond laser are affected by varying hinge position, hinge angle, or flap thickness. University-based academic practice, Ann Arbor, Michigan, USA. This prospective randomized contralateral-eye study evaluated eyes after bilateral myopic LASIK with a femtosecond laser (IntraLase). Superior and temporal hinge positions, 45-degree and 90-degree hinge angles, and 100 microm and 130 microm corneal flap thicknesses were compared. Postoperative follow-up at 1 week and 1, 3, 6, and 12 months included central Cochet-Bonnet esthesiometry, the Ocular Surface Disease Index questionnaire, a Schirmer test with anesthesia, tear breakup time (TBUT), corneal fluorescein staining, and conjunctival lissamine green staining. The study evaluated 190 consecutive eyes (95 patients). Corneal sensation was reduced at all postoperative visits, with improvement over 12 months (P<.001). There was no difference in corneal sensation between the different hinge positions, angles, or flap thicknesses at any time point. The overall ocular surface disease index score was increased at 1 week, 1 month, and 3 months (P<.0001, P<.0001, and P = .046, respectively). The percentage of patients with a TBUT longer than 10 seconds was significantly lower at 1 week and 1 month (P<.0001). Dry-eye syndrome after myopic LASIK with a femtosecond laser was mild and improved after 3 months. Corneal flap hinge position, hinge angle, and thickness had no effect on corneal sensation or dry-eye syndrome.

Small incision lenticule extraction (SMILE) and femtosecond laser LASIK: comparison of corneal wound healing and inflammation

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Dong, Zixian; Zhou, Xingtao; Wu, Jihong; Zhang, Zhehuan; Li, Tao; Zhou, Zimei; Zhang, Shenghai; Li, Gang

2014-01-01

Aim To evaluate and compare early corneal wound healing and inflammatory responses after small incision lenticule extraction (SMILE) versus femtosecond laser laser in situ keratomileusis (LASIK). Methods Thirty-six eyes of 36 rabbits underwent SMILE, while another 36 eyes of 36 rabbits were treated with femtosecond laser LASIK. All the eyes were subjected to the same refractive correction of −6.00 DS/−1.00 DC. Twelve eyes that had no surgery were included for control. After euthanisation, corneal tissue sections were evaluated with terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling (TUNEL) assay to detect apoptosis at postoperative 4 and 24 h, immunocytochemistry for Ki67 to detect keratocyte proliferation at postoperative day 3, week 1 and month 1, and immunocytochemistry for CD11b to detect inflammation at postoperative day 1, day 3 and week 1, respectively. Results No adverse effects were noted after SMILE or LASIK. Corneal healing postoperatively was uneventful in all cases. There were significantly fewer TUNEL-positive corneal stromal cells after the SMILE procedure at 4 and 24 h postoperatively (pLASIK procedure. In addition, immunocytochemistry showed significantly fewer Ki67-positive cells in the SMILE group than those in the femtosecond laser LASIK group at day 3 and week 1 postoperatively (pLASIK. PMID:24227802

Three-year changes in epithelial and stromal thickness after PRK or LASIK for high myopia.

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Ivarsen, Anders; Fledelius, Walther; Hjortdal, Jesper Ø

2009-05-01

To compare 3-year changes in corneal sublayer thickness after photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK). Forty-six patients with spheroequivalent refraction of -6.0 to -8.0 diopters (D) were randomly assigned to PRK or LASIK. One eye from each patient was included in the study. Examinations included manifest refraction and confocal microscopy through focusing (CMTF) and were performed preoperatively and postoperatively at 1 week and at 1, 3, 6, 12, and 36 months. From CMTF scans, the thicknesses of the central cornea (CT), epithelium (ET), stroma (ST), LASIK flap (FT), and residual stromal bed (BT) were calculated. After LASIK, spheroequivalent refraction averaged -0.76 D by 1 week and -1.19 D by 1 month, with no subsequent significant change. ET increased 9.0 +/- 7.0 microm within 1 week and remained constant thereafter. ST increased 12.9 +/- 9.4 microm within 1 year because of increased BT. One week after PRK, refraction averaged -0.23 D and stabilized at -1.42 D by 6 months. By 1 week, ET was reduced by 7.5 +/- 5.7 microm, reached preoperative thickness by 6 months, and increased further 7.3 +/- 6.0 microm by 3 years. ST increased 25.3 +/- 17.2 microm during 1 year, correlating with the postoperative refractive regression. After both procedures, changes in CT also correlated with refractive changes. No other correlations were identified. PRK and LASIK induce a persistent increase in ET that stabilizes 1 week after LASIK and 1 year after PRK. Stromal regrowth is most pronounced after PRK. After LASIK, regrowth is restricted to the residual stromal bed. Postoperative refractive changes correlate with changes in ST (PRK) and CT (PRK and LASIK) but not with changes in ET.

Role of percent peripheral tissue ablated on refractive outcomes following hyperopic LASIK

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Stapleton, Fiona; Versace, Patrick

2017-01-01

Objectives To determine the effect of hyperopic laser in situ keratomileusis (H-LASIK) on corneal integrity, by investigating relationships between proportionate corneal tissue ablated and refractive outcomes at 3 months. Methods 18 eyes of 18 subjects treated with H-LASIK by Technolas 217c Excimer Laser were included in the study. Orbscan II Topography System was used to determine corneal volume and pachymetry 3mm temporally (3T). The volume of corneal tissue ablated was determined from the laser nomogram. Univariate associations between age, treatment, corneal volume, overall proportion of tissue removed, proportion of tissue removed at 3T, residual bed thickness at 3T and refractive outcomes 3 months post-LASIK were examined and independent factors associated with refractive outcomes determined using linear regression models. Results At 3 months post-LASIK, the mean difference to expected refractive outcome was -0.20 ± 0.64 (Range -2.00 to +1.00). In univariate analysis, difference to expected refractive outcome was associated with proportion of tissue removed at 3T (PLASIK, may present as either over or under-corrected at 3 months. The proportion of tissue removed at 3T was the single significant determinant of this outcome, suggesting unexpected biomechanical alterations resulting in corneal steepening. Future hyperopic LASIK procedures could consider proportionate volume of corneal tissue removed at 3T in addition to laser nomograms to achieve improved refractive outcomes. PMID:28151939

Astigmatism induced by conventional spherical ablation after PRK and LASIK in myopia with astigmatism < 1.00 D.

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Christiansen, Steven M; Mifflin, Mark D; Edmonds, Jason N; Simpson, Rachel G; Moshirfar, Majid

2012-01-01

The purpose of this study was to evaluate surgically-induced astigmatism after spherical ablation in photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK) for myopia with astigmatism PRK or LASIK for the correction of myopia with minimal astigmatism of PRK, average cylinder increased from 0.39 ± 0.25 (0.00-0.75) preoperatively to 0.55 ± 0.48 (0.00-1.75) postoperatively (P = 0.014), compared with an increase in LASIK eyes from 0.40 ± 0.27 (0.00-0.75) preoperatively to 0.52 ± 0.45 (0.00-2.00) postoperatively (P = 0.041). PRK eyes experienced an absolute value change in cylinder of 0.41 ± 0.32 (0.00-1.50) and LASIK eyes experienced a change of 0.41 ± 0.31 (0.00-1.50, P = 0.955). Mean surgically-induced astigmatism was 0.59 ± 0.35 (0.00-1.70) in PRK eyes, with an increase in surgically-induced astigmatism of 0.44 D for each additional 1.00 D of preoperative cylinder; in LASIK eyes, mean surgically-induced astigmatism was 0.55 ± 0.32 (0.00-1.80, P = 0.482), with an increase in surgically-induced astigmatism of 0.29 D for each 1.00 D of preoperative cylinder. Spherical ablation can induce substantial astigmatism even in eyes with less than one diopter of preoperative astigmatism in both PRK and LASIK. No significant difference in the magnitude of surgically-induced astigmatism was found between eyes treated with PRK and LASIK, although surgically-induced astigmatism was found to increase with greater levels of preoperative astigmatism in both PRK and LASIK.

The effect of vitamin A palmitate eye gel on ocular surface recovery after LASIK

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Yan Lu

2013-04-01

Full Text Available AIM: To study the effect of vitamin A palmitate eye gel on ocular surface reconstruction after laser in situ keratomileusis(LASIK, and to evaluate the efficacy and safety. METHODS: One hundred and twenty patients(240 eyesperforming LASIK were enrolled in this study. The right and left eyes were randomly divided into experimental group and control group. The experimental group were treated with vitamin A palmitate eye gel for 1 month, four times a day after LASIK, and the same as control group in other treatments. The SchirmerⅠ test, break-up time(BUTand corneal sensation were detect at preoperation and the postoperative 1st day, 1st month, 3rd month in two groups. RESULTS: There were significant difference in BUT and tear secretion quantity between the experimental group and the control group at the postoperative 1st month and 3rd month(P0.05, which revealed that vitamin A palmitate eye gel had no obvious effect on recovery of corneal sensation after LASIK. During the treatment, there was no adverse drug event occurred. CONCLUSION: Early use of vitamin A palmitate eye gel postoperatively is applicable for ocular surface reconstruction, but has no obvious effect on the regeneration of corneal sensation.

Outcomes of LASIK and PRK in previous penetrating corneal transplant recipients.

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Kovoor, Timmy A; Mohamed, Engy; Cavanagh, H Dwight; Bowman, R Wayne

2009-09-01

To evaluate the safety and efficacy of excimer laser refractive surgery in correcting refractive error in eyes that have undergone previous penetrating keratoplasty (PK). Twenty-three keratorefractive procedures on 16 eyes from 16 consecutive subjects were evaluated between 2002 and 2008. Each patient presented a previous history of a PK with subsequent postoperative myopia and astigmatism. Keratometric value, manifest refraction, best-corrected visual acuity, uncorrected visual acuity, and complications were determined. There were a total of 14 photorefractive keratectomy (PRK) procedures performed on 11 eyes and 9 laser in situ keratomileusis (LASIK) procedures performed on 5 eyes. In the PRK group, the preoperative post-PK manifest refractive spherical equivalent and cylindrical error were -6.22 +/- 6.23 diopter and 5.23 +/- 2.26 D, respectively. The PRK postoperative manifest refractive spherical equivalent and cylindrical error were -3.61 +/- 4.23 D (P=0.25) and 3.21 +/- 1.78 D (P=0.02), respectively. In the LASIK group, the preoperative post-PK manifest refractive spherical equivalent and cylindrical error were -3.05 +/- 3.29 D and 4.11 +/- 2.38 D, respectively. The LASIK postoperative manifest refractive spherical equivalent and cylindrical error were -1.51 +/- 2.02 D (P=0.24) and 2.08 +/- 1.26 D (P=0.03), respectively. There was a 2-line or greater improvement of uncorrected visual acuity in 8 of the 14 PRK treatments and 5 of the 9 LASIK treatments. There were two episodes of acute graft rejection. One of the episodes resolved with topical and oral corticosteroids, and the other episode required a repeat corneal transplantation. PRK and LASIK are effective tools in reducing surgically induced astigmatism after penetrating corneal transplantation in most patients in this case series. The reduction of astigmatism may allow improved contact lens or spectacle fitting to achieve best-corrected binocular visual acuity.

Three-year results of small incision lenticule extraction and wavefront-guided femtosecond laser-assisted laser in situ keratomileusis for correction of high myopia and myopic astigmatism

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Li-Kun Xia

2018-03-01

Full Text Available AIM: To compare and calculate the 3-year refractive results, higher-order aberrations (HOAs, contrast sensitivity (CS and dry eye parameters after small incision lenticule extraction (SMILE and wavefront-guided femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK for correction of high myopia and myopic astigmatism. METHODS: In this prospective, non-randomized comparative study, 78 eyes with spherical equivalent (SE of -8.11±1.09 diopters (D received a SMILE surgery, and 65 eyes with SE of -8.05±1.12 D received a wavefront-guided FS-LASIK surgery with the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany for flap cutting. Visual acuity, manifest refraction, CS, HOAs, ocular surface disease index (OSDI and tear break-up time (TBUT were evaluated during a 3-year follow-up. RESULTS: The difference of uncorrected distance visual acuity (UDVA postoperatively was achieved at 1mo and at 3mo, whereas the difference of the mean UDVA between two groups at 3y were not statistically significant (t=-1.59, P=0.13. The postoperative change of SE was 0.89 D in the FS-LASIK group (t=5.76, P=0.00, and 0.14 D in the SMILE group (t=0.54, P=0.59 from 1mo to 3y after surgery. At 3-year postoperatively, both HOAs and spherical aberrations in the SMILE group were obviously less than those in the FS-LASIK group (P=0.00, but the coma root mean square (RMS was higher in the SMILE group (0.59±0.26 than in the FS-LASIK group (0.29±0.14, P=0.00. The mesopic CS values between two groups were not statistically significant at 3y postoperatively. Compared with the FS-LASIK group, lower OSDI scores and longer TBUT values were found in the SMILE group at 1mo and 3mo postoperatively. With regard to safety, no eye lost any line of CDVA in both groups at 3y after surgery. CONCLUSION: Both SMILE and wavefront-guided FS-LASIK procedures provide good visual outcomes. Both procedures are effective and safe, but SMILE surgery achieve more stable long

Plasma Rich in Growth Factors for the Treatment of Dry Eye after LASIK Surgery.

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Sanchez-Avila, Ronald Mauricio; Merayo-Lloves, Jesus; Fernandez, Maria Laura; Rodriguez-Gutierrez, Luis Alberto; Jurado, Nancy; Muruzabal, Francisco; Orive, Gorka; Anitua, Eduardo

2018-06-08

The aim of this study was to evaluate the use of plasma rich in growth factors (PRGF) eye drops in patients with dry eye disease after laser-assisted in situ keratomileusis (LASIK) surgery. This is a longitudinal, retrospective, comparative, and descriptive study of 77 eyes of 42 patients with dry eye disease following LASIK surgery. This study was designed to evaluate the efficacy of PRGF treatment compared to conventional therapy (control group). Outcome measures including signs and symptoms of dry eye disease were evaluated before and after treatment. The percentage of change before and after treatment for each clinical variable measured was compared between both groups. There were 1-4 treatment cycles with PRGF eye drops (1 cycle = 6 weeks). Results showed a statistically significant improvement in the Ocular Surface Disease Index (38.12%), visual analogue scale scores for frequency (41.89%) and severity (42.47%), and the Schirmer test scores (88.98%) after PRGF treatment (p eye drops are effective for the improvement of dry eye symptoms in patients who underwent LASIK surgery in comparison to the conventional therapy. The treatment with PRGF is an alternative for patients who suffer from postoperative dry eye. © 2018 S. Karger AG, Basel.

Sensibilidade corneana e secreção lacrimal após LASIK Corneal sensivity and tear secretion after LASIK

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Marcelo Guimarães Brandão Rêgo

2003-01-01

Full Text Available OBJETIVO: Avaliar as alterações que ocorrem na sensibilidade corneana e secreção lacrimal após a cirurgia de "laser in situ keratomileusis" (LASIK. MÉTODOS: Foram examinados 38 olhos de 19 pacientes, 9 homens e 10 mulheres submetidos à cirurgia de LASIK para correção de miopia com equivalente esférico médio de -3,79 D (± 1,29 D. A sensibilidade corneana foi medida com o estesiômetro de Cochet-Bonnet, na região central da córnea. A secreção lacrimal foi avaliada pelos testes de Schirmer I, secreção basal, medida do tempo de rotura do filme lacrimal, e sintomatologia apresentada. Os exames foram realizados antes e após 7, 30, 90, 180 e 270 dias da cirurgia ou até que os níveis pré-operatórios fossem atingidos. RESULTADOS: Antes da cirurgia, o valor mediano da sensibilidade tátil corneana foi de 60,0 mm (variando de 50 a 60 mm; o teste de Schirmer I apresentou mediana de 21,5 mm (variando de 10 a 30 mm; o teste de secreção basal obteve mediana de 11,5 mm (variando de 6 a 20 mm; o tempo de rotura do filme lacrimal alcançou mediana de 16,0 segundos (variando de 8 a 22 segundos. Todos os pacientes recuperaram seus valores pré-operatórios de sensibilidade corneana e secreção lacrimal entre 90 e 180 dias após a cirurgia. Durante os 9 meses de seguimento, 5 pacientes (10 olhos não apresentaram qualquer sintoma relacionado a olho seco. CONCLUSÃO: Após a cirurgia de LASIK a sensibilidade corneana e a secreção lacrimal podem ficar reduzidos por até 6 meses. Neste período, 73,6% dos pacientes apresentaram sintomas de olho seco. Estudos futuros são necessários para avaliar os efeitos destas alterações sobre a fisiologia corneana.PURPOSE: To analyze the changes in corneal sensitivity and tear secretion after "laser in situ keratomileusis" (LASIK. METHODS: Thirty-eight eyes from nineteen patients, 9 men and 10 women, were submitted to myopic LASIK. The mean spherical equivalent before surgery was -3.79D (± 1

[Advantages and disadvantages of femtosecond laser assisted LASIK and SMILE].

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Zhang, F J; Sun, M S

2018-01-11

With the development of excimer laser and femtosecond laser equipment, application of diversified and customized surgical decision in modern corneal refractive surgery has been an inevitable trend. However, how to make a personalized decision with an accurate surgical design to achieve better visual quality becomes the main focus in clinical applications. Small-incision lenticule extraction (SMILE) and femtosecond assisted laser in situ keratomileusis (FS-LASIK) have been commonly acknowledged as the mainstream of corneal refractive surgery for ametropia correction nowadays. Both methods have been verified by clinical practice for many years. This article compares and elaborates the different characteristics with advantages and disadvantages of the two methods so as to provide some reasonable treatment options for refractive surgery. (Chin J Ophthalmol, 2018, 54: 7-10) .

Analysis of Macular and Retinal Nerve Fiber Layer Thickness in Children with Refractory Amblyopia after Femtosecond Laser-assisted Laser In situ Keratomileusis: A Retrospective Study.

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Zhao, Peng-Fei; Zhou, Yue-Hua; Zhang, Jing; Wei, Wen-Bin

2017-09-20

Localized macular edema and retinal nerve fiber layer (RNFL) thinning have been reported shortly after laser in situ keratomileusis (LASIK) in adults. However, it is still unclear how LASIK affects the retina of children. This study aimed to investigate the macular retina and RNFL thickness in children with refractive amblyopia who underwent femtosecond laser-assisted LASIK (FS-LASIK). In this study, we included 56 eyes of 32 patients with refractive amblyopia who underwent FS-LASIK in our hospital from January 2012 to December 2016. Foveal (foveal center retinal, parafoveal retinal, and perifoveal), macular inner retinal (superior and inferior), and peripapillary RNFL thicknesses (superior, inferior, temporal, and nasal) were measured using Fourier-domain optical coherence tomography before surgery and 1 day, 3 days, and 1 week after surgery. We divided these patients into three groups based on their refractive error: High myopic group with 22 eyes (equivalent sphere, >6.00 D), mild myopic group with 19 eyes (equivalent sphere, 0-6.00 D), and hyperopic group with 15 eyes (equivalent sphere, >+0.50 D). We compared the macular retina and RNFL thickness before and after LASIK. A paired simple t-test was used for data analysis. One week after surgery, the visual acuity for all 56 eyes of the 32 patients reached their preoperative best-corrected vision. Visual acuity improved two lines or better for 31% of the patients. The residual refractive errors in 89% of the patients were within ±0.5 D. In the high myopic group, the foveal center retinal and parafoveal retinal thicknesses were thicker 1 day and 3 days after surgery than before surgery (t = 2.689, P = 0.012; t = 2.383, P = 0.018, respectively); no significant difference was found 1 week after surgery (P > 0.05). The foveal center retinal and parafoveal retinal thicknesses were greater 1 day after surgery than they were before surgery (P = 0.000 and P = 0.005, respectively) in the mild myopic and hyperopic groups

Clinical outcomes of small incision lenticule extraction versus femtosecond laser-assisted LASIK for myopia: a Meta-analysis

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Yan, Huan; Gong, Li-Yan; Huang, Wei; Peng, Yan-Li

2017-01-01

AIM To evaluate the possible differences in visual quality between small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK) for myopia. METHODS A Meta-analysis was performed. Patients were from previously reported comparative studies treated with SMILE versus FS-LASIK. The PubMed, EMBASE, Cochrane, Web of Science and Chinese databases (i.e. WANFANG and CNKI) were searched in Nov. of 2016 using RevMan 5.1 version software. The differences in visual acuity, aberration and biomechanical effects within six months postoperatively were showed. Twenty-seven studies including 4223 eyes were included. RESULTS No significant differences were observed between SMILE and FS-LASIK in terms of the proportion of eyes that lost one or more lines of corrected distance visual acuity after surgery (P=0.14), the proportion of eyes achieving an uncorrected distance visual acuity of 20/20 or better (P=0.43), the final refractive spherical equivalent (P=0.89), the refractive spherical equivalent within ±1.00 diopter of the target values (P=0.80), vertical coma (P=0.45) and horizontal coma (P=0.06). Compared with the FS-LASIK group, total higher-order aberration (PLASIK are comparable in efficacy, safety and predictability for correcting myopia. However, the aberration in the SMILE group is superior to that in the FS-LASIK group, and the loss of biomechanical effects may occur less frequently after SMILE than after FS-LASIK. PMID:28944205

A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function.

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Hatch, Bryndon B; Moshirfar, Majid; Ollerton, Andrew J; Sikder, Shameema; Mifflin, Mark D

2011-01-01

To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs) in eyes with stable myopia undergoing either photo-refractive keratectomy (PRK) or thin-flap laser in situ keratomileusis (LASIK) (intended flap thickness of 90 μm) using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively. In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and complications. At 6 months, mean values for UDVA (logMAR) were -0.043 ± 0.668 and -0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466). UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600). Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156) or CDVA (P = 0.800) at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears. Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.

Z-LASIK and Trans-PRK for correction of high-grade myopia: safety, efficacy, predictability and clinical outcomes.

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Gershoni, Assaf; Mimouni, Michael; Livny, Eitan; Bahar, Irit

2018-03-12

The aim of the study was to examine the outcomes of transepithelial photorefractive keratectomy (Trans-PRK) and Femtosecond Laser-assisted in situ keratomileusis (Z-LASIK) for the correction of high myopia. A retrospective cohort study design was used. The study group included 792 eyes with high-grade myopia (- 6.0 diopters or higher) or high-grade myopia with astigmatism that were treated with Z-LASIK or Trans-PRK in 2013 through 2014 in an optical outpatient clinic of a large private medical service. The Trans-PRK group comprised of 674 eyes with a spherical equivalent (SE) of - 7.87 ± 1.46 and the Z-LASIK group comprised of 118 eyes with a SE of - 7.19 ± 0.81 (P PRK group was - 0.06 and - 0.02 in the Z-LASIK group (P = 0.545). Efficacy index values were 0.92 in the Trans-PRK group and 0.95 in the Z-LASIK group (P = 0.083), and corresponding safety index values were 0.95 and 0.97 (P = 0.056). An UCVA of 20/40 or better was achieved in 94.20% of eyes in the Trans-PRK group, and 98.31% in the Z-LASIK group (P = 0.063). The majority of eyes in both the Trans-PRK and Z-LASIK groups were within ± 0.5D of attempted correction: 59.35 and 64.71%, respectively (P = 0.271). Both Trans-PRK and Z-LASIK demonstrated excellent efficacy, safety and predictability profiles, with results comparable and in some cases superior to the current literature. Results of Z-LASIK were slightly better than those of Trans-PRK, though the preoperative SE of the latter was higher.

Effects of different cutting centers on LASIK surgery in myopic patients

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Yan-Wei Liu

2017-07-01

Full Text Available AIM:To investigate the effect of different cutting centers on the visual acuity, refractive diopter and visual quality of patients undergoing laser assisted in situ keratomileusis(LASIK. METHODS: A total of 80 patients(160 eyeswith myopia treated by elective LASIK were divided into two groups. Thirty-six cases(72 eyeswith visual axis corneal reflection point(VACRPas the cutting center were included into the VACRP group while 44 cases(88 eyeswith pupil center(PCas the cutting center were included into the PC group. The uncorrected visual acuity(UCVA, the best corrected visual acuity(BCVA, refractive diopter, corneal aberration \\〖total corneal and anterior corneal surface higher-order aberrations(HOA, spherical aberration(Z40, vertical coma(Z3-1, horizontal coma(totZ31and offset of cutting centers were determined before surgery and 1mo after surgery. RESULTS: There was no difference in the probability of UCVA ≥ 0.1, BCVA and refractive diopter between the two groups at 1mo after surgery(P>0.05. The astigmatism and cutting center deviation of VACRP group were lower than those of PC group(P40, totZ3-1, totZ31, froHOA, froZ3-1、froZ31 and froZ40 were lower in VACRP group than PC group at 1mo after surgery(PCONCLUSION: The UCVA of patients treated with both cutting centers for LASIK is good but VACRP has more advantages in reducing the offset of cutting center and improving postoperative visual quality.

The Effect of LASIK Procedure on Peripapillary Retinal Nerve Fiber Layer and Macular Ganglion Cell-Inner Plexiform Layer Thickness in Myopic Eyes

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Maja Zivkovic

2017-01-01

Full Text Available Purpose. To evaluate the effect of applied suction during microkeratome-assisted laser in situ keratomileusis (LASIK procedure on peripapillary retinal nerve fiber layer (RNFL thickness as well as macular ganglion cell-inner plexiform layer (GC-IPL thickness. Methods. 89 patients (124 eyes with established myopia range from −3.0 to −8.0 diopters and no associated ocular diseases were included in this study. RNFL and GC-IPL thickness measurements were performed by spectral domain optical coherence tomography (SD OCT one day before LASIK and at 1 and 6 months postoperatively. Results. Mean RNFL thickness prior to LASIK was 93.86±12.17 μm while the first month and the sixth month postoperatively were 94.01±12.04 μm and 94.46±12.27 μm, respectively. Comparing results, there is no significant difference between baseline, one month, and six months postoperatively for mean RNFL (p>0.05. Mean GC-IPL thickness was 81.70±7.47 μm preoperatively with no significant difference during the follow-up period (82.03±7.69 μm versus 81.84±7.64 μm; p>0.05. Conclusion. RNFL and GC-IPL complex thickness remained unaffected following LASIK intervention.

