Moria M2 Microkeratome Research Articles

ANALYSIS OF MICROKERATOME ASSISTED CORNEAL FLAP THICKNESS IN LASER IN SITU KERATOMILEUSIS USING ANTERIOR SEGMENT OPTICAL COHERENCE TOMOGRAPHY.

Purpose:To evaluate corneal ap thickness with Moria M2 microkeratome in Laser in situ keratomileusis (LASIK) using Anterior segment optical coherence tomography (AS-OCT). Methods: 170 eyes of 85 patients underwent LASIK using VISX Star S4 Excimer Laser System. The Moria M2 single-use head 90m microkeratome was used to create nasal hinged corneal aps. The right eye (RE) was operated rst followed by the left eye (LE), using the same blade. Flap thickness was analyzed using AS-OCT. Statistical Analysis: SPSS Software for Windows (version 18.0, SPSS, Inc). Results: The mean spherical equivalent (MSE) was - 4.17 diopters (D) + 2.5(range: -12.5 to + 2.375 D), preoperative keratometry was 44.02 +1.58D (range 40.19-48.95D), and corneal thickness was 535.62 ± 34.6 m (468-661m) in all eyes. The mean corneal ap thickness was 117.80 ± 9.12m (96 -138m), 112.98 ± 9.86m (93-142m), and 115.35 ± 9.7m (93-142m) in the RE, LE, and both eyes respectively. There was a negative signicant relationship between MSE and the ap thickness (p<0.001). Females had thinner aps as compared to males (p=0.013). There was a weak positive correlation between the pre-operative pachymetry and ap thickness (p=0.039). No signicant relationship was found between preoperative keratometry, age and ap thickness. RE had a thicker ap than the LE which was statistically signicant (p<0.001). Conclusions:The aps created using Moria M2 90 microkeratome were thicker than intended and reproducible. Preoperative keratometry and age did not inuence ap formation. Thick corneas had thicker aps and vice versa. Higher refractive errors and re-use of blades cause thinner aps.

Clinical outcome of femtosecond laser flap formation versus mechanical microkeratome in laser in situ keratomileusis for treatment of myopia

Purpose The aim of this study was to evaluate and to compare the thickness and morphology of femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and mechanical microkeratome flaps using anterior segment optical coherence tomography (AS-OCT).Patients and methods This prospective, interventional, comparative clinical study was performed on 60 eyes of 30 patients. Flaps were created in 30 eyes using the WaveLight FS200 FS laser and in 30 eyes using the Moria M2 microkeratome. AS-OCT was used at 1 month postoperatively to evaluate the thickness of each flap at four points, which were 1 and 2 mm from the corneal vertex on the horizontal meridian.Results At the sixth month postoperatively, the uncorrected visual acuity was 0.98±0.10 in the FS-LASIK group and 0.98±0.11 in the microkeratome group, which denotes the efficacy of both procedures. No vision-threatening complications occurred in either group. The average flap thickness at 1 mm was 114.93±3.04 µm in the FS-LASIK group compared with 128.57±3.98 µm in the microkeratome group, with a statistically significant difference (P=0.000). The difference between the achieved and intended flap thickness at 1 mm (accuracy) was 4.93±3.04 µm in the FS-LASIK group compared with 18.57±3.98 µm in the microkeratome group, with a statistically significant difference (P=0.000). At 2 mm, the average flap thickness was 115.22±3.34 µm in the FS-LASIK group compared with 139.00±4.75 µm in the microkeratome group (P=0.000). The flap accuracy at 2 mm was 5.22±3.34 µm and 29.00±4.75 µm in the FS-LASIK group and the microkeratome group, respectively (P=0.000). Flap morphology showed a planar shape (uniform) in the FS-LASIK group and a meniscus shape in the microkeratome group.Conclusion Both FS-LASIK and microkeratome techniques were safe and efficient in correcting myopia and myopic astigmatism, achieving good visual outcome. AS-OCT showed that flaps created by the FS laser were more accurate and uniform than those created by the Moria M2 microkeratome.

