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Sample records for contact lens shack-hartmann

  1. Shack-Hartmann reflective micro profilometer

    Science.gov (United States)

    Gong, Hai; Soloviev, Oleg; Verhaegen, Michel; Vdovin, Gleb

    2018-01-01

    We present a quantitative phase imaging microscope based on a Shack-Hartmann sensor, that directly reconstructs the optical path difference (OPD) in reflective mode. Comparing with the holographic or interferometric methods, the SH technique needs no reference beam in the setup, which simplifies the system. With a preregistered reference, the OPD image can be reconstructed from a single shot. Also, the method has a rather relaxed requirement on the illumination coherence, thus a cheap light source such as a LED is feasible in the setup. In our previous research, we have successfully verified that a conventional transmissive microscope can be transformed into an optical path difference microscope by using a Shack-Hartmann wavefront sensor under incoherent illumination. The key condition is that the numerical aperture of illumination should be smaller than the numerical aperture of imaging lens. This approach is also applicable to characterization of reflective and slightly scattering surfaces.

  2. Coded Shack-Hartmann Wavefront Sensor

    KAUST Repository

    Wang, Congli

    2016-12-01

    Wavefront sensing is an old yet fundamental problem in adaptive optics. Traditional wavefront sensors are limited to time-consuming measurements, complicated and expensive setup, or low theoretically achievable resolution. In this thesis, we introduce an optically encoded and computationally decodable novel approach to the wavefront sensing problem: the Coded Shack-Hartmann. Our proposed Coded Shack-Hartmann wavefront sensor is inexpensive, easy to fabricate and calibrate, highly sensitive, accurate, and with high resolution. Most importantly, using simple optical flow tracking combined with phase smoothness prior, with the help of modern optimization technique, the computational part is split, efficient, and parallelized, hence real time performance has been achieved on Graphics Processing Unit (GPU), with high accuracy as well. This is validated by experimental results. We also show how optical flow intensity consistency term can be derived, using rigor scalar diffraction theory with proper approximation. This is the true physical law behind our model. Based on this insight, Coded Shack-Hartmann can be interpreted as an illumination post-modulated wavefront sensor. This offers a new theoretical approach for wavefront sensor design.

  3. Curvature sensing with a Shack-Hartmann sensor

    NARCIS (Netherlands)

    Soloviev, O.A.; Verhaegen, M.H.G.; Vdovine, G.V.; Bonora, S

    2015-01-01

    Shack-Hartmann (SH) sensor, based on sampling of wavefront tilts in subapertures, is a simple, reliable, and widely used in adaptive optics wavefront sensor. A wavefront curvature sensor has the advantage of providing the results suitable for direct control of membrane and bimorph deformable mirrors

  4. Design, validation and application of an ocular Shack-Hartmann aberrometer

    Science.gov (United States)

    Straub, Jochen

    The design and testing of an ocular Shack-Hartmann aberrometer is presented. The aberrometer objectively measures optical aberrations in the human eye in vivo. The sensor was successfully tested for measurements of refractive error (sphere and cylinder) and spherical aberration. Vignetting limits the measurement range of the wavefront to a range of -10 D to +15 D. Large refractive errors and decentration of the measurement induce aberrations in the test wavefront. Analytical tools to correct for these systematic errors were developed. A clinical study was conducted assessing visual performance in 158 eyes of 89 subjects before and after LARK refractive surgery. The main results of the study were that refractive surgery corrects refractive errors very accurately. A slight regression in refraction during the 12 months after surgery was noted. Measurements of ocular aberrations using the Shack-Hartmann aberrometer revealed that refractive surgery introduced large amounts of higher order aberrations, mainly spherical aberration and coma. The amount of aberrations changed significantly during the 12 months wound healing period. The dark adapted pupil diameter of the eye increased significantly during the first 6 months after surgery. The changes in ocular aberrations and pupil diameter were correlated to changes in contrast sensitivity in the human eye. The analysis of corneal topography showed that while the anterior corneal curvature changed due to surgery, we also saw a change in the posterior corneal curvature as a biomechanical response to surgery. A Customized Eye Model was designed and tested based on the clinical measurements. The model used conic surfaces and modeled defocus and spherical aberration. This computer eye model was then used in optical lens design software to calculate an optimal Customized Ablation Pattern for individual eyes.

  5. Hyper Suprime-Cam: autoguider and Shack-Hartmann systems

    Science.gov (United States)

    Morokuma, Tomoki; Komiyama, Yutaka; Miyazaki, Satoshi; Nakaya, Hidehiko; Furusawa, Hisanori; Tomono, Daigo; Kawanomoto, Satoshi; Tanaka, Yoko

    2008-07-01

    We present methodology of the autoguider (AG) and Shack-Hartmann (SH) sensing systems which will be used for a wide-field camera, Hyper Suprime-Cam (HSC), on the prime focus of the Subaru 8.2-m telescope. For both systems, stellar images are formed on the HSC science CCDs. Although light from AG stars must pass through bandpass filters, we can obtain enough photons for AG stars brighter than mAB autoguiding. Spatial number density of such bright stars from the SDSS database requires an area of about two 2k×4k CCDs for AG stars. The optics of SH system except for the imaging CCDs is located within the HSC filter unit.

  6. Using Shack-Hartmann wavefront sensors and Zernike coefficients for beam characterisation: numerical procedures

    Science.gov (United States)

    Bosch, Salvador; Vallmitjana, Santiago; Marzoa, Antonio; Arines, Justo; Acosta, Eva

    2017-06-01

    When using Shack-Hartmann wavefront sensors (SH) and Zernike coefficients (Zs) in applications where the position of the measurement and the point of interest are far apart, as it is common practice in ophthalmic optics, problems in the interpretation of the values of the Zs arise, related to how the shape of the wavefront propagates along the beam. One typical example is pupil conjugation where an auxiliary lens is added to match the size of the area of the interest of the beam with the size of the entrance pupil of the SH used for measurements. In the present work, we address this problem in the framework of a numerical scheme for modeling the beam propagation. We calculate the wavefronts with exact ray tracing plus the fitting of the impacts so as to match a rectangular grid. This procedure allows the subsequent calculation of the Zs or, similarly, the pupil function at an arbitrary plane perpendicular to the optical axis. All the numerical methods and procedures have been implemented in MATLAB code and can be illustrated by running the MATLAB script for the setup configuration that is being considered. Several examples are presented to illustrate the previous ideas and to show the real capabilities of our procedures. They will help to clarify the issues actually found in practical setups for beam manipulation, often encountered in ophthalmic optics.

  7. Design and performances of the Shack-Hartmann sensor within the Active Phasing Experiment

    Science.gov (United States)

    Mazzoleni, R.; Gonté, F.; Surdej, I.; Araujo, C.; Brast, R.; Derie, F.; Duhoux, P.; Dupuy, C.; Frank, C.; Karban, R.; Noethe, L.; Yaitskova, N.

    2008-07-01

    The Shack-Hartmann Phasing Sensor (SHAPS) has been integrated in the Active Phasing Experiment (APE) at ESO. It is currently under test in the laboratory. The tests on sky are foreseen for the end of 2008, when APE will be mounted at the Nasmyth focus of one of the VLT unit telescopes. SHAPS is based on the Shack-Hartmann principle: the lenslet array is located in a plane which is optically conjugated to the Active Segmented Mirror (ASM) of APE and is composed of two types of microlenses, circular and cylindrical, which give information about the wavefront slope and the piston steps, respectively. This proceeding contains a description of SHAPS and of the algorithms implemented for the wavefront reconstruction and for the phasing. The preliminary results obtained during the laboratory tests are discussed and compared with the theoretical predictions. The performances of SHAPS at the VLT and at the European Extremely Large Telescope (E-ELT) are estimated.

  8. Shack-Hartmann wavefront sensor using a Raspberry Pi embedded system

    Science.gov (United States)

    Contreras-Martinez, Ramiro; Garduño-Mejía, Jesús; Rosete-Aguilar, Martha; Román-Moreno, Carlos J.

    2017-05-01

    In this work we present the design and manufacture of a compact Shack-Hartmann wavefront sensor using a Raspberry Pi and a microlens array. The main goal of this sensor is to recover the wavefront of a laser beam and to characterize its spatial phase using a simple and compact Raspberry Pi and the Raspberry Pi embedded camera. The recovery algorithm is based on a modified version of the Southwell method and was written in Python as well as its user interface. Experimental results and reconstructed wavefronts are presented.