Três anos pós-LASIK em crianças anisométropes de 8 a 15 anos de idade Three years after LASIK in anisometropic children from 8 to 15 years old

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Belquiz R. Amaral Nassaralla

2003-01-01

Full Text Available OBJETIVO: Determinar a segurança, eficácia, previsibilidade e estabilidade da técnica "laser in situ keratomileusis" (LASIK, três anos após a cirurgia, para a correção de alta anisometropia em crianças, para as quais os tratamentos convencionais não obtiveram êxito. MÉTODOS: Nove olhos de nove pacientes, três meninos e 6 meninas, com idade média de 11,5 anos (variando de 8 a 15 anos, foram submetidos à técnica LASIK utilizando-se o excimer laser Chiron Technolas 217. O tempo mínimo de seguimento foi de 36 meses. RESULTADOS: Três anos após o LASIK, a acuidade visual sem correção (AVSC melhorou pelo menos 5 linhas em todos os olhos; cinco olhos (55,5% apresentavam AVSC de 20/50 ou melhor. Seis olhos (66,6%, apresentavam acuidade visual com correção (AVCC de 20/50 ou melhor e cinco olhos (55,5% ganharam pelo menos 1 linha na AVCC. Devido a ambliopia, nenhum olho apresentou AVSC de 20/20 ou melhor. A média do equivalente esférico pré-operatório foi reduzida de -7,66 (± 3,75 D para -1,02 (± 1,26 D e a do astigmatismo, de -3,11 (± 2,09 D para -0,75 (± 0,25 D. A maior anisometropia encontrada foi de 1,5 D. CONCLUSÕES: Após três anos de seguimento, a técnica LASIK parece ser opção segura e eficaz na correção de alta anisometropia em crianças entre 8 e 15 anos de idade, para os quais os tratamentos convencionais não obtiveram êxito. A progressão do erro refracional relacionada à idade não impediu o uso da correção visual adequada.PURPOSE: To determine the safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK, three years after surgery, to correct high myopia or high myopic astigmatism in children with high anisometropia in whom conventional treatments had failed. METHODS: Nine eyes of 9 patients, 3 boys and 6 girls with a mean age of 11.5 years (range, 8 to 15 years underwent LASIK using the Chiron Technolas 217 excimer laser. Minimum follow-up was 36 months. RESULTS: Three

Characteristics and Surgical Outcomes of Rhegmatogenous Retinal Detachment Following Myopic LASIK

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Daftarian, Narsis; Dehghan, Mohammad-Hossein; Ahmadieh, Hamid; Soheilian, Masoud; Karkhaneh, Reza; Lashay, Alireza; Mirshahi, Ahmad; Parhizkar, Hamid; Kazemimoghadam, Mohsen; Modarreszadeh, Mehdi; Hashemi, Masih; Fadaei, Mojtaba; Entezari, Morteza

2009-01-01

Purpose To describe the clinical features and surgical outcomes of rhegmatogenous retinal detachment (RRD) following myopic laser in situ keratomileusis (LASIK). Methods In a retrospective, non-comparative case series, 46 eyes that had undergone vitreoretinal surgery for management of RRD following myopic LASIK were identified. Data was reviewed with emphasis on characteristics of the RRD, employed surgical techniques, and anatomic and visual outcomes. Results Mean pre-LASIK myopia was −9.7±3.9 (range −4.00 to −18.00) diopters (D). Mean interval between LASIK and development of RRD was 11.6±11.2 months. Posterior vitreous detachment was present in 44 eyes (95.6%). The retinal breaks included flap tears in 36 (78.3%) eyes, giant tears in 8 (17.4%) eyes and atrophic holes in 2 (4.3%) eyes. In eyes with flap tears, the breaks were multiple, large or posterior to the equator in 24(66.7%) eyes. Retinal breaks were related to lattice degeneration in 20 (43.5%) eyes of which, three had history of prophylactic barrier laser photocoagulation. Scleral buckling was performed as the initial procedure in 32 (69.6%) eyes and primary vitrectomy was undertaken in 14 (30.4%) eyes. The initial surgical procedure failed in 14 (30.4%) eyes due to proliferative vitreoretinopathy (PVR). Retinal reattachment was finally achieved in 43 (93.4%) eyes. Postoperative visual acuity ≥20/40 and ≥20/200 was achieved in 16 (34.8%) and 25 (54.3%) eyes, respectively. Conclusion Post-LASIK retinal detachment has a complex nature in eyes with moderate to high myopia. The retinal detachment is complex in terms of size, number and location of retinal breaks, is associated with a high rate of PVR and entails unfavorable visual outcomes. PMID:23198065

Comparison of efficacy, safety, and predictability of laser in situ keratomileusis using two laser suites

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Meidani A

2016-08-01

Full Text Available Alexandra Meidani,1–3 Chara Tzavara3 1Hypervision Laser Centre, 2Eye Day Clinic, 3Department of Hygiene, University of Athens Medical School, Centre for Health Services Research, Epidemiology and Medical Statistics, Athens, Greece Purpose: The main aim of this study was to compare the efficacy, safety, and predictability of femtosecond laser-assisted in situ keratomileusis performed by two different laser suites in the treatment of myopia for up to 6 months.Methods: In this two-site retrospective nonrandomized study, myopic eyes that underwent laser-assisted in situ keratomileusis using IntraLase FS 60 kHz formed group 1 and those using WaveLight FS200 femtosecond laser system formed group 2. Ablation was performed with Visx Star S4 IR and WaveLight EX500 Excimer lasers, respectively, in groups 1 and 2. Both groups were well matched for age, sex, and mean level of preoperative refractive spherical equivalent (MRSE. Uncorrected distance visual acuity, corrected distance visual acuity, and MRSE were evaluated preoperatively and at 1 week, 1 month, and 6 months after treatment.Results: Fifty-six eyes of 28 patients were included in the study. At 6-month follow-up postop, 78.6% of eyes in group 1 and 92.8% of eyes in group 2 achieved an uncorrected distance visual acuity of 20/20 or better (P=0.252. 35.7% and 50% in group 1 and group 2, respectively, gained one line (P=0.179. No eye lost lines of corrected distance visual acuity. Twenty-five eyes in group 1 (92.7% and 27 eyes in group 2 (96.3% had MRSE within ±0.5 D in the 6-month follow-up (P>0.999. The mean efficacy index at 6 months was similar in group 1 and group 2 (mean 1.10±0.12 [standard deviation] vs 1.10±0.1 (P=0.799. The mean safety index was similar in group 1 and group 2 (mean 1.10±0.10 [standard deviation] vs 1.10±0.09 (P=0.407.Conclusion: The outcomes were excellent between the two laser suites. There were no significant differences at 6-month follow-up postop between the two

Femtosecond-Assisted LASIK Versus PRK: Comparison of 6-Month Visual Acuity and Quality Outcome for High Myopia.

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Hashemi, Hassan; Miraftab, Mohammad; Ghaffari, Reza; Asgari, Soheila

2016-11-01

To compare the results of femtosecond-assisted laser in situ keratomileusis (femto-LASIK) and photorefractive keratectomy with mitomycin C (PRK-MMC) for the correction of myopia more than 7.0 diopters (D). In this comparative nonrandomized trial, 60 eyes (30 eyes in each group) were enrolled. Patients were tested for uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent, ocular and corneal aberrations, and contrast sensitivity (CS) before surgery and at 3 and 6 months postoperatively. Mean preoperative myopia was -8.65±1.51 and -8.04±1.70 D in the femto-LASIK and PRK-MMC groups, respectively (P=0.149). Intergroup differences in baseline indices were not statistically significant. At 6 months after surgery, UDVA showed an improving trend, but it was better in the femto-LASIK group (P=0.026). CDVA in the two groups remained similarly unchanged (P=0.170). For the femto-LASIK and PRK-MMC groups, the safety indices were 1.01±0.05 and 1.01±0.14 (P=0.949), respectively, and the efficacy indices were 0.99±0.07 and 0.93±0.22 (P=0.192), respectively. Comparing CS, only CS18 showed a significantly greater decrease in the femto-LASIK group compared with the PRK-MMC group (P=0.016). Intergroup differences were not statistically significant in other spatial frequencies. Changes in the ocular and corneal higher order aberrations were not statistically different between the two groups except ocular coma, which increased in the femto-LASIK group (P=0.041). Femto-LASIK improves UDVA better than PRK-MMC in high myopia. However, because of increased coma, the quality of vision is reduced. In other words, visual acuity outcome is better with femto-LASIK and visual quality outcome is better with PRK-MMC.

Reliability of Entire Corneal Thickness Mapping in Normal Post-Laser in situ Keratomileusis and Keratoconus Eyes Using Long Scan Depth Spectral Domain Optical Coherence Tomography.

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Xu, Zhe; Chen, Sisi; Yang, Chun; Huang, Shenghai; Shen, Meixiao; Wang, Yuanyuan

2018-01-01

To investigate the repeatability and reproducibility of mapping the entire corneal thickness using spectral domain optical coherence tomography (SD-OCT). Thirty normal eyes, 30 post-laser in situ keratomileusis (LASIK) surgery eyes, and 30 keratoconus eyes were analyzed. A custom-built long scan depth SD-OCT device was used to obtain entire corneal images. Ten-millimeter-diameter corneal thickness maps were generated by an automated segmentation algorithm. Intraclass correlation coefficients of repeatability (ICC1) and reproducibility (ICC2), and coefficients of repeatability (CoR1) and reproducibility (CoR2), were calculated to quantify the precision and accuracy of corneal pachymetry measurements using the Bland-Altman method. For SD-OCT measurements in healthy subjects, CoR1 and CoR2 were less than 5.00 and 5.53 μm. ICC1 and ICC2 were more than 0.997 and 0.996. For SD-OCT measurements in LASIK patients, CoR1 and CoR2 were less than 5.09 and 5.34 μm. ICC1 and ICC2 were more than 0.997 and 0.996. For SD-OCT measurements in keratoconus patients, CoR1 and CoR2 were less than 11.57 and 10.92 μm. ICC1 and ICC2 were more than 0.995 and 0.996. The measurements of corneal pachymetric mapping by long scan depth SD-OCT can be assessed over the entire corneal area with good repeatability and reproducibility. © 2017 S. Karger AG, Basel.

Rate of ectasia and incidence of irregular topography in patients with unidentified preoperative risk factors undergoing femtosecond laser-assisted LASIK

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Moshirfar M

2013-12-01

Full Text Available Majid Moshirfar,1 Jared G Smedley,2 Valliammai Muthappan,1 Allison Jarsted,3 Erik M Ostler1 1John A Moran Eye Center, University of Utah, Salt Lake City, UT, USA; 2College of Human Medicine, Michigan State University, Lansing, MI, USA; 3Department of Ophthalmology, State University of New York Upstate Medical University, Syracuse, NY, USA Purpose: To report the rate of postoperative ectasia after laser-assisted in situ keratomileusis (LASIK with femtosecond laser-assisted flap creation, in a population of patients with no identified preoperative risk factors. Methods: A retrospective case review of 1,992 eyes (1,364 patients treated between March 2007 and January 2009 was conducted, with a follow up of over 4 years. After identifying cases of ectasia, all the patient charts were examined retrospectively for preoperative findings suggestive of forme fruste keratoconus (FFKC. Results: Five eyes of four patients with post-LASIK ectasia were identified. All eyes passed preoperative screening and received bilateral LASIK. One of the five patients developed ectasia in both eyes. Three patients retrospectively revealed preoperative topography suggestive of FFKC, while one patient had no identifiable preoperative risk factors. Upon review of all the charts, a total 69 eyes, including four of the five eyes with ectasia, were retrospectively found to have topographies suggestive of FFKC. Conclusion: We identified four cases of post-LASIK ectasia that had risk factors for FFKC on reexamination of the chart and one case of post-LASIK ectasia with no identifiable preoperative risk factors. The most conservative screening recommendations would not have precluded this patient from LASIK. The rate of purely iatrogenic post-LASIK ectasia at our center was 0.05% (1/1,992, and the total rate of post-LASIK ectasia for our entire study was 0.25% (1/398. The rate of eyes with unrecognized preoperative FFKC that developed post-LASIK ectasia was 5.8% (1/17. Keywords

Anterior chamber gas bubble emergence pattern during femtosecond LASIK-flap creation.

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Robert, Marie-Claude; Khreim, Nour; Todani, Amit; Melki, Samir A

2015-09-01

To characterise the emergence pattern of cavitation bubbles into the anterior chamber (AC) following femtosecond laser-assisted in situ keratomileusis (LASIK)-flap creation Retrospective review of patients undergoing femtosecond LASIK surgery at Boston Laser, a private refractive surgery practice in Boston, Massachusetts, between December 2008 and February 2014. Patient charts were reviewed to identify all cases with gas bubble migration into the AC. Surgical videos were examined and the location of bubble entry was recorded separately for right and left eyes. Five thousand one hundred and fifty-eight patients underwent femtosecond LASIK surgery. Air bubble migration into the AC, presumably via the Schlemm's canal and trabecular meshwork, occurred in 1% of cases. Patients with AC bubbles had an average age of 33±8 years with a measured LASIK flap thickness of 96±21 μm. The occurrence of gas bubbles impaired iris registration in 64% of cases. Gas bubbles appeared preferentially in the nasal or inferior quadrants for right (92% of cases) and left (100% of cases) eyes. This bubble emergence pattern is significantly different from that expected with a random distribution (p<0.0001) and did not seem associated with decentration of the femtosecond laser docking system. The migration of gas bubbles into the AC is a rare occurrence during femtosecond laser flap creation. The preferential emergence of gas bubbles into the nasal and inferior quadrants of the AC may indicate a distinctive anatomy of the nasal Schlemm's canal. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Rescue of Primary Incomplete Microkeratome Flap with Secondary Femtosecond Laser Flap in LASIK

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E. A. Razgulyaeva

2014-01-01

Full Text Available For laser-assisted in situ keratomileusis (LASIK retreatments with a previous unsuccessful mechanical microkeratome-assisted surgery, some surgical protocols have been described as feasible, such as relifting of the flap or the creation of a new flap and even the change to a surface ablation procedure (photorefractive keratectomy (PRK. This case shows the use of femtosecond technology for the creation of a secondary flap to perform LASIK in a cornea with a primary incomplete flap obtained with a mechanical microkeratome. As we were unable to characterize the interface of the first partial lamellar cut, a thick flap was planned and created using a femtosecond laser platform. As the primary cut was very thick in the nasal quadrant, a piece of loose corneal tissue appeared during flap lifting which was fitted in its position and not removed. Despite this condition and considering the regularity of the new femtosecond laser cut, the treatment was uneventful. This case report shows the relevance of a detailed corneal analysis with an advanced imaging technique before performing a secondary flap in a cornea with a primary incomplete flap. The femtosecond laser technology seems to be an excellent tool to manage such cases successfully.

In vivo confocal microscopy and tear cytokine analysis in post-LASIK ectasia.

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Pahuja, Natasha Kishore; Shetty, Rohit; Deshmukh, Rashmi; Sharma, Anupam; Nuijts, Rudy M M A; Jhanji, Vishal; Sethu, Swaminathan; Ghosh, Arkasubhra

2017-12-01

Corneal keratectasia is one of the complications associated with laser in situ keratomileusis (LASIK) that results in vision impairment. The pathogenesis of post-LASIK ectasia (PLE) remains underexplored. We report the tear cytokine profile and in vivo confocal microscopy (IVCM) findings in eyes with PLE. This retrospective study included age-matched 7 (14 eyes) post-LASIK controls (PLCs) and 6 (12 eyes) PLE subjects. Corneal topography was used to categorise the subjects into PLC and PLE groups. Ocular Surface Disease Index (OSDI) scores obtained were based on standard questionnaire and IVCM images were used to determine corneal dendritic cells density (DCD) and sub-basal nerve plexus morphology. Inflammatory cytokines/chemokines in the tears were quantified using flow cytometry based cytometric bead array. Pentacam-based scores, OSDI scores and corneal DCD were significantly (pPLE compared with PLC. Discomfort-related subscale of OSDI score exhibited a positive correlation with total corneal DCD in the PLE cohort. The fold difference of chemokine (C-C motif) ligand/monocyte chemotactic protein-1 (CCL2/MCP1) (3.4±0.6) was found to be significantly (pPLE cohorts and a positive correlation between CCL2/MCP1 levels and total corneal DCD was also observed in the PLE cohort. The current study found a significant difference in the tear film cytokine profile between normal and PLE eyes. Presence of increased corneal dendritic cells and altered tear cytokines suggests an ongoing inflammatory response in PLE. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Evaluation of point-of-care test for elevated tear matrix metalloproteinase 9 in post-LASIK dry eyes.

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Chan, Tommy C Y; Ye, Cong; Chan, Kwok Ping; Chu, Kai On; Jhanji, Vishal

2016-09-01

To evaluate the performance of a point-of-care test for detection of matrix metalloproteinase 9 (MMP-9) levels in post-laser-assisted in situ keratomileusis (LASIK) dry eyes. A comparative study between patients with mild to moderate post-LASIK dry eyes and age-matched normal subjects was conducted. Ocular surface disease index (OSDI), tear break-up time (TBUT), and tear film MMP-9 and total protein levels were compared between the two groups. A point-of-care test device (RPS InflammaDry, Sarasota, Florida, USA) was utilised to confirm elevated MMP-9 levels in tear film. Fourteen post-LASIK dry eyes and 34 normal eyes were included. There was no significant difference in age and gender between both groups (p>0.175). The OSDI was significantly higher (25.5±7.7 vs 7.4±2.5; pdry eye compared with normal subjects. The tear film MMP-9 levels were 52.7±32.5 ng/mL in dry eyes and 4.1±2.1 ng/mL in normal eyes (p40 ng/mL in 7/14 (50.0%) post-LASIK dry eyes. The InflammaDry was positive in 8/14 (57.1%) post-LASIK eyes. All positive cases had tear film MMP-9 levels ≥38.03 ng/mL. Agreement between InflammaDry and MMP-9 was excellent with Cohen κ value of 0.857 in post-LASIK dry eyes. Only half of post-LASIK dry eyes were found to have significant inflammation associated with elevated MMP-9. The OSDI is useful to non-specifically identify patients with symptomatic dry eye while the InflammaDry determined which patients with dry eye were associated with significant inflammation that may guide therapeutic management decisions. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Comparison of the effects of cylindrical correction with and without iris recognition technology in wavefront laser-assisted in situ keratomileusis.

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Wang, Tsung-Jen; Lin, Yu-Huang; Chang, David C-K; Chou, Hsiu-Chu; Wang, I-Jong

2012-04-01

  To analyse the magnitude of cylindrical corrections over which cyclotorsion compensation with iris recognition (IR) technology is beneficial during wavefront laser-assisted in situ keratomileusis.   A retrospectively comparative case series.   Fifty-four eyes that underwent wavefront laser-assisted in situ keratomileusis without IR (non-IR group) and 53 eyes that underwent wavefront laser-assisted in situ keratomileusis with IR (IR group) were recruited.   Subgroup analysis based on baseline astigmatism were: a low degree of astigmatism (≥1.00 D to <2.00 D), a moderate degree of astigmatism (≥2.00 D to <3.00 D) and a high degree of astigmatism (≥3.00 D).   Vector and non-vector analyses were used for comparison.   The mean cylinder was -1.89 ± 0.76 D in the non-IR group and -2.00 ± 0.77 D in the IR group. Postoperatively, 38 eyes (74.50%) in the IR group and 31 eyes (57.50%) in the non-IR group were within ± 0.50 D of the target induced astigmatism vector (P = 0.063). The difference vector was 0.49 ± 0.28 in the IR group and 0.63 ± 0.40 in the non-IR group (P = 0.031). In the analysis of subgroups, the magnitude of error was significantly lower in the moderate IR subgroup than that of the moderate non-IR subgroup (P = 0.034). Furthermore, the moderate IR subgroup had a lower mean difference vector (P = 0.0078) and a greater surgically induced astigmatism (P = 0.036) than those of the moderate non-IR group.   Wavefront laser-assisted in situ keratomileusis for the treatment of astigmatism using IR technology was effective and accurate for the treatment of myopic astigmatism. © 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists.

A prospective, contralateral comparison of photorefractive keratectomy (PRK versus thin-flap LASIK: assessment of visual function

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Hatch BB

2011-04-01

Full Text Available Bryndon B Hatch1, Majid Moshirfar1, Andrew J Ollerton1, Shameema Sikder2, Mark D Mifflin11John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USAPurpose: To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs in eyes with stable myopia undergoing either photorefractive keratectomy (PRK or thin-flap laser in situ keratomileusis (LASIK (intended flap thickness of 90 µm using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively.Methods: In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, contrast sensitivity, and complications.Results: At 6 months, mean values for UDVA (logMAR were -0.043 ± 0.668 and -0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466. UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600. Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156 or CDVA (P = 0.800 at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears.Conclusion: Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.Keywords: photorefractive keratectomy, thin-flap LASIK, visual

Changes of tear film after LASIK with corneal flap created by femtosecond laser and microkeratome

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Yuan Zhang

2014-09-01

Full Text Available AIM: To observe the changes of tear film on the patients after laser in situ keratomileusis(LASIKwith corneal flap created by femtosecond laser and microkeratome.METHODS: Totally 150 patients(300 eyeswith myopia received operation of LASIK. Patients were divided into two groups according to the methods of making corneal flap. The patients of group one were assigned to receiving LASIK with corneal flap creation by Intralase femtosecond laser(190 eyes of 95 patients, group two were assigned to receiving LASIK with corneal flap creation by microkeratome(110 eyes of 55 patients. Dry eye symptom score, tear break-up time(BUT, Schirmer Ⅰ test(S I t, corneal fluorescein staining(FLwere recorded preoperatively and postoperatively at 1wk; 1, 3 and 6mo. RESULTS: Dry eye symptom score: there existed obvious differences at 1wk; 1, 3mo between two groups(PP>0.05. BUT: there existed obvious differences at 1wk, 1, 3mo between two groups(PP>0.05. SchirmerⅠ test: there existed obvious differences in the 1wk, 1, 3mo between two groups(PP>0.05. FL: there existed obvious differences in the 1wk, 1, 3mo between two groups(PP>0.05.CONCLUSION: The early stability of tear film decrease after operation in both of the two groups. The dry eye symptoms are lighter and recover faster.

[Comparative results evaluation of residual myopia and astigmatism correction after radial keratotomy by photorefraction keratectomy and laser specialized keratomileusis].

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Dias-Martines, T E; Sheludchenko, V M; Kurenkov, V V

1999-01-01

The results of correction of residual myopia by photorefraction keratectomy (PRK) (51 eyes) and laser specialized keratomileusis (LASIK) (36 eyes) after radial keratotomy (RK) are compared. The patients were observed for up to 12 months. After PRK, 7.3% patients developed late fleur of the cornea, evaluated by at least 2 points. The incidence of fleur directly depended on the value of residual myopia. After LASIK none of the patients developed such fleur. The best visual acuity (0.5 and higher without correction) was attained in 70.73% after PRK and RK, vs. 100% after LASIK. The results of photorefraction operations and severity of residual myopia after RK correlated. In residual myopia of up to -3 diopters the results of correction by PRK and LASIK were virtually the same. In residual myopia higher than -3 diopters, LASIK is preferable.

LASIK X PRK após cirurgia de descolamento de retina

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Rodovalho Adriano Jorge Mattoso

2003-01-01

Full Text Available OBJETIVO: Comparar os resultados obtidos pelas técnicas de "laser in situ keratomileusis" (LASIK e "photorefractive keratectomy" (PRK na correção de miopia e astigmatismo em olhos previamente submetidos à cirurgia de descolamento de retina (DR com "buckle" escleral. MÉTODOS: Vinte e cinco olhos de 22 pacientes com alterações refracionais significativas após a cirurgia de DR foram submetidos à cirurgia refrativa. Em 14 olhos de 13 pacientes foi realizado LASIK e em 11 olhos de 9 pacientes, PRK. O intervalo mínimo entre a cirurgia de DR e a cirurgia refrativa foi de 12 meses. O tempo de seguimento foi de, pelo menos, 12 meses. RESULTADOS: Doze meses após a cirurgia, a média do equivalente esférico (EE no grupo submetido ao LASIK diminuiu de -6,49 D antes da cirurgia para -0,17 D e a média do cilindro de -1,10 D para -0,23 D. A média do EE no grupo submetido ao PRK foi reduzida de -5,35 D para +0,02 D e a média do cilindro, de -1,38 D para -0,54D. Em ambos os grupos, 11 olhos apresentaram melhora da acuidade visual sem correção de pelo menos 4 linhas. CONCLUSÃO: Tanto o LASIK quanto o PRK foram seguros e eficazes para a correção do erro refracional induzido após a cirurgia de DR. Nossos resultados não apresentaram diferenças significativas entre os procedimentos. Estudos posteriores envolvendo maior amostragem e seguimento mais prolongado contribuirão para melhor avaliação da cirurgia refrativa em pacientes submetidos à cirurgia com "buckle" escleral.

Predictability of Pilot Performance from Simulated to Real Flight in the UH-60 (Black Hawk) Helicopter

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2008-02-01

keratectomy ( PRK ) and laser in-situ keratomileusis ( LASIK ) procedures to determine compatibility, safety, and efficacy of these procedures for rated Army...performance data. Table B- 1. Simulator and aircraft mean flight performance. LASIK PRK Simulator Aircraft Simulator Aircraft Pre-op 60.81 (2.65) 56.41...12 7. Aircraft vs . Simulator scatter plot, hover turn maneuvers

Assessment of tear osmolarity and other dry eye parameters in post-LASIK eyes.

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Hassan, Ziad; Szalai, Eszter; Berta, Andras; Modis, Laszlo; Nemeth, Gabor

2013-07-01

To assess the tear osmolarity using the TearLab device after laser in situ keratomileusis (LASIK) and to compare the values with those obtained by traditional tear film tests before and after the procedure. Thirty eyes of 15 refractive surgery candidates (5 men and 10 women of mean age: 30.55 ± 11.79 years) were examined. Using a special questionnaire (Ocular Surface Disease Index), subjective dry eye complaints were evaluated, and then, the tear osmolarity was measured with the TearLab system (TearLab Corporation) and conventional dry eye tests were carried out. Examinations were performed preoperatively and at 1, 30, and 60 days after the surgery. The mean value of tear osmolarity was 303.62 ± 12.29 mOsm/L before the surgery and 303.58 ± 20.14 mOsm/L at 60 days after the treatment (P = 0.69). Mean lid parallel conjunctival folds value was 0.68 ± 0.68 before the procedure and 0.58 ± 0.65 subsequent to surgery (P = 0.25). Meibomian gland dysfunction was not detected. No significant deviation was observed in the values of Schirmer test, corneal staining, tear break-up time, and lid parallel conjunctival folds when compared with postoperatively obtained values during the follow-up period (P > 0.05). During LASIK flap creation, intact corneal innervation is damaged, and the ocular surface lacrimal functional unit can be impaired. In our study, no abnormal dry eye test results were observed before or after the procedure. Based on our results, LASIK treatment is safe for dry eye involving the administration of adequate artificial tears for a minimum of 3 months.

The applicability of correction factor for corneal thickness on non-contact tonometer measured intraocular pressure in LASIK treated eyes.

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Jethani, Jitendra; Dave, Paaraj; Jethani, Monica; Desai, Yogesh; Patel, Purvi

2016-01-01

To determine the applicability of central corneal thickness (CCT) based correction factor for non-contact tonometer (NCT) measured intraocular pressure (IOP) readings. A prospective, non-randomized study involved 346 eyes of 173 consecutive patients with age ⩾21 years undergoing laser-assisted in situ keratomileusis (LASIK) for myopia and/or myopic astigmatism. The CCT and IOP were measured before and after the LASIK procedure. The IOP pre and post-LASIK was compared after applying the correction factor for CCT. Patients not completing the 3 month postoperative follow-up were excluded. The median spherical equivalent before undergoing LASIK was -4.25D (inter-quartile range, -3.25D). The mean preoperative CCT was 536.82 ± 33.71 μm which reduced to 477.55 ± 39.3 μm (p < 0.01) post-LASIK. The mean IOP reduced from a preoperative value of 14.6 ± 2.32 mmHg to 10.64 ± 2.45 mmHg postoperatively (p < 0.01). On applying correction for the corneal thickness, the pre and postoperative IOP was 15.14 ± 2.8 mmHg and 15.37 ± 2.65 mmHg (p = 0.06) respectively with a strong positive correlation (r = 0.7, p < 0.01). Three hundred eyes (86.7%) had an absolute difference in IOP of less than 3.0 mmHg post-CCT correction which is within the retest variability of NCT. Only 46 eyes (13.3%) had an absolute difference of more than 3.0 mmHg. The modified Ehler's correction algorithm used in this study can be effectively applied in the normal IOP range in a majority of patients.

