bluuebunny/crossref_metadata_2025 huggingface dataset:
GYROSCOPE‐BASED CONTROL AND STABILIZATION OF UNMANNED AERIAL MINI‐VEHICLE (MINI‐UAV)
Authors: Chatys Rafał , Koruba Zbigniew
Published: January 2019

This work discusses the use of a mini gyroscope with three degrees of freedom to control or remote control an unmanned aerial mini‐vehicle (mini‐UAV). The gyroscope determines the reference system for the navigation of the UAV. The algorithm of the gyroscope control moments and the law of deflection of the UAV surface control are presented. The mini autopilot plays a role of a system that makes the longitudinal line coincide with the gyroscope axis. The structure and durability aspects of the remote and programmed navigation are considered.
COMPARISON BETWEEN TWO AND THREE PARAMETERS OF FATIGUE CRACK GROWTH MODELS IN AIRFRAME STRUCTURES
Authors: Wahab Muhammad Shujauddin , Paramonov Yuri M.
Published: January 2019

Comparison of two and three parameters models of fatigue crack growth is discussed. For calculation of failure probability, the Monte Carlo (MC) method is used. The number of MC trials was 60. Multiple site fatigue damage specimens corroded to 5% to 6% average thickness loss and non‐corroded specimens were used in the fatigue tests. As initial data, the result of these fatigue tests of corroded and non‐corroded specimens are used. It is shown that at a small number of inspections there is a significant difference between probabilities of failure (fatigue crack is not discovered before specified life). But if the number of inspections is large enough, than the difference between considered models is negligible for both corroded and non‐corroded specimens.
HATS-70b: A 13 MJ Brown Dwarf Transiting an A Star*
Authors: Zhou G. , Bakos G. Á. , Bayliss D. , Bento J. , Bhatti W. , Brahm R. , Csubry Z. , Espinoza N. , Hartman J. D. , Henning T. , Jordán A. , Mancini L. , Penev K. , Rabus M. , Sarkis P. , Suc V. , Val-Borro M. de , Rodriguez J. E. , Osip D. , Kedziora-Chudczer L. , Bailey J. , Tinney C. G. , Durkan S. , Lázár J. , Papp I. , Sári P.
Published: January 2019

We report the discovery of HATS-70b, a transiting brown dwarf at the deuterium burning limit. HATS-70b has a mass of

and a radius of

, residing in a close-in orbit with a period of

days. The host star is a

A star rotating at

, enabling us to characterize the spectroscopic transit of the brown dwarf via Doppler tomography. We find that HATS-70b, like other massive planets and brown dwarfs previously sampled, orbits in a low projected-obliquity orbit with

. The low obliquities of these systems is surprising given all brown dwarf and massive planets with obliquities measured orbit stars hotter than the Kraft break. This trend is tentatively inconsistent with dynamically chaotic migration for systems with massive companions, though the stronger tidal influence of these companions makes it difficult to draw conclusions on the primordial obliquity distribution of this population. We also introduce a modeling scheme for planets around rapidly rotating stars, accounting for the influence of gravity darkening on the derived stellar and planetary parameters.
Three Dynamical Evolution Regimes for Coupled Ring-satellite Systems and Implications for the Formation of the Uranian Satellite Miranda
Authors: Hesselbrock Andrew J. , Minton David A.
Published: January 2019

In coupled ring-satellite systems, satellites exchange angular momentum with both the primary through tides and the ring through Lindblad torques, and may exchange material with the ring through accretion and tidal disruption. Here we show that these coupled ring-satellite systems fall into three distinct dynamical regimes, which we refer to as “Boomerang,” “Slingshot,” and “Torque-dependent.” These regimes are determined by the relative locations of the fluid Roche limit, the synchronous orbit, and the maximum orbit in which Lindblad torques can perturb a satellite. Satellites that accrete from rings in the Boomerang regime remain interior to the synchronous orbit, and may be driven back toward the primary by tides. Satellites that accrete from rings in the Slingshot regime form exterior to the synchronous orbit, and are always driven away from the primary. Satellites that accrete from rings in the Torque-dependent regime may exhibit either Boomerang or Slingshot behavior, depending on ring and satellite masses. We consider both known and hypothesized ring-satellite systems in the solar system, and identify which of these three regimes they fall into. We determine that Uranus exists within the Torque-dependent regime. Using the RING-MOONS code, which models the dynamical evolution of coupled ring-satellite systems, we show that the Uranian satellite Miranda may have accreted from a massive ancient Roche-interior ring and followed a Slingshot-like dynamical path to its present orbit beyond the synchronous orbit, while satellites that accreted after Miranda followed Boomerang-like evolutionary paths and remained interior to the synchronous orbit.
Dependence of Biological Activity on the Surface Water Fraction of Planets
Authors: Lingam Manasvi , Loeb Abraham
Published: January 2019

One of the unique features associated with the Earth is that the fraction of its surface covered by land is comparable to that spanned by its oceans and other water bodies. Here, we investigate how extraterrestrial biospheres depend on the ratio of the surficial land and water fractions. We find that worlds that are overwhelmingly dominated by landmasses or oceans are likely to have sparse biospheres. Our analysis suggests that major evolutionary events such as the build-up of O2 in the atmosphere and the emergence of technological intelligence might be relatively feasible only on a small subset of worlds with surface water fractions ranging approximately between 30% and 90%. We also discuss how our predictions can be evaluated by future observations and the implications for the prevalence of microbial and technological species in the universe.
BAT AGN Spectroscopic Survey. XI. The Covering Factor of Dust and Gas in Swift/BAT Active Galactic Nuclei
Authors: Ichikawa Kohei , Ricci Claudio , Ueda Yoshihiro , Bauer Franz E. , Kawamuro Taiki , Koss Michael J. , Oh Kyuseok , Rosario David J. , Shimizu T. Taro , Stalevski Marko , Fuller Lindsay , Packham Christopher , Trakhtenbrot Benny
Published: January 2019