  9. Experimental detection of optical vortices with a Shack-Hartmann wavefront sensor.

    Science.gov (United States)

    Murphy, Kevin; Burke, Daniel; Devaney, Nicholas; Dainty, Chris

    2010-07-19

    Laboratory experiments are carried out to detect optical vortices in conditions typical of those experienced when a laser beam is propagated through the atmosphere. A Spatial Light Modulator (SLM) is used to mimic atmospheric turbulence and a Shack-Hartmann wavefront sensor is utilised to measure the slopes of the wavefront surface. A matched filter algorithm determines the positions of the Shack-Hartmann spot centroids more robustly than a centroiding algorithm. The slope discrepancy is then obtained by taking the slopes measured by the wavefront sensor away from the slopes calculated from a least squares reconstruction of the phase. The slope discrepancy field is used as an input to the branch point potential method to find if a vortex is present, and if so to give its position and sign. The use of the slope discrepancy technique greatly improves the detection rate of the branch point potential method. This work shows the first time the branch point potential method has been used to detect optical vortices in an experimental setup.

  10. Optimization of scanning strategy of digital Shack-Hartmann wavefront sensing.

    Science.gov (United States)

    Guo, Wenjiang; Zhao, Liping; Li, Xiang; Chen, I-Ming

    2012-01-01

    In the traditional Shack-Hartmann wavefront sensing (SHWS) system, a lenslet array with a bigger configuration is desired to achieve a higher lateral resolution. However, practical implementation limits the configuration and this parameter is contradicted with the measurement range. We have proposed a digital scanning technique by making use of the high flexibility of a spatial light modulator to sample the reflected wavefront [X. Li, L. P. Zhao, Z. P. Fang, and C. S. Tan, "Improve lateral resolution in wavefront sensing with digital scanning technique," in Asia-Pacific Conference of Transducers and Micro-Nano Technology (2006)]. The lenslet array pattern is programmed to laterally scan the whole aperture. In this paper, the methodology to optimize the scanning step for the purpose of form measurement is proposed. The correctness and effectiveness are demonstrated in numerical simulation and experimental investigation. © 2012 Optical Society of America

  11. Nonlinear spline wavefront reconstruction from Shack-Hartmann intensity measurements through small aberration approximations.

    Science.gov (United States)

    Brunner, Elisabeth; de Visser, Cornelis C; Verhaegen, Michel

    2017-09-01

    We propose an extension of the Spline based ABerration Reconstruction (SABRE) method to Shack-Hartmann (SH) intensity measurements, through small aberration approximations of the focal spot models. The original SABRE for SH slope measurements is restricted to the use of linear spline polynomials, due to the limited amount of data, and the resolution of its reconstruction is determined by the number of lenslets. In this work, a fast algorithm is presented that directly processes the pixel information of the focal spots, allowing the employment of nonlinear polynomials for high accuracy reconstruction. In order to guarantee the validity of the small aberration approximations, the method is applied in two correction steps, with a first compensation of large, low-order aberrations through the gradient-based linear SABRE followed by compensation of the remaining high-order aberrations with the intensity-based nonlinear SABRE.

  12. Influence of contact lens power profile on peripheral refractive error.

    Science.gov (United States)

    de la Jara, Percy Lazon; Sankaridurg, Padmaja; Ehrmann, Klaus; Holden, Brien A

    2014-06-01

    To measure the power profile across the optic zone (OZ) of four commercially available soft contact lenses and establish the impact on the peripheral refractive error of the eye. The power profiles of a spherical conventional hydrogel contact lens (etafilcon A, J&J Vistakon, Jacksonville, FL USA) and three spherical silicone hydrogel contact lenses (lotrafilcon A and B, CIBA Vision, Duluth, GA USA; enfilcon A, CooperVision, Pleasanton, CA USA) with a labeled power of -3.00 and -6.00 diopters were measured using a Shack-Hartmann wavefront sensor power mapping device. Central and peripheral refraction across the horizontal meridian (nasal and temporal visual field at 20, 30, and 40 degrees) was measured with an open-field autorefractor (Shin Nippon NVision K5001, Osaka Japan) with and without contact lenses in 26 myopic subjects. The relative peripheral refractive error on the eye was estimated and compared with and without contact lenses and between contact lenses. Differences in the distribution of the power profile across the OZ were apparent between contact lens types and powers. No significant differences (p > 0.05) were found between contact lens types for their effect on on-axis refraction. Significant differences (p < 0.05) were found at all peripheral retinal eccentricities between contact lens types. For a given central power, the four contact lenses exhibited variations in optical power across the OZ of the lens. The distribution of optical power across the OZ has an influence on the peripheral refractive error of the eye.

  13. A Clinical Study to Validate the Pupil Rescaling Technique by using COAS Shack Hartmann Aberrometer.

    Science.gov (United States)

    Kalikivayi, V; Kannan, K; Ganesan, A R

    2015-01-01

    In any optical system, optical aberrations of the imaging system affect the image quality. The human eye is also like an optical system which has optical aberrations influencing the quality of the retinal image. When pupil size exceeds 3 mm, ocular aberrations increase and play a major role on retinal image degradation. Pupil diameter is made constant in commercially available aberrometers by mathematically rescaling it. The aim of this study is to validate the pupil rescaling technique by using COAS (Complete Ophthalmic Analysis System)Shack Hartmann Aberrometer. Five subjects were recruited for this study. The measurements were taken over a moderately large pupil of 5mm in normal room illumination to allow for natural pupil dilation. The analyses diameter is fixed at 5 mm in COAS which means it rescales the aberration data to 5 mm if the pupil diameter recorded was more than 5 mm at the time of measurement. Ocular aberrations for natural and rescaled pupil sizes were analyzed. Estimation of ocular aberrations showed there was no statistical significance between natural pupil and rescaled pupil diameter.

  14. Experimental investigations on characterization of freeform wavefront using Shack-Hartmann sensor

    Science.gov (United States)

    Burada, Dali Ramu; Pant, Kamal K.; Bichra, Mohamed; Khan, Gufran Sayeed; Sinzinger, Stefan; Shakher, Chandra

    2017-08-01

    The metrology of freeform wavefront can be performed by the use of a noninterferometric method, such as a Shack-Hartmann sensor (SHS). Detailed experimental investigations employing an SHS as metrology head are presented. The scheme is of nonnull nature where small subapertures are measured using an SHS and stitched to give the full wavefront. For the assessment of complex misalignment errors during the spiral scanning, a library of residual slope errors has been created, which makes the alignment process fast converging for minimizing the scanning errors. A detailed analysis of the effects of slope and positioning error on reproducibility is presented. It is validated by null test where a null diffractive optical element has been used in a Mach-Zehnder configuration for compensating the freeform shape. A freeform optics is measured by both measurement schemes, and the results are in good agreement. Further, the nonnull-based scanning subaperture stitching scheme is also validated by performing measurements on an aspheric surface and compared with the measurements from the interferometric method (Zygo Verifire).

  15. Shack-Hartmann wavefront sensor with large dynamic range by adaptive spot search method.

    Science.gov (United States)

    Shinto, Hironobu; Saita, Yusuke; Nomura, Takanori

    2016-07-10

    A Shack-Hartmann wavefront sensor (SHWFS) that consists of a microlens array and an image sensor has been used to measure the wavefront aberrations of human eyes. However, a conventional SHWFS has finite dynamic range depending on the diameter of the each microlens. The dynamic range cannot be easily expanded without a decrease of the spatial resolution. In this study, an adaptive spot search method to expand the dynamic range of an SHWFS is proposed. In the proposed method, spots are searched with the help of their approximate displacements measured with low spatial resolution and large dynamic range. By the proposed method, a wavefront can be correctly measured even if the spot is beyond the detection area. The adaptive spot search method is realized by using the special microlens array that generates both spots and discriminable patterns. The proposed method enables expanding the dynamic range of an SHWFS with a single shot and short processing time. The performance of the proposed method is compared with that of a conventional SHWFS by optical experiments. Furthermore, the dynamic range of the proposed method is quantitatively evaluated by numerical simulations.

