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https://www.readbyqxmd.com/read/28646441/safety-efficacy-and-refractive-outcomes-of-lasik-surgery-in-patients-aged-65-or-older
#1
Paloma López-Montemayor, Jorge E Valdez-García, Denise Loya-García, Julio C Hernandez-Camarena
PURPOSE: Report on the safety, efficiency and refractive outcomes of LASIK surgery in patients aged 65 or older. METHODS: This study includes a case series of patients ≥65 years that underwent corneal refractive surgery during the period June 2010 to June 2015 at Hospital Zambrano Hellion, Monterrey, Mexico. Inclusion criteria were normal topography, central corneal thickness >500 μm, preoperative manifest refraction spherical equivalent (MRSE) up to -8...
June 23, 2017: International Ophthalmology
https://www.readbyqxmd.com/read/28646337/-epidemiology-of-refractive-errors
#2
C Wolfram
Refractive errors are very common and can lead to severe pathological changes in the eye. This article analyzes the epidemiology of refractive errors in the general population in Germany and worldwide and describes common definitions for refractive errors and clinical characteristics for pathologicaal changes. Refractive errors differ between age groups due to refractive changes during the life time and also due to generation-specific factors. Current research about the etiology of refractive errors has strengthened the influence of environmental factors, which led to new strategies for the prevention of refractive pathologies...
June 23, 2017: Der Ophthalmologe: Zeitschrift der Deutschen Ophthalmologischen Gesellschaft
https://www.readbyqxmd.com/read/28646167/effectively-infinite-optical-path-length-created-using-a-simple-cubic-photonic-crystal-for-extreme-light-trapping
#3
Brian J Frey, Ping Kuang, Mei-Li Hsieh, Jian-Hua Jiang, Sajeev John, Shawn-Yu Lin
A 900 nm thick TiO2 simple cubic photonic crystal with lattice constant 450 nm was fabricated and used to experimentally validate a newly-discovered mechanism for extreme light-bending. Absorption enhancement was observed extending 1-2 orders of magnitude over that of a reference TiO2 film. Several enhancement peaks in the region from 600-950 nm were identified, which far exceed both the ergodic fundamental limit and the limit based on surface-gratings, with some peaks exceeding 100 times enhancement...
June 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28645265/a-pilot-study-lasek-with-the-triple-a-profile-of-a-mel-90-for-mild-and-moderate-myopia
#4
Yingjun Chen, Dong Yang, Tian Han, Haipeng Xu, Meiyan Li, Xingtao Zhou
BACKGROUND: To investigate the visual and refractive outcomes in patients with mild to moderate myopia after laser-assisted subepithelial keratectomy (LASEK) using the 500 Hz pulse rate of the Triple-A profile. METHODS: Thirty-six eyes of 20 patients (mean age, 27.5 ± 4.6 years) were included in this prospective, consecutive study. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), corneal topography, and corneal aberrations were measured preoperatively and 1 day, 1 week, 1, 3 and 6 months post-operation...
June 23, 2017: BMC Ophthalmology
https://www.readbyqxmd.com/read/28644239/effect-of-the-learning-curve-on-visual-and-refractive-outcomes-of-small-incision-lenticule-extraction
#5
Tommy C Y Chan, Alex L K Ng, George P M Cheng, Victor C P Woo, Jiamei Zhang, Yan Wang, Vishal Jhanji
PURPOSE: To investigate the effect of the learning curve for small-incision lenticule extraction during the first 2 years of experience. METHODS: Small-incision lenticule extraction was performed using the 500-kHz VisuMax femtosecond laser (Carl Zeiss Meditec) by the same surgeon. The initial 100 patients since the surgeon started operating independently were considered as group 1; the recent 100 patients were considered as group 2. The same laser settings and technique were used...
June 21, 2017: Cornea
https://www.readbyqxmd.com/read/28643717/spectacles-use-in-a-rural-population-in-the-state-of-telangana-in-south-india
#6
Srinivas Marmamula, Rohit C Khanna, Eswararao Kunuku, Gullapalli N Rao
CONTEXT: Uncorrected refractive errors are the leading cause of visual impairment. AIMS: To assess the prevalence and patterns of spectacles use among those aged ≥40 years in the South Indian state of Telangana. SETTINGS AND DESIGN: This was a population-based, cross-sectional study, in which 6150 people were enumerated from 123 clusters in the two districts of Telangana state (Adilabad and Mahbubnagar) using a two-stage cluster random sampling methodology...
June 2017: Indian Journal of Ophthalmology
https://www.readbyqxmd.com/read/28643716/prevalence-of-ocular-morbidity-in-school-going-children-in-west-uttar-pradesh
#7
Veer Singh, K P S Malik, V K Malik, Kirti Jain
AIM OF THE STUDY: This study aims to evaluate the prevalence and to make a comparison between the ocular morbidity pattern in school going children of urban and rural areas of West Uttar Pradesh. MATERIALS AND METHODS: A school-based cross-sectional study design was adopted to examine children aged 5-15 years in randomly selected urban and rural schools of West Uttar Pradesh from June 2012 to August 2014. An optometrist did the vision and refraction, and a detailed ophthalmic examination was done by an ophthalmologist...