We quantify the luminosity contribution of active galactic nuclei (AGNs) to the 12 μm, mid-infrared (MIR; 5–38 μm), and total IR (5–1000 μm) emission in the local AGNs detected in the all-sky 70 month Swift/Burst Alert Telescope (BAT) ultrahard X-ray survey. We decompose the IR spectral energy distributions (SEDs) of 587 objects into the AGN and starburst components using templates for an AGN torus and a star-forming galaxy. This enables us to recover the emission from the AGN torus including the low-luminosity end, down to

, which typically has significant host galaxy contamination. The sample demonstrates that the luminosity contribution of the AGN to the 12 μm, the MIR, and the total IR bands is an increasing function of the 14–150 keV luminosity. We also find that for the most extreme cases, the IR pure-AGN emission from the torus can extend up to 90 μm. The total IR AGN luminosity obtained through the IR SED decomposition enables us to estimate the fraction of the sky obscured by dust, i.e., the dust covering factor. We demonstrate that the median dust covering factor is always smaller than the median X-ray obscuration fraction above an AGN bolometric luminosity of

. Considering that the X-ray obscuration fraction is equivalent to the covering factor coming from both the dust and gas, this indicates that an additional neutral gas component, along with the dusty torus, is responsible for the absorption of X-ray emission.
Source Imaging of a Moving Type IV Solar Radio Burst and Its Role in Tracking Coronal Mass Ejection from the Inner to the Outer Corona
Authors: Vasanth V. , Chen Yao , Lv Maoshui , Ning Hao , Li Chuangyang , Feng Shiwei , Wu Zhao , Du Guohui
Published: January 2019

Source imaging of solar radio bursts can be used to track energetic electrons and associated magnetic structures. Here we present a combined analysis of data at different wavelengths for an eruption associated with a moving type IV (t-IVm) radio burst. In the inner corona, the sources are correlated with a hot and twisted eruptive EUV structure, while in the outer corona, the sources are associated with the top front of the bright core of a white-light coronal mass ejection (CME). This reveals the potential of using t-IVm imaging data to continuously track the CME by lighting up the specific component containing radio-emitting electrons. It is found that the t-IVm burst presents a clear spatial dispersion with observing frequencies. The burst manifests broken power law–like spectra in brightness temperature, which is as high as 107–109 K, while the polarization level is generally weak. In addition, the t-IVm burst starts during the declining phase of the flare with a duration as long as 2.5 hr. From the differential emission measure analysis of AIA data, the density of the T-IVm source is found to be at the level of 108 cm−3 at the start of the burst, and the temperature may reach up to several MK. These observations do not favor gyrosynchrotron to be the radiation mechanism but are in line with a coherent plasma emission excited by energetic electrons trapped within the source. Further studies are demanded to elucidate the emission mechanism and explore the full diagnostic potential of t-IVm bursts.
An updated checklist of the European Butterflies (Lepidoptera, Papilionoidea)
Authors: Wiemers Martin , Balletto Emilio , Dincă Vlad , Fric Zdenek Faltynek , Lamas Gerardo , Lukhtanov Vladimir , Munguira Miguel L. , van Swaay Chris A. M. , Vila Roger , Vliegenthart Albert , Wahlberg Niklas , Verovnik Rudi
Published: January 2019

This paper presents an updated checklist of the butterflies of Europe, together with their original name combinations, and their occurrence status in each European country. According to this checklist, 496 species of the superfamily Papilionoidea occur in Europe. Changes in comparison with the last version (2.6.2) of Fauna Europaea are discussed. Compared to that version, 16 species are new additions, either due to cryptic species most of which have been discovered by molecular methods (13 cases) or due to discoveries of Asian species on the eastern border of the European territory in the Ural mountains (three cases). On the other hand, nine species had to be removed from the list, because they either do not occur in Europe or lost their species status due to new evidence. In addition, three species names had to be changed and 30 species changed their combination due to new evidence on phylogenetic relationships. Furthermore, minor corrections were applied to some authors’ names and years of publication. Finally, the namePolyommatusottomanusLefèbvre, 1831, which is threatened by its senior synonymLycaenalegeriFreyer, 1830, is declared anomen protectum, thereby conserving its name in the current combinationLycaenaottomana.
Resistance training and modulation of cardiac autonomic control in animal models: a systematic review
Authors: Bhati P. , Singla D. , Hussain M.E.
Published: January 2019

The purpose of the present review is to systematically evaluate the existing literature on the effects of resistance training (RT) on cardiac autonomic control in animal models. Electronic search was conducted in Pubmed, PEDro and Scopus databases from inception till June 2018. Randomised controlled trials and quasi-experimental trials which investigated the effects of RT (for at least 4 weeks) on cardiac autonomic control (assessed either by heart rate variability, baroreflex sensitivity or post-exercise heart rate recovery) in animal models were included. Out of the total 3,442 studies retrieved by the electronic search, 9 were found to be suitable as per the eligibility criteria and were included in this review. The majority of these studies (6 out of 9) demonstrated improvement in cardiovascular autonomic control after RT in animals; however, three studies did not illustrate any significant change. Standardised mean differences (SMD) showed a significant effect of RT on root mean square of successive differences between adjacent inter-beat (R-R) intervals (RMSSD) [SMD (confidence interval (CI)) = 4.56 (2.89, 6.23); P<0.0001] and bradycardic response to change in arterial blood pressure [SMD (CI)=-2.27 (-4.50, -0.03; P=0.05)] whereas no significant change was observed for other variables of cardiac autonomic control post-RT. The present systematic review do not give a clear conclusion regarding the effect of RT on cardiac autonomic control in animal models and thus highlight the need for good quality research in future.
Bioaccessibility in daily diet and bioavailabilityin vitro of aflatoxins from maize after cooking
Authors: Lin X. , Hu X. , Zhang Y. , Xia Y. , Zhang M.
Published: January 2019