  16. Optical alignment procedure utilizing neural networks combined with Shack-Hartmann wavefront sensor

    Science.gov (United States)

    Adil, Fatime Zehra; Konukseven, Erhan İlhan; Balkan, Tuna; Adil, Ömer Faruk

    2017-05-01

    In the design of pilot helmets with night vision capability, to not limit or block the sight of the pilot, a transparent visor is used. The reflected image from the coated part of the visor must coincide with the physical human sight image seen through the nonreflecting regions of the visor. This makes the alignment of the visor halves critical. In essence, this is an alignment problem of two optical parts that are assembled together during the manufacturing process. Shack-Hartmann wavefront sensor is commonly used for the determination of the misalignments through wavefront measurements, which are quantified in terms of the Zernike polynomials. Although the Zernike polynomials provide very useful feedback about the misalignments, the corrective actions are basically ad hoc. This stems from the fact that there exists no easy inverse relation between the misalignment measurements and the physical causes of the misalignments. This study aims to construct this inverse relation by making use of the expressive power of the neural networks in such complex relations. For this purpose, a neural network is designed and trained in MATLAB® regarding which types of misalignments result in which wavefront measurements, quantitatively given by Zernike polynomials. This way, manual and iterative alignment processes relying on trial and error will be replaced by the trained guesses of a neural network, so the alignment process is reduced to applying the counter actions based on the misalignment causes. Such a training requires data containing misalignment and measurement sets in fine detail, which is hard to obtain manually on a physical setup. For that reason, the optical setup is completely modeled in Zemax® software, and Zernike polynomials are generated for misalignments applied in small steps. The performance of the neural network is experimented and found promising in the actual physical setup.

  17. Modal processing of Hartmann and Shack-Hartmann patterns by means of a least squares fitting of the transverse aberrations.

    Science.gov (United States)

    Hernández-Gómez, Geovanni; Malacara-Doblado, Daniel; Malacara-Hernández, Zacarías; Malacara-Hernández, Daniel

    2014-11-01

    Instead of measuring the wavefront deformations, Hartmann and Shack-Hartmann tests measure wavefront slopes, which are equivalent to ray transverse aberrations. Numerous integration methods have been described in the literature to obtain the wavefront deformations from these measurements. Basically, they can be classified in two different categories, i.e., modal and zonal. Frequently, a least squares fit of the transverse aberrations in the x direction and a least squares fit of the transverse aberrations in the y direction is performed to obtain the wavefront. In this work, we briefly describe a modal method to integrate Hartmann and Shack-Hartmann patterns by means of a single least squares fit of the transverse aberrations simultaneously instead of the traditional x-y separate method. The proposed method uses monomial calculation instead of using Zernike polynomials, to simplify numerical calculations. Later, a method is proposed to convert from monomials to Zernike polynomials. An important obtained result is that if polar coordinates are used, angular transverse aberrations are not actually needed to obtain all wavefront coefficients.

  18. Contact lens in keratoconus

    Directory of Open Access Journals (Sweden)

    Varsha M Rathi

    2013-01-01

    Full Text Available Contact lenses are required for the visual improvement in patients with keratoconus. Various contact lens options, such as rigid gas permeable (RGP lenses, soft and soft toric lenses, piggy back contact lenses (PBCL, hybrid lenses and scleral lenses are availble. This article discusses about selection of a lens depending on the type of keratoconus and the fitting philosophies of various contact lenses including the starting trial lens. A Medline search was carried out for articles in the English language with the keywords keratoconus and various contact lenses such as Rose k lens, RGP lens, hybrid lens, scleral lens and PBCL.

  19. Contact Lens Compliance

    OpenAIRE

    Jinabhai, A.

    2013-01-01

    Although contact lens-related complications are rare, and most are managed without any lasting side-effects, several reports have identified a variety of risk factors associated with lens wear complications. Among these risk factors, some are unalterable, such as age or gender. Others, however, are modifiable, for example, poor lens case hygiene or hand-washing and, therefore, can be targeted to maximise successful lens wear. This article reviews different aspects of contact lens non-compliance

  20. Validation of a method for measuring the retinal thickness with Shack-Hartmann aberrometry in an artificial eye

    Science.gov (United States)

    Karitans, Varis; Jansone, Liene; Ozolins, Maris; Krumina, Gunta

    2015-05-01

    In Shack-Hartmann aberrometry, it is assumed that a wave front emerges from a single point focused on a retina. However, the retina is a multi-layered structure and reflections may occur from several layers. This may result in several overlapping spot patterns on the CCD due to different vergences of the outgoing wave fronts. The amount by which these spot patterns are displaced may contain information about the retinal thickness. In this study, we perform simulations of formation of double spots in a living eye and also apply this method to measure the thickness of an artificial retina with a simple structure. We also compare the results obtained with artificial eye and compare them to the simulated data. We evaluate the recommended range of the lenslet parameters for analyzing the retinal thickness. We conclude that this method could be used in a living eye for estimating the total retinal thickness and to confirm retinal pathologies associated with significant increase in the retinal thickness like glaucoma, macular edema, etc.

  1. Contact lens in keratoconus

    OpenAIRE

    Rathi, Varsha M; Preeji S Mandathara; Srikanth Dumpati

    2013-01-01

    Contact lenses are required for the visual improvement in patients with keratoconus. Various contact lens options, such as rigid gas permeable (RGP) lenses, soft and soft toric lenses, piggy back contact lenses (PBCL), hybrid lenses and scleral lenses are availble. This article discusses about selection of a lens depending on the type of keratoconus and the fitting philosophies of various contact lenses including the starting trial lens. A Medline search was carried out for articles in the En...

  2. Colored Contact Lens Dangers

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    Full Text Available ... lens. In Butler's case, the lenses caused an infection and left her with a corneal abrasion. "I ... lenses? Sep 13, 2017 Contact Lens-Related Eye Infections Mar 01, 2017 New Technology Helps the Legally ...

  3. Colored Contact Lens Dangers

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  4. Colored Contact Lens Dangers

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    Full Text Available ... Purchase the colored contact lenses from an eye product retailer who asks for a prescription. Follow the contact lens care directions for cleaning, disinfecting, and wearing the lenses. Never share contact ...

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  10. Colored Contact Lens Dangers

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    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... new application of artificial intelligence shows whether a patient’s eyes point to high blood pressure or risk ...

  11. Colored Contact Lens Dangers

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    Full Text Available ... in a pair of colored contact lenses, Laura Butler of Parkersburg, W.Va., had "extreme pain in ... to wear any kind of contact lens. In Butler's case, the lenses caused an infection and left ...

  12. Colored Contact Lens Dangers

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    Full Text Available ... level of care or consideration as a standard contact lens because they can be purchased over-the-counter ... Teenager Blinded In One Eye By Non-Prescription Contact Lens Laura: Vision Loss After Just 10 Hours Robyn: ...

  13. Telescopic vision contact lens

    Science.gov (United States)

    Tremblay, Eric J.; Beer, R. Dirk; Arianpour, Ashkan; Ford, Joseph E.

    2011-03-01

    We present the concept, optical design, and first proof of principle experimental results for a telescopic contact lens intended to become a visual aid for age-related macular degeneration (AMD), providing magnification to the user without surgery or external head-mounted optics. Our contact lens optical system can provide a combination of telescopic and non-magnified vision through two independent optical paths through the contact lens. The magnified optical path incorporates a telescopic arrangement of positive and negative annular concentric reflectors to achieve 2.8x - 3x magnification on the eye, while light passing through a central clear aperture provides unmagnified vision.

  14. Colored Contact Lens Dangers

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  15. Colored Contact Lens Dangers

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    Full Text Available ... Lens-Related Eye Infections Mar 01, 2017 New Technology Helps the Legally Blind Be More Independent Oct 31, 2016 What You Should Know About Swimming and Your Eyes Aug 16, 2016 5 Steps to Healthy Contact Lens Use May 31, 2016 More Eye Health News Top ...

  16. Colored Contact Lens Dangers

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    Full Text Available ... an Ophthalmologist Patient Stories Español Eye Health / News Halloween Hazard: The Hidden Dangers of Buying Decorative Contact ... After One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter ...

  17. [Correct contact lens hygiene].

    Science.gov (United States)

    Blümle, S; Kaercher, T; Khaireddin, R

    2013-06-01

    Although contact lenses have long been established in ophthalmology, practical aspects of handling contact lenses is becoming increasingly less important in the clinical training as specialist for ophthalmology. Simultaneously, for many reasons injuries due to wearing contact lenses are increasing. In order to correct this discrepancy, information on contact lenses and practical experience with them must be substantially increased from a medical perspective. This review article deals with the most important aspects for prevention of complications, i.e. contact lens hygiene.

  18. Contact Allergy To Hard Contact Lens

    Directory of Open Access Journals (Sweden)

    J S Pasricha

    1985-01-01

    Full Text Available Three patients developed recurrent irritation, redness and watery discharge from their eyes after using hard contact lens. Patch tests were positive with the material of the hard contact lens and negative with teepol, sodium lauryl sulphate and material of the soft contact lens. All the three patients became alright after they stopped,using hard contact lens.