A prospective bilateral comparison of epi-LASIK and LASEK for myopia.

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Hondur, Ahmet; Bilgihan, Kamil; Hasanreisoglu, Berati

2008-11-01

To compare the clinical and confocal microscopic results of mechanical (epi-LASIK) versus alcohol-assisted laser epithelial keratomileusis (LASEK) for the correction of myopia. Twenty-five patients with myopia received epi-LASIK in one eye and LASEK in the other. The difference of spherical equivalent refraction of myopia and astigmatism was less than 1.00 diopter (D) in two eyes of each case. Mechanical separation of the epithelium was performed with the Lasitome epithelial separator and alcohol-assisted separation with 25 second application of 18% alcohol. Ablation was performed with the ESIRIS laser. Patients were seen daily until epithelial closure, and at 1, 3, 6, and 12 months. Time to epithelial healing, uncorrected visual acuity (UCVA), manifest refraction, haze, and grey scale value in confocal microscopy were recorded. Preoperative myopic spherical equivalent refraction was -3.95+/-1.49 D in the epi-LASIK and -3.91+/-1.39 D in the LASEK-treated eyes. The mean time to epithelial healing was slightly longer after epi-LASIK (4.86+/-0.64 vs 4.18+/-0.58 days). Of both epi-LASIK and LASEK-treated eyes, 92% achieved 20/20 or better UCVA and were within +/-0.50 D of emmetropia at 12 months. The grade of haze and mean grey scale value in confocal microscopy were similar in epi-LASIK and LASEK-treated eyes at all postoperative periods. One eye treated with epi-LASIK suffered a minor stromal cut. Epi-LASIK and LASEK offer effective correction of myopia with comparable results at 1 year.

Correlation between Post-LASIK Starburst Symptom and Ocular Wavefront Aberrations

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Liu, Yong-Ji; Mu, Guo-Guang; Wang, Zhao-Qi; Wang-Yan

2006-06-01

Monochromatic aberrations in post laser in-situ keratomileusis (LASIK) eyes are measured. The data are categorized into reference group and starburst group according to the visual symptoms. Statistic analysis has been made to find the correlation between the ocular wavefront aberrations and the starburst symptom. The rms aberrations of the 3rd and 4th orders for the starburst group are significantly larger than those for the reference group. The starburst symptom shows a strong correlation with vertical coma, total coma, spherical aberrations. For 3-mm pupil size and 5.8-mm pupil size, the modulation transfer function (MTF) of the starburst group are lower than those of the reference group, but their visual acuities are close. MTF and PSF analyses are made for two groups, and the results are consistent with the statistical analysis, which means the difference between the two groups is mainly due to the third- and fourth-order Zernike aberrations.

Long term results of Epi-LASIK and LASEK for myopia.

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Yuksel, Nilay; Bilgihan, Kamil; Hondur, Ahmet M; Yildiz, Burcin; Yuksel, Erdem

2014-06-01

To evaluate the long term clinical and confocal results of mechanical (Epi-LASIK) versus alcohol-assisted laser epithelial keratomileusis (LASEK) for correction of myopia. Gazi University Medical School, Department of Ophthalmology, Ankara, Turkey. Retrospective study. Twenty-two eyes treated with LASEK and twenty eyes treated with Epi-LASIK were evaluated with a mean follow-up duration of 45 months. Mechanical separation of the epithelium was performed with Lasitome epithelial separator, and alcohol-assisted separation with 25s application of 18% alcohol. Laser ablation was performed with the ESIRIS laser. All patients were examined daily until epithelial closure; at 1, 3, 6, and 12 months; and every year subsequently. Main outcome measures were uncorrected visual acuity (UCVA), manifest refraction, haze, and gray scale value in confocal microscopy, efficacy and safety indexes. Preoperative myopic spherical equivalent refraction was -4.65 ± 1.74 D in the LASEK and -3.87 ± 1.30 D in the Epi-LASIK-treated eyes (p=0.36). Of both LASEK and Epi-LASIK-treated eyes, 95% achieved 20/25 or better final UCVA. The grade of haze and mean gray scale value in confocal microscopy were similar in LASEK and Epi-LASIK-treated eyes at all postoperative periods. The efficacy index was 0.94 in LASEK group and 0.96 in Epi-LASIK group (p=0.44). The safety index was 1.01 in LASEK group and 1.02 in Epi-LASIK group (p=0.42). Both LASEK and Epi-LASIK offer safe and effective correction of myopia in the long term. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Satisfactory clinical outcome following delayed repositioning of a traumatic post-LASIK flap with dislocation and shrinkage managed by irrigation, stretching, and debridement.

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Xu, Ye-Sheng; Xie, Wen-Jia; Yao, Yu-Feng

2017-06-01

To report surgical management and favorable outcome in a case with delayed repair of traumatic laser in situ keratomileusis (LASIK) flap dislocation with shrinkage and folds. A 30-year-old man with a five-year history of bilateral LASIK experienced blunt trauma to his right eye followed by decreased vision for 5 weeks. The surgical management included initially softening the flap by irrigation with balanced salt solution (BSS). The shrinkage folds were carefully and gently stretched by scraping with a 26-gauge cannula accompanied by BSS irrigation. All of the epithelial ingrowth on the flap inner surface and on the bed was thoroughly debrided by scraping and irrigation. After the flap was repositioned to match its original margin, a soft bandage contact lens was placed. At his initial visit, slit-lamp microscopy and optical coherence tomography (OCT) showed shrinkage of the LASIK flap with an elevated margin approximately 3 mm above the original position. The flap covered half of the pupil and had multiple horizontal folds. Two months after surgery, the flap remained well positioned with only faint streaks in the anterior stroma. The uncorrected visual acuity of the right eye was 20/20 with a manifest refraction of Plano. For delayed repair of traumatically dislocated LASIK flaps, sufficient softening by BSS, stretching the shrinkage folds, and thorough debridement of ingrowth epithelium enable resetting the flap and provide satisfactory results.

Live or Let Die: Epithelial Flap Vitality and Keratocyte Proliferation Following LASEK and Epi-LASIK in Human Donor and Porcine Eyes.

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Angunawela, Romesh I; Winkler von Mohrenfels, Christoph; Kumar, Anupma; O'Brart, David P S; Marshall, John

2011-02-01

To determine the relationship between epithelial flap vitality and stromal keratocyte proliferation following two epithelial refractive techniques: epi-LASIK and laser epithelial keratomileusis (LASEK). Human corneas were maintained in organ culture and underwent standard -6.00-diopter ablation. Rates of stromal keratocyte proliferation were detected 1 week postoperative using a Ki67 antibody specific to proliferating cells. Images were captured with a laser scanning confocal microscope and analyzed by a masked observer. Epithelial flap vitality was determined with propidium iodide using fresh porcine corneas. Epithelial flaps were created with Gebauer Epikeratome epi-LASIK or alcohol-assisted LASEK method. Flaps treated with 100% alcohol and uninjured corneas were used as controls. The number of proliferating keratocytes was greatest at 1 week in the epi-LASIK corneas (Pvitality was greatest in the epi-LASIK flaps and declined in the LASEK and 100% alcohol flaps (Plive cells. There is also a greater number of proliferating stromal cells following epi-LASIK at 1 week. Based on these in vitro observations, epi-LASIK may result in greater levels of haze compared to LASEK. Copyright 2011, SLACK Incorporated.

Ultrasound monitoring of vitreous in pre and postLasik patients

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Amanda Alvarado, MD

2003-12-01

Full Text Available Title: Echografic Vitreoretinal Findings afterLaser In Situ Keratomileusis.Objective: To report the echographic changesobserved in the vitreous of patients followingLasik. Design: Prospective, observational,descriptive study. Method: We performed anultrasound of the vitreous of patients elegiblefor refractive surgery. Vitreous Changes weremeasured by video B scan ultrasonographybefore and at the first and third month after Lasikat Fundación Oftalmológica Nacional betweenJune 2002 and March 2003. Results: A total of16 patients, 67% women, 33% men, mean ageof 31.6 years (range between 22 and 40 years.A total of 29 eyes were studied, 16 right and 13left for a total of 87 echographies. The refractiveerrors in a range of -10.50 and +3.50 of sphericalequivalent. There were 24 myopic and 5hypermetropic eyes. The vitreous changes correspondedto a posterior vitreous detachment(PVD and the presence of opacities in thevitreous. At the beginning of the study 18 eyes(62% had evidenced PVD and all of the 29 eyes(100% had opacities; At the end of the controls changes were evidenced in 22 eyes (81%, thevitreous opacities increased in 14 eyes (48.27%,while they remained without changes in 15 eyes(51.7%. The presence of newly developed PVDwas documented in 10 eyes (30 %, there was anincrease of PVD in 8 eyes (27.5%, and in onecase we observed the presence of a traction areaat the vitreoretinal interfase that correspondedto 3.4% of the eyes studied; it was an hypermetropicpatient in whom ophthalmoscopically,after the echographic findings, we evidenced twooperculated like retinal holes that requiredtreatment with laser. Conclusions: We demostratedthat true changes are evidenced at thevitreous post Lasik. Posterior vitreous detachmentis the most significant discovery and itcould be implied in the genesis of tears anddetachment of the retina, but its incidence is evensmaller than in the general population and thisallows refractive surgery to remain as a

[Laser in situ keratomyleusis (LASIK) for correction of myopia and hypermetropia--our one year experience].

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Vukosavljević, Miroslav; Milivojević, Milorad; Resan, Mirko; Cerović, Vesna

2009-12-01

Laser in situ keratamileusis (LASIK) is the most commonly used refractive surgical method worldwide. The aim of this study was to examine the effectiveness and safety of LASIK in the correction of myopia and hyperopia. The study included myopic and hyperopic eyes with preoperative best corrected visual acuity (BCVA) = 1 (20/20), of the total number of 322 divided into 2 groups--1) myopic eyes (n = 241) which were divided into 4 subgroups according to the myopia strength: a) or = -7 D (n = 24); 2) hyperopic eyes (n = 81) which were divided into 3 subgroups according to the hyperopia strength: a) or = +4 D (n = 25). Myopic and hyperopic eyes with preoperative BCVA ambliopia) were excluded from the study, as well as eyes with astigmatism > 1.5 D. To assess the effectiveness of LASIK we examined the percentage of eyes in the mentioned subgroups, which derived uncorrected visual acuity (UCVA) 6 month after the intervention to the following: a) UCVA = 1 (20/20) and b) UCVA > or = 0.5 (20/40). To assess the safety of LASIK we examined the frequency of intraoperative and postoperative complications. A prospective study was performed in a 6-months follow-up period. RESULTS. Refractive spherical equivalent (RSE) of myopic eyes was in the range from -0.75 D to -12 D. In the first subgroup preoperative mean value of RSE with standard deviation (mean RSE +/- SD) was -1.39 +/- 0.36 D, and 6 months after the LASIK 100% of the eyes had UCVA = 20/20. In the second subgroup preoperative mean RSE +/- SD was -2.85 +/- 0.50 D, and 6 months after LASIK 93% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA > or = 20/40. In the third subgroup preoperative mean RSE +/- SD was -5.03 +/- 0.75 D, and 6 months after the LASIK 90% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA > or = 20/40. In the fourth subgroup preoperative mean RSE +/- SD was -7.68 +/- 1.03 D, and 6 months after the LASIK 96% of the eyes had UCVA = 20/20, but 100% of eyes had UCVA > or = 20

Satisfactory clinical outcome following delayed repositioning of a traumatic post-LASIK flap with dislocation and shrinkage managed by irrigation, stretching, and debridement*

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Xu, Ye-sheng; Xie, Wen-jia; Yao, Yu-feng

2017-01-01

Objective: To report surgical management and favorable outcome in a case with delayed repair of traumatic laser in situ keratomileusis (LASIK) flap dislocation with shrinkage and folds. Methods: A 30-year-old man with a five-year history of bilateral LASIK experienced blunt trauma to his right eye followed by decreased vision for 5 weeks. The surgical management included initially softening the flap by irrigation with balanced salt solution (BSS). The shrinkage folds were carefully and gently stretched by scraping with a 26-gauge cannula accompanied by BSS irrigation. All of the epithelial ingrowth on the flap inner surface and on the bed was thoroughly debrided by scraping and irrigation. After the flap was repositioned to match its original margin, a soft bandage contact lens was placed. Results: At his initial visit, slit-lamp microscopy and optical coherence tomography (OCT) showed shrinkage of the LASIK flap with an elevated margin approximately 3 mm above the original position. The flap covered half of the pupil and had multiple horizontal folds. Two months after surgery, the flap remained well positioned with only faint streaks in the anterior stroma. The uncorrected visual acuity of the right eye was 20/20 with a manifest refraction of Plano. Conclusions: For delayed repair of traumatically dislocated LASIK flaps, sufficient softening by BSS, stretching the shrinkage folds, and thorough debridement of ingrowth epithelium enable resetting the flap and provide satisfactory results. PMID:28585430

Accuracy of Alcon WaveLight® EX500 optical pachymetry during LASIK

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Mifflin MD

2017-08-01

Full Text Available Mark D Mifflin,1 Xavier M Mortensen,1 Brent S Betts,1 Cole Gross,2 Brian Zaugg1 1Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah, Salt Lake City, UT, 2University of Nevada School of Medicine, Reno, NV, USA Purpose: To study the accuracy and reliability of optical pachymetry using the Alcon WaveLight EX500 during laser-assisted in situ keratomileusis (LASIK. Materials and methods: This was a retrospective chart review of 90 eyes from 45 patients who had undergone LASIK (mean age 35.2±8.2 years; 19 males, 26 females. The WaveLight FS200 femtosecond laser was programmed to cut LASIK flaps at a desired depth of 120 µm. Optical low-coherence reflectometry (WaveLight EX500 was used to measure central corneal thickness prior to lifting the flap, and the residual stromal bed immediately after excimer ablation. Flap thickness (FT was calculated using simple subtraction. Optical coherence tomography (OCT was used to measure central corneal thickness, flap thickness, and residual stromal bed in the postoperative period and the results compared to intraoperative measurements. Results: Mean programmed FS200 FT was 119 µm. Mean FT using EX500 optical pachymetry was 109 µm. The difference between FS200- programmed and EX500-measured FT was 9 µm (P<0.001. There was also a significant difference between the EX500 and OCT FT (109 µm vs 119 µm, respectively; P<0.001. Conclusion: FT values calculated using intraoperative EX500 optical pachymetry were significantly lower than programmed FS200 values or OCT measurements. Keywords: flap thickness, optical coherence tomography, femtosecond laser

Corneal power, thickness, and stiffness: results of a prospective randomized controlled trial of PRK and LASIK for myopia.

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Hjortdal, Jesper Ø; Møller-Pedersen, Torben; Ivarsen, Anders; Ehlers, Niels

2005-01-01

To compare the short-, medium-, and long-term changes in corneal optical power and corneal aberrations, central corneal thickness, and corneal "stiffness" assessed by pneumotonometry readings in patients having laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) for myopia. Department of Ophthalmology, Arhus University Hospital, Arhus, Denmark. One eye of each of 45 patients with myopia ranging from -6.00 to -8.00 diopters (D) (spherical equivalent spectacle refraction [SER]) was randomized to LASIK (n=25; mean SER -7.12 D +/- 0.57 [SD]) or PRK (n=20; mean SER -6.91 +/- 0.57 D). Data were collected prospectively before and 1, 3, 6, 12, and 36 months after surgery. Measurements included corneal topography (TMS-1, Tomey), corneal thickness (ultrasound pachymetry), and apparent intraocular pressure (IOP) (pneumotonometry). Retreatments were not performed during the first year, and retreated eyes were excluded from the 3-year follow-up. Changes in corneal power and aberrations, thickness, and apparent IOP were calculated in a pair-wise manner for 3 time periods: short term (preoperative to 1 month after surgery), medium term (1 to 12 months after surgery), and long term (1 to 3 years after surgery). In the short term, corneal power decreased equally in LASIK and PRK eyes. Spherical aberrations and coma-like aberrations increased equally, while corneal thickness decreased significantly less in LASIK eyes than in PRK eyes. The apparent IOP decreased more in LASIK eyes than in PRK eyes. In the medium term, corneal power increased significantly in both groups. Spherical aberrations decreased significantly in PRK eyes but not in LASIK eyes. From 1 to 12 months, corneal thickness increased more in PRK eyes than in LASIK eyes. During this period, the apparent IOP increased significantly in LASIK eyes. In the long term, corneal power and corneal aberrations did not change significantly in either group. Corneal thickness increased slightly but

A prospective, contralateral eye study comparing thin-flap LASIK (sub-Bowman keratomileusis) with photorefractive keratectomy.

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Slade, Stephen G; Durrie, Daniel S; Binder, Perry S

2009-06-01

To determine the differences in the visual results, pain response, biomechanical effect, quality of vision, and higher-order aberrations, among other parameters, in eyes undergoing either photorefractive keratectomy (PRK) or thin-flap LASIK/sub-Bowman keratomileusis (SBK; intended flap thickness of +/-100 microm and 8.5-mm diameter) at 1, 3, and 6 months after surgery. A contralateral eye pilot study. Fifty patients (100 eyes) were enrolled at 2 sites. The mean preoperative spherical refraction was -3.66 diopters (D) and the mean cylinder was -0.66 D for all eyes. Eyes in the PRK group underwent 8.5-mm ethanol-assisted PRK, whereas in eyes in the SBK group, an 8.5-mm, (intended) 100-microm flap was created with a 60-kHz IntraLase femtosecond laser (Advanced Medical Optics, Santa Ana, CA). All eyes underwent a customized laser ablation using an Alcon LADARVision 4000 CustomCornea excimer laser (Alcon Laboratories, Fort Worth, TX). Preoperative and postoperative tests included best spectacle-corrected visual acuity, uncorrected visual acuity (UCVA), corneal topography, wavefront aberrometry, retinal image quality, and contrast sensitivity. Patients completed subjective questionnaires at each visit. One- and 3-month UCVA results showed a statistically significant difference: SBK, 88% 20/20 or better vs. 48% 20/20 or better for PRK. At 6 months, UCVA was 94% 20/20 or better for PRK and 92% for SBK. At 1 and 3 months, the SBK group had lower higher-order aberrations (coma and spherical aberration; PPRK group. By 3 months, the vision in the 2 groups had begun to equalize, although the SBK eyes continued to have better vision. At 6 months, there were no statistical differences between the 2 groups. Proprietary or commercial disclosure may be found after the references.

Implantation of a multifocal toric intraocular lens with a surface-embedded near segment after repeated LASIK treatments.

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Khoramnia, Ramin; Auffarth, Gerd U; Rabsilber, Tanja M; Holzer, Mike P

2012-11-01

We report a 66-year-old patient who presented with increasing hyperopia, astigmatism, and presbyopia in both eyes 8 years after bilateral laser in situ keratomileusis (LASIK) and LASIK enhancement in the left eye aiming for spectacle independence. Bilateral multifocal toric Lentis Mplus intraocular lenses (IOLs) with an embedded near segment and individually customized cylinder correction were implanted uneventfully following phacoemulsification. The Haigis-L formula after previous hyperopia correction was chosen for IOL power calculation and provided reliable results. Emmetropia was targeted and achieved. Three months postoperatively, the uncorrected distance visual acuity had increased from 0.40 logMAR to 0.10 logMAR in the right eye and from 0.20 logMAR to 0.00 logMAR in the left eye. The patient gained 6 lines of uncorrected near visual acuity: 0.20 logMAR in the right eye and 0.10 logMAR in the left eye. This case shows that customized premium IOL implantation can provide accurate results even in challenging cases. The International Vision Correction Research Centre, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany, has received research grants, lecture fees, and travel reimbursement from Oculentis GmbH. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Laser in situ keratomyleusis (LASIK for correction of myopia and hypermetropia: Our one year experience

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Vukosavljević Miroslav

2009-01-01

Full Text Available Background/Aim. Laser in situ keratamileusis (LASIK is the most commonly used refractive surgical method worldwide. The aim of this study was to examine the effectiveness and safety of LASIK in the correction of myopia and hyperopia. Methods. The study included myopic and hyperopic eyes with preoperative best corrected visual acuity (BCVA = 1 (20/20, of the total number of 322 divided into 2 groups - 1 myopic eyes (n = 241 which were divided into 4 subgroups according to the myopia strength: a ≤ -1.75 D (n = 23, b from -2 to -3.75 D (n = 81, c from -4 to -6.75 D (n = 113, d ≥ -7 D (n = 24; 2 hyperopic eyes (n = 81 which were divided into 3 subgroups according to the hyperopia strength: a ≤ +1.75D (n = 10, b from +2 to +3.75 D (n = 46, c ≥ +4 D (n = 25. Myopic and hyperopic eyes with preoperative BCVA ≤ 0.9 (eyes with ambliopia were excluded from the study, as well as eyes with astigmatism > 1.5 D. To assess the effectiveness of LASIK we examined the percentage of eyes in the mentioned subgroups, which derived uncorrected visual acuity (UCVA 6 month after the intervention to the following: a UCVA = 1 (20/20 and b UCVA ≥ 0.5 (20/40. To assess the safety of LASIK we examined the frequency of intraoperative and postoperative complications. A prospective study was performed in a 6-months follow-up period. Results. Refractive spherical equivalent (RSE of myopic eyes was in the range from -0.75 D to -12 D. In the first subgroup preoperative mean value of RSE with standard deviation (mean RSE ± SD was -1.39 ± 0.36 D, and 6 months after the LASIK 100% of the eyes had UCVA = 20/20. In the second subgroup preoperative mean RSE ± SD was -2.85 ± 0.50 D, and 6 months after LASIK 93% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA ≥ 20/40. In the third subgroup preoperative mean RSE ± SD was -5.03 ± 0.75 D, and 6 months after the LASIK 90% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA ≥ 20/40. In the fourth

Complicações primárias da interface do 'flap' de LASIK

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Renata Loures Bueno de Moraes

2016-02-01

Full Text Available RESUMO Laser in situ Keratomileusis (LASIK é uma das técnicas mais aceitas na cirurgia refrativa atualmente. Sua previsibilidade, reprodutibilidade, segurança e baixos índices de efeitos colaterais justificam a ampla difusão dessa técnica. Trata-se de um procedimento cirúrgico a laser cujo objetivo consiste na modificação da estrutura corneana, permitindo uma mudança do ponto focal do olho. Dessa forma, é possível corrigir ametropias tais como a miopia, astigmatismo e pequenos graus de hipermetropia. A técnica do LASIK consiste na criação de um flap corneano por meio da utilização de um microcerátomo ou do laser de femtossegundo. Em seguida, é realizada a aplicação do excimer laser sobre o leito estromal com posterior reposicionamento do flap, criando-se uma interface entre as lamelas anterior e posterior da córnea. Apesar das inúmeras vantagens, existem patologias que resultam de complicações primárias da interface do flap, que podem causar confusão no momento do diagnóstico, por possuírem semelhanças quanto à sua apresentação clínica. O objetivo desse trabalho é definir, caracterizar e comparar tais entidades com intuito de facilitar o diagnóstico diferencial dessas patologias evitando a adoção de um tratamento equivocado. Como resultado do estudo, são apresentadas recomendações quanto à conduta nos casos de cada patologia de interface, com investigação por meio da anamnese e exame clínico, a fim de permitir diagnóstico diferencial entre as principais entidades primárias da interface do procedimento LASIK.

Anel corneano intra-estromal para baixa miopia: estudo comparativo com a técnica de LASIK

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Forseto Adriana dos Santos

2004-01-01

Full Text Available OBJETIVO: Avaliar prospectivamente a eficácia e segurança dos segmentos de anéis corneanos intra-estromais (ICRS para a correção de baixa miopia e comparar os resultados obtidos com a técnica de laser in situ keratomileusis (LASIK. MÉTODOS: Estudo prospectivo, bilateral e não randomizado. Quatorze pacientes com equivalente esférico entre -1,00 e -4,50 D foram submetidos ao implante de ICRS em um olho e à técnica de LASIK no olho contralateral. As avaliações pós-operatórias foram realizadas com um e sete dias, um, três, seis, 12 e 24 meses. RESULTADOS: Ao último exame, 64,29% dos olhos (9/14 do grupo ICRS e 85,71% (12/14 após o LASIK estavam entre ± 0,50 D da correção desejada (p=0,385. Acuidade visual sem correção >20/20 foi obtida em quatro dos 14 olhos (28,57% do grupo ICRS, e em 12 dos 14 olhos (85,71% do grupo LASIK (p=0,002¹. Durante o seguimento, não foram observadas variações refracionais superiores a 1,00 D, entre dois exames consecutivos, em ambos os grupos, ou perda significante da melhor acuidade visual corrigida. Maior indução de astigmatismo foi encontrada nos olhos implantados com ICRS. Ao exame de 24 meses, o grupo ICRS apresentou valores inferiores no exame de sensibilidade ao contraste, especialmente nas freqüências espaciais mais altas (p=0,032¹ em 18 cpd. Foram relatadas mais queixas subjetivas no período pós-operatório precoce de ICRS em relação ao LASIK. CONCLUSÕES: Os ICRS foram considerados eficazes na correção de baixa miopia, porém sua segurança foi limitada pela indução de astigmatismo no pós-operatório, e seus resultados foram inferiores aos do grupo controle.

Epithelial ingrowth under a laser in situ keratomileusis flap after phacoemulsification.

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Braunstein, Richard E; Airiani, Suzanna; Chang, Stanley

2003-11-01

A 47-year-old man was referred to us for management of a cataract in the left eye. The patient had an ocular history of high myopia with anisometropia, amblyopia in the left eye, and stable myopic lattice degeneration in both eyes. The patient had successful bilateral laser in situ keratomileusis 3 years before and multiple retinal surgeries for treatment of a rhegmatogenous retinal detachment associated with a giant retinal tear in the temporal region of the retina with subsequent proliferative vitreoretinopathy. Phacoemulsification was performed uneventfully. A single interrupted 10-0 nylon suture was placed in the temporal clear corneal wound and removed 7 weeks postoperatively. One month later, slitlamp examination revealed a 1.5 mm tongue-like area of epithelial ingrowth under the corneal flap. The epithelial cells seemed to enter the flap-stroma interface through the previously placed suture tract and advanced centrally.

[Study on the change of optical zone after femtosecond laser assisted laser in situ keratomileusis].