Bioavailability is not a constant percentage of a contaminant in food but is affected by many factors, such as food type, treatment, diet structure and interaction with other compounds. To evaluate these influences, we measured the bioaccessibility of aflatoxins from nine naturally polluted maize samples, collected from southeast China, using anin vitro digestion model, and analysed the intestinal transport of aflatoxins by a Caco-2 cell model. Steam cooking treatment could reduce the aflatoxin levels in maize bread. The degradation rates of aflatoxin B1, aflatoxin B2, aflatoxin G1, and aflatoxin G2 ranged from 24.9±3.2 to 33.9±3.5%, 27.0±2.0 to 39.0±1.8%, 27.9±7.9 to 34.4±8.2% and 25.6±3.6 to 37.2±6.5%, respectively. As a result, the bioaccessibility of aflatoxins determined by anin vitro digestion model (41.5-63.3%) was much lower than the previously reported 80%. Edible oil could increase the bioaccessibility of aflatoxin, whereas lettuce would decrease the exposure amount from maize. With a Caco-2 cell model, the apparent permeability coefficient exceeding 10-5 cm/s indicated that there is high absorption of aflatoxins in the human body, while the intestinal transport can be effectively restrained in the presence of chlorophyll.
Faculty Preparation: Is Clinical Specialization a Benefit or a Deterrent to Quality Nursing Education?
Authors: Zungolo Eileen
Published: January 2019

ABSTRACT

This article presents a point of view regarding the impact of specialty preparation at the master's level on performance as a faculty member in an entry-level program. Essentially, the focus in depth on a particular branch of nursing practice restricts the perception of the individual to the role and demands of the beginning generalist nurse. Continued attention to the development of expertise in the specialty reduces the effectiveness of the faculty member to develop a comprehensive view of the knowledge required by the beginning generalist nurse. Because faculty prepared in this manner also frequently lack formal knowledge regarding teaching and curriculum, they continue to teach in the same manner as they were taught, often with an eye toward teaching the extensive content taught in the specialty program. More broadly based master's degree programs that couple advanced nursing knowledge with nursing education content and skill can foster in new nurse faculty a more comprehensive picture of the learning needs of beginning general ist nurses.
Principled Thinking: A Comparison of Nursing Students and Experienced Nurses
Authors: Ham Kathy
Published: January 2019

ABSTRACT

Background: A descriptive study was used to compare ethical reasoning abilities in senior baccalaureate nursing students and experienced registered nurses. The effects of environmental factors and previous experience with ethical dilemmas in regard to nursing principled thinking were also examined.

Results: Findings on the Nursing Dilemma Test indicated a significant difference in the level of nursing principled thinking in the two groups, with nursing students scoring higher than experienced nurses. There was a significant negative correlation between years of experience and level of nursing principled thinking. The level of nursing education (e.g., associate degree of nursing, diploma, bachelor of science in nursing, masters degree, or doctorate) did not appear to have an effect on nursing principled thinking. In addition, subjects who were most affected by practical considerations demonstrated less use of higher level moral reasoning. The effect of previous experience with ethical dilemmas on nursing principled thinking was found to be nonsignificant.

Conclusion: Ethical dilemmas continue to create much confusion and uncertainty for practicing nurses. Suggestions are made regarding individual analysis of personal and professional values in nurses. In addition, recommendations include ongoing educational offerings and nursing administration support to assist nurses during times of moral distress.
Learning and Teaching: The Reciprocal Link
Authors: Forrest Sandy
Published: January 2019

ABSTRACT

Background: Learning and teaching are active processes occurring simultaneously on a continual basis. Within this framework, the learner and the teacher are reliant on each other. Understanding the intricacies of this linkage enhances the teacher's effectiveness in enabling learners to achieve their full potential.

Method: A review of the literature on teaching and learning styles was completed.

Conclusion: Learning best occurs when learners are motivated and attend to the important aspects of what is to be learned. Using a wide variety of teaching approaches in the hope of covering most individuals' preferences is expedient but not necessarily effective. The process of exploring the effectiveness of one's teaching styles enhances the ability to facilitate the learning process.
Lincoln's Vertical Strabismus
Authors: Goldstein Joseph H
Published: January 2019

ABSTRACT

Background: The vertical strabismus manifested by Abraham Lincoln has been noted. This article reviews the historical findings and provides a specific diagnosis.

Materials: Previous reports of symptoms and history relating to Lincoln's left hypertropia were reviewed. A series of photographs were reviewed. Lincoln's own description of his symptoms is provided.

Results: Previous history indicates an intermittent left hypertropia. A family history of vertical strabismus was noted with regard to Mr Lincoln's cousin. There also is a history of trauma to the left frontal area and life-mask evidence of fracture over the left eye. The findings include a history of head tilt and diplopia, presumably most readily in downgaze.