  19. Colored Contact Lens Dangers

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    Full Text Available ... Eye By Non-Prescription Contact Lens Laura: Vision Loss After Just 10 Hours Robyn: Blurry Vision and ... Therapy Approved to Treat Rare Cause of Vision Loss DEC 21, 2017 By Dan Gudgel The U.S. ...

  1. Colored Contact Lens Dangers

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    Full Text Available ... had not been properly fitted by an eye care professional, the lenses stuck to my eye like ... lenses do not require the same level of care or consideration as a standard contact lens because ...

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  5. Rethinking contact lens aftercare.

    Science.gov (United States)

    Efron, Nathan; Morgan, Philip B

    2017-09-01

    The evolution of contact lens technology and clinical practice over the past three decades has been remarkable, with dramatic improvements in material biocompatibility, better lens designs and care systems, and more flexible and convenient modalities of wear. However, our approach to the aftercare examination has remained conservative, with the general modus operandi having not fully evolved from the difficult, early years of fitting non-regular replacement rigid and low water content hydrogel lenses. In this paper, we review current aftercare practice and in particular, the preferred frequency that lens wearers should return for routine visits and the appropriateness of regulations governing contact lens prescription expiry. Four key clinical reasons for conducting a routine aftercare visit are identified: preserving ocular health, maintaining good vision, optimising comfort and ensuring satisfactory lens fitting performance. Commercial reasons for conducting aftercare visits are also considered. A decision matrix is presented to help practitioners decide on an appropriate time interval between routine aftercare visits. The first aftercare visit should always take place within one to two weeks of lens dispensing. After this, the following time intervals between routine aftercare visits are advised as a general guideline: soft daily disposable, 24 months; soft daily reusable and rigid daily wear, 12 months; soft and rigid extended wear, six months. These aftercare visit frequencies may need to be adjusted when rapid rates of refractive change are anticipated, such as every six months during child/teenager myopic progression and every 12 months during the advancement of presbyopia. Numerous clinical caveats for varying these recommended aftercare frequencies are also discussed. Those new to lens wear should be seen within the first two months of lens dispensing. Regulatory authorities charged with the responsibility of stipulating the validity of a contact

  6. Contact Lens Risks

    Science.gov (United States)

    ... any lens solution. Do not expose your contact lenses to any water: tap, bottled, distilled, lake or ocean water. Never ... resistant to treatment and cure. Remove your contact lenses before swimming. ... in swimming pool water, hot tubs, lakes and the ocean Replace your ...

  7. Colored Contact Lens Dangers

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    Full Text Available ... in the United States. All contact lenses are medical devices that require a prescription and proper fitting by an eye-care professional. ... care professional such as an ophthalmologist — an eye medical doctor — who will ... a valid prescription that includes the brand name, lens measurements, and ...

  8. Prolonging contact lens wear and making contact lens wear safer.

    Science.gov (United States)

    Foulks, Gary N

    2006-02-01

    To summarize the present status of safety and efficacy of contact lens wear. Literature review. Ovid Medline searches were performed on records from 1966 through 2005 using keywords: keratitis, contact lens complications, extended-wear contact lenses, and silicone-hydrogel contact lenses. Patients desire comfort, clarity of vision, and prolonged contact lens wear when contact lenses are used to correct refractive error. Practitioners desire patient satisfaction but also require maintenance of the integrity of the eye and no complications that jeopardize vision or health of the eye. Improvements in the oxygen permeability of the contact lens materials, design of the contact lens and its surface, and solutions for the maintenance of the lens have reduced but not eliminated the risks of infection, inflammation, and conjunctival papillary reaction associated with contact lens wear. The lessons of past and recent history suggest that patient education and practitioner participation in the management of contact lens wear continue to be critical factors for patient satisfaction and safety in the extended wear of contact lenses. The availability of highly oxygen permeable contact lenses has increased the tolerance and safety of extended contact lens wear, but patient instruction and education in proper use and care of lenses is required and caution is advised.

  9. Contact lens correction of presbyopia.

    Science.gov (United States)

    Morgan, Philip B; Efron, Nathan

    2009-08-01

    The ageing population highlights the need to provide effective optical solutions for presbyopic contact lens wearers. However, data gathered from annual contact lens fitting surveys demonstrate that fewer than 40% of contact lens wearers over 45 years of age (virtually all of whom can be presumed to suffer a partial or complete loss of accommodation) are prescribed a presbyopic correction. Furthermore, monovision is prescribed as frequently as multifocal lenses. These observations suggest that an optimal solution to the contact lens correction of presbyopia remains elusive.

  10. A Prototype Antifungal Contact Lens

    OpenAIRE

    Ciolino, Joseph B; Hudson, Sarah P.; Mobbs, Ashley N.; Hoare, Todd R.; Iwata, Naomi G.; Fink, Gerald R.; Kohane, Daniel S.

    2011-01-01

    Econazole-eluting contact lenses with a novel design provided extended antifungal activity against the Candida albicans fungus. This drug-eluting contact lens could be used to treat and prevent fungal ocular infections.

  11. Focusing on Contact Lens Safety

    Science.gov (United States)

    ... these solutions require special care. Always remove contact lenses before swimming. Never reuse any lens solution. Always discard all of the used solution after each use, and add fresh solution to your lens case. Do not expose your contacts to any water (which includes lake, pond, and ocean water as ...

  12. Shack-Hartmann wave front measurements in cortical tissue for deconvolution of large three-dimensional mosaic transmitted light brightfield micrographs.

    Science.gov (United States)

    Oberlaender, M; Broser, P J; Sakmann, B; Hippler, S

    2009-02-01

    We present a novel approach for deconvolution of 3D image stacks of cortical tissue taken by mosaic/optical-sectioning technology, using a transmitted light brightfield microscope. Mosaic/optical-sectioning offers the possibility of imaging large volumes (e.g. from cortical sections) on a millimetre scale at sub-micrometre resolution. However, a blurred contribution from out-of-focus light results in an image quality that usually prohibits 3D quantitative analysis. Such quantitative analysis is only possible after deblurring by deconvolution. The resulting image quality is strongly dependent on how accurate the point spread function used for deconvolution resembles the properties of the imaging system. Since direct measurement of the true point spread function is laborious and modelled point spread functions usually deviate from measured ones, we present a method of optimizing the microscope until it meets almost ideal imaging conditions. These conditions are validated by measuring the aberration function of the microscope and tissue using a Shack-Hartmann sensor. The analysis shows that cortical tissue from rat brains embedded in Mowiol and imaged by an oil-immersion objective can be regarded as having a homogeneous index of refraction. In addition, the amount of spherical aberration that is caused by the optics or the specimen is relatively low. Consequently the image formation is simplified to refraction between the embedding and immersion medium and to 3D diffraction at the finite entrance pupil of the objective. The resulting model point spread function is applied to the image stacks by linear or iterative deconvolution algorithms. For the presented dataset of large 3D images the linear approach proves to be superior. The linear deconvolution yields a significant improvement in signal-to-noise ratio and resolution. This novel approach allows a quantitative analysis of the cortical image stacks such as the reconstruction of biocytin-stained neuronal dendrites

  13. Contact lens care in keratoconus.

    Science.gov (United States)

    Zhou, Alana J; Kitamura, Keiko; Weissman, Barry A

    2003-12-01

    To quantify the complexity involved in fitting contact lenses on the eyes of patients with keratoconus. The contact lens care of one randomly selected eye each of 38 keratoconus patients was retrospectively analyzed and compared to that of 38 gender and age matched controls. We evaluated the number of diagnostic contact lenses used to establish the initial contact lens order, number of ordered rigid gas permeable (RGP) contact lenses needed to complete the fit, number of office visits during the initial 4 months of care, best spectacle and RGP contact lenses corrected Log MAR visual acuities, complications encountered, and whether or not the patient was successful in contact lens wear. Keratoconic eyes statistically used more diagnostic lenses, more ordered lenses, and more office visits than did normal eyes. Visual acuities improved from an average of 20/40 with spectacles to an average of 20/20 by use of RGP contact lenses in keratoconic eyes. Visions were corrected to 20/20 with both spectacles and contact lenses in control eyes. Sixty nine percent (69%) of keratoconic eyes and 95% of controls were successful in contact lens wear. Contact lens care of keratoconic eyes is more challenging than care of normal eyes because of the need for more diagnostic and ordered contact lenses and the use of more professional time. Keratoconic eyes may suffer more complications than normals during contact lens care, but this does not affect the success rates, and such patients benefit from enhanced visual acuity with RGP contact lenses compared to that achieved with spectacles.