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Li, H; Chen, M; Tian, L; Li, D W; Peng, Y S; Zhang, F F

2018-01-11

Objective: To explore the change of optical zone after femtosecond laser assisted laser in sitn keratomileusis(FS-LASIK) so as to provide the reference for measurement and design of clinical optical zone. Methods: This retrospective case series study covers 41 eyes of 24 patients (7 males and 17 females, aged from 18 to 42 years old) with myopia and myopic astigmatism who have received FS-LASIK surgery at Corneal Refractive Department of Qingdao Eye Hospital and completed over 6 months of clinical follow-up. Pentacam system (with the application of 6 corneal topographic map modes including: the pure axial curvature topographic map, the pure tangential curvature topographic map, the axial curvature difference topographic map, the tangential curvature difference topographic map, the postoperative front elevation map and the corneal thickness difference topographic map), combined with transparent concentric software (a system independently developed by Qingdao Eye Hospital) was used to measure the optical zone at 1, 3 and 6 months postoperatively, the optical zone diameters measurement results among different follow-up times in group were analyzed with the repeated measures analysis of variance, and the actual measured values and the theoretical design values of the optical zone were analyzed with independent-samples t-testing. Spearman correlation coefficient ( r(s) ) have been applied to evaluate the relationship between postoperative optical zone measurement values and the potential influencing factors. Results: The optical zone diameters measured by pure axial curvature topographic map at 1, 3 and 6 months after FS-LASIK showed (6.55±0.50)mm, (6.50±0.53)mm and (6.48±0.53)mm respectively. The differences between values are of no statistical significance ( F= 1.60, P= 0.21), the optical zone diameter measured by pure tangential curvature topographic map at 1, 3 and 6 months after FS-LASIK showed (5.44±0.46)mm, (5.46±0.52)mm and (5.44±0.50)mm respectively, the

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Full Text Available ... This web site also provides information on FDA’s role in LASIK surgery, FDA’s current LASIK activities , and ... and after surgery? LASIK Surgery Checklist LASIK: FDA's Role LASIK: Glossary FDA-Approved Lasers for LASIK / Patient ...

Meta-analysis of Pentacam vs. ultrasound pachymetry in central corneal thickness measurement in normal, post-LASIK or PRK, and keratoconic or keratoconus-suspect eyes.

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Wu, Wenjing; Wang, Yan; Xu, Lulu

2014-01-01

The aim of this meta-analysis is to evaluate the central corneal thickness (CCT) measurement differences between Pentacam (Oculus Inc., Germany) and Ultrasound Pachymetry (USP) in normal (unoperated eyes , myopic and astigmatic eyes without corneal disease or topographic irregularity), after laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK), and keratoconic or keratoconus suspected eyes. We assess whether Pentacam and USP have similar CCT differences in normal, thinner corneas after LASIK or PRK procedures, and kerotoconic or keratoconus suspected eyes. Data sources, including PubMed, Medline, EMBASE, and Cochrane Central Registry of Controlled Trials on the Cochrane Library, were searched to find the relevant studies. Primary outcome measures were CCT measurement between Pentacam and USP. Three groups of eyes were analyzed: normal; LASIK or PRK eyes; and keratoconus suspected or keratoconic eyes. Nineteen studies describing 1,908 eyes were enrolled in the normal group. Pentacam results were 1.47 μm ,95 % confidence interval (CI) -2.32 to 5.27, higher than USP without statistically significant difference (P = 0.45). Nine studies with total 539 eyes were included in the corneas after LASIK or PRK. The mean difference in the CCT measurement with Pentacam and ultrasound pachymetry was 1.03 μm, with the 95 % CI -3.36 to 5.42, there was no statistically difference (P = 0.64). Four studies with a total of 185 eyes were included in the keratoconic eyes or keratoconus-suspect group, however,the mean difference was -6.33 μm (95 % CI -9.17 to-3.49), which was statistically different between Pentacam and ultrasound pachymetry in the CCT measurement (P LASIK or PRK procedures. However, in keratoconic or keratoconus-suspect eyes, Pentacam slightly underestimates the central corneal thickness than does ultrasound pachymetry, which may result from the difficulty in fixation of keratoconic eyes, misalignment of Pentacam and the variation

A randomized clinical evaluation of the safety of Systane® Lubricant Eye Drops for the relief of dry eye symptoms following LASIK refractive surgery

Directory of Open Access Journals (Sweden)

Daniel Durrie

2008-12-01

Full Text Available Daniel Durrie, Jason StahlDurrie Vision, Overland Park, Kansas, USAPurpose: To evaluate the safety of Systane® Lubricant Eye Drops in relieving the symptoms of dry eye following laser-assisted in situ keratomileusis (LASIK surgery.Methods: This was a randomized, double-masked, single-center, placebo-controlled, contralateral eye study of 30 patients undergoing LASIK surgery. The mean age of patients was 42.4 ± 10.7 years, and the mean spherical equivalent was −3.29 (range, +1.75 to −7.38. Patients’ right and left eyes were randomized to receive either Systane® or placebo – a preserved, thimerosal-free saline solution – beginning from the day of surgery and ending 30 days following surgery. Outcome measures included tear film break up time (TFBUT, visual acuity, degree of corneal and conjunctival staining, and treatment-related adverse events.Results: Preoperatively, placebo-treated eyes had statistically significantly higher sum corneal staining score than Systane®-treated eyes (p = 0.0464; however, the difference was clinically insignificant (p = 0.27. Two weeks post operatively, the average TFBUT in the Systane®-treated eyes was 1.23 seconds longer than that of the placebo-treated eyes (p = 0.028. All other evaluated variables were comparable between the two treatments. No adverse events were reported in the study.Conclusion: Systane® Lubricant Eye Drops are safe for use following LASIK surgery to relieve the discomfort symptoms of dry eye associated with the procedure.Keywords: Systane®, safety, dry eye, LASIK

[Ablation on the undersurface of a LASIK flap. Instrument and method for continuous eye tracking].

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Taneri, S; Azar, D T

2007-02-01

The risk of iatrogenic keratectasia after laser in situ keratomileusis (LASIK) increases with thinner posterior stromal beds. Ablations on the undersurface of a LASIK flap could only be performed without the guidance of an eye tracker, which may lead to decentration. A new method for laser ablation with flying spot lasers on the undersurface of a LASIK flap was developed that enables the use of an active eye tracker by utilizing a novel instrument. The first clinical results are reported. Patients wishing an enhancement procedure were eligible for a modified repeat LASIK procedure if the flaps cut in the initial procedure were thick enough to perform the intended additional ablation on the undersurface leaving at least 90 microm of flap thickness behind. (1) The horizontal axis and the center of the entrance pupil were marked on the epithelial side of the flap using gentian violet dye. (2) The flap was reflected on a newly designed flap holder which had a donut-shaped black marking. (3) The eye tracker was centered on the mark visible in transparency on the flap. (4) Ablation with a flying spot Bausch & Lomb Technolas 217z laser was performed on the undersurface of the flap with a superior hinge taking into account that in astigmatic ablations the cylinder axis had to be mirrored according to the formula: axis on the undersurface=180 degrees -axis on the stromal bed. (5) The flap was repositioned. Detection of the marking on the modified flap holder and continuous tracking instead of the real pupil was possible in all of the 12 eyes treated with this technique. It may be necessary to cover the real pupil during ablation in order not to confuse the eye tracker. Ablation could be performed without decentration or loss of best spectacle-corrected visual acuity. Refractive results in minor corrections were good without nomogram adjustment. Using this novel flap holder with a marking that is tracked instead of the real pupil, centered ablations with a flying spot laser

Structural and functional changes in corneal innervation after laser in situ keratomileusis and their relationship with dry eye.

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Chao, Cecilia; Stapleton, Fiona; Zhou, Xiangtian; Chen, Shihao; Zhou, Shi; Golebiowski, Blanka

2015-11-01

The most likely etiology of post-LASIK dry eye is corneal nerve damage; however, no direct relationship between post-LASIK dry eye symptoms and nerve damage has been established, and limited information is available about the relationship between dry eye signs and corneal reinnervation after LASIK. Tear neuropeptides (SP and CGRP) are important in the maintenance of corneal nerve health, but the impact of LASIK has not yet been studied. This study evaluated changes in nerve morphology, tear neuropeptide, and dry eye, so as to establish the relationship between reinnervation and dry eye and to assess the role of tear neuropeptides in reinnervation post-LASIK. Twenty non-dry eye volunteers who had undergone bilateral myopic-LASIK completed this study. Corneal nerve morphology (density, width, interconnections, and tortuosity), SP and CGRP concentration, and dry eye were monitored over time prior to, 1 day, 1 week, 1, 3, and 6 months post-LASIK. Dry eye symptoms and tear function, except for osmolarity (P = 0.003), remained unchanged post-LASIK. Corneal nerve morphology decreased immediately, and did not return to preoperative levels by 6 months post-LASIK (P dry eye symptoms (P = 0.01) were found post-LASIK. An inverse relationship between reinnervation post-LASIK and dry eye symptoms was found, confirming that post-LASIK dry eye is a neuropathic disease. This study is the first to demonstrate an association between tear SP and post-LASIK reinnervation, suggesting that strategies for manipulating neuropeptide concentration to improve reinnervation may improve ocular comfort post-LASIK.

Håndtering af keratitis efter laserbehandling adskiller sig fra almindelig keratitis

DEFF Research Database (Denmark)

Ahmed, Shakil; Ahmed, Hassan Javed; Holm, Lars Morten

2014-01-01

Keratitis after laser in situ keratomileusis (LASIK) is rare and challenging as patients may present with mild symptoms and initial management differs significantly. Post-LASIK keratitis is usually due to gram-positive bacteria or opportunistic/atypical microorganisms located beneath the corneal...... flap. Due to relative protective interface location it is necessary to lift the corneal flap for cultures and antibiotic irrigation. The case report demonstrates that post-LASIK keratitis requires prompt referral to ophthalmology department as correct initial management is pivotal for good visual...

Predictability and stability of refraction with increasing optical zone diameter in hyperopic LASIK

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Mostafa A El-Helw

2010-05-01

Full Text Available Mostafa A El-Helw, Ahmed M EmarahCairo University, Cairo, EgyptObjective: We undertook a prospective nonrandomized study to assess refractive outcome and patient satisfaction with hyperopic laser in situ keratomileusis (LASIK using variable optical zone diameters in correction of hyperopia of more than 4.00 diopters.Methods: Fourteen adults (comprising 28 hyperopic eyes underwent hyperopic LASIK correction for hyperopia of more than 4.00 diopters. The sample was divided into two groups. Group 1 included the right eyes of the 14 patients who underwent hyperopic LASIK using a 6.5 mm optical zone diameter. Group 2 comprised the left eyes of the same patients with the only difference being that the optical zone diameter was 6.0 mm.Results: The mean age of the patients was 36.42 ± 5.10 years. Group 1 eyes had a median (range preoperative uncorrected visual acuity (UCVA of 0.79 (0.52 and best-corrected visual acuity (BCVA of 0.15 (0.08. Group 2 had a median preoperative UCVA of 0.79 (0.60 and BCVA of 0.15 (0.08. The median postoperative UCVA in Group 1 was 0.17 (0.21 and BCVA was 0.15 (0.13. In Group 2, the median postoperative UCVA was 0.30 (0.32 and BCVA was 0.15 (0.26. Group 1 had a median preoperative refraction of +5.37 (1.75 diopters and the median postoperative refraction at one week was −0.23 (1.25 diopters, at three months was +0.75 (0.75 diopters, and at six months was +0.75 (1.00 diopters. Group 2 had a median preoperative refraction of +5.00 (1.75 diopters, and the median postoperative refraction at one week was +0.13 (1.5 diopters, at three months was +1.00 (0.75 diopters and at six months +1.25 (1.25 diopters. The difference was statistically significant between groups 1 and 2. The difference within each group was also significant. Group 1 eyes were stabilizing after the three-month period in contrast with Group 2 in which the refractive changes continued throughout the follow-up period.Conclusion: Larger optical zone diameter in

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Visual quality analysis of femtosecond LASIK and iris location guided mechanical SBK for high myopia

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Hong-Su Jiang

2015-07-01

Full Text Available AIM: To make a analysis of visual quality of iris location guided femtosecond laser assisted in situ keratomi(LASIKand iris location guided mechanical sub-bowman keratomileusis(SBKfor high myopia treatment. METHODS:Femtosecond LASIK(study groupwas performed in 102 eyes of 51 patients with high myopia and 70 eyes of 35 patients were received mechanical SBK(control groupfrom January to October 2013. The spherical refraction of all the patients was from -6.00～-9.50D. Best corrected visual acuity(BCVAof the patients was ≥1.0. Uncorrected visual acuity(UCVA, BCVA, thickness of cornea flap, contrast sensitivity function(CSFand senior ocular aberration were examined in these patients and follow-up was 1a. RESULTS: At 1a after surgery 94.1% UCVA in study group reached ≥1.0 and there was 94.3% in control group. There was no significant difference between two groups(P>0.05. Residual refraction of study group was -0.08±0.10 D and control group was -0.10±0.07 D. There was no significant difference of residual refraction between two groups(P>0.05. C12, C8 of senior ocular aberration and RMSH in study group was less than control group, amplification: 0.1642±0.0519 and 0.2229±0.0382(t=8.077, Pt=0.556, P>0.05. C8 was 0.0950±0.069 and 0.1858±0.095(t=7.261, Pt=12.801, PP>0.05.CONCLUSION: Femtosecond LASIK and mechanical SBK is effective for high myopia. Compared to mechanical SBK, femtosecond LASIK shows more advantages in the senior ocular aberration and visual quality. The cornea flap is more regular from central to peripheral area with femtosecond laser.

Management of post-LASIK dry eye: a multicenter randomized comparison of a new multi-ingredient artificial tear to carboxymethylcellulose

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Wallerstein A

2018-05-01

Full Text Available Avi Wallerstein,1,2 W Bruce Jackson,3 Jeffrey Chambers,4 Amir M Moezzi,5 Hugh Lin,6 Peter A Simmons6 1Department of Ophthalmology, McGill University, Montreal, QC, Canada; 2LASIK MD, Montreal, QC, Canada; 3University of Ottawa Eye Institute of the Ottawa Hospital, Ottawa, ON, Canada; 4Kelowna Eye Care Center, Kelowna, BC, Canada; 5Centre for Ocular Research & Education (CORE, formerly Centre for Contact Lens Research, School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada; 6Allergan Clinical Research, Allergan plc, Irvine, CA, USA Purpose: To compare the efficacy and safety of a preservative-free, multi-ingredient formulation of carboxymethylcellulose 0.5%, hyaluronic acid 0.1%, and organic osmolytes (CMC-HA, to preservative-free carboxymethylcellulose 0.5% (CMC in the management of postoperative signs and symptoms of dry eye following laser-assisted in situ keratomileusis (LASIK. Methods: This was a double-masked, randomized, parallel-group study conducted in 14 clinical centers in Canada and Australia. Subjects with no more than mild dry eye instilled CMC-HA or CMC for 90 days post-LASIK. Ocular Surface Disease Index© (OSDI; primary efficacy measure, corneal staining, tear break-up time (TBUT, Schirmer’s test, acceptability/tolerability surveys, and visual acuity were assessed at screening and days 2, 10, 30, 60, and 90 post-surgery. Safety analyses included all enrolled. Results: A total of 148 subjects (CMC-HA, n=75; CMC, n=73 were enrolled and assigned to receive treatment, and 126 subjects completed the study without any protocol violations. Post-LASIK, dry eye signs/symptoms peaked at 10 days. OSDI scores for both groups returned to normal with no differences between treatment groups at day 90 (P=0.775. Corneal staining, Schirmer’s test, TBUT, and survey results were comparable. Higher mean improvements in uncorrected visual acuity were observed in the CMC-HA group at all study visits, reaching

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Full Text Available ... common links HHS U.S. Department of Health and Human Services U.S. Food and Drug Administration A to ... Information LASIK - FAQs (Frequently Asked Questions) LASIK: Other Resources Contact Us Latest on FDA's LASIK Program LASIK ...

Comparison of the femtosecond laser and mechanical microkeratome for flap cutting in LASIK

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Li-Kun Xia

2015-08-01

Full Text Available AIM: To compare refractive results, higher-order aberrations (HOAs, contrast sensitivity and dry eye after laser in situ keratomileusis (LASIK performed with a femtosecond laser versus a mechanical microkeratome for myopia and astigmatism.METHODS: In this prospective, non-randomized study, 120 eyes with myopia received a LASIK surgery with the VisuMax femtosecond laser for flap cutting, and 120 eyes received a conventional LASIK surgery with a mechanical microkeratome. Flap thickness, visual acuity, manifest refraction, contrast sensitivity function (CSF curves, HOAs and dry-eye were measured at 1wk; 1, 3, 6mo after surgery.RESULTS:At 6mo postoperatively, the mean central flap thickness in femtosecond laser procedure was 113.05±5.89 µm (attempted thickness 110 µm, and 148.36±21.24 µm (attempted thickness 140 µm in mechanical microkeratome procedure. An uncorrected distance visual acuity (UDVA of 4.9 or better was obtained in more than 98% of eyes treated by both methods, a gain in logMAR lines of corrected distance visual acuity (CDVA occurred in more than 70% of eyes treated by both methods, and no eye lost ≥1 lines of CDVA in both groups. The difference of the mean UDVA and CDVA between two groups at any time post-surgery were not statistically significant (P＞0.05. The postoperative changes of spherical equivalent occurred markedly during the first month in both groups. The total root mean square values of HOAs and spherical aberrations in the femtosecond treated eyes were markedly less than those in the microkeratome treated eyes during 6mo visit after surgery (P＜0.01. The CSF values of the femtosecond treated eyes were also higher than those of the microkeratome treated eyes at all space frequency (P＜0.01. The mean ocular surface disease index scores in both groups were increased at 1wk, and recovered to preoperative level at 1mo after surgery. The mean tear breakup time (TBUT of the femtosecond treated eyes were markedly

Comparison of the femtosecond laser and mechanical microkeratome for flap cutting in LASIK.

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Xia, Li-Kun; Yu, Jie; Chai, Guang-Rui; Wang, Dang; Li, Yang

2015-01-01

To compare refractive results, higher-order aberrations (HOAs), contrast sensitivity and dry eye after laser in situ keratomileusis (LASIK) performed with a femtosecond laser versus a mechanical microkeratome for myopia and astigmatism. In this prospective, non-randomized study, 120 eyes with myopia received a LASIK surgery with the VisuMax femtosecond laser for flap cutting, and 120 eyes received a conventional LASIK surgery with a mechanical microkeratome. Flap thickness, visual acuity, manifest refraction, contrast sensitivity function (CSF) curves, HOAs and dry-eye were measured at 1wk; 1, 3, 6mo after surgery. At 6mo postoperatively, the mean central flap thickness in femtosecond laser procedure was 113.05±5.89 µm (attempted thickness 110 µm), and 148.36±21.24 µm (attempted thickness 140 µm) in mechanical microkeratome procedure. An uncorrected distance visual acuity (UDVA) of 4.9 or better was obtained in more than 98% of eyes treated by both methods, a gain in logMAR lines of corrected distance visual acuity (CDVA) occurred in more than 70% of eyes treated by both methods, and no eye lost ≥1 lines of CDVA in both groups. The difference of the mean UDVA and CDVA between two groups at any time post-surgery were not statistically significant (P>0.05). The postoperative changes of spherical equivalent occurred markedly during the first month in both groups. The total root mean square values of HOAs and spherical aberrations in the femtosecond treated eyes were markedly less than those in the microkeratome treated eyes during 6mo visit after surgery (P<0.01). The CSF values of the femtosecond treated eyes were also higher than those of the microkeratome treated eyes at all space frequency (P<0.01). The mean ocular surface disease index scores in both groups were increased at 1wk, and recovered to preoperative level at 1mo after surgery. The mean tear breakup time (TBUT) of the femtosecond treated eyes were markedly longer than those of the microkeratome

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Full Text Available ... of this Web site is to provide objective information to the public about LASIK surgery. See other ... undergoing LASIK surgery. This web site also provides information on FDA’s role in LASIK surgery, FDA’s current ...

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Full Text Available ... information on FDA’s role in LASIK surgery, FDA’s current LASIK activities , and FDA-approved lasers for LASIK . ... Emergency Preparedness International Programs News & Events Training & Continuing Education Inspections & Compliance Federal, State & Local Officials Consumers Health ...

LASIK hipermetrópico pós-DSAEK (Descement Stripping Automated Endotelial Keratoplasty

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Antonio Carlos Manhas Meireles

Full Text Available RESUMO O DSAEK (Descemet stripping automated endotelial Keratoplasty é um dos procedimentos de escolha para tratamento das doenças que acometem o endotélio corneano. Apesar do sucesso terapêutico, o procedimento pode induzir uma hipermetropia residual. Em média a refração se estabiliza em um perído que varia de 6 a 12 meses após o transplante. O objetivo desse relato é descrever a evolução dessa opção terapêutica utilizada em um paciente de 54 anos portador de Distrofia de Fuchs. O paciente foi submetido ao transplante de córnea (DSAEK e a remoção do cristalino no mesmo tempo cirúrgico o que resultou em hipermetropia residual. Após 3 anos de acompanhamento apresentava-se com a melhor visão corrigida de 20/20 (Snellen no olho operado com uma refração de +3,25 -1,00 (5º. Optou-se por realização de LASIK (Laser assisted in situ Keratomileusis hipermetrópico, obtendo um resultado visual satisfatório.

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... Devices Products and Medical Procedures Surgery Devices LASIK LASIK Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Report a Problem LASIK is a surgical procedure intended to reduce a ...

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Full Text Available ... Devices Home Medical Devices Products and Medical Procedures Surgery Devices LASIK LASIK Share Tweet Linkedin Pin it ... provide objective information to the public about LASIK surgery. See other sections of this site to learn ...

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Full Text Available ... middle section of the cornea. Pulses from a computer-controlled laser vaporize a portion of the stroma ... FDA's LASIK Program LASIK Quality of Life Collaboration Project LASIK: Report a Problem Page Last Updated: 03/ ...

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Full Text Available ... More sharing options Linkedin Pin it Email Print Report a Problem LASIK is a surgical procedure intended ... Program LASIK Quality of Life Collaboration Project LASIK: Report a Problem Page Last Updated: 03/26/2018 ...

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Full Text Available ... Devices Products and Medical Procedures Surgery Devices LASIK LASIK Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Report a Problem LASIK is a surgical procedure intended to reduce a ...

Related research on corneal higher-order aberrations after different ways refractive surgery

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Shu-Xi He

2015-08-01

Full Text Available AIM:To evaluate the changes of corneal high-order aberration(including Coma, Spab, RMShafter laser in situ keratomileusis(LASIKwith femtosecond laser, sub-Bowman keratomileusis(SBKand laser epithelial keratomileusis(LASEK.METHODS: Of 82 myopic patients(164 eyes, 31 patients(62 eyeswere treated by FS-LASIK, 31 patients(62 eyeswere treated by SBK, 20 patients(40 eyeswere treated by LASEK. Sirius system was used for measuring the coma aberration, spherical aberration, and high order aberration at 1, 15d,1, 3mo after surgery.RESULTS: 1Vision: The uncorrected visual acuity of the three groups had no differences(P>0.05. 2Corneal aberrations: Three kinds of surgical procedure for patients with corneal aberration had significant impact. The C7, C8, C12 and RMSh of three groups were increased significantly(P0.05. The C7, C8, C12 and RMSh were not recovered to preoperative levels after 3mo. But the increase of patients after FS-LASIK was smaller than the other two groups, with statistical significance(P0.05.CONCLUSION: Compared with SBK and LASEK,FS-LASIK has better visual acuity in the early postoperative and corneal higher-order aberrations increase is relatively small.

Changes in higher order aberrations after wavefront guided FS-LASIK for myopia combined with moderate to high astigmatism

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Cang-Yu Guan

2018-02-01

Full Text Available AIM: To assess the changes in higher order aberrations after wavefront guided femtosecond laser assisted laser in situ keratomileusis(FS-LASIKfor moderate to high astigmatism. METHODS: Eighty-eight eyes of 50 myopia patients with moderate to high astigmatism were included in this prospective study. There were 51 eyes with moderate astigmatism(≥-1.50D and RESULTS: At the 3mo after operation, the mean UDVA of all eyes was above 20/20, better than before operation(PP=0.36and no eyes lost ≥2 lines of CDVA. Mean astigmstism of 85 eyes(97%was reduced below -1.00D, mean astigmatism of 70 eyes(80%was reduced below -0.50D(PPP=0.078, 0.065. The spherical aberration, secondary astigmatism and the HOA root mean square(RMSincreased from 0.19±0.06, 0.05±0.02 and 0.42±0.12, preoperatively to 0.32±0.17, 0.26±0.08 and 0.78±0.28(PCONCLUSION: Wavefront-guided FS-LASIK is a safe and effective option for the patients with moderate to high astigmstism although parts of HOAs increased.

Refractive lenticule extraction (ReLEx through a small incision (SMILE for correction of myopia and myopic astigmatism: current perspectives

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Ağca A

2016-10-01

Full Text Available Alper Ağca,1 Ahmet Demirok,2 Yusuf Yıldırım,1 Ali Demircan,1 Dilek Yaşa,1 Ceren Yeşilkaya,1 İrfan Perente,1 Muhittin Taşkapılı1 1Beyoğlu Eye Research and Training Hospital, 2Department of Ophthalmology, Istanbul Medeniyet University, Istanbul, Turkey Abstract: Small-incision lenticule extraction (SMILE is an alternative to laser-assisted in situ keratomileusis (LASIK and photorefractive keratectomy (PRK for the correction of myopia and myopic astigmatism. SMILE can be performed for the treatment of myopia ≤-12 D and astigmatism ≤5 D. The technology is currently only available in the VisuMax femtosecond laser platform. It offers several advantages over LASIK and PRK; however, hyperopia treatment, topography-guided treatment, and cyclotorsion control are not available in the current platform. The working principles, potential advantages, and disadvantages are discussed in this review. Keywords: SMILE, small-incision lenticule extraction, femtosecond laser, laser in situ keratomileusis, corneal biomechanics

The Incidence of Central Serous Chorioretinopathy after Photorefractive Keratectomy and Laser In Situ Keratomileusis

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Majid Moshirfar

2012-01-01

A chart review was performed to identify all patients with CSCR and a previous history of LASIK or PRK. Results. Over the 6-year study period, 1 of 4,876 eyes which had LASIK or PRK at the Moran Eye Center was diagnosed with CSCR. One other patient was referred from an outside center, developed CSCR symptoms one month after PRK. Both patients were managed conservatively with a final visual acuity of 20/20 or better. All other patients presented 4 or more years after refractive surgery. Conclusions. We report the first 2 CSCR cases developing within one month after PRK. The low incidence argues against a causal association. Topical corticosteroids or anxiety may elevate cortisol levels presenting therapeutic challenges for the management of CSCR after PRK or LASIK.

Intacs for keratoconus and post-LASIK ectasia: mechanical versus femtosecond laser-assisted channel creation.

Science.gov (United States)

Carrasquillo, Karen G; Rand, Janet; Talamo, Jonathan H

2007-09-01

To evaluate the efficacy of intracorneal ring segments to treat keratoconus and post-laser in situ keratomileusis (LASIK) keratectasia implanted by using either mechanical dissection or a femtosecond laser. Thirty-three eyes of 29 patients had intracorneal ring segments implanted by using mechanical dissection (17 eyes) or a femtosecond laser (16 eyes). Mean follow-up was 10.3 months. Parameters assessed before and after surgery included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refractive spherical equivalent (MRSE), refractive cylinder (RC), best contact lens-corrected visual acuity (BCLVA), and contact lens tolerance. Statistically significant changes occurred for all parameters when we analyzed all 33 eyes as 1 group. Mean UCVA LogMar values improved from 1.0 +/- 0.3 (20/200) to 0.6 +/- 0.4 (20/80) (P < 0.0005). Mean BSCVA changed from 0.3 +/- 0.2 (20/40) to 0.2 +/- 0.2 (20/30) (10%; P < 0.05), and MRSE from -9 +/- 4 to -7 +/- 4 D (P < 0.05; 20%). There was a decrease of 0.5 D or more of RC in 62% of eyes. BCLVA improved from 0.2 +/- 0.2 (20/30) to 0.1 +/- 0.1 (20/25) after surgery (P < 0.02). Contact lens tolerance improved in 81% of eyes. There was no statistically significant difference in outcomes between mechanical dissection and femtosecond laser-assisted techniques. However, although statistical power was adequate to detect changes in clinical parameters as a result of surgery, it was not sufficient to conclusively show such differences between surgical techniques. For mild to moderate cases of keratoconus and post-LASIK keratectasia, the use of a femtosecond laser for Intacs channel creation seems as effective as mechanical dissection. Future studies are warranted to further evaluate channel creation by a femtosecond laser.