June 2017: Indian Journal of Ophthalmology
https://www.readbyqxmd.com/read/28643701/self-anti-reflective-density-modulated-thin-films-by-hips-technique
#8
Filiz Keles, Emad O Badraddin, Tansel Karabacak
A critical factor for an efficient light harvesting device is reduced reflectance in order to achieve high optical absorptance. In this regard, refractive index engineering becomes important to minimize reflectance. In this study, a new fabrication approach to obtain the density-modulated CuInxGa(1-x)Se2 (CIGS) thin films with self-anti-reflective properties has been demonstrated. Density-modulated CIGS samples were fabricated by utilizing high pressure sputtering (HIPS) at Ar gas pressure of 2.75 x 10-2 mbar along with the conventional low pressure sputtering (LPS) at Ar gas pressure of 3...
June 23, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28643407/childhood-exposure-to-constricted-living-space-a-possible-environmental-threat-for-myopia-development
#9
Kai Yip Choi, Wing Yan Yu, Christie Hang I Lam, Zhe Chuang Li, Man Pan Chin, Yamunadevi Lakshmanan, Francisca Siu Yin Wong, Chi Wai Do, Paul Hong Lee, Henry Ho Lung Chan
PURPOSE: People in Hong Kong generally live in a densely populated area and their homes are smaller compared with most other cities worldwide. Interestingly, East Asian cities with high population densities seem to have higher myopia prevalence, but the association between them has not been established. This study investigated whether the crowded habitat in Hong Kong is associated with refractive error among children. METHODS: In total, 1075 subjects [Mean age (S...
June 22, 2017: Ophthalmic & Physiological Optics: the Journal of the British College of Ophthalmic Opticians (Optometrists)
https://www.readbyqxmd.com/read/28641418/measuring-the-carrier-dynamics-of-photocatalyst-micrograins-using-the-christiansen-effect
#10
Gangbei Zhu, Wei Lu, Jiangrui Zhu, Yunliang Li, Liwei Guo, Yuxiang Weng
The optical measurement of photocatalyst materials is subject to Mie scattering when the particle size is comparable to the wavelength of the probe light. A novel approach was developed to deal with this scattering problem in the transient spectroscopy of photocatalyst micrograins using the Christiansen effect because the probe light in the vicinity of the Christiansen frequency can be transmitted. Scattering theory was used to analyze the transient spectra of micrograins and estimate the extinction coefficient at the Christiansen frequency...
June 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28641253/a-closed-form-solution-to-single-underwater-camera-calibration-using-triple-wavelength-dispersion-and-its-application-to-single-camera-3d-reconstruction
#11
Xida Chen, Yee-Hong Yang
In this paper, we present a new method to estimate the housing parameters of an underwater camera by making full use of triple wavelength dispersion. Our method is based on an important finding that there is a closed-form solution to the distance from the camera center to the refractive interface once the refractive normal is known. The correctness of this finding is mathematically proved in this paper. To our best knowledge, such a finding has not been studied or reported, and hence is never proved theoretically...
June 16, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28639450/-bilateral-congenital-multiple-pigmented-vitreous-cysts-in-a%C3%A2-three-year-old-girl-ten-years-follow-up
#12
J Štěpánková, M Hósová, D Dotřelová
The authors present a case report of a three-year-old female patient with bilateral multiple anterior vitreous cysts. During examination for intermittent esotropia of the right eye was diagnosed not only hypermetropia, astigmatism and anisometropia, but also pigmented changes in peripheral retrolental space of both eyes. Clinical examination under general anaesthesia revealed bilateral multiple pigmented immobile vitreous cysts. There were five almost spherical, translucent, but slightly pigmented cysts on its cover on the right eye and four similar on the left, but visible only with dilated pupils...
2017: Ceská a Slovenská Oftalmologie
https://www.readbyqxmd.com/read/28639449/-optic-properties-of-myopic-correction-by-orthokeratology-contact-lenses-a-case-report
#13
M Mýlková, F Pluháček
INTRODUCTION: Orthokeratology lenses present a special type of hard contact lenses, which is used especially for myopic correction. The lenses are applied during the night, when thanks to their special shape cause temporally (reversible) change of the cornea shape. During the day, there is not necessary to wear any other refractive correction. Due to the wearing regimen, there is, comparing to the classical contact lenses, higher risk of health complications. For their safe use, it is necessary to pay attention to the application of lenses of adequate parameters, follow up the care and hygiene precautions, regular controls and early treatment of possible problems...
2017: Ceská a Slovenská Oftalmologie
https://www.readbyqxmd.com/read/28639447/-clinical-results-of-the-implantation-of-two-types-of-multifocal-rotational-asymmetric-intraocular-lenses
#14
V Veliká, L Hejsek, F Raiskup
PURPOSE: The aim of the study was evaluation and comparison of clinical results of two types of rotationally asymmetric multifocal intraocular lens (LENTIS Mplus and LENTIS MplusX). MATERIAL AND METHODS: The study included 247 eyes of 124 patients aged 25 - 76 years (mean, 58 years). After phacoemulsification multifocal intraocular lens LENTIS Mplus (group A, n = 141) or LENTIS MplusX (group B, n = 106) was implanted. Patients were divided into two groups according to the type of intraocular lens...