Conclusion: Given the history and findings, the diagnosis of left superior oblique paresis of either congenital or traumatic origin seems appropriate.
Vision-related Quality of Life Comparison for Emmetropes, Myopes After Refractive Surgery, and Myopes Wearing Spectacles or Contact Lenses
Authors: Chen Christine Y , Keeffe Jill E , Garoufalis Pam , Islam Fakir M A , Dirani Mohamed , Couper Terry A , Taylor Hugh R , Baird Paul N
Published: January 2019

ABSTRACT

PURPOSE: To compare the vision-related quality of life among emmetropes, myopes who had refractive surgery, and myopes who wore spectacles and/or contact lenses.

METHODS: This cross-sectional study assessed vision-related quality of life using the Vision Quality of Life Index. Participants were age 18 years or older with a presenting visual acuity of 20/40 or better and no other ocular pathology. Responses were compared among three groups: emmetropes (spherical equivalent [SE] <0.50 to >-0.50 diopters [D]), myopes (SE ≤ -0.50 D) who wore spectacles and/or contact lenses, and myopes who had refractive surgery.

RESULTS: The study population included 64 emmetropes, 66 myopes who wore spectacles and/or contact lenses, and 65 myopes who had refractive surgery. No significant differences were found between the refractive surgery and emmetropic groups. In contrast, the spectacle and/or contact lens group had significantly increased odds of having concerns about injuring themselves (odds ratio=11.5, 95% confidence interval [CI] 2.3, 57.1), difficulties coping with demands in life (odds ratio=23.6, 95% CI 23.8, 198.1), difficulties fulfilling roles (odds ratio=5.6, 95% CI 1.4, 22.1), and less confidence joining in everyday activities (odds ratio=30.6, 95% CI 3.2, 292.3) compared to emmetropes.

CONCLUSIONS: Myopia corrected with spectacles or contact lenses had a negative impact on some areas of vision-related quality of life. However, individuals with myopia who had refractive surgery enjoyed the same vision-related quality of life as those with emmetropia. The potential improvement in vision-related quality of life should be considered when recommending treatment for myopia. [J Refract Surg, 2007;23:752-759.]
Corneal Wavefront-guided LASIK Retreatments for Correction of Highly Aberrated Corneas Following Refractive Surgery
Authors: Alió Jorge , Galal Ahmed , Montalbán Raúl , Piñero David
Published: January 2019

ABSTRACT

PURPOSE: To investigate the safety and efficacy of customized corneal wavefront-guided retreatment in symptomatic patients with highly aberrated corneas following LASIK.

METHODS: This prospective study included 75 eyes of 59 patients with significant visual symptoms who underwent LASIK for the correction of residual refractive error. Ablation profiles were calculated using CSO corneal topography and ESIRIS/Schwind laser platform. Eyes were divided into two groups: those with significant night vision symptoms (37 eyes; night symptoms group) and those with decentration, irregular ablation profile, and flap complications (38 eyes; corneal complications group). Corneal topography and aberrations, visual acuity, point spread function (PSF), refractive outcome, and subjective symptoms were evaluated preoperatively, and 1, 3, and 6 months postoperatively.

RESULTS: Mean uncorrected visual acuity was 20/32 preoperatively and 20/25 at 6 months postoperatively in the night symptoms group and 20/40 preoperatively and 20/30 at 6 months postoperatively in the corneal complications group. Mean best spectacle-corrected visual acuity was 20/25 both preoperatively and 6 months postoperatively in both groups (t test, P=.219 and P =.149 for the night symptoms and corneal complications groups, respectively). Safety index was 1.1 in both groups, and efficacy index was 0.93 and 0.92, respectively. Statistically significant improvement of total corneal higher order aberrations, tilt, and improvement of spherical aberrations and coma were observed, with corresponding improvement of PSF.

CONCLUSIONS: Corneal wavefront-guided LASIK retreatment with CSO topography, ORK-W software, and ESIRIS/Schwind laser platform is safe and effective for treating symptomatic patients affected by corneal higher order aberrations or corneal irregularities following LASIK surgery. [J Refract Surg. 2007;23:760-773.]
Higher Order Wavefront Aberrations and Topography in Early and Suspected Keratoconus
Authors: Jafri Batool , Li Xiaohui , Yang Huiying , Rabinowitz Yaron S
Published: January 2019

ABSTRACT

PURPOSE: To determine whether higher order wavefront aberrations or a combination of topography and wavefront variables distinguishes between early and suspected keratoconus.

METHODS: This prospective comparative study evaluated 70 eyes using videokeratography (Tomey TMS-1) and aberrometry (Alcon LADARWave). Videokeratography and clinical evaluation were used to divide the eyes into three groups: 50 normal eyes, 10 eyes with early keratoconus, and 10 eyes with suspected keratoconus. Data were analyzed to determine whether higher order aberrations could separate eyes with early and suspected keratoconus from normal eyes. The product of the Inferior-Superior (I-S) topographic value in combination with the wavefront vertical coma also was evaluated to determine whether this could distinguish normal eyes from eyes with early and suspected keratoconus.

RESULTS: Differences in vertical coma, root-meansquare coma, and secondary astigmatism for the three groups were statistically significant. Vertical coma was -0.03±0.28 for normal eyes, -0.525±0.253 for eyes with suspected keratoconus, and -1.949±1.416 for eyes with early keratoconus. Root-mean-square coma was 0.229±0.149 for normal eyes, 0.639±0.250 for eyes with suspected keratoconus, and 2.034±1.532 for eyes with early keratoconus. The product of vertical coma and the topographic I-S value separated the three groups better than aberrometry alone (P<.0001).