A Comparison of the American Society of Cataract and Refractive Surgery post-myopic LASIK/PRK Intraocular Lens (IOL calculator and the Ocular MD IOL calculator

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Hsu M

2011-09-01

Full Text Available David L DeMill1, Majid Moshirfar1, Marcus C Neuffer1, Maylon Hsu1, Shameema Sikder21John A Moran Eye Center, University of Utah, Salt Lake City, UT, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USABackground: To compare the average values of the American Society of Cataract and Refractive Surgery (ASCRS and Ocular MD intraocular lens (IOL calculators to assess their accuracy in predicting IOL power in patients with prior laser-in-situ keratomileusis (LASIK or photorefractive keratectomy.Methods: In this retrospective study, data from 21 eyes with previous LASIK or photorefractive keratectomy for myopia and subsequent cataract surgery was used in an IOL calculator comparison. The predicted IOL powers of the Ocular MD SRK/T, Ocular MD Haigis, and ASCRS averages were compared. The Ocular MD average (composed of an average of Ocular MD SRK/T and Ocular MD Haigis and the all calculator average (composed of an average of Ocular MD SRK/T, Ocular MD Haigis, and ASCRS were also compared. Primary outcome measures were mean arithmetic and absolute IOL prediction error, variance in mean arithmetic IOL prediction error, and the percentage of eyes within ±0.50 and ±1.00 D.Results: The Ocular MD SRK/T and Ocular MD Haigis averages produced mean arithmetic IOL prediction errors of 0.57 and –0.61 diopters (D, respectively, which were significantly larger than errors from the ASCRS, Ocular MD, and all calculator averages (0.11, –0.02, and 0.02 D, respectively, all P < 0.05. There was no statistically significant difference between the methods in absolute IOL prediction error, variance, or the percentage of eyes with outcomes within ±0.50 and ±1.00 D.Conclusion: The ASCRS average was more accurate in predicting IOL power than the Ocular MD SRK/T and Ocular MD Haigis averages alone. Our methods using combinations of these averages which, when compared with the individual averages, showed a trend of decreased mean arithmetic IOL

Avaliação das alterações biomecânicas da córnea antes e após lasik em pacientes míopes e hipermetrópes utilizando Moriá® Sub-Bowman's Keratomileusis (SBK

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Bruno de Freitas Valbon

2012-10-01

Full Text Available OBJETIVO: Avaliar e comparar as alterações biomecânicas da córnea por meio do Ocular Response Analyzer® (ORA Reichert Ophtalmics Instruments, Buffalo, New York, USA antes e após Lasik com Moriá ® Sub Bowman Keratomileusis (SBK One Use Plus (OUP em pacientes míopes e hipermetrópes. MÉTODOS: Foram estudados 33 olhos, sendo 19 olhos míopes e 14 olhos hipermetrópes submetidos à cirurgia refrativa com técnica Lasik com flap fino (100 µ utilizando Moriá SBK OUP. O ORA foi realizado no pré-operatório e 1 mês após a cirurgia para avaliar a biomecânica da córnea. O CH (Corneal Hysteresis, CRF (Corneal Resistance Factor, IOPg (goldmann gold standard, Goldmann correlated intraocular pressure a IOPcc (corneal compensated intraocular pressure e mais 38 variáveis biomecânicas da córnea derivadas do sinal de resposta foram avaliados. O Teste de Kolmogorov-Smirnov foi utilizado para avaliar a distribuição normal. O teste de Wilcoxon foi utilizado para comparar as variáveis antes e após a cirurgia para cada grupo. As diferenças entre as medidas pré e pós-operatórias dos olhos míopes foram comparadas com as diferenças obtidas nos olhos hipermetrópes, utilizando-se o teste de Mann-Whitney. Foi considerado como estatisticamente significante p < 0,05%. RESULTADOS: Houve diferença significativa antes e após Lasik em olhos míopes e hipermetrópes na variável IOPg(Wilcoxon, p <0,05, porém não houve em IOPcc. Somente em olhos míopes houve diferenças significativas em CH e CRF, antes e após Lasik com Moriá SBK OUP, como também 9 parâmetros derivados do ORA Waveform_Sinal Gráfico (aspect1, h1, dive1, path1, p1area1, W11, H11, and w2 path11; Wilcoxon, p <0,05. Em olhos hipermetrópes houve diferenças antes e após Lasik das seguintes variáveis: aspect2, h2, dive2, mslew2 e H21 (Wilcoxon p<0,05.Diferenças nas variáveis IOPg e p1area, antes e após Lasik foram maiores em olhos míopes do que hipermetrópes (Mann-Whitey, p

LASIK

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Full Text Available ... about. Below is a video that summarizes some risks of LASIK surgery and other important information. The ... is LASIK not for me? What are the risks and how can I find the right doctor ...

Small-aperture corneal inlay in patients with prior radial keratotomy surgeries

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Huseynova T

2013-09-01

Full Text Available Tukezban Huseynova,1,* Tomomi Kanamori,1 George O Waring IV,2 Minoru Tomita1,3,* 1Shinagawa LASIK Center, Chiyoda-ku, Tokyo, Japan; 2Medical University of South Carolina, Storm Eye Institute, Charleston, SC, USA; 3Department of Ophthalmology, Wenzhou Medical College, Wenzhou, People's Republic of China *These authors contributed equally to this study Abstract: This paper describes the 3-month results of two patients who underwent KAMRA™ (AcuFocus, Inc, Irvine, CA, USA inlay implantation surgery with a history of prior radial keratotomy. The refractive error just before KAMRA inlay implantation was corrected in one patient with a laser-assisted in situ keratomileusis (LASIK procedure. The post-inlay implantation surgery results showed effective uncorrected near visual acuity outcomes with no impact on uncorrected distance visual acuity in both patients. Keywords: KAMRA™, RK, LASIK, uncorrected distance visual acuity, refractive error, uncorrected near visual acuity

LASIK

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Full Text Available ... options Linkedin Pin it Email Print Report a Problem LASIK is a surgical procedure intended to reduce a person's dependency on glasses or contact lenses. The goal of this Web site is to provide objective information to the public about LASIK surgery. See other sections of this ...

Consistent comparison of angle Kappa adjustment between Oculyzer and Topolyzer Vario topography guided LASIK for myopia by EX500 excimer laser.

Science.gov (United States)

Sun, Ming-Shen; Zhang, Li; Guo, Ning; Song, Yan-Zheng; Zhang, Feng-Ju

2018-01-01

To evaluate and compare the uniformity of angle Kappa adjustment between Oculyzer and Topolyzer Vario topography guided ablation of laser in situ keratomileusis (LASIK) by EX500 excimer laser for myopia. Totally 145 cases (290 consecutive eyes )with myopia received LASIK with a target of emmetropia. The ablation for 86 cases (172 eyes) was guided manually based on Oculyzer topography (study group), while the ablation for 59 cases (118 eyes) was guided automatically by Topolyzer Vario topography (control group). Measurement of adjustment values included data respectively in horizontal and vertical direction of cornea. Horizontally, synclastic adjustment between manually actual values (dx manu ) and Oculyzer topography guided data (dx ocu ) accounts 35.5% in study group, with mean dx manu /dx ocu of 0.78±0.48; while in control group, synclastic adjustment between automatically actual values (dx auto ) and Oculyzer topography data (dx ocu ) accounts 54.2%, with mean dx auto /dx ocu of 0.79±0.66. Vertically, synclastic adjustment between dy manu and dy ocu accounts 55.2% in study group, with mean dy manu /dy ocu of 0.61±0.42; while in control group, synclastic adjustment between dy auto and dy ocu accounts 66.1%, with mean dy auto /dy ocu of 0.66±0.65. There was no statistically significant difference in ratio of actual values/Oculyzer topography guided data in horizontal and vertical direction between two groups ( P =0.951, 0.621). There is high consistency in angle Kappa adjustment guided manually by Oculyzer and guided automatically by Topolyzer Vario topography during corneal refractive surgery by WaveLight EX500 excimer laser.

Heme Oxygenase-2 as a novel target to treat inflammation and chronic neuropathic pain associated with corneal injury and surgery

OpenAIRE

Marrazzo, Giuseppina

2012-01-01

Corneal refractive surgery aims at correcting alteration of the shape of the cornea correlated with myopia, hyperopia and astigmatism. More than 12 million patients have undergone refractive surgery since it was approved (see http://www. laser-eye-surgery statistics.com/). Laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) are the most used techniques to perform experimental corneal surgery. Several studies demonstrated that after epithelial removal (first...

Topography-guided hyperopic and hyperopic astigmatism femtosecond laser-assisted LASIK: long-term experience with the 400 Hz eye-Q excimer platform

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Kanellopoulos AJ

2012-06-01

Full Text Available Anastasios John KanellopoulosDepartment of Ophthalmology, New York University Medical School, New York, NY, and LaserVision.gr Eye Institute, Athens, GreeceBackground: The purpose of this study was to evaluate the safety and efficacy of topography-guided ablation using the WaveLight 400 Hz excimer laser in laser-assisted in situ keratomileusis (LASIK for hyperopia and/or hyperopic astigmatism.Methods: We prospectively evaluated 208 consecutive LASIK cases for hyperopia with or without astigmatism using the topography-guided platform of the 400 Hz Eye-Q excimer system. The mean preoperative sphere value was +3.04 ± 1.75 (range 0.75–7.25 diopters (D and the mean cylinder value was –1.24 ± 1.41 (–4.75–0 D. Flaps were created either with Intralase FS60 (AMO, Irvine, CA or FS200 (Alcon, Fort Worth, TX femtosecond lasers. Parameters evaluated included age, preoperative and postoperative refractive error, uncorrected distance visual acuity, corrected distance visual acuity, flap diameter and thickness, topographic changes, higher order aberration changes, and low contrast sensitivity. These measurements were repeated postoperatively at regular intervals for at least 24 months.Results: Two hundred and two eyes were available for follow-up at 24 months. Uncorrected distance visual acuity improved from 5.5/10 to 9.2/10. At 24 (8–37 months, 75.5% of the eyes were in the ±0.50 D range and 94.4% were in the ±1.00 D range of the refractive goal. Postoperatively, the mean sphere value was –0.39 ± 0.3 and the cylinder value was –0.35 ± 0.25. Topographic evidence showed that ablation was made in the visual axis and not in the center of the cornea, thus correlating with the angle kappa. No significant complications were encountered in this small group of patients.Conclusion: Hyperopic LASIK utilizing the topography-guided platform of the 400 Hz Eye-Q Allegretto excimer and a femtosecond laser flap appears to be safe and effective for

Femtosecond (FS) laser vision correction procedure for moderate to high myopia

DEFF Research Database (Denmark)

Vestergaard, Anders Højslet; Ivarsen, Anders; Asp, Sven

2013-01-01

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...

LASIK - Laser Eye Surgery

Science.gov (United States)

... Refractive Surgery Procedures What Is Photorefractive Keratectomy (PRK)? LASIK — Laser Eye Surgery Leer en Español: LASIK—Cirugía ocular con láser ... loss of close-up focusing power. How the LASIK procedure works LASIK is performed while the patient ...

Treatment of the Cornea Using Transcytotic Delivery into the Tear Film

Science.gov (United States)

2015-12-01

following popular refractive proce- dures, such as photorefractive keratectomy ( PRK ) and laser in situ keratomileusis ( LASIK ), directly rely on the...chronic inflammation of the eyelid) vs . normal tears [9]. LG-targeted delivery of this therapeutic within our novel delivery system is chosen for...particle compared to SI. If so, this might result from a larger hydro- philic fraction for KSI (66% vs . 48% for SI), which could result in a larger radius of

The Effects of Scattered Light from Optical Components on Visual Function

Science.gov (United States)

2016-02-01

zones (e.g., 0-5° vs 5-10°) occurs, then the general distribution of scatter, uniform or not, or that some ratio of scatter between different angular...affect the sensitivity of the eye and none reported having refractive surgery within the past year (photorefractive keratectomy ( PRK ) or laser...assisted in situ keratomileusis ( LASIK )). They performed all the visual function tasks monocularly, using the right eye. 2.3 Visual Function Assessment

Queratitis lamelar difusa después del Lasik Diffuse lamellar keratitis after LASIK

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Lorelei Ortega Díaz

2010-12-01

Full Text Available OBJETIVO: Describir el comportamiento de la queratitis lamelar difusa como complicación después de emplear la técnica quirúrgica queratomileusis in situ con láser. MÉTODOS: Se realizó un estudio descriptivo, de corte transversal en el Servicio de Cirugía Refractiva Corneal del Instituto Cubano de Oftalmología "Ramón Pando Ferrer" en el último trimestre del año 2008. La muestra quedó conformada por 16 ojos a los que se les realizó la queratomileusis in situ con láser como técnica quirúrgica para corregir ametropía y que presentaron complicaciones con esta cirugía. Se analizaron variables como la agudeza visual sin corrección; los ojos con esta complicación fueron analizados según la clasificación de Linebarger. RESULTADOS: La frecuencia de queratitis lamelar difusa fue de 3,0 por cada 100. La agudeza visual no corregida se comportó entre 0,8 y 1,0 en 12 ojos de 16 afectados, el estadio 1 se presentó en 12 ojos. CONCLUSIONES: La queratitis lamelar difusa es una complicación poco frecuente, los casos que la padecieron alcanzaron una buena agudeza visual final sin corrección. Predominó la forma leve de este cuadro.OBJECTIVE: To describe the situation of Diffuse lamellar keratitis as a complication after in situ keratomileusis with laser. METHODS: A descriptive cross-sectional study was carried out in the Refractive Corneal Service of "Ramón Pando Ferrer" Cuban Institute of Ophthalmology during the last quarter of 2008. The sample embraced 16 eyes that underwent in situ keratomileusis plus laser as the refractive procedure to correct ametropy and presented with some complications. Visual acuity without correction was one the analyzed variables and the eyes with this type of complication were classified according to Linebarger´s classification. RESULTS: The diffuse lamellar keratitis frequency was 3.0 per one hundred cases, the visual acuity without correction was 0.8 to 1.0 in 12 out of 16 eyes whereas stage 1 was

Basics of LASIK Eye Surgery

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... Vea esta página en español The Basics of LASIK Eye Surgery Share This Page Facebook Twitter Linked- ... Surgery Surgical Alternatives to LASIK For More Information  LASIK Basics If you wear glasses or contact lenses, ...

[Complications after refractive surgery abroad].

Science.gov (United States)

Terzi, E; Kern, T; Kohnen, T

2008-05-01

In this article a retrospective analysis of patients presenting at a German university following refractive surgery abroad is presented. A total of 20 cases of patients who had undergone treatment between 1998 and 2006 in China (1 case), Greece (1 case), Iran (1 case), Russia (2 cases), Switzerland (1 case), Slovakia (1 case), Spain (2 cases), South Africa (3 cases), Turkey (6 cases) and the USA (2 cases) were analyzed retrospectively. The following complications were observed: epithelial ingrowth into the interface with or without melting of the flap (6 cases), corneal ectasia (2 cases), dislocation of a phakic posterior chamber intraocular lens and prolapse into the anterior chamber with endothelial cell loss (1 case), secondary increase of intraocular pressure following implantation of a phakic intraocular lens (1 case), flap-related complications following laser-in-situ keratomileusis (LASIK) (2 cases), keratitis (1 case), dislocation of the complete flap (1 case), diffuse lamellar keratitis (DLK) grade IV (1 case), hyperopia as a consequence of radial keratotomy (1 case), and under correction/over correction and poor optical quality following laser epithelial keratomileusis (LASEK) and LASIK for high myopia (5 cases) with possible early corneal ectasia. There are four important problems arising from refractive surgery abroad, often referred to as "LASIK tourism": wrong indications, insufficient management of complications, lack of postoperative care and the health economic aspect.

Qualidade visual após retratamento de LASIK personalizado versus convencional Visual quality after custom versus standard LASIK retreatment

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Andréia Peltier Urbano

2008-12-01

Full Text Available OBJETIVO: Avaliar a qualidade visual após retratamento personalizado e retratamento convencional em olhos submetidos a LASIK primário convencional. MÉTODOS: Foi realizado estudo prospectivo de 74 olhos submetidos ao retratamento de LASIK para correção de miopia e astigmatismo. Cada paciente foi submetido ao retratamento de LASIK com ablação personalizada (Zyoptix, Bausch & Lomb em um olho e ablação convencional (Planoscan, Bausch & Lomb no olho contralateral. Foram comparados os resultados do teste de ofuscamento e da sensibilidade ao contraste durante o acompanhamento de seis meses. RESULTADOS: Os olhos do grupo Zyoptix apresentaram melhores resultados no teste de ofuscamento e na sensibilidade ao contraste do que o olho contralateral, quando se compararam os resultados. CONCLUSÕES: O retratamento personalizado resultou em melhor qualidade visual pós-operatória do que o retratamento convencional de LASIK primário convencional.PURPOSE: To evaluate visual quality after wavefront-guided LASIK versus standard LASIK in retreatment of primary LASIK for myopia and myopic astigmatism. METHODS: A prospective study was performed with paired eye control of 74 eyes with LASIK retreatment. Each patient underwent retreatment using custom ablation (Zyoptix, Bausch & Lomb in 1 eye and standard ablation LASIK (PlanoScan, Bausch & Lomb in the contralateral eye. A complete ophthalmologic examination was performed, including evaluation of glare test and contrast sensitivity test, with a follow-up of 6 months. RESULTS: Zyoptix eyes showed better results of glare test and contrast sensitivity test than the contralateral eyes. CONCLUSIONS: Wavefront-guided LASIK produces better visual quality than standard LASIK in the retreatment of refractive errors after primary LASIK.

Estudio topoaberrométrico en Lasik después de queratotomía radial Topoaberrometric study in Lasik after radial keratotomy

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Yamila Díaz Parra

2007-12-01

Full Text Available La cirugía refractiva personalizada consiste en adecuar el tratamiento de cada paciente según las características de la córnea y corregir defectos que afectan la calidad de la visión; por ejemplo, las aberraciones ópticas. Se seleccionaron 21 ojos de 13 pacientes con miopía residual después de queratotomía radial. Se realizó agudeza visual sin corrección y con ella, queratometría, refracción dinámica, refracción ciclopléjica; topografía corneal, taquimetría, tonometría, biomicroscopia, estudio de la lágrima y fondoscopia. A todos se les aplicó el software de análisis de frente de onda corneal y se realizó Lasik (Queratomileusis in situ con láser y queratectomía refractiva optimizada. La agudeza visual sin corrección varió de 0,17 a 0,75. El equivalente esférico promedio se modificó de -4,81 D a -0,67 D. Las aberraciones de alto orden (HORMS prequirúrgicas y posquirúrgicas variaron de 0,970 um hasta 1,130 um. La agudeza visual sin corrección fue superior a 0,8 en todos los casos después de la cirugía de Lasik. Disminuyó el equivalente esférico y el componente cilíndrico en todos los ojos. Las aberraciones totales disminuyeron también en todos los casos.Customized refractive surgery means adapting treatment to the patient according to the corneal characteristics and correcting defects that affect the quality of vision, for example, optical aberrations. Twenty one eyes from 13 patients with residual myopia after undergoing radial keratotomy were selected. Visual acuity without correction and also, keratometry, dynamic refraction, cycloplegic refraction, corneal topography, tachymetry, tonometry, biomicroscopy, study of the tear and funduscopy were performed. All the eyes were applied the sofware for analysis of corneal wavefront and Lasik (Queratomileusis in situ with laser and optimized refractive keratectomy were performed. Visual acuity without correction changed from 0.17 to 0.75. Average sphere equivalent

Single-step transepithelial ASLA (SCHWIND) with mitomycin-C for the correction of high myopia: long term follow-up.

Science.gov (United States)

Aslanides, Ioannis M; Georgoudis, Panagiotis N; Selimis, Vasilis D; Mukherjee, Achyut N

2015-01-01

We wanted to compare the outcomes of single-step modified transepithelial photorefractive keratectomy (tPRK) termed a SCHWIND all surface laser ablation (ASLA) versus conventional alcohol-assisted photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK) for the correction of higher myopia of 6.00 diopters (D) or more, in an area with high risk of haze due to high intensity of sunlight. We used a prospective interventional cohort with matched retrospective control groups. Patients with >6 D myopia and 0.05). Mean logMAR (logarithm of the minimum angle of resolution) uncorrected distance visual acuity at 12 months was 0.00 (SD: 0.05), 0.06 (SD: 0.1), and 0.05 (SD: 0.09) in the ASLA, PRK, and LASIK groups, with significantly better vision in the tPRK group versus LASIK (P=0.01) and PRK (P=0.01) groups. ASLA (SCHWIND) tPRK with mitomycin C for high myopia demonstrates comparable refractive outcomes to LASIK and PRK, with relatively favorable visual acuity outcomes. There was no increased incidence of haze in the ASLA group.

Current status of accelerated corneal cross-linking

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Michael Mrochen

2013-01-01

Full Text Available Corneal cross-linking with riboflavin is a technique to stabilize or reduce corneal ectasia, in diseases such as keratoconus and post-laser-assisted in situ keratomileusis (LASIK ectasia. There is an interest by patient as well as clinicians to reduce the overall treatment time. Especially, the introduction of corneal cross-linking in combination with corneal laser surgery demands a shorter treatment time to assure a sufficient patient flow. The principles and techniques of accelerated corneal cross-linking is discussed.

A modified risk assessment scoring system for post laser in situ keratomileusis ectasia in topographically normal patients

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Mohammad Miraftab

2014-01-01

Conclusion: Our modified ectasia risk scoring system for patients with normal corneal topography can predict post LASIK ectasia risk with acceptable sensitivity and specificity. However, there are still unidentified risk factors for which further studies are required.

LASIK

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Full Text Available ... glasses or contact lenses. The goal of this Web site is to provide objective information to the ... ask your doctor before undergoing LASIK surgery. This web site also provides information on FDA’s role in ...

LASIK

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Full Text Available ... site is to provide objective information to the public about LASIK surgery. See other sections of this site to learn about what ... U.S. Food and Drug Administration 10903 New Hampshire ...

LASIK

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Full Text Available ... information. The video includes images of common visual problems that a LASIK patient may see. ... the risks and how can I find the right doctor for me? What should I expect before, during, ...

LASIK

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Full Text Available ... Medical Devices Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco ... Report a Problem LASIK is a surgical procedure intended to reduce a person's dependency on glasses or contact lenses. The goal ...

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Full Text Available ... site is to provide objective information to the public about LASIK surgery. See other sections of this ... Education Inspections & Compliance Federal, State & Local Officials Consumers Health Professionals Science & Research Industry Scroll back to top ...

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Full Text Available ... a glossary of terms and a checklist of issues for you to consider, practices to follow, and ... is replaced. There are other techniques and many new terms related to LASIK that you may hear ...

LASIK

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Full Text Available ... is replaced. There are other techniques and many new terms related to LASIK that you may hear ... Website Policies U.S. Food and Drug Administration 10903 New Hampshire Avenue Silver Spring, MD 20993 1-888- ...

LASIK

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Full Text Available ... important information. The video includes images of common visual problems that a LASIK patient may see. Please ... FEAR Act Site Map Nondiscrimination Website Policies U.S. Food and Drug Administration 10903 New Hampshire Avenue Silver ...

Effects of 3% trehalose as an adjuvant treatment after LASIK

Directory of Open Access Journals (Sweden)

Mateo Orobia AJ

2017-02-01

Full Text Available Antonio J Mateo Orobia,1–3 Paula Casas Pascual,1,4 José Á Cristóbal Bescós,1 Diana Perez García,1,4 Carlos Peiro Embid,1,4 M Ángeles del Buey Sayas,1,4 Valentyna Korobko Kulikova,1 Noelia Lafuente Ojeda5 1Department of Ophthalmology, Hospital Quirón, 2Department of Ophthalmology, Hospital Universitario Miguel Servet, 3Instituto de Investigación Sanitaria de Aragón (IIS, 4Department of Ophthalmology, Hospital Clínico Universitario Lozano-Blesa, 5Department of Anesthesiology, Hospital Universitario Miguel Servet, Zaragoza, Spain Purpose: To evaluate the effect of 3% trehalose as an adjuvant in the standard treatment after laser-assisted in situ keratomileusis.Design: Interventional prospective comparative single-blind study.Setting: Department of Ophthalmology, Hospital Quirón Zaragoza, Spain.Methods: A total of 26 eyes (13 patients were included, of which 12 eyes (group 1 received conventional treatment with lubricant drops of hyaluronic acid (0.15% and 14 eyes (group 2 received, additionally, an ophthalmic solution of 3% trehalose. Pre- and postoperative quality-of-life tests and vital stains, tear breakup time, and osmolarity measurements were made.Results: We obtained statistically significant differences between the groups in the Symptom Assessment in Dry Eye test in all visits with respect to severity, and in the postoperative day 1 visit with respect to frequency, in all cases favoring the trehalose treatment. The values of osmolarity were not significantly different between groups. However, we did find significant differences in the Oxford scale in day 90 for the trehalose treatment (P<0.001, and in the National Eye Institute scale in day 30 (P=0.02.Conclusion: The results of this exploratory study indicate that the adjuvant treatment with 3% trehalose could be superior with respect to the standard treatment, with improvements in the objective and subjective parameters of tear quality. Keywords: dry eye syndrome, trehalose

Calidad de visión y satisfacción del paciente usuario de pantallas de visualización de datos tras cirugía refractiva

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Mª Isabel Rubio Cuevas

2007-03-01

Full Text Available Objetivo: Evaluar la influencia en la calidad de vida y satisfacción de los trabajadores usuarios de pantallas de visualización de datos (PVD que se asocia a la mejora de la función visual tras queratomileusis in situ con láser excimer (LASIK. Métodos: Estudio observacional y longitudinal en una población de 96 pacientes intervenidos de cirugía refractiva con láser excimer según técnica LASIK mediante aplicación de un cuestionario construído al efecto aplicado antes y después de cirugía por un observador independiente. Resultados: Agudeza visual y refracción ocular han mejorado tras LASIK, siendo el índice de eficacia de 1.1. La sensibilidad al contraste tras cirugía mejora en todas las frecuencias (6 c/g, 3 c/g y 1 c/g en el ojo derecho. Mientras que en el ojo izquierdo no hay diferencias significativas. La calidad de visión con y sin corrección es mejor tras LASIK (significativa p Purpose: To evaluate the influence in quality of vision and satisfaction of video display terminal (VDT users related to improvement of visual functions following excimer laser in situ keratomileusis (LASIK. Methods: Longitudinal and observational study in a population of 96 patients that underwent LASIK using a questionnaire made for that, applied before and after surgery by an independent observer. Results: Visual acuity and ocular refraction have improved after LASIK, being the efficiency index 1.1. Contrast sensitivity postoperative improved at all spatial frequencies in the right eye (6 c/g, 3 c/g and 1 c/. While in the left eye there were no significant differences. Quality of vision with and without correction is also better after LASIK (p < 0.05. And 84.38 % of patients would repeat themselves and recommend this surgery to other patients. Conclusions: The results show that LASIK improves visual function and quality of life of patients.