Analysis and Causation of All Inaccurate Outcomes After WaveLight Contoura LASIK with LYRA Protocol.

PurposeThis study analyzes every eye that had an outcome greater than 0.25D of sphere or astigmatism from planned goal after treatment with WaveLight Contoura with LYRA Protocol.MethodsThe study included 266 consecutive eyes treated with LASIK Contoura using the LYRA Protocol. All LASIK procedures were performed on the WaveLight EX500 excimer laser. Flaps were created with either the Alcon WaveLight FS200 femtosecond laser or the Moria M2 microkeratome. Eyes that were off by >0.25 diopters (D) sphere or cylinder from the targeted goal within 3 months after surgery were identified and analyzed for cause. Topographical, higher-order aberration, and epithelial maps were created.ResultsCauses for inaccurate outcomes were biomechanical corneal change from LASK flap creation (9.78% of total eyes), pre-operative epithelial compensation of corneal higher-order aberration (4.1% of total eyes), changes to lamellar corneal tension from laser ablation causing a hyperopic shift (1.9% of total eyes), epithelial thickening over the ablation area post-operatively causing a refractive change (1.5% of total eyes), and posterior astigmatism (0.75%).ConclusionThe causes of the majority of inaccurate outcomes have not been properly defined and must be incorporated into further improving outcomes. Current and planned advances in technology do not address the majority of these causes.

Biomechanical Changes to the Cornea from LASIK Flap Creation Resulting in Inaccurate Ablations and Suboptimal Refractive Outcomes with Topographic-Guided Ablation.

PurposeThis study documents a biomechanical corneal change related to corneal flap creation in certain patients leading to an irregular ablation pattern and an inaccurate refractive outcome.MethodsThis retrospective study included consecutive eyes treated with primary LASIK Contoura using the LYRA Protocol. All LASIK procedures were performed on the WaveLight EX500 excimer laser. Flaps were created with either the Alcon WaveLight FS200 femtosecond laser or the Moria M2 microkeratome. Eyes that were off by greater than or equal to 0.50 diopters (D) sphere or cylinder from the targeted goal within 3 months after surgery were identified. Topographical, higher order aberration, and epithelial maps were created. Of these eyes, approximately 10% of eyes were found to have undergone a biomechanical change upon flap creation that led to an inaccurate outcome.ResultsSix representative cases are presented that demonstrate the biomechanical change, outcomes, and treatment. All patients demonstrated an elliptical, irregular ablation pattern on post-operative topography, lateralized the thinnest point of the cornea relative to the corneal apex on Pentacam pachymetry maps, and irregular corneal epithelial thickening at the periphery of the elliptical ablation.ConclusionA biomechanical change during flap creation can occur in certain types of corneas during LASIK flap creation and subsequent treatment with topographic-guided ablation leading to an irregular ablation and suboptimal refractive outcomes.

The outcome of femtosecond laser in situ keratomileusis compared to conventional laser insitu keratomileusis in myopic patients

AbstractIntroduction: This is a prospective comparative clinical study conducted to assess the safety , effectiveness, and complications of Intralase femtosecond laser (FSL) compared to Moria M2 microkeratome (MK) in high myope. Methods : This study consisted of 51 myopic eyes, divided into two groups( A & B) . Twenty-five eyes in group A in which the flap was created by Intralase FSL, while twenty-six eyes in group B in which the flap was created by Moria M2 MK. Refractive , keratometric and flap complications were compared preoperative and 6 months postoperative by using the intraoperative subtraction pachymetry . (Scheimpflug imaging (CSO, Florence, Italy). Results:No substantial difference was found as regarding postoperative manifest sphere ,astigmatic and keratometry .In group A mean postoperative actual flap thickness was98.12 ± 16.1 μm and in group B it was100.6 ± 20.1 μm with statistically significant difference P value( 0.001).Conclusion: Both the femtosecond laser and the mechanical microkeratome are safe and effective in correcting myopia, with no statistically significant difference during 6-month follow-up between the two groups. The femtosecond laser has better flap creation than the microkeratome . Key words :FSL ,Moria M2 ,Myope