  14. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... be purchased over-the-counter or on the Internet," says Thomas Steinemann, MD, professor of ophthalmology at ... Lens-Related Eye Infections Mar 01, 2017 New Technology Helps the Legally Blind Be More Independent Oct ...

  15. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Lens-Related Eye Infections Mar 01, 2017 New Technology Helps the Legally Blind Be More Independent Oct ... Privacy Policy Terms of Service For Advertisers For Media Ophthalmology Job Center © American Academy of Ophthalmology 2017 ...

  16. Colored Contact Lens Dangers

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    Full Text Available ... People, Real Problems with Colored Contact Lenses Julian: Teenager Blinded In One Eye By Non-Prescription Contact ... colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses you are ...

  17. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... or in beauty salons, novelty shops or in pop-up Halloween stores are not FDA-approved and are ... Lens-Related Eye Infections Mar 01, 2017 New Technology Helps the Legally Blind Be More Independent Oct ...

  18. [Contact lens care and maintenance].

    Science.gov (United States)

    Bloise, L

    2017-04-01

    All contact lenses with replacement schedules longer than daily must be maintained. At each step of their use, the lenses may be contaminated. Contact lens solutions perform the essential functions of cleaning, decontaminating and preserving the lenses to prevent infectious problems and improve wearing comfort. Contact lens contamination essentially comes from hands, cleaning solutions, cases, water and the environment. The pathogenic microorganisms are mainly Gram-negative bacteria, fungi and amoebae. Contact lens deposits may or may not have an organic origin. Their presence increases the risk of infection because they serve as a nutrient matrix for microbes, and they are responsible for wearing discomfort. Contact lens solutions differ in their composition, their mechanism of action and the concentration of the various agents. To prescribe the best lens care system to each wearer and for each material, it is necessary to be very familiar with them. Maintenance is the main cause of discomfort with contact lenses, either through improper use, solution-material incompatibility, or a reaction of the wearer to the components. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Halloween is a popular time for people to use colored contact lenses to enhance their costumes. From ... Blurry Vision and Daily Eye Drops After One Use Facts About Colored Contacts and Halloween Safety Colored ...

  20. Colored Contact Lens Dangers

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    Full Text Available ... Cleveland. "This is far from the truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager ... Counter Costume Contact Lenses Can Ruin Vision Eye Makeup Safety In fact, it is illegal to sell ...

  1. Colored Contact Lens Dangers

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    Full Text Available ... contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses you are considering ... Follow The Academy Professionals: Education Guidelines News Multimedia Public & Patients: Contact Us About the Academy Jobs at ...

  2. Colored Contact Lens Dangers

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    Full Text Available ... popping touch. But colored contact lenses are popular year-round, not just at Halloween. But few know ... contact lenses for Halloween or any time of year, follow these guidelines: Get an eye exam from ...

  3. Colored Contact Lens Dangers

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    Full Text Available ... like a suction cup." Halloween is a popular time for people to use colored contact lenses to ... wear costume contact lenses for Halloween or any time of year, follow these guidelines: Get an eye ...

  4. Colored Contact Lens Dangers

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    Full Text Available ... is far from the truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager Blinded In ... colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses you are ...

  5. Colored Contact Lens Dangers

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    Full Text Available ... contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses you are considering buying approved by the FDA? Check the FDA's database of approved contact lenses . Related Stories Gene Therapy ...

  6. Colored Contact Lens Dangers

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    Full Text Available ... and are being sold illegally," Dr. Steinemann said. Never buy colored contact lenses from a retailer that ... directions for cleaning, disinfecting, and wearing the lenses. Never share contact lenses with another person. Get follow ...

  7. Colored Contact Lens Dangers

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    Full Text Available ... buy colored contact lenses from a retailer that does not ask for a prescription. There is no ... of approved contact lenses . Related Stories How long does it take the eye to go back to ...

  8. Colored Contact Lens Dangers

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    Full Text Available ... contact lenses, remove the lenses and seek immediate medical attention from an ophthalmologist. Related resources: Learn how to properly care for contact lenses . Learn about the members of ...

  9. Colored Contact Lens Dangers

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    Full Text Available ... Costume Contact Lenses Can Ruin Vision Eye Makeup Safety In fact, it is illegal to sell colored contact lenses without a prescription in the United States. All contact lenses are medical devices that require a prescription and proper fitting by ...

  10. [Contact lens-related keratitis].

    Science.gov (United States)

    Steiber, Zita; Berta, András; Módis, László

    2013-11-10

    Nowadays, keratitis, corneal infection due to wearing contact lens means an increasingly serious problem. Neglected cases may lead to corneal damage that can cause blindness in cases of otherwise healthy eyes. Early diagnosis based on the clinical picture and the typical patient history is an important way of prevention. Prophylaxis is substantial to avoid bacterial and viral infection that is highly essential in this group of diseases. Teaching contact lens wearers the proper contact lens care, storage, sterility, and hygiene regulations is of great importance. In case of corneal inflammation early accurate diagnosis supported by microbiological culture from contact lenses, storage boxes or cornea is very useful. Thereafter, targeted drug therapy or in therapy-resistant cases surgical treatment may even be necessary in order to sustain suitable visual acuity.

  11. Fabricating customized hydrogel contact lens

    OpenAIRE

    Andre Childs; Hao Li; Daniella M. Lewittes; Biqin Dong; Wenzhong Liu; Xiao Shu; Cheng Sun; Zhang, Hao F.

    2016-01-01

    Contact lenses are increasingly used in laboratories for in vivo animal retinal imaging and pre-clinical studies. The lens shapes often need modification to optimally fit corneas of individual test subjects. However, the choices from commercially available contact lenses are rather limited. Here, we report a flexible method to fabricate customized hydrogel contact lenses. We showed that the fabricated hydrogel is highly transparent, with refractive indices ranging from 1.42 to 1.45 in the spe...

  12. Multifocal contact lens myopia control.

    Science.gov (United States)

    Walline, Jeffrey J; Greiner, Katie L; McVey, M Elizabeth; Jones-Jordan, Lisa A

    2013-11-01

    Previous studies on soft multifocal contact lens myopia control published in the peer-reviewed literature reported findings of noncommercial contact lenses worn for 1 year or less. This study sought to determine the progression of myopia and axial elongation of children fitted with commercially available distance center soft multifocal contact lenses for 2 years. Eight- to eleven-year-old children with -1.00 D to -6.00 D spherical component and less than 1.00 D astigmatism were fitted with soft multifocal contact lenses with a +2.00 D add (Proclear Multifocal "D"; CooperVision, Fairport, NY). They were age- and gender-matched to participants from a previous study who were fitted with single-vision contact lenses (1 Day Acuvue; Vistakon, Jacksonville, FL). A-scan ultrasound and cycloplegic autorefraction were performed at baseline, after 1 year, and after 2 years. Multilevel modeling was used to compare the rate of change of myopia and axial length between single-vision and soft multifocal contact lens wearers. Forty participants were fitted with soft multifocal contact lenses, and 13 did not contribute complete data (5 contributed 1 year of data). The adjusted mean ± standard error spherical equivalent progression of myopia at 2 years was -1.03 ± 0.06 D for the single-vision contact lens wearers and -0.51 ± 0.06 for the soft multifocal contact lens wearers (p < 0.0001). The adjusted mean axial elongation was 0.41 ± 0.03 and 0.29 ± 0.03 for the single-vision and soft multifocal contact lens wearers, respectively (p < 0.0016). Soft multifocal contact lens wear resulted in a 50% reduction in the progression of myopia and a 29% reduction in axial elongation during the 2-year treatment period compared to a historical control group. Results from this and other investigations indicate a need for a long-term randomized clinical trial to investigate the potential for soft multifocal contact lens myopia control.

  13. Colored Contact Lens Dangers

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    Full Text Available ... People, Real Problems with Colored Contact Lenses Julian: Teenager Blinded In One Eye By Non-Prescription Contact ... the United States. Gene Therapy May Be a Game-Changer for People With ... Professionals Link your website to EyeSmart Embed EyeSmart videos on your website Promotional materials for eye health ...

  14. Colored Contact Lens Dangers

    Science.gov (United States)

    ... People, Real Problems with Colored Contact Lenses Julian: Teenager Blinded In One Eye By Non-Prescription Contact ... the United States. Gene Therapy May Be a Game-Changer for People With ... Professionals Link your website to EyeSmart Embed EyeSmart videos on your website Promotional materials for eye health ...