CONCLUSIONS: Although both vertical coma and the I-S topographic value were useful for distinguishing among the three study groups, a combination of wavefront aberrometry and videokeratography appears to be the most sensitive way for distinguishing among normal eyes, eyes with suspected keratoconus, and eyes with early keratoconus. [J Refract Surg. 2007;23:774-781.]
Determination of the Modulus of Elasticity of the Human Cornea
Authors: Elsheikh Ahmed , Wang Defu , Pye David
Published: January 2019

ABSTRACT

PURPOSE: To determine the material behavior of the human cornea in the form of simple relationships between the modulus of elasticity and intraocular pressure (IOP) and to establish the effect of age on the material behavior.

METHODS: Human corneal specimens with age between 50 and 95 years were tested under inflation conditions to determine their behavior. The corneas were subjected to two extreme load rates to represent dynamic and static loading conditions. The pressure-deformation results were analyzed using shell theory to derive the relationship between the modulus of elasticity and IOP.

RESULTS: The corneas demonstrated a nonlinear hyperelastic behavior pattern with an initial low stiffness stage and a final high stiffness stage. Despite the non linearity of the pressure deformation results, the relationship between the modulus of elasticity and the applied pressure was almost linear. A considerable increase was noted in the values of the modulus of elasticity associated with both age and load rate. General equations were derived to calculate the values of the secant and tangent moduli of elasticity in terms of IOP for any age greater than 50 years, and these equations are presented in a simple form suitable for use in numerical simulations.

CONCLUSIONS: Adequate representation of corneal material behavior is essential for the accurate predictive modeling of corneal biomechanics. The material models developed in this work could be implemented in numerical simulations of refractive surgery procedures, corneal shape changes due to contact lens wear, and other applications. [J Refract Surg. 2007;23:808-818.]
Anterior Chamber Gas Bubble Formation During Femtosecond Laser Flap Creation for LASIK
Authors: Srinivasan Sathish , Rootman David S
Published: January 2019

ABSTRACT

PURPOSE: To report anterior chamber gas bubble formation during corneal flap creation in a myopic patient who underwent LASIK using a femtosecond laser (IntraLase).

METHODS: A 30-year-old man underwent customized wavefront-guided LASIK for myopia. The IntraLase FS15 was used to create the corneal flap.

RESULTS: During flap creation, gas bubble formation was noted in the anterior chamber, in addition to cavitation bubbles under the flap. Flap creation was successful and myopic ablation was uneventful. One day postoperatively, the flap was well apposed, and no air bubbles were present in the anterior chamber.

CONCLUSIONS: Gas bubbles in the anterior chamber can be an infrequent occurrence during the use of femtosecond laser for corneal flap creation. Although gas bubbles do not hinder flap creation, their presence may interfere with eye-tracking mechanisms. [J Refract Surg. 2007;23:828-830.]
The Kelman Duet Phakic Intraocular Lens: 1-year Results
Authors: Alió Jorge L , Piñero David , Bernabeu Gonzalo , Galal Ahmed , Vargas José Manuel , Ismail Mahmoud M
Published: January 2019

ABSTRACT

PURPOSE: To evaluate the efficacy and safety of the Kelman Duet phakic intraocular lens (PIOL) for correction of moderate and high myopia.

METHODS: Kelman Duet PIOLs were implanted in 169 eyes of 110 patients with moderate or high myopia. In all cases, implantation of the lens was feasible through an incision of less than 2.5 mm without complications. Uncorrected visual acuity (UCVA), manifest refraction, best spectacle-corrected visual acuity (BSCVA), intraocular pressure, central corneal endothelial change, and complications were recorded preoperatively and during 12 months of follow-up.

RESULTS: Following PIOL implantation, 23 (13.61%) eyes required LASIK retreatment for the correction of residual astigmatic refractive error and were excluded from the refractive analysis. Best spectacle-corrected visual acuity remained the same or improved in 95.04% of eyes, 81.30% of eyes (100) were within ±1.00 diopter (D) of emmetropia, and 57.72% (71) were within ±0.50 D. Intraocular pressure increased slightly in the first 4 weeks postoperatively but stabilized to the preoperative level by 3 months. Mean endothelial cell ioss at 12 months was 5.43%. Oval pupils developed in 10.1% of eyes. Haptic exchange or reposition was performed in 7.76% of cases.

CONCLUSIONS: The Kelman Duet PIOL was safe and effective for the correction of moderate to high myopia in this study with 1-year follow-up and offered the advantage of using a 2. 5-mm or less incision width. Accurate haptic sizing remains a challenge and haptic exchange to correct haptic size mismatching is possible. [J Refract Surg. 2007;23:868-879.]
Central Corneal Thickness Measurements in Unoperated Eyes and Eyes After PRK For Myopia Using Pentacam, Orbscan II, and Ultrasonic Pachymetry
Authors: Kim Sun Woong , Byun Yeo Jue , Kim Eung Kweon , Kim Tae-im
Published: January 2019

ABSTRACT

PURPOSE: To compare central corneal thickness measurements obtained in unoperated eyes and eyes after myopic photorefractive keratectomy (PRK) using a rotating Scheimpflug camera (Pentacam), a scanning slit corneal topography system (Orbscan II), and ultrasonic pachymetry.

METHODS: Corneal thickness was measured using Pentacam, Orbscan II, and ultrasonic pachymetry in 25 unoperated eyes (unoperated group), 24 eyes 1 to 3 months after myopic PRK (early postoperative PRK group), and 21 eyes 4 months or more after myopic PRK (late postoperative PRK group).