Flap thickness and side-cut angle using sub-Bowman keratomileusis microkeratome, 200-kHz femtosecond laser system, and Moria M2 microkeratome

Purpose The aim of this study was to compare the thickness and side-cut angle of corneal flap in candidates undergoing laser-assisted in situ keratomileusis using sub-Bowman keratomileusis (SBK) microkeratome, femtosecond (FS) laser, or Moria M2 microkeratome (MK). Patients and methods This prospective clinical study included 60 eyes of 30 patients. They were divided into three groups (20 eyes in each group). The study was conducted from January 2019 till December 2019. Corneal flaps were created using Moria SBK microkeratome, Alcon Wavelight FS-200 FS laser, or Moria MK. Heidelberg anterior segment optical coherence tomography was done 1 month postoperatively to assess the central flap thickness and side-cut angle. Results The mean error cut angle was −39.00±19.00, 24.75±12.56, and −25.65±10.31° in the SBK, FS, and MK groups, respectively (P Conclusion There was a statistically significant difference between the intended and achieved side-cut angle in the three groups. Flap thickness was more predictable in the SBK and FS group, with an insignificant difference between the intended and achieved flap thickness, whereas in the MK group, the difference was statistically significant.

Risk factors for early flap misalignment following microkeratome-assisted laser in situ keratomileusis: A retrospective large database analysis.

To determine factors associated with early flap misalignment following microkeratome-assisted laser in situ keratomileusis. This retrospective study included the right eyes of consecutive patients who underwent laser in situ keratomileusis procedure between 2005 and 2016 at Care-Vision Laser Centers, Tel-Aviv, Israel. Patients were divided into two groups according to whether or not they subsequently developed early flap misalignment. A total of 14,582 eyes (mean age of patients: 32.4 ± 10.3 years) were included. Post-laser in situ keratomileusis early flap misalignment developed in 158 eyes (1.1%). Misalignment was more frequent during the spring (32.3% vs 22.8%, p = 0.003) and in a higher operating room temperature (23.34 ± 1.06 vs 22.98 ± 1.26, p < 0.001). In addition, in the misalignment group, there was a higher rate with the of use of the a Moria M2 microkeratome (rather than sub-Bowman's keratomileusis microkeratome) head (55.2% vs 40.5%, respectively, p < 0.001). In a multivariable analysis adjusted for surgeon and year of surgery, high operating room temperature (odds ratio = 1.22, p = 0.006), treatment zone of 9.0 mm (as opposed to smaller treatment zones, odds ratio = 1.54, p = 0.04), and springtime (odds ratio = 1.58, p = 0.02) were associated with flap misalignment. There was a significant difference in misalignment rates between surgeons (p = 0.02). This study found that larger treatment zones, higher operating room temperature, operating during the spring, and the use of Moria M2 microkeratome were associated with increased flap misalignment rates. The association with operating room temperature and seasonal variation is of interest and merits further research.

Risk Factors for Sporadic Diffuse Lamellar Keratitis After Microkeratome Laser-Assisted In Situ Keratomileusis: A Retrospective Large Database Analysis.