  15. Colored Contact Lens Dangers

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    Full Text Available ... in Cleveland. "This is far from the truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager Blinded ... use of colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses ...

  16. Colored Contact Lens Dangers

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    Full Text Available ... Global Ophthalmology Guide Eye Health Find an Ophthalmologist Academy Store Eye Health A-Z Symptoms Glasses & Contacts Tips & Prevention News ... videos on your website Promotional materials for eye health observances EyeSmart resources are also available in Spanish . Follow The ... Public & Patients: Contact ...

  17. Colored Contact Lens Dangers

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    Full Text Available ... medical attention from an ophthalmologist. Related resources: Learn how to properly care for contact lenses . Learn about the ... FDA's database of approved contact lenses . Related Stories How long does it take the eye to go back to its original shape after wearing ...

  18. Colored Contact Lens Dangers

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    Full Text Available ... Halloween Hazard: The Hidden Dangers of Buying Decorative Contact Lenses Without a Prescription Leer en Español: Peligros asociados ... the truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager Blinded In One Eye By Non- ...

  19. Colored Contact Lens Dangers

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    Full Text Available ... from the truth." Real People, Real Problems with Colored Contact Lenses Julian: Teenager Blinded In One Eye By Non- ... Safety In fact, it is illegal to sell colored contact lenses without a prescription in the United States. All ...

  20. Contact lens hygiene compliance and lens case contamination: A review.

    Science.gov (United States)

    Wu, Yvonne Tzu-Ying; Willcox, Mark; Zhu, Hua; Stapleton, Fiona

    2015-10-01

    A contaminated contact lens case can act as a reservoir for microorganisms that could potentially compromise contact lens wear and lead to sight threatening adverse events. The rate, level and profile of microbial contamination in lens cases, compliance and other risk factors associated with lens case contamination, and the challenges currently faced in this field are discussed. The rate of lens case contamination is commonly over 50%. Coagulase-negative Staphylococcus, Bacillus spp., Pseudomonas aeruginosa and Serratia marcescens are frequently recovered from lens cases. In addition, we provide suggestions regarding how to clean contact lens cases and improve lens wearers' compliance as well as future lens case design for reducing lens case contamination. This review highlights the challenges in reducing the level of microbial contamination which require an industry wide approach. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  1. Colored Contact Lens Dangers

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    Full Text Available ... Hidden Dangers of Buying Decorative Contact Lenses Without a Prescription Leer en Español: Peligros asociados con los ... 2013 It started as an impulsive buy from a souvenir shop, but 10 hours after she first ...

  2. Colored Contact Lens Dangers

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    Full Text Available ... FDA's database of approved contact lenses . Related Stories Gene Therapy May Be a Game-Changer for People ... Eyes Aug 16, 2016 More Eye Health News Gene Therapy May Be a Game-Changer for People ...

  3. Colored Contact Lens Dangers

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    Full Text Available ... sell contacts without a prescription are breaking the law, and may be fined $11,000 per violation. " ... American Academy of Ophthalmology 2017 Our Sites EyeWiki International Society of Refractive Surgery * Required * First Name: * Last ...

  4. Colored Contact Lens Dangers

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    Full Text Available ... she said. "I now live with a corneal scar, vision damage and a drooping eyelid." To safely ... database of approved contact lenses . Related Stories Gene Therapy May Be a Game-Changer for People With ...

  5. Colored Contact Lens Dangers

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    Full Text Available ... Multimedia Public & Patients: Contact Us About the Academy Jobs at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of Service For Advertisers For Media Ophthalmology ...

  6. Colored Contact Lens Dangers

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    Full Text Available ... use of colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses ... and Your Eyes Aug 16, 2016 More Eye Health News Gene Therapy May Be a Game-Changer ...

  7. Colored Contact Lens Dangers

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    Full Text Available ... about the members of the eye-care team . Consumer warning about the improper use of colored contact ... Eyes SEP 20, 2017 By Dan Gudgel A report published in a medical journal reinforces what that ...

  8. Colored Contact Lens Dangers

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    Full Text Available ... New Dry Eye Treatment is a Tear-Jerker JUL 21, 2017 By Susanne Medeiros Patients suffering from ... ointments. 27 Contact Lenses Found in Woman’s Eye JUL 17, 2017 By Susanne Medeiros and Beatrice Shelton ...

  9. Colored Contact Lens Dangers

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    Full Text Available ... medical attention from an ophthalmologist. Related resources: Learn how to properly care for contact lenses . Learn about ... People With Inherited Retinal Disease Oct 30, 2017 How long does it take the eye to go ...

  10. Colored Contact Lens Dangers

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    Full Text Available ... Ophthalmology Guide Eye Health Find an Ophthalmologist Academy Store Eye Health A-Z Symptoms Glasses & Contacts Tips & ... salons, novelty shops or in pop-up Halloween stores are not FDA-approved and are being sold ...

  11. Colored Contact Lens Dangers

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    Full Text Available ... lentes de contacto de color Sep. 26, 2013 It started as an impulsive buy from a souvenir ... Can Ruin Vision Eye Makeup Safety In fact, it is illegal to sell colored contact lenses without ...

  12. Colored Contact Lens Dangers

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    Full Text Available ... Patient Stories Español Eye Health / News Halloween Hazard: The Hidden Dangers of Buying Decorative Contact Lenses Without a Prescription Leer en Español: Peligros asociados con los ...

  13. Colored Contact Lens Dangers

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    Full Text Available ... in beauty salons, novelty shops or in pop-up Halloween stores are not FDA-approved and are ... share contact lenses with another person. Get follow up exams with your eye care provider. If you ...

  14. Colored Contact Lens Dangers

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    Full Text Available ... use of colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses you are ... With Inherited Retinal Disease Oct 30, 2017 How long does it take ...

  15. Colored Contact Lens Dangers

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    Full Text Available ... sell contacts without a prescription are breaking the law, and may be fined $11,000 per violation. " ... Academy of Ophthalmology 2017 Our Sites EyeWiki International Society of Refractive Surgery * Required * First Name: * Last Name: ...

  16. Colored Contact Lens Dangers

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    Full Text Available ... for people to use colored contact lenses to enhance their costumes. From blood-drenched vampire eyes to ... Ophthalmologist Browse Answers Free Newsletter Get ophthalmologist-reviewed tips and information about eye health and preserving your ...

  17. Colored Contact Lens Dangers

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    Full Text Available ... The Academy Professionals: Education Guidelines News Multimedia Public & Patients: Contact Us About the Academy Jobs at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of ...

  18. Colored Contact Lens Dangers

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    Full Text Available ... MD, professor of ophthalmology at Case Western Reserve University in Cleveland. "This is far from the truth." ... Multimedia Public & Patients: Contact Us About the Academy Jobs at the Academy Financial Relationships with Industry Medical ...

  19. Colored Contact Lens Dangers

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    Full Text Available ... Hidden Dangers of Buying Decorative Contact Lenses Without a Prescription Leer en Español: Peligros asociados con los ... contacto de color Sep. 26, 2013 It started as an impulsive buy from a souvenir shop, but ...

  20. Colored Contact Lens Dangers

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    Full Text Available ... contact lenses for Halloween or any time of year, follow these guidelines: Get an eye exam from a licensed eye care professional such as an ophthalmologist — an eye medical ...

  1. Colored Contact Lens Dangers

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    Full Text Available ... colored contact lenses to enhance their costumes. From blood-drenched vampire eyes to glow-in-the-dark ... properly fitted may scratch the eye or cause blood vessels to grow into the cornea. Even if ...

  2. Colored Contact Lens Dangers

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    Full Text Available ... Health A-Z Symptoms Glasses & Contacts Tips & Prevention News Ask an Ophthalmologist Patient Stories Español Eye Health / News Halloween Hazard: The Hidden Dangers of Buying Decorative ...

  3. Colored Contact Lens Dangers

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    Full Text Available ... by an eye care professional, the lenses stuck to my eye like a suction cup." Halloween is a popular time for people to use colored contact lenses to enhance their costumes. ...

  4. Colored Contact Lens Dangers

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    Full Text Available ... Patient Stories Español Eye Health / News Halloween Hazard: The Hidden Dangers of Buying Decorative Contact Lenses Without ... been properly fitted by an eye care professional, the lenses stuck to my eye like a suction ...

  5. Colored Contact Lens Dangers

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    Full Text Available ... videos on your website Promotional materials for eye health observances EyeSmart resources are also available in Spanish . Follow The Academy Professionals: Education Guidelines News Multimedia Public & Patients: Contact Us About the Academy Jobs at ...