RESULTS: In the unoperated group, corneal thickness measurements were similar for all three methods (P =.12 5). In the early postoperative PRK group, Orbscan measurements were thinner than Pentacam and ultrasonic measurements by a mean of 69.4 µm and 63.4 µm (P<.001 and P=.002, respectively). In the late postoperative PRK group, Orbscan measurements were thinner than Pentacam measurements by a mean of 36.0 pm (P= .017). Pentacam and ultrasonic pachymetry measurements were similar for all three groups with a mean difference of approximately 10 ???.

CONCLUSIONS: Following myopic PRK, Pentacam was comparable to ultrasonic pachymetry in measuring corneal thickness, whereas Orbscan measurements were thinner. [J Refract Surg. 2007;23:888-894.]
Medennium Posterior Chamber Phakic Refractive Lens to Correct High Myopia
Authors: Verde Celeste Marina , Teus Miguel A , Arranz-Marquez Esther , Cazorla Raquel Gil
Published: January 2019

ABSTRACT

PURPOSE: To determine the efficacy and safety of phakic refractive lens implantation to correct high myopia.

METHODS: In this prospective study, a phakic refractive lens was implanted in 90 myopic eyes in which refractive errors ranged from -6.00 to -20.00 diopters (D) and laser refractive surgery was contra indicated. Uncorrected visual acuity (UCVA) and best-spectacle corrected visual acuity (BSCVA), manifest and cycloplegic refractions, and intraocular pressure (IOP) were assessed during a 1-year follow-up period. Possible complications, including endothelial cell counts, were evaluated.

RESULTS: Spherical equivalent refraction measurements revealed a significant change from the preoperative mean value of -11.90±5.00 D to 0.04±0.20 D 1 year postoperatively (P= .001). The UCVA and BSCVA significantly improved postoperatively (P =.001 and P =.01, respectively). Seventy-two (80%) eyes and 61 (68%) eyes were within ±1.00 D and ±0.50 D of the target refraction, respectively. A significant increase in IOP was found at every postoperative visit (P=. 01). There was a trend toward decreased endothelial cell density postoperatively, although the difference did not reach significance. No major complications were found during the 1-year follow-up period.

CONCLUSIONS: The implantation of a phakic refractive lens seems to be a predictable and well -to Ie rated procedure for correcting high myopia. Complications such as development of cataract, implant dislocation, decreases in endothelial cell counts, or development of glaucoma did not occur in this study. [J Refract Surg, 2007;23:900-904.]
Conductive Keratoplasty for Presbyopia: 3-year Results
Authors: Stahl Jason E
Published: January 2019

ABSTRACT

PURPOSE: To assess the long-term safety, efficacy, and stability of conductive keratoplasty (CK) in the treatment of presbyopia.

METHODS: Ten near-piano presbyopic patients (6 women and 4 men) underwent unilateral CK with standardpressure technique in the non -dominant eye to improve their near vision. Mean age was 51 ?3.1 years (range: 46 to 56 years). Nine of the 10 patients were available for both 1- and 3-year follow-up examinations.

RESULTS: Preoperative mean manifest refraction spherical equivalent (MRSE) was -0.17?0.29 diopters (D), yielding a mean near uncorrected visual acuity (UCVA) of JlO. Three years after CK, the mean near UCVA was J3. The mean MRSE at 3 years was -1.06?0.81 D, which represents a 0.25 D change from the MRSE at 1 year. The MRSE in the dominant untreated eyes had a +0.26 D change during the 3-year period, which was not statistically different when compared to the CKtreated eyes during the 3-year postoperative period. No eye lost best spectacle-corrected visual acuity or had induced cylinder ^ 0.75 D. Seventy-eight percent had binocular distance UCVA 20/20 or better and near UCVA J3 or better. The average keratometry remained stable at 45.09 D 3 years postoperatively compared to 45.08 D 1 year postoperatively.

CONCLUSIONS: Conductive keratoplasty for the treatment of presbyopia provided safe, effective, predictable, and stable results 3 years following the initial surgery. Refractive stability was similar for both the CK-treated and untreated eyes with a small hyperopic shift noted during the 3-year follow-up period. [J Refract Surg. 2007;23:905-910.]
Intraoperative Autorefraction for Combined Phakic Intraocular Lens Explantation and Cataract Surgery
Authors: Leccisotti Antonio
Published: January 2019

ABSTRACT

PURPOSE: To evaluate intraoperative auto refraction during combined phakic intraocular lens (PIOL) explantation and cataract surgery.

METHODS: Phakic intraocular lens explantation was followed by crystalline lens emulsification and reformation of the anterior chamber with balanced salt solution. Autoref raction was performed intraoperatively with the Nikon Retinomax 2, and the IOL power was calculated using a formula for myopic eyes: IOL for emmetropia = 1.3 x aphakic spherical equivalent refraction + 1.45.

RESULTS: Nineteen myopic eyes of 15 patients with anterior or posterior chamber PIOL (including 6 eyes that had undergone photorefractive keratectomy) were treated. Two months postoperatively, mean spherical equivalent refraction was -0.56 ?0.40 diopters (D) (range: Oto -1.50 D).

CONCLUSIONS: In myopic eyes, intraoperative a uto- refraction provided a simple and reliable method to calculate IOL power in combined PIOL explantation and cataract surgery. [J Refract Surg. 2007;23:931-934.]
Nine-year Follow-up of a Posterior Chamber Phakic IOL in One Eye and LASIK in the Fellow Eye of the Same Patient
Authors: Tsiklis Nikolaos S , Kymionis George D , Karp Carol L , Naoumidi Tatianna , Pallikaris Aristofanis I
Published: January 2019

ABSTRACT

PURPOSE: To compare the long-term results (9 years) of LASIK in one eye and phakic intraocular lens (implantable contact lens [ICL]) implantation in the fellow eye of the same patient.