To determine the factors associated with sporadic diffuse lamellar keratitis (DLK) after microkeratome laser-assisted in situ keratomileusis (LASIK). This large database retrospective study included consecutive cases of LASIK performed between 2007 and 2016 at Care-Vision Laser Centers, Tel-Aviv, Israel. Patients were divided into 2 groups according to whether or not they subsequently developed DLK. A total of 24,026 eyes of 12,013 patients with a mean age of 32.9 ± 10.3 years were included. Post-LASIK DLK developed in 464 eyes (1.9%), and the annual rate decreased from 7.1% (2007) to 1.7% (2016) (P < 0.001). The DLK group had a higher proportion of males (58.5% vs. 52.1%, P = 0.006), greater preoperative central corneal thickness (549.5 ± 32.6 vs. 545.3 ± 30.5 μm, P = 0.005), and a lower proportion of high astigmatism (>3 D) (0.4% vs. 1.6%, P = 0.05). The DLK group had a higher proportion of previous LASIK treatment (2.8% vs. 1.3%, P = 0.006), Moria M2 (rather than the SBK) microkeratome (71.1% vs. 34.0%, P < 0.001), smaller suction ring number (P < 0.001), greater stop size (P < 0.001), and greater flap thickness (119.2 ± 50.4 vs. 110.8 ± 22.2, P = 0.007). In multivariable analysis, a smaller suction ring number [odds ratio (OR) 0.89, P = 0.04], Moria M2 microkeratome (OR 5.26, P < 0.001), larger optical zone (OR = 2.04, P = 0.01), and higher spherical equivalent (OR = 1.08, P = 0.02) were associated with DLK. In the modern LASIK era, the incidence of DLK continues to decrease. Higher preoperative ametropia, smaller suction ring number, an older type of microkeratome, and larger optical zones are associated with higher DLK rates after LASIK.

Visumax femtolasik versus Moria M2 microkeratome in mild to moderate myopia: efficacy, safety, predictability, aberrometric changes and flap thickness predictability

IntroductionThis is an interventional prospective clinical study which was conducted to evaluate the efficacy, safety, predictability, ocular aberrations, and flap thickness predictability of Visumax femtosecond laser (FSL) compared to Moria M2 microkeratome (MK) in mild to moderate myopia.MethodsThis study included 60 eyes who were divided into two groups. Thirty eyes in group (I) in which the flap was created with Visumax FSL, while in group II (30 eyes) the Moria M2 MK was used. Keratometric, refractive, and aberrometric measurements were compared preoperatively and 3 months postoperatively. The intraoperative subtraction pachymetry (the SP 100 Handy pachymeter (Tomey, Nagoya, Japan) was used for preoperative pachymetry and flap thickness measurement.ResultsNo significant difference was found between the two groups in regards to postoperative manifest sphere, spherical equivalent, astigmatism, safety indices nor ocular aberrations. Twenty six eyes (86.6%) in group I and 23 eyes in group II (76.6%) were within ±0.5D of the intended correction and 23 eyes (76.6%) in group I and 15 eyes in group II (50%) were within ±0.25D of the intended correction. In group I, the mean postoperative actual flap thickness was 100.12 ± 16.1 μm (81 to 122 μm), while in group II, it was 104.6 ± 20.1 μm (62 to 155 μm). The difference was statistically significant (p = 0.001).ConclusionsBoth Visumax and Moria M2 MK are safe and effective in treating myopia with no statistically significant difference in induction of ocular aberrations but with potential advantage for Visumax regarding predictability. More accurate flap thickness is achieved with Visumax femtolasik.Trial registrationThis study was retrospectively registered on 19/6/2017. Trial registration number NCT03193411, clinicalTrials.gov.

Effect of femtosecond and microkeratome flaps creation on the cornea biomechanics during laser in situ keratomileusis: one year follow-up.