  6. Colored Contact Lens Dangers

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    Full Text Available ... colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses you are ... from dry eye now have a completely new, drug-free alternative to lubricating eye drops and topical ...

  7. Colored Contact Lens Dangers

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    Full Text Available ... Tips & Prevention News Ask an Ophthalmologist Patient Stories Español Eye Health / News Halloween Hazard: The Hidden Dangers ... Decorative Contact Lenses Without a Prescription Leer en Español: Peligros asociados con los lentes de contacto de ...

  8. Colored Contact Lens Dangers

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    Full Text Available ... be purchased over-the-counter or on the Internet," says Thomas Steinemann, MD, professor of ophthalmology at Case Western Reserve University in Cleveland. "This is far from the truth." Real People, Real Problems with Colored Contact Lenses Julian: ...

  9. Colored Contact Lens Dangers

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    Full Text Available ... contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses you are considering ... By Dan Gudgel The U.S. Food and Drug Administration has approved sales of a gene therapy treatment ...

  10. Colored Contact Lens Dangers

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    Full Text Available ... Professionals Link your website to EyeSmart Embed EyeSmart videos on your website Promotional materials for eye health observances EyeSmart resources are also available in Spanish . Follow The Academy Professionals: Education Guidelines News Multimedia Public & Patients: Contact Us About ...

  11. Colored Contact Lens Dangers

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    Full Text Available ... colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses you are ... 2017 By Dan Gudgel The U.S. Food and Drug Administration has approved sales of a gene therapy ...

  12. Colored Contact Lens Dangers

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    Full Text Available ... eye health observances EyeSmart resources are also available in Spanish . Follow The Academy Professionals: Education Guidelines News Multimedia Public & Patients: Contact Us About the Academy Jobs at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms ...

  13. Colored Contact Lens Dangers

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    Full Text Available ... Retailers that sell contacts without a prescription are breaking the law, and may be fined $11,000 per violation. "Many of the lenses found online or in beauty salons, novelty shops or in pop-up Halloween stores are not FDA-approved and are ...

  14. Colored Contact Lens Dangers

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    Full Text Available ... Facts Over-the-Counter Costume Contacts May Contain Chemicals Harmful to Eyes Four Ways Over-the-Counter ... vision. Privacy Policy Free EyeSmart Resources for Professionals Link your website to EyeSmart Embed EyeSmart videos on ...

  15. Colored Contact Lens Dangers

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    Full Text Available ... use of colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses ... DEC 21, 2017 By Dan Gudgel The U.S. Food and Drug Administration has approved sales of a ...

  16. Colored Contact Lens Dangers

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    Full Text Available ... FDA's database of approved contact lenses . Related Stories Gene Therapy May Be a Game-Changer for People With ... Eyes Aug 16, 2016 More Eye Health News Gene Therapy May Be a Game-Changer for People With ...

  17. Colored Contact Lens Dangers

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    Full Text Available ... seek immediate medical attention from an ophthalmologist. Related resources: Learn how to properly care for contact lenses . ... and preserving your vision. Privacy Policy Free EyeSmart Resources for Professionals Link your website to EyeSmart Embed ...

  18. Compliance among soft contact lens wearers.

    OpenAIRE

    Kuzman, Tomislav; Barišić Kutija, Marija; Masnec, Sanja; Jandroković, Sonja; Mrazovac, Danijela; Jurišić, Darija; Škegro, Ivan; Kalauz, Miro; Kordić, Rajko

    2014-01-01

    Contact lens compliance is proven to be crucial for preventing lens wear-related complications because of the interdependence of the steps in lens care regime and their influence on lens system microbial contamination. Awareness of the patients' lens handling compliance as well as correct recognition of non-compliant behaviours is the basis for creating more targeted strategies for patient education. The aim of this study was to investigate compliance among soft contact lens (SCL) wearers in ...

  19. Fabricating customized hydrogel contact lens

    Science.gov (United States)

    Childs, Andre; Li, Hao; Lewittes, Daniella M.; Dong, Biqin; Liu, Wenzhong; Shu, Xiao; Sun, Cheng; Zhang, Hao F.

    2016-10-01

    Contact lenses are increasingly used in laboratories for in vivo animal retinal imaging and pre-clinical studies. The lens shapes often need modification to optimally fit corneas of individual test subjects. However, the choices from commercially available contact lenses are rather limited. Here, we report a flexible method to fabricate customized hydrogel contact lenses. We showed that the fabricated hydrogel is highly transparent, with refractive indices ranging from 1.42 to 1.45 in the spectra range from 400 nm to 800 nm. The Young’s modulus (1.47 MPa) and hydrophobicity (with a sessile drop contact angle of 40.5°) have also been characterized experimentally. Retinal imaging using optical coherence tomography in rats wearing our customized contact lenses has the quality comparable to the control case without the contact lens. Our method could significantly reduce the cost and the lead time for fabricating soft contact lenses with customized shapes, and benefit the laboratorial-used contact lenses in pre-clinical studies.

  20. Comparing the Optical Properties of Soft Contact Lenses On and Off the Eye

    Science.gov (United States)

    Kollbaum, Pete S.; Bradley, Arthur; Thibos, Larry N.

    2014-01-01

    Purpose The purpose of the current study was to examine the on- and off-eye optical performance of two types of soft contact lenses (hydrogel and silicone hydrogel). Methods The monochromatic aberrations (lambda = 850 nm) of contact lenses were measured on-eye using a clinical Shack-Hartmann ocular aberrometer. Additionally, we used an off-eye single-pass contact lens aberrometer (lambda = 540 nm) in which the soft contact lens was placed within a wet cell. Comparison of the lower and higher order aberrations measured with these two methods required compensation for different wavelengths and knowledge of the refractive index of the contact lens materials. Results The measured on-eye sphere and spherical aberration values were generally similar to those measured off-eye and those specified by the lens manufacturers for both types of soft contact lenses. However, there were notable differences, especially for high plus-powered lenses, which typically exhibited lower sphere power on the eye than expected from the lens specifications and from the off-eye measured powers, both of which were almost identical. Longitudinal spherical aberration varied with lens power in the hydrogel lenses, as expected from geometrical optics theory. Longitudinal spherical aberration measurements on- and off-eye, however, deviated significantly from that expected of a thin lens with spherical surfaces due to surface asphericities. The difference between on- and off-eye optics can be modeled as a tear lens, or as relative lens thickness changes caused by lens flexure. Conclusions The results of the current study reveal that the major difference between the on-eye lens optics and the manufacturers’ specifications are not due to lens errors, but due to eye-lens interactions, which could be either lens flexure or a tear lens forming behind the soft contact lens. PMID:23969894

  1. CONTACT LENS RELATED CORNEAL ULCER

    Directory of Open Access Journals (Sweden)

    AGARWAL P

    2010-01-01

    Full Text Available A corneal ulcer caused by infection is one of the major causes of blindness worldwide. One of the recent health concerns is the increasing incidence of corneal ulcers associated with contact lens user especially if the users fail to follow specific instruction in using their contact lenses. Risk factors associated with increased risk of contact lens related corneal ulcers are:overnight wear, long duration of continuous wear, lower socio-economic classes, smoking, dry eye and poor hygiene. The presenting symptoms of contact lens related corneal ulcers include eye discomfort, foreign body sensation and lacrimation. More serious symptoms are redness (especially circum-corneal injection, severe pain, photophobia, eye discharge and blurring of vision. The diagnosis is established by a thorough slit lamp microscopic examination with fluorescein staining and corneal scraping for Gram stain and culture of the infective organism. Delay in diagnosing and treatment can cause permanent blindness, therefore an early referral to ophthalmologist and commencing of antimicrobial therapy can prevent visual loss.

  2. Histochemical analysis of bandage contact lens precipitates.

    Science.gov (United States)

    Nessim, Maged; Pandey, Suresh K; Werner, Liliana; Mohammed, Musadiq; Kumar, Vinod

    2008-02-01

    Contact lens deposits have been reported previously with extended wear of soft contact lenses, with proteins, lipids, mucous, and various salts such as chloride, potassium and calcium being deposited on the lens surface [1]. We report an unusual case of precipitates on the surface of a bandage contact lens (BCL) following intensive treatment with topical preservative free artificial tears. Evaluation included microscopic and histochemical analysis of the BCL. We have also reviewed the literature for previous reports of contact lens precipitates.