Implantable collamer lens and femtosecond laser for myopia: comparison using an adaptive optics visual simulator

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Cari Pérez-Vives

2014-04-01

Full Text Available Purpose: To compare optical and visual quality of implantable collamer lens (ICL implantation and femtosecond laser in situ keratomileusis (F-LASIK for myopia. Methods: The CRX1 adaptive optics visual simulator (Imagine Eyes, Orsay, France was used to simulate the wavefront aberration pattern after the two surgical procedures for -3-diopter (D and -6-D myopia. Visual acuity at different contrasts and contrast sensitivities at 10, 20, and 25 cycles/degree (cpd were measured for 3-mm and 5-mm pupils. The modulation transfer function (MTF and point spread function (PSF were calculated for 5-mm pupils. Results: F-LASIK MTF was worse than ICL MTF, which was close to diffraction-limited MTF. ICL cases showed less spread out of PSF than F-LASIK cases. ICL cases showed better visual acuity values than F-LASIK cases for all pupils, contrasts, and myopic treatments (p0.05. For -6-D myopia, however, statistically significant differences in contrast sensitivities were found for both pupils for all evaluated spatial frequencies (p<0.05. Contrast sensitivities were better after ICL implantation than after F-LASIK. Conclusions: ICL implantation and F-LASIK provide good optical and visual quality, although the former provides better outcomes of MTF, PSF, visual acuity, and contrast sensitivity, especially for cases with large refractive errors and pupil sizes. These outcomes are related to the F-LASIK producing larger high-order aberrations.

LASIK

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Full Text Available ... important information. The video includes images of common visual problems that a LASIK patient may see. Please ... ارسی | English FDA Accessibility Careers FDA Basics FOIA No FEAR Act Site Map Nondiscrimination Website ...

Risk factors for corneal ectasia after LASIK.

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Tabbara, Khalid F; Kotb, Amgad A

2006-09-01

To establish a grading system that helps identify high-risk individuals who may experience corneal ectasia after LASIK. Retrospective, comparative, interventional case series. One hundred forty-eight consecutive patients (148 eyes) were included in this study. Thirty-seven patients who underwent LASIK at other refractive centers experienced corneal ectasia in 1 eye after LASIK. One hundred eleven eyes of 111 patients who underwent successful LASIK during the same period were age and gender matched and served as controls. All patients underwent preoperative and postoperative topographic analysis of the cornea. The follow-up period in both groups of patients ranged from 2 to 5 years, with a mean follow-up of 3.6 years. All patients underwent LASIK for myopia (spherical equivalent, -4.00 to -8.00 diopters). Corneal keratometry, oblique cylinder, pachymetry, posterior surface elevation, difference between the inferior and superior corneal diopteric power, and posterior best sphere fit (BSF) over anterior BSF were given a grade of 1 to 3 each. An ectasia grading system was established, and the cumulative risk score was assessed. Patients who had a grade of 7 or less showed no evidence of corneal ectasia, whereas 16 (59%) of 27 patients who had a grade of 8 to 12 had corneal ectasia. Twenty-one (100%) of 21 patients with a grade of more than 12 had corneal ectasia after LASIK (P<0.0001). A risk score may help in the prediction of patients who are at risk of experiencing corneal ectasia after LASIK. A prospective clinical study is needed to assess the validity of these risk factors.

Risk Factors for Retreatment Following Myopic LASIK with Femtosecond Laser and Custom Ablation for the Treatment of Myopia.

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Kruh, Jonathan N; Garrett, Kenneth A; Huntington, Brian; Robinson, Steve; Melki, Samir A

2017-01-01

To identify risks factors for retreatment post-laser in situ keratomeliusis (LASIK). A retrospective chart review from December 2008 to September 2012 identified 1,402 patients (2,581 eyes) that underwent LASIK treatment for myopia with the Intralase™ FS, STAR S4 IR™ Excimer Laser, and WaveScan WaveFront™ technology. In this group, 83 patients were retreated. All charts were reviewed for preoperative age, gender, initial manifest refraction spherical equivalent (MRSE), total astigmatism, and iris registration. Increased incidence rates of retreatment post-LASIK were preoperative age >40 years (p -3.0 D (p = 0.02), and astigmatism >1D (p = 0.001). Iris registration capture did not significantly reduce the retreatment rate (p = 0.12). Risk factors for retreatment included preoperative age >40 years, initial MRSE > -3.0 D, and astigmatism >1D. There was no difference in retreatment rate for patients based on gender or iris registration capture.

New developments in corneal and external disease--LASIK.

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Dhaliwal, Deepinder K; Mather, Rookaya

2003-03-01

Lamellar refractive surgery has evolved into LASIK, which is a widely performed, versatile procedure with a high patient acceptance. In this chapter, the two main components of LASIK were discussed: flap creation and stromal ablation. In each of these areas, the authors explored current technology and new advances, including the femtosecond laser and wavefront-guided ablations. Expanded indications and therapeutic application of LASIK also have come to the forefront. The treatment of anisomyopic amblyopia in the pediatric population is a prime example and was discussed fully in this chapter. The field of refractive surgery has never been stagnant. Surgeons and scientists continue to explore new modalities to increase safety, to improve results, and to broaden applications that benefit the patient population.

LASIK

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Full Text Available ... is a surgical procedure intended to reduce a person's dependency on glasses or contact lenses. The goal ... and the flap is replaced. There are other techniques and many new terms related to LASIK that you may hear about. Below is ... Inspections & Compliance Federal, State & Local Officials ...

LASIK versus photorefractive keratectomy for high myopic (> 3 diopter) astigmatism.

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Katz, Toam; Wagenfeld, Lars; Galambos, Peter; Darrelmann, Benedikt Große; Richard, Gisbert; Linke, Stephan Johannes

2013-12-01

To compare the efficacy, safety, predictability, and vector analysis indices of LASIK and photorefractive keratectomy (PRK) for correction of high cylinder of greater than 3 diopters (D) in myopic eyes. The efficacy, safety, and predictability of LASIK or PRK performed in 114 consecutive randomly selected myopic eyes with an astigmatism of greater than 3 D were retrospectively analyzed at the 2- to 6-month follow-up visits. Vector analysis of the cylindrical correction was compared between the treatment groups. A total of 57 eyes receiving PRK and 57 eyes receiving LASIK of 114 refractive surgery candidates were enrolled in the study. No statistically significant difference in efficacy [efficacy index = 0.76 (±0.32) for PRK vs 0.74 (±0.19) for LASIK (P = .82)], safety [safety index = 1.10 (±0.26) for PRK vs 1.01 (±0.17) for LASIK (P = .121)], or predictability [achieved astigmatism PRK- and 54% of LASIK-treated eyes, and PRK- and 89% of LASIK-treated eyes (P = .218)] was demonstrated. Using Alpins vector analysis, the surgically induced astigmatism and difference vector were not significantly different between the surgery methods, whereas the correction index showed a slight and significant advantage of LASIK over PRK (1.25 for PRK and 1.06 for LASIK, P LASIK and PRK are comparably safe, effective, and predictable procedures for excimer laser correction of high astigmatism of greater than 3 D in myopic eyes. Predictability of the correction of the cylindrical component is lower than that of the spherical equivalent. Copyright 2013, SLACK Incorporated.

Macroeconomic landscape of refractive surgery in the United States.

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Corcoran, Kevin J

2015-07-01

This review examines the economic history of refractive surgery and the decline of laser-assisted in-situ keratomileusis (LASIK) in the USA, and the emergence of refractive cataract surgery as an area of growth. Since it peaked in 2007 at 1.4 million procedures per year, LASIK has declined 50% in the USA, whereas refractive cataract surgery, including presbyopia-correcting intraocular lenses (IOLs), astigmatism-correcting IOLs, and femtosecond laser-assisted cataract surgery, has grown to 350 000 procedures per year, beginning in 2003. Patients are price-sensitive and responsive to publicity (good or bad) about refractive surgery and refractive cataract surgery. LASIK's decline has been partially offset by the emergence of refractive cataract surgery. About 11% of all cataract surgery in the USA involves presbyopia-correcting IOLs, astigmatism-correcting IOLs, or a femtosecond laser. From the surgeon's perspective, there are high barriers to entry into the marketplace for refractive surgery and refractive cataract surgery due to the high capital cost of excimer and femtosecond lasers, the high skill level required to deliver spectacular results to demanding patients who pay out of pocket, and the necessity to perform a high volume of surgeries to satisfy both of these requirements. Probably, less than 7% of US cataract surgeons can readily meet all of these requirements.

The effect of humidity and temperature on visual outcomes after myopic corneal laser refractive surgery

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Hood CT

2016-11-01

Full Text Available Christopher T Hood,1 Roni M Shtein,1 Daniel Veldheer,1,2 Munira Hussain,1 Leslie M Niziol,1 David C Musch,1,3 Shahzad I Mian1 1Department of Ophthalmology and Visual Sciences, University of Michigan W.K. Kellogg Eye Center, Ann Arbor, MI, 2Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, 3Department of Epidemiology, University of Michigan, Ann Arbor, MI, USA Objective: To determine whether procedure room environmental conditions are associated with outcomes after myopic laser in situ keratomileusis (LASIK or laser-assisted keratomileusis (LASEK. Design: Retrospective chart review. Participants: Eight hundred sixty-three eyes of 458 consecutive patients at a university-based academic practice. Methods: We reviewed the medical records of consecutive patients who underwent LASIK or LASEK over a 3-year period. Linear mixed regression models were used to investigate the association of laser room temperature and humidity with the outcomes of visual acuity and postoperative manifest spherical equivalent refraction. Repeated measures logistic regression models were used for the outcomes of diffuse lamellar keratitis (DLK and need for enhancement surgery. Results: Subjects were on an average 38.6 years old at the time of surgery (standard deviation [SD] =10.3 and the average spherical equivalent refraction of eyes was 3.8 diopters (SD =2.03. Regression models did not reveal a significant association between temperature and uncorrected distance visual acuity (UDVA or corrected distance visual acuity (CDVA, or between humidity and UDVA (P>0.05 for all. However, increased humidity was associated with a small but statistically significant improvement in CDVA after LASIK at 1 day, 1 month, 3 months, and 1 year postoperatively (P<0.05 for all. There was no significant association between temperature and humidity and the need for enhancement, the incidence of DLK, or postoperative manifest refraction. Conclusion: While increased laser

Klīnisko atradņu salīdzinājums FemtoLASIK un LASIK metodēs

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Bistere, Aivija

2010-01-01

Maģistra darbs ir uzrakstīts latviešu valodā uz 60 lpp. Tas satur 36 att., 1 tab., 4 pielikumus. Izmantoti 57 literatūras avoti. Darba mērķis:Novērtēt un salīdzināt klīniskos rezultātus starp metodēm, kur radzenes vāciņš lāzerķirurģijas laikā veidots ar VisuMax femtosekunžu lāzeri(FemtoLASIK metode) un ar mehānisko mikrokeratomu(LASIK metode). Metodika:Pētījumā tika analizēti 84 miopi pacienti(154 acis)-LASIK metodē-59 pacienti,FemtoLASIK-25. Vidējais vecums 29±8 gadi. Pirms operācijas subjek...

Evaluation of corneal biomechanics in patients with keratectasia following LASIK using dynamic Scheimpflug analyzer.

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Ueki, Ryotaro; Maeda, Naoyuki; Fuchihata, Mutsumi; Asai, Tomoko; Koh, Shizuka; Fujimoto, Hisataka; Uematsu, Masafumi; Nishida, Kohji

2018-04-26

To investigate the corneal biomechanics in eyes with keratectasia following LASIK using a dynamic Scheimpflug analyzer. Case-Control study. The subjects in the study included 12 eyes with keratectasia after LASIK (KE), 24 eyes with keratoconus (KC), 17 eyes without keratectasia after LASIK (LASIK), and 34 eyes with normal corneas (Normal). Corneal biomechanics of the four groups were evaluated using a dynamic Scheimpflug analyzer. Compared with Normal (7.06 ± 0.54), the radius at the highest concavity (radius, mm) of LASIK (5.96 ± 0.76), KE (4.93 ± 0.61) and KC (5.39 ± 1.02) were significantly small. The Deflection Amplitude (HCDLA, mm) of Normal (0.94 ± 0.07) was significantly lower than those of KE (1.11 ± 0.10) and KC (1.06 ± 0.16), and was not significantly different from that of LASIK (0.98 ± 0.07). There were significant differences between LASIK and KE in radius and HCDLA (P biomechanical features evaluated using the dynamic Scheimpflug analyzer suggest that biomechanical properties in eyes with keratectasia, keratoconus, and LASIK are different from those of normal eyes. Although the biomechanics in eyes with keratectasia differs from that in eyes with LASIK, it is similar to that in eyes with keratoconus.

Correção das aberrações oculares nos retratamentos de LASIK personalizado e convencional Correction of ocular aberrations in custom and standard LASIK retreatments

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Andréia Peltier Urbano

2009-10-01

Full Text Available OBJETIVO: Comparar a correção das aberrações oculares nos retratamentos de LASIK personalizado e convencional. MÉTODOS: Foi realizado um estudo prospectivo, randomizado, de 74 olhos de 37 pacientes submetidos ao retratamento de LASIK para correção de miopia e astigmatismo. Cada paciente foi submetido ao retratamento de LASIK personalizado Zyoptix (Bausch & Lomb em um olho e convencional Planoscan (Bausch & Lomb no olho contralateral. Foi comparada a correção das aberrações oculares nos retratamentos personalizado e convencional. RESULTADOS: No sexto mês pós-operatório, os olhos submetidos ao retratamento Zyoptix apresentaram diminuição estatisticamente significativa do defocus, astigmatismo, coma, aberração esférica, segunda ordem, terceira ordem, alta ordem e aberrações totais. Os olhos submetidos ao retratamento Planoscan apresentaram diminuição estatisticamente significativa do defocus, segunda ordem e aberrações totais. CONCLUSÕES: O retratamento personalizado foi superior ao retratamento convencional para a correção das aberrações oculares de baixa e alta ordens.PURPOSE: To compare the correction of ocular aberrations between custom and standard LASIK retreatment. METHODS: Prospective, randomized trial with paired eye control of 74 eyes from 37 patients who underwent LASIK retreatment. Each patient underwent retreatment using Zyoptix LASIK (Bausch & Lomb in 1 eye and Planoscan LASIK (Bausch & Lomb in the fellow eye. Correction of ocular aberrations was compared between custom and standard LASIK retreatments. RESULTS: At 6 months, there was a statistically significant reduction in defocus, astigmatism, coma, spherical aberration, second, third, higher-order and total aberration in Zyoptix eyes. There was a statistically significant reduction in defocus, second-order and total aberration in Planoscan eyes. CONCLUSIONS: Custom retreatment was statistically superior than standard retreatment for correction of lower

Is LASIK for Me? A Patient's Guide to Refractive Surgery

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Is LASIK for Me? A Patient’s Guide to Refractive Surgery October 2008 Is LASIK for Me? A Patient’s Guide to Refractive Surgery Table of Contents LASIK: A COMPREHENSIVE GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 What Is ...

Late onset corneal ectasia after LASIK surgery.

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Said, Ashraf; Hamade, Issam H; Tabbara, Khalid F

2011-07-01

To report late onset corneal ectasia following myopic LASIK. A retrospective cohort case series. Nineteen patients with late onset corneal ectasia following LASIK procedure were examined at The Eye Center, Riyadh, Saudi Arabia. Patients underwent LASIK for myopia with spherical equivalent ranging from -1.4 to -13.75 diopters. Age and gender, history of systemic or local diseases, and time of onset of corneal ectasia were recorded. Eye examination and corneal topographical analyses were done before and after LASIK surgery. Nineteen patients (29 eyes) with late onset corneal ectasia were identified from 1998 to 2008 in 13 male and six female patients. The mean follow-up period was 108 ± 23 months (range 72-144 months). No patient had pre-operative identifiable risk factors for corneal ectasia and the mean time of onset was 57 ± 24 months (range 24-120 months after LASIK). The pre-operative values included mean central pachymetry 553 ± 25 μm, mean keratometry reading of 42.9 ± 1.5 diopters, average oblique cylinder of 1.4 ± 1.2 diopters, posterior surface elevation of 26 ± 2.1 diopters, corneal flap thickness of 160 μm, mean spherical equivalent of -5.6 ± 3.6 diopters, and calculated residual corneal stromal bed thickness was 288 ± 35 μm. Three (5 eyes) patients developed ectasia after pregnancy. Three (4 eyes) patients developed corneal ectasia following severe adenoviral keratoconjunctivitis and had positive PCR for adenovirus type 8. Corneal ectasia may develop many years after LASIK surgery and symptoms could go undetected for some time. Pregnancy and adenoviral keratoconjunctivitis occurred post-operatively in six patients.

Femtosecond laser refractive surgery: small-incision lenticule extraction vs. femtosecond laser-assisted LASIK.

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Lee, Jimmy K; Chuck, Roy S; Park, Choul Yong

2015-07-01

Small-incision lenticule extraction (SMILE) is a novel technique devised to correct refractive errors. SMILE circumvents excimer laser photoablation of cornea, as the stromal lenticule cut by femtosecond laser is removed manually. Smaller incisions and preservation of anterior corneal biomechanical strength have been suggested as some of the advantages of SMILE over femtosecond laser-assisted LASIK (FS-LASIK). In this review, we compared previous published results of SMILE and FS-LASIK. The advantage, efficacy and safety of SMILE are compared with FS-LASIK. SMILE achieved similar efficacy, predictability and safety as FS-LASIK. Greater preservations of corneal biomechanical strength and corneal nerves were observed in SMILE when compared with LASIK or PRK. Additionally, the incidence of postoperative dry eye syndrome was found to be less problematic in SMILE than in FS-LASIK. SMILE is a promising new surgery for refractive error correction. Prospective and retrospective studies of SMILE have shown that results of SMILE are similar to FS-LASIK. With advances in femtosecond laser technology, SMILE may gain greater acceptance in the future.

Estudo comparativo entre duas plataformas para realização de Lasik personalizado para correção de miopia e astigmatismo: Alcon CustomCornea® versus Bausch & Lomb Zyoptix® Wavefront-Guided Lasik for low to moderate myopia: CustomCornea® versus Zyoptix®

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Telma Pereira Barreiro

2009-08-01

Full Text Available OBJETIVO: Comparar os resultados obtidos após o Lasik personalizado utilizando duas plataformas diferentes. MÉTODOS: Estudo prospectivo, randomizado com 50 pacientes míopes submetidos a cirurgia refrativa em ambos os olhos. Foram selecionados para o estudo, pacientes com equivalente esférico semelhante entre os olhos. Todos foram submetidos a Lasik bilateral e simultâneo, sendo que um olho foi operado pela plataforma CustomCornea® e o outro pela Zyoptix®. Acuidade visual sem e com correção, refração dinâmica e estática, medida das aberrações oculares, teste de sensibilidade ao contraste foram realizados no período pré-operatório e pós-operatório de 1, 3 e 6 meses. RESULTADOS: No período pré-operatório a média do equivalente esférico era de -3,29 ± 1,56 D no grupo CustomCornea® e de -3,22 ± 1,50 D no Zyoptix® (p=0,267. No sexto mês de pós-operatório, a média do equivalente esférico no grupo CustomCornea® era de -0,077 ± 0,23 D e -0,282 ± 0,30 D no Zyoptix® (p 20/20 foi alcançada em 86% dos olhos no grupo CustomCornea® e 70% no grupo Zyoptix® (p=0,094. Nenhum paciente perdeu duas ou mais linhas da melhor acuidade visual corrigida. Cem por cento dos olhos CustomCornea® e 88% dos Zyoptix® ficaram entre ± 0,50 D da emetropia (p=0,014*. Melhora da sensibilidade ao contraste em todas as frequências espaciais testadas foi observada em ambos os grupos. A aberração esférica apresentou aumento em ambos os grupos, porém este foi estatisticamente maior na plataforma Zyoptix® (pPURPOSE: To compare the visual and clinical outcomes of Wavefront-guided laser in situ keratomileusis (Lasik with Alcon CustomCornea® and Zyoptix® systems. METHODS: A prospective, randomized, masked and bilateral study was conducted. Fifty patients with preoperative spherical equivalent ranging from -1.00 to -6.50 D were enrolled for customized ablation in both eyes. All of them were submitted to Lasik CustomCornea® treatment in one

Excimer laser-assisted anterior lamellar keratoplasty for keratoconus, corneal problems after laser in situ keratomileusis, and corneal stromal opacities.

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Bilgihan, Kamil; Ozdek, Sengül C; Sari, Ayça; Hasanreisoğlu, Berati

2006-08-01

To evaluate excimer laser-assisted anterior lamellar keratoplasty to augment thin corneas as in keratoconus ( .05). This technique presents a different modality for the treatment of keratoconus, post-LASIK corneal problems, and other corneal stromal opacities with anterior lamellar keratoplasty. Additional studies with more patients and longer follow-up will help determine the role of this technique as a substitute for penetrating keratoplasty in these patients.

Corneal polarimetry after LASIK refractive surgery

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Bueno, Juan M.; Berrio, Esther; Artal, Pablo

2006-01-01

Imaging polarimetry provides spatially resolved information on the polarization properties of a system. In the case of the living human eye, polarization could be related to the corneal biomechanical properties, which vary from the normal state as a result of surgery or pathologies. We have used an aberro-polariscope, which we recently developed, to determine and to compare the spatially resolved maps of polarization parameters across the pupil between normal healthy and post-LASIK eyes. The depolarization distribution is not uniform across the pupil, with post-surgery eyes presenting larger levels of depolarization. While retardation increases along the radius in normal eyes, this pattern becomes irregular after LASIK refractive surgery. The maps of slow axis also differ in normal and post-surgery eyes, with a larger disorder in post-LASIK eyes. Since these changes in polarization indicate subtle structural modifications of the cornea, this approach can be useful in a clinical environment to follow the biomechanical and optical changes of the cornea after refractive surgery or for the early diagnosis of different corneal pathologies.

Late Disciform Endotheliitis after LASIK

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Faik Oruçoğlu

2013-08-01

Full Text Available Clinical and imaging features of the patient with late herpetic keratouveitis after LASIK were investigated. A 25-year-old male patient applied with a chief complaint of blurred vision and photophobia in the left eye. He had a history of herpetic keratitits and elsewhere underwent LASIK procedure in 2005. Oral and topical acyclovir treatments were started a week ago when his complaints started. His corrected distance visual acuity was 0.2 and intraocular pressure was 14 mmHg on the left eye. Slit-lamp revealed deep central disciform edema, keratic precipitates, and 2 positive cells in the anterior chamber. Although the patient had myopic LASIK ablation, the central corneal thickness was 652 microns. Scheimpflug imaging was drawing attention to the thickening of the posterior cornea and the keratic precipitates. Sagital and anterior elevation maps were not affected, however, posterior elevation map showed marked central flattening. Asphericity value Q was within normal limits anteriorly (Q=-0.14 and it was in oblate appearance posteriorly (Q=+5.24. In addition to the antiviral medications, a topical dexamethasone treatment was started. The vision improved to 0.6, and the edema was markedly reduced after 4 days of treatment. Scheimpflug imaging parameters were significantly improved. (Turk J Ophthalmol 2013; 43: 282-5

Intraoperative cyclorotation and pupil centroid shift during LASIK and PRK.

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Narváez, Julio; Brucks, Matthew; Zimmerman, Grenith; Bekendam, Peter; Bacon, Gregory; Schmid, Kristin

2012-05-01

To determine the degree of cyclorotation and centroid shift in the x and y axis that occurs intraoperatively during LASIK and photorefractive keratectomy (PRK). Intraoperative cyclorotation and centroid shift were measured in 63 eyes from 34 patients with a mean age of 34 years (range: 20 to 56 years) undergoing either LASIK or PRK. Preoperatively, an iris image of each eye was obtained with the VISX WaveScan Wavefront System (Abbott Medical Optics Inc) with iris registration. A VISX Star S4 (Abbott Medical Optics Inc) laser was later used to measure cyclotorsion and pupil centroid shift at the beginning of the refractive procedure and after flap creation or epithelial removal. The mean change in intraoperative cyclorotation was 1.48±1.11° in LASIK eyes and 2.02±2.63° in PRK eyes. Cyclorotation direction changed by >2° in 21% of eyes after flap creation in LASIK and in 32% of eyes after epithelial removal in PRK. The respective mean intraoperative shift in the x axis and y axis was 0.13±0.15 mm and 0.17±0.14 mm, respectively, in LASIK eyes, and 0.09±0.07 mm and 0.10±0.13 mm, respectively, in PRK eyes. Intraoperative centroid shifts >100 μm in either the x axis or y axis occurred in 71% of LASIK eyes and 55% of PRK eyes. Significant changes in cyclotorsion and centroid shifts were noted prior to surgery as well as intraoperatively with both LASIK and PRK. It may be advantageous to engage iris registration immediately prior to ablation to provide a reference point representative of eye position at the initiation of laser delivery. Copyright 2012, SLACK Incorporated.

[Comparative clinical study of wavefront-guided laser in situ keratomileusis with versus without iris recognition for myopia or myopic astigmatism].

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Wang, Wei-qun; Zhang, Jin-song; Zhao, Xiao-jin

2011-10-01

iris recognition group increased (t = 3.414, -2.870; P = 0.027, 0.045), in particular of coma; the general higher-order aberrations (t = 0.386, 1.132; P = 0.719, 0.321), 4-order aberrations (t = 0.808, 2.720; P = 0.464, 0.063), and 5-order aberrations (t = 0.148, -1.717; P = 0.890, 0.161) show no statistically significant difference. Three months after surgery, two groups have recovered at all spatial frequencies of CSF, iris recognition group at 3.0 c/d (t = 3.209, P = 0.002) and 6.0 c/d (t = 2.997, P = 0.004) spatial frequencies of CSF under mesopic condition was better than non-iris recognition group, glare contrast sensitivity function (GCSF) for 3.0 c/d (t = 3.423, P = 0.001) and 6.0 c/d (t = 6.986, P = 0.000) spatial frequencies under mesopic condition and 1.5 c/d (t = 9.839, P = 0.000) and 3.0 c/d (t = 7.367, P = 0.000) spatial frequencies under photopic condition in iris recognition group were better than non-iris recognition group, there were no significant difference between two groups at the other spatial frequencies. Wavefront-guided LASIK with or without iris recognition both acquired better postoperative visual acuity, but in comparison with without iris recognition, wavefront-guided LASIK with iris recognition is efficient to reduce coma and enhance contrast sensitivity of postoperative.

Outcomes of photorefractive keratectomy enhancement after LASIK.