To compare the corneal biomechanical outcomes at one year after laser in situ keratomileusis (LASIK) with the flaps created by Ziemer and Moria M2 microkeratome with 110 head and -20 blade. Totally 100 eyes of 50 consecutive patients were enrolled in this prospective study and divided into two groups for corneal flaps created by ZiemerFemto LDV and Moria M2 microkeratome with 110 head and -20 blade. Corneal biomechanical properties including cornea resistance factor (CRF) and cornea hysteresis (CH) were measured before and 1, 3, 6, 12mo after surgery by ocular response analyzer. Central cornea thickness and corneal flap thickness were measured by optical coherence tomography. The ablation depth (P=0.693), residual corneal thickness (P=0.453), and postoperative corneal curvature (P=0.264) were not significant different between Ziemer group and Moria 110-20 group after surgery. The residual stromal bed thickness, corneal flap thickness, CH and CRF at 12mo after surgery were significant different between Ziemer group and Moria 110-20 group (P<0.01);Ziemer group gained better corneal biomechanical results. The CRF and CH increased gradually from 1 to 12mo after surgery in Ziemer group, increased from 1 to 6mo but decreased from 6 to 12mo in Moria 110-20 group. Both CRF and CH at one year after surgery increased with the increasing of residual cornea thickness; pre-LASIK CRF, CRF also increased with residual stromal bed thickness, while CH decreased with the increasing of pre-LASIK intraocular pressure and cornea flap thickness (P<0.01). In one year follow-up, femtosecond laser can provide better cornea flaps with stable cornea biomechanics than mechanical microkeratome.

Intraoperative Flap Complications in LASIK Surgery Performed by Ophthalmology Residents.

Purpose:To report the rate of flap-related complications in LASIK surgery performed by in-training ophthalmology residents and to analyze the risk factors for these complications.Methods:We analyzed 273 flap dissections in 145 patients from March 2013 to February 2014. We included all LASIK surgeries performed by 32 ophthalmology residents using a Moria M2 microkeratome. All the flap-related complications were noted. Comparison between both groups with and without complications was performed with an independent Student's t-test and relative risks were calculated.Results:There were 19 flap-related complications out of the 273 flap dissections (6.95%). The most common complication was incomplete flap dissection (n = 10; 3.66%), followed by free-cap (n = 5; 1.83%), and flap-buttonhole (n = 2; 0.73%). There was no significant difference between the complicated and uncomplicated cases in terms of the right versus the left eye, pachymetry results, white-to-white diameter, and spherical equivalent. But this difference was significant for mean keratometry (P = 0.008), K-min (P = 0.01), and K-max (P = 0.03) between these groups. Final visual acuity after rescheduling laser treatment was similar in both groups. Relative risks for flap-related complications were 2.03 for the first LASIK surgery (CI 95% 0.64 to 6.48; P = 0.22) and 1.26 (CI 95% 0.43 to 3.69; P = 0.66) for the surgeon's flap-related complications. Female gender presented an odds ratio of 2.48 (CI 95% 0.68 to 9.00; P = 0.16) for complications.Conclusion:Flap-related complications are common intraoperative event during LASIK surgery performed by in-training ophthalmologists. Keratometries and surgeon's first procedure represent a higher probability for flap related complications than some other biometric parameters of patient's eye.

Surface quality of human corneal SMILE lenticules in comparison with microkeratome free caps

Purpose The aim of this study was to compare electron microscopic morphological images of the posterior surface of corneal lenticules removed during femtosecond laser small-incision lenticule extraction (SMILE) with free corneal caps created using a mechanical microkeratome. Design An in-vitro comparative study was carried out including 30 human corneal lenticules from 15 patients who underwent bilateral SMILE refractive procedure (SMILE group) using the 500 kHz VisuMax femtosecond laser and 20 cadaveric donor corneas that were cut creating free caps using the Moria M2 microkeratome. Setting The present study was carried out at Roayah Vision Correction Center and Faculty of Science, Alexandria University. Participants and methods A total of 15 SMILE lenticules and 15 microkeratome free caps were examined by scanning electron microscopy (SEM), and another 15 SMILE lenticules and five microkeratome free caps were examined by transmission electron microscopy. The JEOL JSM-5300LV SEM was used for observations. A new scoring system was used for comparison. Results The surface and edge of SMILE lenticules showed more roughness in the form of tissue bridges, dome-shaped elevations, more cavitational changes, and tiny tissue fragments compared with the undersurface of free corneal microkeratome caps, but the difference was not statistically significant on SEM ( P =0.40654). Conclusion SMILE induces corneal surface roughness and structural changes that are slightly more pronounced than those induced by the microkeratome. The observed changes may cause surgically induced optical aberrations. Energy settings still need further adjustment to be able to create reproducible, predictable smooth surfaces in lenticules of SMILE cases.