2017: Ceská a Slovenská Oftalmologie
https://www.readbyqxmd.com/read/28639168/sensitivity-of-chaos-measures-in-detecting-stress-in-the-focusing-control-mechanism-of-the-short-sighted-eye
#15
Karen M Hampson, Matthew P Cufflin, Edward A H Mallen
When fixating on a stationary object, the power of the eye's lens fluctuates. Studies have suggested that changes in these so-called microfluctuations in accommodation may be a factor in the onset and progression of short-sightedness. Like many physiological signals, the fluctuations in the power of the lens exhibit chaotic behaviour. A breakdown or reduction in chaos in physiological systems indicates stress to the system or pathology. The purpose of this study was to determine whether the chaos in fluctuations of the power of the lens changes with refractive error, i...
June 21, 2017: Bulletin of Mathematical Biology
https://www.readbyqxmd.com/read/28639088/comparison-of-visual-acuity-measurements-via-three-different-methods-in-preschool-children-lea-symbols-crowded-lea-symbols-snellen-e-chart
#16
Asli Inal, Osman Bulut Ocak, Ebru Demet Aygit, Ihsan Yilmaz, Berkay Inal, Muhittin Taskapili, Birsen Gokyigit
PURPOSE: The aim of this study was to compare three different methods to measure visual acuity (VA) in healthy and amblyopic preschool children: a Snellen E chart (SE), a single Lea symbols (SLS), and a crowded Lea symbols (CLS). METHODS: Seventy-eight eyes of 54 patients (28 females, 26 males) were included in this cross-sectional, comparative study. The control group consisted of 30 healthy cases, and the amblyopic group consisted of 24 patients with amblyopia...
June 20, 2017: International Ophthalmology
https://www.readbyqxmd.com/read/28639087/haigis-and-srkt-formulae-accuracy-for-intentional-myopic-overcorrection
#17
Rodrigo Faeda Dalto, Miriam A Ferreira, Wilian Queiroz, Roberto Pinto Coelho, Jayter Silva Paula, Andre Messias
PURPOSE: To investigate the influence of preoperative biometric parameters on the accuracy of Haigis and SRKT formulae in predicting postoperative target refraction. METHODS: Retrospective analysis of 108 eyes (70 patients) underwent uneventful phacoemulsification surgery with implant of Alcon-SN60WF intraocular lens (IOL). Forty-five eyes were intentionally targeted to myopia (-0.75 to -1.25 dpt), while the others targeted between 0 and -0.75 dpt. Preoperative axial length and keratometry (K) were measured with optical biometry (LENSTAR-Haag-Streit)...
June 21, 2017: International Ophthalmology
https://www.readbyqxmd.com/read/28638910/dark-plasmonic-mode-based-perfect-absorption-and-refractive-index-sensing
#18
W H Yang, C Zhang, S Sun, J Jing, Q Song, S Xiao
Dark plasmonic resonances in metallic nanostructures are essential for many potential applications such as refractive index sensing, single molecule detection, nanolasers etc. However, it is difficult to excite the dark modes in optical experiments and thus the practical applications are severely limited. Herein, we demonstrate a simple method to experimentally excite the quadrupolar and higher-order plasmonic modes with normal incident light. By directionally depositing silver films onto the sidewalls of metal-covered one-dimensional grating, we have experimentally observed a series of asymmetrical resonances at the plasmonic ranges of silver gratings...
June 22, 2017: Nanoscale
https://www.readbyqxmd.com/read/28638058/theoretical-analyses-on-orbital-angular-momentum-modes-in-conventional-graded-index-multimode-fibre
#19
Shi Chen, Jian Wang
Orbital angular momentum (OAM) modes are another mode basis to represent spatial modes. There have been increasing interests in exploiting OAM modes in specialty fibres. In this paper, we present a comprehensive characterisation of OAM modes in conventional graded-index multimode fibre (MMF). 1) We synthesise the circularly polarized OAM modes by properly combining two fold degenerate cylindrical vector modes (eigenmodes) and analyse the total angular momentum, i.e. spin angular momentum and orbital angular momentum...
June 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28635294/tunable-anisotropic-photon-emission-from-self-organized-cspbbr3-perovskite-nanocrystals
#20
Matthew Jurow, Thomas Lampe, Erika Penzo, Jun Kang, Matthew A Koc, Thomas Zechel, Zachary Nett, Michael A Brady, Lin-Wang Wang, A Paul Alivisatos, Stefano Cabrini, Wolfgang Brutting, Yi Liu
We report controllable anisotropic light emission of photons originating from vertically aligned transition dipole moments in spun-cast films of CsPbBr3 nanocubes. By depositing films of nanocrystals on pre-coated substrates we can control the packing density and resultant radiation pattern of the emitted photons. We develop a technical framework to calculate the average orientation of light emitters, i.e. the angle between the transition dipole moment vector (TDM) and the substrate. This model is applicable to any emissive material with a known refractive index...
June 21, 2017: Nano Letters
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