METHODS: A patient with high myopia underwent LASIK with a MEL 60 excimer laser in one eye (spherical equivalent refraction -9.75 diopters [D], 5-mm optical zone with no transition zone) and phakic intraocular lens (STAAR Collamer implantable contact lens [ICL]) implantation (spherical equivalent refraction -9.50 D) in the fellow eye.

RESULTS: At 9 years postoperatively, the mean spherical equivalent refraction was -1.00 in the eye with the ICL and -1.75 D in the eye that underwent LASIK. During the first 6 postoperative months in the LASIK eye, refraction regressed, but remained stable during the remainder of follow-up. Uncorrected visual acuity was 20/25 in the eye with the ICL and 20/30 in the LASIK eye, whereas best spectacle-corrected visual acuity was 20/20 in both eyes. Less night vision problems (glare and halos) were experienced in the eye with the ICL compared to the LASIK eye. Although the patient initially preferred the LASIK procedure, at last follow-up 9 years postoperatively, increased overall satisfaction was reported for the eye with the ICL compared to the LASIK eye.

CONCLUSIONS: Nine years after treatment of high myopia with the ICL and LASIK in the same patient, better quality of vision, stability, and satisfaction score were achieved in the eye with the ICL compared to the eye that had undergone LASIK. No longterm sight-threatening complications were found during followup. [J Refract Surg. 2007;23:935-937.]
Correcting Highly Aberrated Eyes Using Large-stroke Adaptive Optics
Authors: Sabesan Ramkumar , Ahmad Kamran , Yoon Geunyoung
Published: January 2019

ABSTRACT

PURPOSE: To investigate the optical performance of a large-stroke deforma ble mirror in correcting large aberrations in highly aberrated eyes.

METHODS: A large-stroke deformable mirror (Mirao 52 D; Imagine Eyes) and a Shack- Hartmann wavefront sensor were used in an adaptive optics system. Closedloop correction of the static aberrations of a phase plate designed for an advanced keratoconic eye was performed for a 6-mm pupil. The same adaptive optics system was also used to correct the aberrations in one eye each of two moderate keratoconic and three normal human eyes for a 6-mm pupil.

RESULTS: With closed -loop correction of the phase plate, the total root-mean -square (RMS) over a 6-mm pupil was reduced from 3.54 to 0.04 µm in 30 to 40 iterations, corresponding to 3 to 4 seconds. Adaptive optics closed-loop correction reduced an average total RMS of 1.73±0.998 to 0.10±0.017 µm (higher order RMS of 0.39±0.124 to 0.06±0.004 µm) in the three normal eyes and 2.73±1.754 to 0.10±0.001pm (higher order RMS of 1.82±1.058 to 0.05±0.017 µm) in the two keratoconic eyes.

CONCLUSIONS: Aberrations in both normal and highly aberrated eyes were successfully corrected using the large-stroke deformable mirror to provide almost perfect optical quality. This mirror can be a powerful tool to assess the limit of visual performance achievable after correcting the aberrations, especially in eyes with abnormal corneal profiles. [J Refract Surg. 2007;23:947-952.]
Long-term Effects on Corneal Keratocytes of Mitomycin C During Photorefractive Keratectomy: A Randomized Contralateral Eye Confocal Microscopy Study
Authors: Midena Edoardo , Gambato Catia , Miotto Stefania , Cortese Marta , Salvi Rudy , Ghirlando Alessandra
Published: January 2019

ABSTRACT

PURPOSE: To evaluate the long-term side effects of mitomycin C (MMC) assisted photorefractive keratectomy (PRK) on corneal keratocytes of highly myopic eyes.

METHODS: Twenty-eight patients with bilateral myopia from -7.00 to -14.25 diopters (D) underwent PRK on both eyes, one eye of each patient received topical application of 0.02% MMC for 2 minutes immediately after the PRK procedure. Corneal keratocyte density was quantified by corneal confocal microscopy at baseline and 5 years postoperatively.

RESULTS: Photorefractive keratectomy reduced keratocyte density in the most anterior stromal layer, without a statistically significant difference between MMC and standard treated eyes. Posterior stromal layers showed no signs of keratocyte loss with either techniques.

CONCLUSIONS: Phototherapeutic keratectomy with 0.02% topical MMC has no significant side effects on corneal keratocytes compared to standard PRK, as documented by in vivo corneal confocal microscopy. [J Refract Surg. 2007;23:S1011-S1014.]
A Prospective, Randomized, Contralateral Eye Comparison of Epithelial Laser in situ Keratomileusis and Photorefractive Keratectomy in Eyes Prone to Haze
Authors: Gamaly Tamer O , El Danasoury Alaa , El Maghraby Akef
Published: January 2019

ABSTRACT

PURPOSE: To compare refractive outcome, subepithelial haze, and pain after epithelial laser in situ keratomileusis (epi-LASIK) and photorefractive keratectomy (PRK).

METHODS: In this prospective, randomized study, 32 eyes of 16 patients were treated for myopia with epi-LASIK (epi-LASIK group) in one eye and PRK in the fellow eye (PRK group). All patients underwent ablation using the NIDEK EC-5000 CX Il excimer laser platform. Mean patient age was 24.8 years (range: 19 to 35 years). Mean preoperative manifest refractive spherical equivalent (MRSE) was -2.76 diopters (D) (range: -1.00 to -4.88 D). Refractive outcome, subepithelial haze, and pain out to 6 months postoperatively were compared between groups.