Effect of suction on macular thickness and retinal nerve fiber layer thickness during LASIK used femtosecond laser and Moria M2 microkeratome.

To compare the effect of suction on the macular thickness and retinal nerve fiber layer (RNFL) thickness during laser in situ keratomileusis (LASIK) used Ziemer FEMTO LDV femtosecond laser (Ziemer group) and Moria M2 automated microkeratome (Moria group) for flap creation. Fourier-domain optical coherence tomography (FD-OCT) was used to measure macular thickness, ganglion cell complex thickness and (RNFL) thickness of 204 eyes of 102 patients with the Ziemer femtosecond laser (102 eyes) and the Moria M2 microkeratome (102 eyes) before surgery and 30min; 1, 3d; 1wk; 1, 3mo; 1y after surgery. The average foveal thickness and parafoveal retinal thickness 30min after the surgery were statistically more than that before surgery (Ziemer P<0.001, P=0.003 and Moria P=0.001, P=0.006) and the effect was less in the Ziemer group than that in the Moria group (P all<0.05). The ganglion cell complex thickness was not significantly changed in both groups (P all>0.05). The RNFL thickness was statistically less 30min after surgery in both groups (P=0.014, P<0.001), but the influence was less in Ziemer group than that in Moria group (P=0.038). However, the RNFL thickness had recovered to the preoperative level only 1d after surgery. The suction of femtosecond laser and mechanical microkeratome led to the increase in macular central fovea thickness and the decrease in RNFL thickness values at the early stage after LASIK. The effect of suction on macular and the RNFL thicknesses in Ziemer group is smaller than that in Moria group.

Hyperopic laser in situ keratomileusis: Comparison of femtosecond laser and mechanical microkeratome flap creation

To evaluate and compare the refractive predictability and stability of laser in situ keratomileusis (LASIK) flap creation performed with a femtosecond laser and with a mechanical microkeratome to correct mild to moderate hyperopia. American University of Beirut Medical Center, Beirut, Lebanon. Retrospective case series. Patients who had hyperopic LASIK treatment using the Amaris excimer laser were included. Eyes in which the LDV femtosecond laser was used for flap creation were compared with eyes in which the Moria M2 microkeratome was used. The microkeratome group comprised 53 eyes and the femtosecond laser group, 72 eyes. Baseline characteristics were similar between groups (P > .05). The mean spherical equivalent (SE) deviation from target 1 week postoperatively was -0.08 diopter (D) ± 0.58 (SD) in the femtosecond laser group and -0.06 ± 0.87 D in the microkeratome group (P = .92). Thereafter, the mean SE deviation from target increased gradually and by 6 months postoperatively was +0.30 ± 0.50 D and +0.70 ± 0.71 D, respectively (P = .001). The correlation between the achieved and the attempted SE refraction was better in the femtosecond laser group (R(2) = 0.806) than the microkeratome group (R(2) = 0.671). Using the same nomogram, the short-term refractive outcomes of hyperopic LASIK with flap creation performed with the femtosecond laser were comparable to those for the microkeratome; however, the femtosecond group showed significantly better stability over the 6-month follow-up and better predictability, as reflected by a lower standard deviation and stronger Pearson correlation. Dr. Arba Mosquera is an employee of Schwind eye-tech-solutions GmbH and Co. KG. No other author has a financial or proprietary interest in any material or method mentioned.