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Lee, Bryan S; Gupta, Preeya K; Davis, Elizabeth A; Hardten, David R

2014-08-01

To report the outcomes of photorefractive keratectomy (PRK) enhancement after LASIK for patients diagnosed as having hyperopic and myopic refractive errors. In this retrospective case series at a single private practice in the United States, all patients undergoing PRK enhancement after LASIK were identified. Patients with visually significant cataract, non-plano targets, and follow-up of fewer than 226 days were excluded. The primary outcome measure was uncorrected distance visual acuity (UDVA) with secondary measures of corrected distance visual acuity (CDVA) and postoperative refractive error. Linear regression analysis was performed for actual versus targeted change in spherical equivalent. Mean UDVA improved from 20/39 to 20/24 for hyperopes (n = 14; P vs 25%, P = .14). Linear regression showed a tendency toward overtreatment in the myopic group. PRK is safe and highly effective for patients who previously underwent LASIK and in whom the surgeon would prefer not to perform a flap-lift enhancement. Copyright 2014, SLACK Incorporated.

Transmittance and scattering during wound healing after refractive surgery

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Mar, Santiago; Martinez-Garcia, C.; Blanco, J. T.; Torres, R. M.; Gonzalez, V. R.; Najera, S.; Rodriguez, G.; Merayo, J. M.

2004-10-01

Photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) are frequent techniques performed to correct ametropia. Both methods have been compared in their way of healing but there is not comparison about transmittance and light scattering during this process. Scattering in corneal wound healing is due to three parameters: cellular size and density, and the size of scar. Increase in the scattering angular width implies a decrease the contrast sensitivity. During wound healing keratocytes activation is induced and these cells become into fibroblasts and myofibroblasts. Hens were operated using PRK and LASIK techniques. Animals used in this experiment were euthanized, and immediately their corneas were removed and placed carefully into a cornea camera support. All optical measurements have been done with a scatterometer constructed in our laboratory. Scattering measurements are correlated with the transmittance -- the smaller transmittance is the bigger scattering is. The aim of this work is to provide experimental data of the corneal transparency and scattering, in order to supply data that they allow generate a more complete model of the corneal transparency.

Clinical study of the clusters of diffuse lamellar keratitis after laser corneal refractive surgery

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Qing-Hong Lin

2017-06-01

Full Text Available AIM: To investigate the potential causes and management of the clusters of diffuse lamellar keratitis(DLKafter laser corneal refractive surgery. METHODS: The study enrolled 98 eyes(53 patientscomplicated with DLK after receiving laser in situ keratomileusis(LASIK, FS-LASIK or small-incision lenticule extraction(SMILEin our center from February 10th,2016 to February 22th,2016. They were given clinical classification treatments according to corneal layer inflammatory extent and then followed up after 1, 3, 5, 7, 10d and 1mo. RESULTS: The clusters of DLK occurred 5 times in the study period. The incidence and degree of DLK significantly decreased after changed the sterilization, surgical equipments, temperature and humidity of the operating room. There were 80 eyes(82%had stage 1 DLK, 11 eyes(11%had stage 2, 4 eyes(4%had stage 3 and 3 eyes(3%had stage 4. The incidence of DLK after FS-LASIK was 40%(79 eyes in 42 patients, that after LASIK assistant by Hastome keratome was 45%(10 eyes in 5 patients, that after SMILE was 20%(9 eyes in 6 patients. After intensive treatment, as glucocorticoid treatment and flap lifting flushing, all cases recovered within 1mo. CONCLUSION: The outbreak of DLK may be associated with the disposable item, flushing liquor, temperature and humidity of the operating room. Early diagnosis, prevention and treatment are the key of decreasing the incidence of DLK.

Lasik eye surgery - slideshow

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... this page: //medlineplus.gov/ency/presentations/100206.htm Lasik eye surgery - series—Normal anatomy To use the ... A.M. Editorial team. Related MedlinePlus Health Topics Laser Eye Surgery A.D.A.M., Inc. is accredited by ...

Downbeat Nystagmus Induced by Sedation in Lasik

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Miguel Paciuc-Beja

2012-01-01

Full Text Available Nystagmus was elicited during lasik under sedation in two patients that were treated for depression. Nystagmus was not present before or after surgery. Nystagmus can be pharmacologically induced and can be a hazard to refractive surgery.

Bilateral diffuse lamellar keratitis triggered by permanent eyeliner tattoo treatment: A case report.

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Lu, Cheng-Wei; Liu, Xiu-Fen; Zhou, Dan-Dan; Kong, Yu-Jiao; Qi, Xiao-Feng; Liu, Tao-Tao; Qu, Ting; Pan, Xiao-Tao; Liu, Cong; Hao, Ji-Long

2017-07-01

Diffuse lamellar keratitis (DLK) is a sterile inflammation of the cornea, which may occur after laser-assisted in situ keratomileusis (LASIK) surgery. Little is known about the association of DLK with permanent eyeliner tattoo. The present case report describes the case of a 37-year-old Chinese woman who developed severe foreign body sensation in both eyes 1 week after receiving bilateral permanent eyeliner tattoo treatment. The patient had received bilateral LASIK surgery 10 years previously. Slit-lamp biomicroscopy revealed diffused granular infiltrates precipitated around the edge of the corneal flaps in both eyes. After topical treatment, DLK persisted. Therefore, the patient underwent surgery to remove the corneal epithelium around the DLK lesion. There was no recurrence of the disease during the 3-month observation period. To our knowledge, this is the first case report describing a case of late-onset of DLK that was triggered by permanent eyeliner tattoo. Doctors should be aware of the diagnosis and treatment of this complication associated with the application of permanent eyeliner tattoo as the popularity of this cosmetic procedure increases.

Visual outcomes after Epi-LASIK and PRK for low and moderate myopia.

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Sia, Rose K; Coe, Charles D; Edwards, Jayson D; Ryan, Denise S; Bower, Kraig S

2012-01-01

To evaluate visual outcomes following epi-LASIK compared to photorefractive keratectomy (PRK). Of a total 294 patients aged ≥21 years, 145 (290 eyes) underwent epi-LASIK and 149 (298 eyes) underwent PRK for low to moderate myopia or myopic astigmatism. Epi-LASIK was performed with the Amadeus II epikeratome (Abbott Medical Optics) and PRK with the Amoils rotary epithelial brush (Innovative Excimer Solutions). All ablations were performed using the same excimer laser system. Outcome measures included intraoperative complications, corneal reepithelialization, postoperative pain, uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent (MRSE), corrected distance visual acuity (CDVA), corneal haze, and quality of vision. Mean preoperative MRSE was -2.97±1.19 diopters (D) for epi-LASIK versus -2.95±1.06 D for PRK. Complete reepithelialization was achieved by postoperative day 4 in 46.9% of epi-LASIK eyes versus 92.4% of PRK eyes, with superior UDVA at postoperative day 1 in the PRK group (P=.002). Using Fisher exact test, a significantly higher percentage of epi-LASIK eyes compared to PRK eyes achieved 20/15 or better at 1 month (25.8% vs 17.8%, P=.031), 3 months (62.3% vs 49.3%, P=.004), 6 months (77.1% vs 57.9%, Pvs 61.9%, P=.002). A change in MRSE >0.50 D occurred in 8.4% of epi-LASIK eyes within the 3- and 12-month interval versus 17.7% of PRK eyes (P=.04). No differences were noted between the two procedures in CDVA or clinically significant haze. Epi-LASIK showed superior refractive efficacy and stability but required more time for wound healing, resulting in inferior early visual outcomes and a tendency to overcorrect higher refractive errors compared to PRK. Both treatments were safe and comparable in terms of pain and haze formation. Copyright 2012, SLACK Incorporated.

Scanning laser polarimetry retinal nerve fiber layer thickness measurements after LASIK.

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Zangwill, Linda M; Abunto, Teresa; Bowd, Christopher; Angeles, Raymund; Schanzlin, David J; Weinreb, Robert N

2005-02-01

To compare retinal nerve fiber layer (RNFL) thickness measurements before and after LASIK. Cohort study. Twenty participants undergoing LASIK and 14 normal controls. Retinal nerve fiber layer thickness was measured before LASIK and approximately 3 months after surgery in one eye each of 20 patients using a scanning laser polarimeter (GDx Nerve Fiber Analyzer) with fixed corneal compensation (FCC), one with variable corneal compensation (GDx VCC), and optical coherence tomography (OCT). Fourteen normal controls also were tested at baseline and approximately 3 months later. Retinal nerve fiber layer thicknesses measured with the GDx FCC, GDx VCC, and OCT. At baseline, mean (95% confidence interval [CI]) RNFL thicknesses for the GDx FCC, GDx VCC, and OCT were 78.1 microm (72.2-83.9), 54.3 microm (52.7-56.0), and 96.8 microm (93.2-100.5), respectively. In both LASIK and control groups, there were no significant changes between baseline and follow-up examinations in GDx VCC and OCT RNFL thickness measurements globally or in the superior and inferior quadrants (mean change, FCC measurements between baseline and follow-up. In LASIK patients, significant reductions were observed in GDx FCC RNFL measurements. Average absolute values of the mean (95% CI) change in thickness were 12.4 microm (7.7-17.2), 15.3 microm (9.6-20.9), and 12.9 microm (7.6-18.1) for GDx FCC RNFL measurements superiorly, inferiorly, and globally, respectively (all Ps FCC RNFL thickness measurements after LASIK is a measurement artifact and is most likely due to erroneous compensation for corneal birefringence. With scanning laser polarimetry, it is mandatory to compensate individually for change in corneal birefringence after LASIK to ensure accurate RNFL assessment.

Tear film stability analysis system: introducing a new application for videokeratography.

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Goto, Tomoko; Zheng, Xiaodong; Okamoto, Shigeki; Ohashi, Yuichi

2004-11-01

To review our previous studies regarding the development of a tear stability analysis system (TSAS) using videokeratography and the clinical application of TSAS for evaluation of tear film stability in patients subject to laser in situ keratomileusis (LASIK). New software, namely TSAS, was developed for the videokeratography system TMS-2N (topographic modeling system). TSAS automatically captures consecutive corneal surface images every second for 10 seconds. Corneal topographs were analyzed for tear breakup time (TMS-BUT) and tear breakup area (TMS-BUA, the ratio of breakup area to entire color-code area). First, we recruited volunteers to test the sensitivity and specificity of this new system in comparison with the routine method for tear stability analysis, tear film breakup time evaluation by slit-lamp microscope (SLE-BUT), with fluorescence staining. Second, we investigated the practicability of TSAS in dynamic evaluation of tear film stability before and after LASIK. TMS-BUT had a positive correlation with SLE-BUT, whereas TMS-BUA showed a negative correlation. Although they showed similar rates of specificity as SLE-BUT, the sensitivity rates of TMS-BUT and TMS-BUA were 97.5% and 95%, respectively, significantly higher than that of SLE-BUT (75%). The study on patients subject to LASIK showed that tear film stability significantly decreased during the early time period following LASIK and resolved at 6 months after surgery. Eyes that had abnormal TSAS evaluation tended to have higher risk of developing superficial punctuate keratitis and dry eye symptoms after LASIK, and their responses to treatment were slow. TSAS is a noninvasive and objective method with higher sensitivity for tear film stability analysis than SLE-BUT.

Confocal microscopy of corneal stroma and endothelium after LASIK and PRK.

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Amoozadeh, Javad; Aliakbari, Soheil; Behesht-Nejad, Amir-Houshang; Seyedian, Mohammad-Amin; Rezvan, Bijan; Hashemi, Hassan

2009-10-01

To compare with confocal microscopy the changes in stromal keratocyte density and endothelial cell count due to photorefractive keratectomy (PRK) and LASIK. In this prospective study, 32 eyes (16 myopic patients) were examined with the NIDEK Confoscan 3 confocal microscope before and 6 months after PRK and LASIK. The preoperative mean myopia was -2.85+/-0.99 diopters (D) (range: -1.00 to -4.00 D) in 24 eyes that underwent PRK and -2.94+/-0.96 D (range: -2.00 to -4.25 D) in 8 eyes that underwent LASIK. Keratocyte density in the anterior and posterior stroma and the endothelial cell count were measured. Statistically significant changes were assessed using the t test. PPRK group. Postoperatively, the percentages were 52.96+/-7.55 and 53.34+/-10.2, respectively. Six months postoperatively, keratocyte density changed by 367.12+/-103.35 cells/mm(2) (34.7% reduction) in the anterior stroma (P.05) for the LASIK group. In the PRK group, these values were 319.71+/-83.45 cells/mm(2) (31.13% reduction) in the anterior stroma (P.05). The changes in keratocyte densities were not statistically significant between groups (P>.05). The mean number of keratocytes decreased by 37.2% in the retroablation zone of the LASIK group (PPRK groups (P>.05). Copyright 2009, SLACK Incorporated.

LASIK flap buttonhole treated immediately by PRK with mitomycin C.

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Kymionis, George D; Portaliou, Dimitra M; Karavitaki, Alexandra E; Krasia, Maria S; Kontadakis, Georgios A; Stratos, Aimilianos; Yoo, Sonia H

2010-03-01

To describe the visual outcomes of three patients who had LASIK flap buttonhole and were treated immediately with photorefractive keratectomy (PRK) and topical mitomycin C (MMC) 0.02%. Three patients underwent bilateral LASIK with the SCHWIND Carriazo-Pendula 90 microm head microkeratome. In all three cases, a buttonhole flap occurred in the left eye. The flap was repositioned and phototherapeutic keratectomy for 50 microm was used for epithelial removal while immediate PRK with MMC was performed to treat the buttonhole flap. Three months after the procedure, uncorrected distance visual acuity and corrected distance visual acuity were 20/20 with regular topographic findings. Using PRK with MCC immediately after the occurrence of the LASIK flap buttonhole may be an effective treatment.

Three-dimensional LASIK flap thickness variability: topographic central, paracentral and peripheral assessment, in flaps created by a mechanical microkeratome (M2 and two different femtosecond lasers (FS60 and FS200

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Kanellopoulos AJ

2013-04-01

Full Text Available A John Kanellopoulos,1,2 George Asimellis1 1Laservision.gr Institute, Athens, Greece; 2NYU Medical School, New York, USA Purpose: To evaluate programmed versus achieved laser-assisted in situ keratomileusis (LASIK flap central thickness and investigate topographic flap thickness variability, as well as the effect of potential epithelial remodeling interference on flap thickness variability. Patients and methods: Flap thickness was investigated in 110 eyes that had had bilateral myopic LASIK several years ago (average 4.5 ± 2.7 years; range 2–7 years. Three age-matched study groups were formed, based on the method of primary flap creation: Group A (flaps made by the Moria Surgical M2 microkeratome [Antony, France], Group B (flaps made by the Abbott Medical Optics IntraLase™ FS60 femtosecond laser [Santa Ana, CA, USA], and Group C (flaps made by the Alcon WaveLight® FS200 femtosecond laser [Fort Worth, TX, USA]. Whole-cornea topographic maps of flap and epithelial thickness were obtained by scanning high-frequency ultrasound biomicroscopy. On each eye, topographic flap and epithelial thickness variability was computed by the standard deviation of thickness corresponding to 21 equally spaced points over the entire corneal area imaged. Results: The average central flap thickness for each group was 138.33 ± 12.38 µm (mean ± standard deviation in Group A, 128.46 ± 5.72 µm in Group B, and 122.00 ± 5.64 µm in Group C. Topographic flap thickness variability was 9.73 ± 4.93 µm for Group A, 8.48 ± 4.23 µm for Group B, and 4.84 ± 1.88 µm for Group C. The smaller topographic flap thickness variability of Group C (FS200 was statistically significant compared with that of Group A (M2 (P = 0.004, indicating improved topographic flap thickness consistency – that is, improved precision – over the entire flap area affected. Conclusions: The two femtosecond lasers produced a smaller flap thickness and reduced variability than the mechanical

Intraocular pressure measurement in patients with previous LASIK surgery using pressure phosphene tonometer.

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Cheng, Arthur C K; Leung, Dexter Y L; Cheung, Eva Y Y; Fan, Dorothy S P; Law, Ricky W K; Lam, Dennis S C

2005-04-01

To compare intraocular pressure (IOP) assessment in post-LASIK patients using non-contact tonometry, pressure phosphene tonometry and applanation tonometry. Sixty-two consecutive LASIK patients were analysed preoperatively and postoperatively with non-contact, pressure phosphene and applanation tonometry. Comparisons among these values were assessed with paired sample Student t-test, Pearson's correlation test and Bland-Altman plotting. There was no significant difference for preoperative IOP measurement between non-contact, pressure phosphene and applanation tonometry. The mean +/-SD difference between the preoperative non-contact tonometry and postoperative pressure phosphene tonometry IOP measurements was 0.80 +/- 2.77 mmHg (P contact tonometry significantly underestimated IOP measurement by 9.96 +/- 2.25 mmHg (P < 0.001). Pressure phosphene tonometry may provide an alternative method for the assessment of IOP in post-LASIK patients.

Comparison of the visual results after SMILE and femtosecond laser-assisted LASIK for myopia.

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Lin, Fangyu; Xu, Yesheng; Yang, Yabo

2014-04-01

To perform a comparative clinical analysis of the safety, efficacy, and predictability of two surgical procedures (ie, small incision lenticule extraction [SMILE] and femtosecond laser-assisted LASIK [FS-LASIK]) to correct myopia. Sixty eyes of 31 patients with a mean spherical equivalent of -5.13 ± 1.75 diopters underwent myopia correction with the SMILE procedure. Fifty-one eyes of 27 patients with a mean spherical equivalent of -5.58 ± 2.41 diopters were treated with the FS-LASIK procedure. Postoperative uncorrected and corrected distance visual acuity, manifest refraction, and higher-order aberrations were analyzed statistically at 1 and 3 months postoperatively. No statistically significant differences were found at 1 and 3 months in parameters that included the percentage of eyes with an uncorrected distance visual acuity of 20/20 or better (P = .556, .920) and mean spherical equivalent refraction (P = .055, .335). At 1 month, 4 SMILE-treated eyes and 1 FS-LASIK-treated eye lost one or more line of visual acuity (P = .214, chi-square test). At 3 months, 2 SMILE-treated eyes lost one or more line of visual acuity, whereas all FS-LASIK-treated eyes had an unchanged or corrected distance visual acuity. Higher-order aberrations and spherical aberration were significantly lower in the SMILE group than the FS-LASIK group at 1 (P = .007, .000) and 3 (P = .006, .000) months of follow-up. SMILE and FS-LASIK are safe, effective, and predictable surgical procedures to treat myopia. SMILE has a lower induction rate of higher-order aberrations and spherical aberration than the FS-LASIK procedure. Copyright 2014, SLACK Incorporated.

Reason analysis and preventive treatment countermeasure of impaired vision after LASIK

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Zhang-Bing Mu

2015-02-01

Full Text Available AIM: To analyze the reasons of impaired vision after LASIK and explore its preventive treatment measures preliminarily. METHODS: In this retrospective study, 175 eyes of 134 patients whose vision was decreased after LASIK were included. The constituent ratio of every reason was counted and uncorrected visual acuity(UCVAbetween pre-treatment and post-treatment were compared by paired t-test respectively. RESULTS: The overall incidence of impaired vision after LASIK was 1.86%. The constituent ratio of regression was 51.43% and UCVA increased from 0.61±0.22 to 0.90±0.38(t=8.00, Pt=20.00, Pt=8.14, Pt=6.33, Pt=2.53, P0.05after treatment. The constituent ratio of fundus lesions and diffuse lamellar keratitis(DLKwas 2.86% and UCVA all increased by different degrees after treatment. CONCLUSION: The reasons of impaired vision after LASIK are many and varied. These cases could recover their vision by discovery and treatment in time, and the appropriate preventive measures were essential.

Initial resident refractive surgical experience: outcomes of PRK and LASIK for myopia.

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Wagoner, Michael D; Wickard, Joseph C; Wandling, George R; Milder, Lisa C; Rauen, Matthew P; Kitzmann, Anna S; Sutphin, John E; Goins, Kenneth M

2011-03-01

To evaluate and compare the outcome of initial resident surgical experience with photorefractive keratectomy (PRK) and LASIK. Retrospective review of all cases performed with the VISX Star S4 platform (Abbott Medical Optics) between July 1, 2003 and June 30, 2007. Inclusion criteria were spherical equivalent of -0.50 to -10.00 diopters (D), refractive astigmatic error of ≤3.00 D, intention to provide full distance correction, and minimum 3-month postoperative follow-up after initial ablation or retreatment (if performed). A total of 153 cases performed by 20 different residents met the inclusion criteria; 38 eyes underwent PRK and 115 eyes had LASIK. After initial treatment, mean Snellen uncorrected distance visual acuity (UDVA) after PRK was 20/17.3 and after LASIK was 20/19.5. Photorefractive keratectomy was associated with a significantly better approximation between preoperative corrected distance visual acuity (CDVA) and postoperative UDVA (ΔlogMAR 0.009 vs 0.091; P=.004) and a greater percentage of eyes that achieved UDVA of 20/20 or better (94.7% vs 78.3%; P=.02) or 20/30 or better (100% vs 87.8%; P=.02). There was a higher prevalence of retreatment in eyes that underwent LASIK (7.0% vs 0%; P=.20). One (0.9%) eye lost 2 lines of CDVA after LASIK. Supervised refractive surgery residents can achieve excellent visual outcomes in patients operated during their initial refractive experience. Photorefractive keratectomy was associated with better visual outcome than LASIK. Copyright 2011, SLACK Incorporated.

Dry Eye Disease following Refractive Surgery: A 12-Month Follow-Up of SMILE versus FS-LASIK in High Myopia

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Bingjie Wang

2015-01-01

Full Text Available Purpose. To compare dry eye disease following SMILE versus FS-LASIK. Design. Prospective, nonrandomised, observational study. Patients. 90 patients undergoing refractive surgery for myopia were included. 47 eyes underwent SMILE and 43 eyes underwent FS-LASIK. Methods. Evaluation of dry eye disease was conducted preoperatively and at 1, 3, 6, and 12 months postoperatively, using the Salisbury Eye Evaluation Questionnaire (SEEQ and TBUT. Results. TBUT reduced following SMILE at 1 and 3 months (p<0.001 and at 1, 3, and 6 months following FS-LASIK (p<0.001. TBUT was greater following SMILE than FS-LASIK at 3, 6, and 12 months (p<0.001, p<0.001, and p=0.009, resp.. SEEQ scores increased (greater symptoms following SMILE at 1 month (p<0.001 and 3 months (p=0.003 and at 1, 3, and 6 months following FS-LASIK (p<0.001. SMILE produced lower SEEQ scores (fewer symptoms than FS-LASIK at 1, 3, and 6 months (p<0.001. Conclusion. SMILE produces less dry eye disease than FS-LASIK at 6 months postoperatively but demonstrates similar degrees of dry eye disease at 12 months.

Evaluation of intraocular pressure according to corneal thickness before and after excimer laser corneal ablation for myopia.

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Hamed-Azzam, Shirin; Briscoe, Daniel; Tomkins, Oren; Shehedeh-Mashor, Raneen; Garzozi, Hanna

2013-08-01

Intraocular pressure is affected by corneal thickness and biomechanics. Following ablative corneal refractive surgery, corneal structural changes occur. The purpose of the study is to determine the relationship between the mean central corneal thickness (CCT) and the change in intraocular pressure measurements following various corneal ablation techniques, using different measurement methods. Two hundred myopic eyes undergoing laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) were enrolled into a prospective, non-randomized study. Corneal parameters examined included full ocular examination, measurement of CCT, corneal topography, corneal curvature and ocular refractivity. Intraocular pressure measurements were obtained using three different instruments-non-contact tonometer, Goldmann applanation tonometer and TonoPen XL (TonoPen-Central and TonoPen-Peripheral). All measurements were performed pre-operatively and 4 months post-operatively. Post-operative intraocular pressure was significantly lower than pre-operative values, with all instruments (p value tonometer and non-contact tonometer (p value < 0.001, ANOVA). Intraocular pressure readings are significantly reduced following corneal ablation surgery. We determined in our myopic patient cohort that the TonoPen XL intraocular pressure measurement method is the least affected following PRK and LASIK as compared to other techniques.

Intraocular straylight and contrast sensitivity after contralateral wavefront-guided LASIK and wavefront-guided PRK for myopia.

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Barreto, Jackson; Barboni, Mirella T S; Feitosa-Santana, Claudia; Sato, João R; Bechara, Samir J; Ventura, Dora F; Alves, Milton Ruiz

2010-08-01

To compare intraocular straylight measurements and contrast sensitivity after wavefront-guided LASIK (WFG LASIK) in one eye and wavefront-guided photorefractive keratectomy (WFG PRK) in the fellow eye for myopia and myopic astigmatism correction. A prospective, randomized study of 22 eyes of 11 patients who underwent simultaneous WFG LASIK and WFG PRK (contralateral eye). Both groups were treated with the NIDEK Advanced Vision Excimer Laser System, and a microkeratome was used for flap creation in the WFG LASIK group. High and low contrast visual acuity, wavefront analysis, contrast sensitivity, and retinal straylight measurements were performed preoperatively and at 3, 6, and 12 months postoperatively. A third-generation straylight meter, C-Quant (Oculus Optikgeräte GmbH), was used for measuring intraocular straylight. Twelve months postoperatively, mean uncorrected distance visual acuity was -0.06 +/- 0.07 logMAR in the WFG LASIK group and -0.10 +/- 0.10 logMAR in the WFG PRK group. Mean preoperative intraocular straylight was 0.94 +/- 0.12 logs for the WFG LASIK group and 0.96 +/- 0.11 logs for the WFG PRK group. After 12 months, the mean straylight value was 1.01 +/- 0.1 log s for the WFG LASIK group and 0.97 +/- 0.12 log s for the WFG PRK group. No difference was found between techniques after 12 months (P = .306). No significant difference in photopic and mesopic contrast sensitivity between groups was noted. Intraocular straylight showed no statistically significant increase 1 year after WFG LASIK and WFG PRK. Higher order aberrations increased significantly after surgery for both groups. Nevertheless, WFG LASIK and WFG PRK yielded excellent visual acuity and contrast sensitivity performance without significant differences between techniques.

Intrastromal crosslinking in post-LASIK ectasia

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Bernardo Kaplan Moscovici

2014-06-01

Full Text Available Descrevemos um caso de ectasia de córnea precoce após cirurgia de LASIK, detectado no primeiro semestre pós-operatório. Nós optamos tratar este paciente com "crosslinking" embaixo do "flap" , sem desepitelização com bons resultados. A paciente permaneceu sem progressão da ectasia até o momento atual, dois anos após o procedimento.

Myopic keratomileusis by excimer laser on a lathe.

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Ganem, S; Aron-Rosa, D; Gross, M; Rosolen, S

1994-01-01

We designed an excimer laser keratomileusis delivery system to increase the regularity of the refractive cut surface and allow greater precision in the level and shape of the ablated zone. A parallel faced corneal disc was produced by microkeratectomy from six human eyes and surgical keratectomy in 12 beagle corneas. A 193-nanometer excimer laser that was used to project an oval beam onto the corneal disc was rotated on a flat surface to ensure overlapping of the ovally ablated areas between pulses. Electron microscopy of eye bank lenticules demonstrated a circular smooth regularly concave ablation zone. Histological examination of nine clear corneas confirmed thinning of the stroma without fibroblastic reaction and no epithelial hypertrophy. Mean preoperative corneal power of 43.15 +/- 2.18 decreased postoperatively to 33.61 +/- 2.34. The new technique of excimer laser keratomileusis has the advantage of a cut surface smoother and the clear zone is devoid of the stepwise concavity and irregularity seen in diaphragm based photoablation delivery systems.