RESULTS: At 6 months postoperatively, the mean MRSE was -0.22±0.27 D (range: 0.25 to -0.88 D) in the epi-LASIK group and -0.23 ±0.29 D (range: 0.50 to -1.125 D) in the PRK group. There was no statistically significant difference in the refractive outcomes between groups. By postoperative day 4, 18% of the epi-LASIK group and 7% of the PRK group achieved the final uncorrected visual acuity (UCVA). On day 1 postoperatively, 14% fewer patients in the PRK group experienced pain compared with the epi-LASIK group. On postoperative day 2, 36% fewer patients in the epi-LASIK group experienced pain. Seventy-one percent of patients in the epi-LASIK group and 36% of patients in the PRK group had no haze postoperatively.

CONCLUSIONS: Epi-LASIK and PRK produced similar refractive outcome. Patients who underwent epi-LASIK experienced faster recovery of vision, less haze, and less pain. [J Refract Surg. 2007;23:S1015-S1020.]
Active Cyclotorsion Error Correction During LASIK for Myopia and Myopic Astigmatism With the NIDEK EC-5000 CX III Laser
Authors: Bharti Sudhank , Bains Harkaran S
Published: January 2019

ABSTRACT

PURPOSE: To investigate the predictability and accuracy of active cyclotorsion compensation during LASIK for myopia with astigmatism.

METHODS: Fifty-two eyes of 26 patients were divided into two groups; one group (30 eyes) underwent primary LASIK with torsion error correction (TEC [TEC group]) and 22 eyes underwent LASIK without TEC (control group). The NIDEK EC-5000 CX III excimer laser was used for all treatments. All eyes were targeted for emmetropia. Manifest refraction spherical equivalent (MRSE), refractive outcomes, and dispersion and predictability of manifest refractive cylinder were compared between the TEC and control groups. A P value <.01 was considered statistically significant. All outcomes are reported at 3 months postoperatively.

RESULTS: Statistically significantly lower cylinder dispersion and mean manifest refractive cylinder postoperatively were demonstrated in the TEC group (P<.01). Final refractive cylinder for the TEC group was -0.21±0.16 diopters (D) (range: -0.62 to 0.00 D) and -0.56±0.34 D (range: -1.25 to 0.00 D) for the control group. No statistically significant differences in mean MRSE or safety (defined as a loss of 2 or more lines of best spectacle-corrected visual acuity) was noted between groups.

CONCLUSIONS: LASIK with active cyclotorsion error correction increases the accuracy of cylinder correction. [J Refract Surg. 2007;23:S1041-S1045.]
Thin-flap LASIK to Increase the Range of Treatments Using the NIDEK EC-5000 CX Excimer Laser
Authors: Grim Millicent , Pablo Rachelle
Published: January 2019

ABSTRACT

PURPOSE: To compare the safety, advantages, and disadvantages of two LASIK groups that underwent surgery with a standard -thickness 130-µm microkeratome head (standard thickness group) and a 90-µm microkeratome head (thin flap group) prior to ablation with the NIDEK EC-5000 CX excimer laser.

METHODS: Two hundred seventeen patients (420 eyes) with myopia or hyperopia underwent LASIK with either a 130-µm microkeratome head (137 eyes of 74 patients) or 90-µm microkeratome head (283 eyes of 143 patients). Corneal and stromal bed thickness prior to ablation were measured three consecutive times using ultrasound pachymetry. Averages of the corneal bed with the flap reflected, the flap thickness, and residual stromal bed were calculated for both groups. The postoperative appearance of the flaps and stroma in both groups were compared by slit-lamp examination.

RESULTS: No difference in preoperative corneal thickness was found between groups. Eyes that underwent treatment with the 130-µm microkeratome head had a mean flap thickness of 163.6±29.60 µm (range: 71 to 246 µm). Eyes that underwent treatment with the 90-µm microkeratome head had a mean flap thickness of 113.30±24.26µm (range: 65 to 182 µm). No intraor postoperative complications occurred in either group. Flap appearance was similar in both groups.

CONCLUSIONS: Both 130-µm and 90-µm microkeratome heads have similar predictability. Using a 90-µm microkeratome head leaves a thicker stromal bed for ablation. [J Refract Surg. 2007;23:S1050-S1053.]
Sentinel-2 for mapping the spatio-temporal development of submerged aquatic vegetation at Lake Starnberg (Germany)
Authors: Fritz Christine , Kuhwald Katja , Schneider Thomas , Geist Juergen , Oppelt Natascha
Published: January 2019

Submerged aquatic vegetation (SAV) plays an important role in freshwater lake ecosystems. Due to its sensitivity to environmental changes, several SAV species serve as bioindicators for the trophic state of freshwater lakes. Variations in water temperature, light availability and nutrient concentration affect SAV growth and species composition. To monitor the trophic state as required by the European Water Framework Directive (WFD), SAV needs to be monitored regularly. This study analyses the development of macrophyte patches at Lake Starnberg, Germany, by exploring four Sentinel-2A acquired within the main growing season in August and September 2015. Two different methods of littoral bottom coverage assessment are compared, i.e. a semi-empirical method using depth-invariant indices and a physically based, bio-optical method using WASI-2D (Water Colour Simulator). For a precise Sentinel-2 imaging by date and hour, satellite measurements were supported by lake bottom spectra delivered by in situ data based reflectance models. Both methods identified vegetated and non-vegetated patches in shallow water areas. Furthermore, tall- and meadow-growing SAV growth classes could be differentiated. Both methods revealed similar results when focusing on the identification of sediment and SAV patches (R² from 0.56 to 0.81), but not for a differentiation on SAV class growth level (R² <0.42).