Accuracy of LASIK Flap Thickness Obtained Using 2 Types of Moria M2 Single-use Head Microkeratome Measured Postoperatively by Optical Coherence Tomography

Background: To investigate the accuracy of corneal flap thickness (FT) and to examine the potential factors that can influence flap thickness obtained using Moria M2 microkeratomes with two kinds of single-use heads. Methods: A retrospective review of the records of 90 patients who had undergone LASIK between Jun 2011 and Jan 2012 at Tri-Service General Hospital was performed. Creation of corneal flap was achieved by automated Moria M2 microkeratome with two different types of single-use head (SU90 and SU130). The right eye was operated before the left eye in each patient, using the same blade. Additionally, the corneal flap thickness was measured in all cases using the Fourier-domain anterior segment optical coherence tomography (AS-OCT) one week later. Results: The mean central thickness of corneal flap was 114.26±4.49μm (Range, 106~127μm) in the SU 90 head and 146.98±3.62μm (Range, 140~157μm) in the SU130 head. The difference between the first and second eye operated was not significant. There were no free flaps, incomplete flaps or flaps with buttonholes in any of our cases. Conclusions: Moria M2 SU 90 and SU 130 produce accurate, reproducible, safe and cost-effective corneal flap. Thin flaps achieved by both single-use heads did not increase the rate of flap-related complications. Furthermore, AS-OCT is a noncontact, rapid, and repeatable tool for measuring corneal flap thickness and making morphological observations.

Comparison of the Ziemer FEMTO LDV Femtosecond Laser and Moria M2 Mechanical Microkeratome

To assess and compare the dimensions of LASIK flaps created by the Ziemer FEMTO LDV "Classic" femtosecond (FS) laser and Moria M2 microkeratome with 110-μm head and -20 blade. Seven hundred twenty eyes from 360 consecutive patients were enrolled in this study and divided into two groups of equal size for flap creation with the Ziemer LDV (FS laser group) and Moria M2 mechanical microkeratome (microkeratome group). Nominal flap thickness was 110 μm for all patients and for both devices. Flap thickness was measured by Fourier-domain optical coherence tomography in 14 specified positions on each flap 1 week after surgery to analyze the regularity, uniformity, and accuracy of the two types of LASIK flaps. The mean deviation between achieved and attempted flap thickness was smaller in the FS laser group than in the microkeratome group. The flaps in the FS laser group were more regular and uniform, showing an almost planar configuration, whereas flaps in the microkeratome group had a meniscus shape and were significantly thicker near the flap edge. Nasal and temporal flap thickness did not differ significantly in the FS laser group, whereas in the microkeratome group, characteristic differences in temporal versus nasal flap thickness were noticed. Within the 5040 individual measurements of the 360 eyes, deviations of >20 μm were observed in 0.73% of eyes in the FS laser group and 42.4% in the microkeratome group. The dimensions of flaps created by the Ziemer LDV femtosecond laser were more uniform and accurate than those created by the Moria M2 microkeratome.

Femtosecond Laser vs Mechanical Microkeratome for Hyperopic Laser In Situ Keratomileusis

To compare the outcomes of laser in situ keratomileusis (LASIK) performed with a femtosecond laser vs a mechanical microkeratome for the correction of low to moderate hyperopia. Retrospective, nonrandomized, interventional, comparative case series. settings: Vissum Santa Hortensia, Madrid, Spain.study population and procedures: Patients who had undergone LASIK to correct their hyperopia using the 60-kHz IntraLase femtosecond laser were compared to age- and refraction-matched patients in whom the Moria M2 microkeratome was used. Visual and refractive results 3 months postoperatively were compared between both groups. A total of 144 eyes were analyzed (72 in each group). Mean preoperative sphere was +3.45 ± 1.0 diopters (D) in the IntraLase group vs +3.18 ± 1.3 D in the M2 group (P = .1). Results 3 months postoperatively were: mean residual sphere, +0.44 ± 0.6D vs +0.72 ± 0.8 D (P = .02), respectively; uncorrected visual acuity (UCVA), 0.89 ± 0.2 vs 0.80 ± 0.2 (P = .04); best spectacle-corrected visual acuity (BSCVA), 0.96 ± 0.2 vs 0.92 ± 0.2 (P = .2); safety index, 0.97 ± 0.1 vs 0.98 ± 0.1 (P = .5); efficacy index, 0.89 ± 0.2 vs 0.84 ± 0.2 (P = .3). Hyperopic LASIK performed with the IntraLase femtosecond laser seems to achieve better refractive results 3 months after the surgery compared to the M2 microkeratome, without significant differences in safety between both procedures.