Two-year results of femtosecond assisted LASIK versus PRK for different severity of astigmatism.

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Miraftab, Mohammad; Hashemi, Hassan; Asgari, Soheila

2018-03-01

To compare two-year results of femtosecond laser assisted LASIK (femto-LASIK) and photorefractive keratectomy (PRK) in terms of astigmatism correction in patients with less than 2.0 diopters (D) of spherical error and more than 2.0 D of cylinder error. In this retrospective study, data were extracted from 100 patient charts. The two study groups were matched by age, gender, and baseline uncorrected distance visual acuity (UDVA) and refractive astigmatism (RA). Preoperative astigmatism was categorized as mild: 2.00 to LASIK and PRK groups was respectively -3.15 ± 0.94 D (-7.00 to -2.00 D) and -3.29 ± 0.95 D (-6.25 to -2.00 D) at baseline ( P  = 0.284), and -0.61 ± 0.40 D and -0.62 ± 0.60 D one year after surgery ( P  = 0.674), but significantly lower in the femto-LASIK group (-0.61 ± 0.39 vs. -0.83 ± 0.56 D, P  = 0.021) at 2 years when the rate of residual astigmatism more than 1.0 D was 6.3% in the femto-LASIK and 19.6% in the PRK group ( P  = 0.046). Mean UDVA in the femto-LASIK group (0.02 ± 0.05 logMAR) was better than the PRK group (0.06 ± 0.10 logMAR) ( P  = 0.025). Mean corrected distance visual acuity (CDVA) was not significantly different between groups (0.01 ± 0.03 vs. 0.01 ± 0.04 logMAR, P  = 0.714). Both groups had 1-4 Snellen lines CDVA improvement. The three subgroups of baseline astigmatism did not differ significantly in terms of residual astigmatism (all P  > 0.05). However, in subgroups with ≥4.00 D cylinder, there was less astigmatic regression at 1 year in the femto-LASIK group (0.28 ± 0.43 D) than the PRK group (0.54 ± 0.68 D) ( P  = 0.007). Our results pointed to better two-year results with femto-LASIK in the treatment of different degrees of astigmatism. UDVA improvement was superior with femto-LASIK, but the two methods did not significantly differ in terms of CDVA improvement.

Effect of iris registration on outcomes of LASIK for myopia with the VISX CustomVue platform

DEFF Research Database (Denmark)

Moshirfar, Majid; Chen, Michael C; Espandar, Ladan

2009-01-01

PURPOSE: To compare visual outcomes after LASIK using the VISX STAR S4 CustomVue, with and without Iris Registration technology. METHODS: In this retrospective study, LASIK was performed on 239 myopic eyes, with or without astigmatism, of 142 patients. Iris registration LASIK was performed on 121...... eyes and non-iris registration LASIK was performed on 118 eyes. Primary outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and manifest refraction. RESULTS: At 6 months, the mean values for UCVA (logMAR) were 0.00 +/- 0.09 in the iris registration...... magnitude of error of surgically induced astigmatism was -0.09 in the iris registration group and -0.04 in the non-iris registration group (P = .25). CONCLUSIONS: Wavefront-guided LASIK with the VISX STAR S4 CustomVue laser system, independent of iris registration status, is effective, safe, and predictable...

Comparing wavefront-optimized, wavefront-guided and topography-guided laser vision correction: clinical outcomes using an objective decision tree.

Science.gov (United States)

Stonecipher, Karl; Parrish, Joseph; Stonecipher, Megan

2018-05-18

This review is intended to update and educate the reader on the currently available options for laser vision correction, more specifically, laser-assisted in-situ keratomileusis (LASIK). In addition, some related clinical outcomes data from over 1000 cases performed over a 1-year are presented to highlight some differences between the various treatment profiles currently available including the rapidity of visual recovery. The cases in question were performed on the basis of a decision tree to segregate patients on the basis of anatomical, topographic and aberrometry findings; the decision tree was formulated based on the data available in some of the reviewed articles. Numerous recent studies reported in the literature provide data related to the risks and benefits of LASIK; alternatives to a laser refractive procedure are also discussed. The results from these studies have been used to prepare a decision tree to assist the surgeon in choosing the best option for the patient based on the data from several standard preoperative diagnostic tests. The data presented here should aid surgeons in understanding the effects of currently available LASIK treatment profiles. Surgeons should also be able to appreciate how the findings were used to create a decision tree to help choose the most appropriate treatment profile for patients. Finally, the retrospective evaluation of clinical outcomes based on the decision tree should provide surgeons with a realistic expectation for their own outcomes should they adopt such a decision tree in their own practice.

Two-year results of femtosecond assisted LASIK versus PRK for different severity of astigmatism

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Mohammad Miraftab

2018-03-01

Conclusions: Our results pointed to better two-year results with femto-LASIK in the treatment of different degrees of astigmatism. UDVA improvement was superior with femto-LASIK, but the two methods did not significantly differ in terms of CDVA improvement.

Análise laboratorial das ceratites infecciosas secundárias à cirurgia refrativa Laboratory analysis of infectious keratitis in patients following refractive surgery

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Fernando Leal

2005-06-01

Full Text Available OBJETIVO: Descrever os resultados laboratoriais de amostras de pacientes com ceratite infecciosa pós-cirurgia refrativa. MÉTODOS: Foram avaliados pacientes do Departamento de Oftalmologia da UNIFESP, que foram submetidos a tratamento para ceratite infecciosa, entre janeiro de 1988 e junho de 2001, e que haviam sido submetidos à ceratomia radial (CR, ceratotomia fotorrefrativa (PRK ou laser in situ keratomileusis (LASIK. Previamente, as infecções foram classificadas como precoces, quando ocorreram até 30 dias após a cirurgia, e tardias quando diagnosticadas após 30 dias. RESULTADOS: Das 93 amostras, 39 eram de (42% pacientes submetidos à ceratotomia radial, sendo 14 (36% infecções precoces e 25 (64% infecções tardias; 38 (41% pacientes submetidos a LASIK, sendo 21 (55% infecções precoces e 17 (45% infecções tardias; 16 (17% eram de pacientes submetidos à ceratotomia fotorrefrativa, sendo 10 (62,5% infecções precoces e 6 (37,5% infecções tardias. Oitenta e seis amostras de córnea coletadas foram submetidas a cultivo e esfregaço para bactérias, 43 cultivos (50% e 43 esfregaços (50% foram positivos. Setenta e duas amostras foram submetidas a cultivo e esfregaço para fungos, 2 cultivos (3% e 4 esfregaços (6% foram positivos. CONCLUSÃO: Os resultados obtidos revelam uma concordância de 80,2% entre cultivo e esfregaço para bactéria. Não houve relação estatisticamente significante entre o tipo de cirurgia e o tempo de manifestação da infecção.PURPOSE: To describe the laboratory findings in patients with infectious keratitis, who underwent refractive surgery, correlating the surgical procedure and the time of infection manifestation, and the results of culture and smears. METHODS: The previous samples were obtained from patients submitted to radial keratotomy (RK, photorefractive keratectomy (PRK and laser in situ keratomileusis (LASIK at the Ophthalmology Department of UNIFESP. The infections were classified as

Regressão refrativa total pós-LASIK: relato de caso Total refractive regression post-LASIK: case report

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Patrícia Ioschpe Gus

2005-06-01

Full Text Available Os corticoesteróides podem aumentar a pressão intra-ocular quando administrados de maneira tópica, sistêmica e até mesmo inalatória. É rotina sua utilização após cirurgias refrativas para diminuir ou prevenir reação inflamatória. No presente relato, apresentamos o caso de uma paciente de 36 anos que, após duas semanas de cirurgia de LASIK para correção de miopia leve, teve regressão total da miopia causada pela hipertensão ocular cortisônica. O objetivo desse relato é descrever como foi conduzido o caso, as hipóteses de diagnósticos que foram levantadas, e salientar a importância da mensuração da pressão intra-ocular no pós-operatório.Corticosteroids can increase intraocular pressure when administered topically, systemically and even when inhaled. They are routinely used after refractive surgeries to lower or prevent an inflammatory action. In this case history, we present a 36-year-old patient who had a total myopic regression two weeks after LASIK for low myopia, caused by steroid-induced ocular hypertension. The purpose of this report is to describe how the case was managed, the diagnostic hypothesis, and to stress the importance of intraocular pressure measurement after LASIK.

Measuring patient's expectation and the perception of quality in LASIK services

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Bair Alex

2009-07-01

Full Text Available Abstract Background LASIK is the use of excimer lasers to treat therapeutic and refractive visual disorders, ranging from superficial scars to nearsightedness (myopia, and from astigmatism to farsightedness (hyperopia. The purposes of this study are to checking the applicability and psychometric properties of the SERVQUAL on Lasik surgery population. Second, use SEM methods to investigate the loyalty, perceptions and expectations relationship on LASIK surgery. Methods The method with which this study was conducted was questionnaire development. A total of 463 consecutive patients, attending LASIK surgery affiliated with Chung Shan Medical University Eye Center, enrolled in this study. All participants were asked to complete revised SERVQUAL questionnaires. Student t test, correlation test, and ANOVA and factor analyses were used to identify the characters and factors of service quality. Paired t test were used to test the gap between expectation and perception scores and structural equation modeling was used to examine relationships among satisfaction components. Results The effective response rate was 97.3%. Validity was verified by several methods and internal reliability Cronbach's alpha was > 0.958. The results from patient's scores were very high with an overall score of 6.41(0.66, expectations at 6.68(0.47, and perceptions at 6.51(0.57. The gap between expectations and perceptions was significant, however, (t = 6.08. Furthermore, there were significant differences in the expectation scores among the different jobs. Also, the results showed that the higher the education of the patient, the lower their perception score (r = -0.10. The factor loading results of factor analysis showed 5 factors of the 22 items of the SERVQUAL model. The 5 factors of perception explained 72.94% of the total variance there; and on expectations it explained 77.12% of the total variance of satisfaction scores. The goodness-of-fit summary, of structure equation

Measuring patient's expectation and the perception of quality in LASIK services.

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Lin, Deng-Juin; Sheu, Ing-Cheau; Pai, Jar-Yuan; Bair, Alex; Hung, Che-Yu; Yeh, Yuan-Hung; Chou, Ming-Jen

2009-07-10

LASIK is the use of excimer lasers to treat therapeutic and refractive visual disorders, ranging from superficial scars to nearsightedness (myopia), and from astigmatism to farsightedness (hyperopia). The purposes of this study are to checking the applicability and psychometric properties of the SERVQUAL on Lasik surgery population. Second, use SEM methods to investigate the loyalty, perceptions and expectations relationship on LASIK surgery. The method with which this study was conducted was questionnaire development. A total of 463 consecutive patients, attending LASIK surgery affiliated with Chung Shan Medical University Eye Center, enrolled in this study. All participants were asked to complete revised SERVQUAL questionnaires. Student t test, correlation test, and ANOVA and factor analyses were used to identify the characters and factors of service quality. Paired t test were used to test the gap between expectation and perception scores and structural equation modeling was used to examine relationships among satisfaction components. The effective response rate was 97.3%. Validity was verified by several methods and internal reliability Cronbach's alpha was > 0.958. The results from patient's scores were very high with an overall score of 6.41(0.66), expectations at 6.68(0.47), and perceptions at 6.51(0.57). The gap between expectations and perceptions was significant, however, (t = 6.08). Furthermore, there were significant differences in the expectation scores among the different jobs. Also, the results showed that the higher the education of the patient, the lower their perception score (r = -0.10). The factor loading results of factor analysis showed 5 factors of the 22 items of the SERVQUAL model. The 5 factors of perception explained 72.94% of the total variance there; and on expectations it explained 77.12% of the total variance of satisfaction scores.The goodness-of-fit summary, of structure equation modeling, showed trends in concept on expectations

Comparison of corneal sensation between small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK for myopia.

Science.gov (United States)

Li, Meiyan; Zhou, Zimei; Shen, Yang; Knorz, Michael C; Gong, Lan; Zhou, Xingtao

2014-02-01

To compare the impact on corneal sensation after small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK (femto-LASIK) in patients with myopia. In this prospective, nonrandomized comparative study, 71 subjects were enrolled. Thirty-eight eyes of 38 patients underwent SMILE and 33 eyes of 33 patients underwent femto-LASIK. Corneal sensation was tested with Cochet-Bonnet esthesiometry in five corneal areas preoperatively and at 1 week and 1, 3, and 6 months postoperatively. Comparison of corneal sensation was performed for the SMILE and femto-LASIK groups. Additionally, the correlations were evaluated between the postoperative corneal sensation, preoperative spherical equivalent, and ablation depth. All tested areas within the cap or flap demonstrated corneal hypoesthesia immediately after both surgeries. SMILE-treated eyes showed less compromised corneal sensation than femto-LASIK-treated eyes at all postoperative visits in the central, inferior, nasal, and temporal areas at the 1-week and 1-month visits. In the SMILE group, the inferior, nasal, and temporal quadrants recovered faster than other areas. In the femto-LASIK group, the sensation over the flap did not recover to preoperative levels by postoperative 6 months. There was no correlation between postoperative corneal sensation, preoperative spherical equivalent, and ablation depth in both groups. The impairment of corneal sensation was less significant in the SMILE group than in the femto-LASIK group and was independent of preoperative spherical equivalent or ablation depth. Copyright 2014, SLACK Incorporated.

Single-step transepithelial ASLA (SCHWIND with mitomycin-C for the correction of high myopia: long term follow-up

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Aslanides IM

2014-12-01

Full Text Available Ioannis M Aslanides, Panagiotis N Georgoudis, Vasilis D Selimis, Achyut N Mukherjee Emmetropia Mediterranean Eye Institute, Heraklion, Crete, Greece Purpose: We wanted to compare the outcomes of single-step modified transepithelial photorefractive keratectomy (tPRK termed a SCHWIND all surface laser ablation (ASLA versus conventional alcohol-assisted photorefractive keratectomy (PRK and laser-assisted in situ keratomileusis (LASIK for the correction of higher myopia of 6.00 diopters (D or more, in an area with high risk of haze due to high intensity of sunlight.Methods: We used a prospective interventional cohort with matched retrospective control groups. Patients with >6 D myopia and <3.5 D of astigmatism were included. All treatments were performed with the SCHWIND Amaris system using aspheric ablation profiles. Mitomycin C was used in all PRK and ASLA cases. Outcomes were postoperative refraction, visual acuity, stability, and complications. The follow-up period was up to 12 months.Results: In total, 101 eyes were included after exclusions. Mean preoperative spherical equivalent refraction was −7.9 D, −8.2 D, and −7.4 D in the ASLA (n=41, PRK (n=29, and LASIK (n=31 groups. Mean postoperative spherical equivalent at 12 months postoperatively was −0.1 (standard deviation [SD]: 0.34, −0.2 (SD: 0.59, and −0.08 (SD: 0.36 in the ASLA, PRK, and LASIK groups, with 91.4%, 85.7%, and 83.9% within 0.5 D of target, respectively. Refractive outcomes and regression at 12 months did not vary among groups (P>0.05. Mean logMAR (logarithm of the minimum angle of resolution uncorrected distance visual acuity at 12 months was 0.00 (SD: 0.05, 0.06 (SD: 0.1, and 0.05 (SD: 0.09 in the ASLA, PRK, and LASIK groups, with significantly better vision in the tPRK group versus LASIK (P=0.01 and PRK (P=0.01 groups.Conclusion: ASLA (SCHWIND tPRK with mitomycin C for high myopia demonstrates comparable refractive outcomes to LASIK and PRK, with relatively

A review of corneal diameter, curvature and thickness values and influencing factors*

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K. P. Mashige

2013-12-01

Full Text Available The cornea is an important ocular structure involved in the mediation of visual perception. It is the principal refractive surface of the eye and vision can be significantly affected by relatively small changes in its structure and parameters. Measurement of corneal parameters is important in the diagnosis and management of ocular diseasessuch as keratoconus and glaucoma, and also in the fitting of contact lenses or with refractive surgery such as Laser-Assisted in situ Keratomileusis(LASIK and photorefractive keratectomy (PRK. The human corneal diameter, anterior curvature and centre thickness as well as factors influencing them are reviewed in this article. This review will be useful to eye care professionals who routinely measure these parameters when fitting contact lenses and assessing, diagnosing as well as managing corneal and other ocular conditions. (S Afr Optom 2013 72(4 185-194

Epi-LASIK e PRK: um ano de estudo comparativo em olhos contralaterais

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Francisco Penteado Crestana

2013-08-01

Full Text Available OBJETIVO: Comparar as técnicas de PRK e Epi-LASIK com relação à recuperação visual e sintomatologia pós-operatória. MÉTODOS: Série de casos intervencionista que incluiu 38 olhos de 19 pacientes com miopia até 5DE e astigmatismo até 1DC. Foram selecionados pacientes com erros refracionais semelhantes nos dois olhos, realizando-se, no mesmo tempo cirúrgico, PRK em um olho e Epi-LASIK no olho contralateral. Os pacientes foram acompanhados por um ano, avaliando-se a eficácia refracional e grau de desconforto pós-operatório. RESULTADOS: Durante as primeiras 12 horas, 79,9% dos pacientes (p=0,0003 referiram dor mais intensa no olho operado com a técnica Epi-LASIK. Após 24 horas, 63,2% dos pacientes (p=0,012 ainda referiam mais dor neste olho e apenas 10,5% no olho contralateral. A acuidade visual não corrigida foi melhor nos olhos do grupo PRK no primeiro dia (p=0,034. Nos demais dias não houve diferença significativa entre os grupos. Houveopacidade corneana grau 0,5 (Fantes em três olhos do grupo PRK e em dois no grupo Epi-LASIK. CONCLUSÃO: Ambos os grupos apresentaram resultado visual refracional satisfatório, porém o grupo Epi-LASIK apresentou maior desconforto no pós-operatório imediato.

Wavefront-guided refractive surgery results of training-surgeons Resultados das cirurgias refrativas guiadas por frentes de ondas de cirurgiões em treinamento

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Iane Stillitano

2010-08-01

Full Text Available PURPOSE: To assess clinical outcomes and changes on higher-order aberrations (HOA after wavefront-guided laser in situ keratomileusis (LASIK and photorefractive keratectomy (PRK for correction of myopia and myopic astigmatism performed by training-surgeons. METHODS: One hundred and seventy patients had customized LASIK (207 eyes and PRK (103 eyes performed by surgeons in-training using the LADARVision 4000 (Alcon, Fort Worth, TX. Preoperative and 1, 3, 6 and 12 months postoperative data of spherical equivalent (SE, best spectacle-corrected visual acuity (BSCVA and uncorrected visual acuity (UCVA were analysed. Wavefront changes were determined using the LADARWave Hartmann-Shack wavefront aberrometer and the pupil size was scaled for 6.5 mm. RESULTS: The mean SE in the LASIK group was -3.04 ±1.07 D and in the PRK group was -1.60 ± 0.59 D. At 1-year follow-up, (80.6% (LASIK and (66.7% (PRK were within ± 0.50 D of the intended refraction. The UCVA was 20/20 or better in (58.1% (LASIK and (66.7% (PRK of the operated eyes. A statistically significant positive correlation was found between achieved versus attempted refractive correction in both groups: LASIK (r=0.975, POBJETIVO: Avaliar os resultados clínicos e mudanças nas aberrações de alta-ordem (HOA, após ceratomileuse assistida por excimer laser in situ (LASIK e ceratectomia fotorrefrativa (PRK guiados por frentes de onda para correção da miopia e astigmatismo miópico realizada por cirurgiões em treinamento. MÉTODOS: Estudo prospectivo de 170 pacientes submetidos a LASIK personalizado (207 olhos e PRK (103 olhos realizados por cirurgiões em treinamento utilizando o LADARVision 4000 (Alcon, Fort Worth, TX. Dados do equivalente esférico (SE, melhor acuidade visual corrigida (BSCVA e acuidade visual não corrigida (UCVA foram analisados no pré-operatório e com 1, 3, 6 e 12 meses de pós-operatório. As alterações de frentes de onda foram determinadas usando o aberrômetro Hartmann

A Novel Laser Refractive Surgical Treatment for Presbyopia: Optics-Based Customization for Improved Clinical Outcome.

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Pajic, Bojan; Pajic-Eggspuehler, Brigitte; Mueller, Joerg; Cvejic, Zeljka; Studer, Harald

2017-06-13

Laser Assisted in Situ Keratomileusis (LASIK) is a proven treatment method for corneal refractive surgery. Surgically induced higher order optical aberrations were a major reason why the method was only rarely used to treat presbyopia, an age-related near-vision loss. In this study, a novel customization algorithm for designing multifocal ablation patterns, thereby minimizing induced optical aberrations, was used to treat 36 presbyopic subjects. Results showed that most candidates went from poor visual acuity to uncorrected 20/20 vision or better for near (78%), intermediate (92%), and for distance (86%) vision, six months after surgery. All subjects were at 20/25 or better for distance and intermediate vision, and a majority (94%) were also better for near vision. Even though further studies are necessary, our results suggest that the employed methodology is a safe, reliable, and predictable refractive surgical treatment for presbyopia.

CLINICAL STUDY TO EVALUATE THE VISUAL OUTCOME AND PATIENT COMFORT IN LASIK AND PHOTOREFRACTIVE KERATECTOMY IN LOW-TO-MODERATE MYOPIC ASTIGMATISM PATIENTS

OpenAIRE

Ashok Kumar P; Ananda Babu M; Radha Priyadharshini R; Jeevitha A

2017-01-01

BACKGROUND To evaluate visual outcomes following LASIK and Photorefractive Keratectomy (PRK) in low-to-moderate myopia and/or myopic astigmatism in age and refractive error matched eyes. MATERIALS AND METHODS Of a total 30 patients aged ≥21 years, 20 (40 eyes) underwent LASIK and 10 (20 eyes) underwent PRK for low-to-moderate myopia or myopic astigmatism. LASIK was performed with the Alcon wave light 500 and PRK with the alcohol application for epithelial removal. All abl...

[Comparison of Discriminant Analysis and Decision Trees for the Detection of Subclinical Keratoconus].

Science.gov (United States)

Kleinhans, Sonja; Herrmann, Eva; Kohnen, Thomas; Bühren, Jens

2017-08-15

Background Iatrogenic keratectasia is one of the most dreaded complications of refractive surgery. In most cases, keratectasia develops after refractive surgery of eyes suffering from subclinical stages of keratoconus with few or no signs. Unfortunately, there has been no reliable procedure for the early detection of keratoconus. In this study, we used binary decision trees (recursive partitioning) to assess their suitability for discrimination between normal eyes and eyes with subclinical keratoconus. Patients and Methods The method of decision tree analysis was compared with discriminant analysis which has shown good results in previous studies. Input data were 32 eyes of 32 patients with newly diagnosed keratoconus in the contralateral eye and preoperative data of 10 eyes of 5 patients with keratectasia after laser in-situ keratomileusis (LASIK). The control group was made up of 245 normal eyes after LASIK and 12-month follow-up without any signs of iatrogenic keratectasia. Results Decision trees gave better accuracy and specificity than did discriminant analysis. The sensitivity of decision trees was lower than the sensitivity of discriminant analysis. Conclusion On the basis of the patient population of this study, decision trees did not prove to be superior to linear discriminant analysis for the detection of subclinical keratoconus. Georg Thieme Verlag KG Stuttgart · New York.

Accuracy of Visual Estimation of LASIK Flap Thickness.

Science.gov (United States)

Brenner, Jason E; Fadlallah, Ali; Hatch, Kathryn M; Choi, Catherine; Sayegh, Rony R; Kouyoumjian, Paul; Wu, Simon; Frangieh, George T; Melki, Samir A

2017-11-01

To assess the accuracy of surgeons' visual estimation of LASIK flap thickness when created by a femtosecond laser by comparing it to ultrasound measurements. Surgeons were asked to visually estimate the thickness of a femtosecond flap during the procedure. Total corneal thickness was measured by ultrasound pachymetry prior to the procedure and the stromal bed was similarly measured after flap lifting. The estimates from three experienced surgeons (cornea fellowship trained and more than 5 years in practice) were compared to those of three cornea fellows, with each surgeon evaluating 20 eyes (120 total). Surgeons were not told the thickness of the flaps unless required for safety reasons. The average difference between visual and ultrasonic estimation of LASIK flap thickness was 15.20 μm. The flap was 10 μm thicker than estimated in 37% of eyes, 20 μm thicker in 17% of eyes, and 30 μm thicker in 10% of eyes. The largest deviation was 53 μm. There was no statistically significant difference between the accuracy of experienced surgeons and fellows (P = .51). There are significant differences between surgeons' visual estimates and ultrasonic measurements of LASIK flap thickness. Relying on these visual estimates may lead to deeper excimer laser ablation than intended. This could lead to thinner residual stromal beds and higher percent tissue altered than planned. The authors recommend that surgeons measure flaps intraoperatively to maximize accuracy and safety. [J Refract Surg. 2017;33(11):765-767.]. Copyright 2017, SLACK Incorporated.

CLINICAL STUDY TO EVALUATE THE VISUAL OUTCOME AND PATIENT COMFORT IN LASIK AND PHOTOREFRACTIVE KERATECTOMY IN LOW-TO-MODERATE MYOPIC ASTIGMATISM PATIENTS

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Ashok Kumar P

2017-04-01

Full Text Available BACKGROUND To evaluate visual outcomes following LASIK and Photorefractive Keratectomy (PRK in low-to-moderate myopia and/or myopic astigmatism in age and refractive error matched eyes. MATERIALS AND METHODS Of a total 30 patients aged ≥21 years, 20 (40 eyes underwent LASIK and 10 (20 eyes underwent PRK for low-to-moderate myopia or myopic astigmatism. LASIK was performed with the Alcon wave light 500 and PRK with the alcohol application for epithelial removal. All ablations were performed using the same excimer laser system. One surgeon operated all patients by using an excimer laser (Alcon wave light 500 system. Age and refractive error matched patients were divided in two groups. Preoperative and one year postoperative uncorrected visual acuity, best corrected visual acuity and manifest refractions were recorded to compare the outcomes of both the procedures. Outcome measures to assess the patient comfort levels in both groups include postoperative pain and quality of vision. Other outcome measures to assess the wound healing includes intraoperative complications, corneal haze and corneal reepithelialisation. RESULTS Sixty eyes of 30 patients were found matched regarding age and refractive error. In PRK group, among 10 patients, 5 (50% were males and 5 (50% were females, whereas in Lasik group, males were 12 (60% and 8 (40% were female patients. Mean preoperative MRSE was -4.06 ± 1.00 Dioptres (D for LASIK versus -4.50 ± 1.25 D for PRK. Complete flap healing was achieved by postoperative day 4 in 86.9% of LASIK eyes versus complete reepithelialisation in 92.4% of PRK eyes. Using Fisher exact test, a significantly higher percentage of LASIK eyes compared to PRK eyes achieved 20/15 or better at 1 month (35.8% vs. 17.8%, P=0.031, 3 months (69.3% vs. 49.3%, P=0.004, 6 months (79.1% vs. 59.9%, P0.50 D occurred in 12.4% of LASIK eyes within the 3- and 12-month interval versus 25.7% of PRK eyes (P=0.04. Patients in both groups were happy