Photorefractive Keratectomy After Late Traumatic LASIK Flap Loss

To present a case of photorefractive keratectomy (PRK) after late traumatic LASIK flap loss. The initial LASIK procedure was performed in 2003 with a Moria M2 microkeratome and NIDEK EC-5000 excimer laser using a 5.0/9.0-mm aspheric ablation pattern, resulting in 20/20(+) uncorrected distance visual acuity (UDVA) and plano refraction. Traumatic flap loss of the right eye occurred in 2007. The patient was treated for the trauma, and PRK for -5.00 -1.25 × 090° was performed 2 months later. Posttraumatic flap loss UDVA was 20/200 in the right eye, with corrected distance visual acuity (CDVA) of 20/25(+2). After PRK with mitomycin C (MMC), UDVA was 20/15 2 months postoperatively and was maintained through the last postoperative follow-up in 2010 (approximately 3 years after PRK). Treating a patient with traumatic LASIK flap loss can be done by careful, conservative treatment of the abrasion followed by correction of the refractive error using PRK with MMC.

A Morphological Study of Corneal Flap after Thin-Flap Laser-Assisted In Situ Keratomileusis by Anterior Segment Optical Coherence Tomography

This prospective study assessed corneal flap morphology in 115 patients undergoing laser-assisted in situ keratomileusis (LASIK). Flaps were created using the Moria M2 90-μm or KM-5000D 110-μm microkeratomes. Flap thickness was measured using anterior segment optical coherence tomography at seven points in a 7-mm diameter zone 1 h, 1 day, 3 days, 1 week and 1 month after surgery. Flap accuracy, reproducibility, uniformity and changes over time were evaluated. The Moria M2 microkeratome created flaps with less accuracy in the centre than the KM-5000D microkeratome (114.06 ± 6.46 μm vs 128.39 ± 6.79 μm, respectively, at 1 week). For both microkeratomes, flap thickness varied between most of the peripheral areas and the central point. Both microkeratomes created flaps with good central predictability and reproducibility, but high variation and significant deviation from intended thickness were observed in peripheral flap thickness.

Anterior Segment Optical Coherence Tomography Measurement of LASIK Flaps: Femtosecond Laser vs Microkeratome

To compare the uniformity and accuracy of LASIK flaps created with a femtosecond laser versus a mechanical microkeratome using optical coherence tomography (OCT). A prospective study was performed on 72 consecutive patients who underwent LASIK in both eyes in alternating fashion with either the AMO IntraLase FS60 (72 eyes) or the Moria M2 microkeratome (72 eyes). One month after surgery, anterior segment OCT was performed on each eye to measure flap thickness at 20 locations and the results were assessed for uniformity and accuracy. At 1 month after surgery, the microkeratome group flap ranges were greater than those found in the femtosecond laser group (P<.05). The meridian and radial flap uniformity in the femtosecond laser group were better, showing an almost planar configuration, than the meniscus-shaped flaps created with the microkeratome. Comparison of the nasal and temporal flap thickness revealed more regularity in the femtosecond laser group than the microkeratome group. The maximum deviation from the intended flap thicknesses was 7 μm in the femtosecond laser group compared to 26 μm in the microkeratome group. During the 1440 measurements of the 72 eyes, a difference >20 μm was observed in 0.42% of eyes in the femtosecond laser group and 15% of eyes in the microkeratome group. LASIK flaps made with the IntraLase FS60 were more uniform with more accurate thickness than those created by the Moria M2 microkeratome.