  3. Contact Lens-related Complications: A Review.

    Science.gov (United States)

    Alipour, Fateme; Khaheshi, Saeed; Soleimanzadeh, Mahya; Heidarzadeh, Somayeh; Heydarzadeh, Sepideh

    2017-01-01

    Contact lens-related problems are common and can result in severe sight-threatening complications or contact lens drop out if not addressed properly. We systematically reviewed the most important and the most common contact lens-related complications and their diagnosis, epidemiology, and management according to the literature published in the last 20 years.

  4. Contact lens-related complications: A review

    Directory of Open Access Journals (Sweden)

    Fateme Alipour

    2017-01-01

    Full Text Available Contact lens-related problems are common and can result in severe sight-threatening complications or contact lens drop out if not addressed properly. We systematically reviewed the most important and the most common contact lens-related complications and their diagnosis, epidemiology, and management according to the literature published in the last 20 years.

  5. Contact Lens-related Complications: A Review

    Science.gov (United States)

    Alipour, Fateme; Khaheshi, Saeed; Soleimanzadeh, Mahya; Heidarzadeh, Somayeh; Heydarzadeh, Sepideh

    2017-01-01

    Contact lens-related problems are common and can result in severe sight-threatening complications or contact lens drop out if not addressed properly. We systematically reviewed the most important and the most common contact lens-related complications and their diagnosis, epidemiology, and management according to the literature published in the last 20 years. PMID:28540012

  6. Clinical survey of lens care in contact lens patients.

    Science.gov (United States)

    Ky, W; Scherick, K; Stenson, S

    1998-10-01

    Overall, contact lenses provide a safe and effective modality for vision correction. However, problems do occasionally arise. Up to 80% of contact lens complications can be traced to poor patient compliance with recommended lens care guidelines. We conducted a survey to evaluate the level of patient compliance in specific areas of lens care and maintenance and to assess patient knowledge of basic contact lens information. Patients were asked to complete an anonymous 15 question survey that focused on lens care--specifically the use of contact lens cleaners, methods of disinfection, enzyme treatments, use of rewetting drops, and the frequency of follow-up exams. In addition, the survey included six true/false questions relating to contact lens care and safety. There were a total of 103 participants in the study. Approximately 24% of patients stated they never cleaned their lenses prior to disinfection, and 5% used saline solutions as their primary mode of disinfection. A sizable portion of those surveyed (43% of soft lens wearers and 71% of rigid gas permeable lens wearers) either never used enzyme cleaners or used them less than once a month. Seventy percent of patients either never used rewetting drops or used them less than once a day. Twenty-nine percent of patients consulted their eye care professionals every 2 years and 6% less often than every two years. Six questions assessed patient knowledge of contact lens care safety. Of a possible six out of six correct answers, the mean number of correct responses was 3.74. A sizable proportion of contact lens wearers do not adequately adhere to recommended contact lens care, and many have an inadequate understanding of contact lens care guidelines. Therefore, it is important that practitioners place more emphasis on patient education at the time of initial contact lens fitting and reinforce such instruction during follow-up visits.

  7. Contact lens surface by electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jung Hyuck [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Suk Ju; Hwang, Kwang Ha; Jeon Jin [Dongshin Univ., Naju (Korea, Republic of)

    2011-07-01

    Contact lens materials needs good biocompatibility, high refractive index, high optical transparency, high water content etc. Surface treat method by using plasma and radiation can modify the physical and/or chemical properties of the contact lens surface. Radiation technology such as electron beam irradiation can apply to polymerization reaction and enhance the functionality of the polymer.The purpose of this study is to modify of contact lens surface by using Eb irradiation technology. Electron beam was irradiated to the contact lens surface which was synthesized thermal polymerization method and commercial contact lens to modify physical and chemical properties. Ft-IR, XP, UV-vis spectrophotometer, water content, oxygen trans-metastability were used to characterize the surface state, physicochemical, and optical property of the contact lens treated with Eb. The water content and oxygen transmissibility of the contact lens treated with Eb were increased due to increase in the hydrophilic group such as O-C=O and OH group on the contact lens surface which could be produced by possible reaction between carbon and oxygen during the Eb irradiation. All of the lenses showed the high optical transmittance above 90%. In this case of B/Es, TES, Ti contact lens, the optical transmittance decreased about 5% with increasing Eb dose in the wavelength of UV-B region. The contact lens modified by Eb irradiation could improve the physical properties of the contact lens such as water content and oxygen transmissibility.

  8. Conjunctival impression cytology in contact lens wearers.

    Directory of Open Access Journals (Sweden)

    Simon Priya

    2002-01-01

    Full Text Available PURPOSE: To evaluate the cytological changes in conjunctiva following regular contact lens wear and to determine the correlation, if any, between severity of cytological alteration and symptoms related to contact lens wear. METHODS: One hundred eyes (50 normal asymptomatic subjects who served as a control group were studied by conjunctival impression cytology (CIC. These subjects were fitted with rigid gas permeable (RGP or soft contact lenses and were followed up at the end of 3 and 6 months. At each follow-up visit the CIC was repeated. A filter paper with the impression specimen was stained with periodic acid schiff (PAS and haematoxylin stain to study goblet cell loss. Papanicolaou stain was done to study squamous metaplasia. The cytological changes were graded using the system described by Natadisastra et al. RESULTS: Severity of cytological changes increased with the duration of contact lens wear (P = 0.00001. At the end of 6 months, 60% of symptomatic eyes wearing soft contact lens and RGP lens showed abnormal CIC changes. None of the asymptomatic RGP contact lens wearing eyes showed abnormal CIC changes whereas 33.4% of the asymptomatic soft contact lens wearing eyes showed abnormal CIC changes (P = 0.033. Epithelial changes occurred within 3-6 months of contact lens fitting. CONCLUSION: Severity of cytological changes increased with duration of lens wear (P = 0.00001. Prevalence and severity of cytological alteration is more in symptomatic contact lens wearers. Soft contact lens wearers although asymptomatic showed severe CIC changes.

  9. Contact lens fitting after photorefractive keratectomy.

    OpenAIRE

    Astin, C. L.; Gartry, D S; McG Steele, A. D.

    1996-01-01

    AIMS/BACKGROUND: This study evaluated contact lens fitting and the longer term response of the photorefractive keratectomy (PRK) cornea to lens wear. In PRK for myopia problems such as regression, anterior stromal haze, irregular astigmatism, halo aberration, and anisometropia have been reported. Certain patients therefore require contact lens correction to obtain best corrected visual acuity (BCVA). METHOD: From an original cohort of 80 patients, 15 were dissatisfied with their visual outcom...

  10. Modified suturing contact lens for penetrating keratoplasty.

    Science.gov (United States)

    Kramer, S G; Stewart, H L

    1978-11-01

    The authors have previously described a suturing contact lens that protects the corneal endothelium by aiding in the maintenance of the anterior chamber during penetrating keratoplasty. This report describes structural modifications of the suturing contact lens, which improve its stability and effectiveness. An additional configuration for use in corneal lacerations is presented.

  11. Compliance among soft contact lens wearers.

    Science.gov (United States)

    Kuzman, Tomislav; Kutija, Marija Barisić; Masnec, Sanja; Jandroković, Sonja; Mrazovac, Danijela; Jurisić, Darija; Skegro, Ivan; Kalauz, Miro; Kordić, Rajko

    2014-12-01

    Contact lens compliance is proven to be crucial for preventing lens wear-related complications because of the interdependence of the steps in lens care regime and their influence on lens system microbial contamination. Awareness of the patients' lens handling compliance as well as correct recognition of non-compliant behaviours is the basis for creating more targeted strategies for patient education. The aim of this study was to investigate compliance among soft contact lens (SCL) wearers in different aspects of lens care handling and wearing habits. In our research 50 asymptomatic lens wearers filled out a questionnaire containing demographic data, lens type, hygiene and wearing habits, lenses and lens care system replacement schedule and self-evaluation of contact lens handling hygiene. We established criteria of compliance according to available manufacturer's recommendations, prior literature and our clinical experience. Only 2 (4%) of patients were fully compliant SCL wearers. The most common non-compliant behaviours were insufficient lens solution soaking time (62%), followed by failure to daily exchange lens case solution and showering while wearing lenses. 44% of patients reported storing lenses in saline solution. Mean lens storage case replacement was 3.6 months, with up to 78% patients replacing lens case at least once in 3 months. Average grade in self evaluating level of compliance was very good (4 +/- 0.78) (from 1-poor level of hygiene to 5-great level of hygiene). Lens wearers who reported excessive daily lens wear and more than 10 years of lens wearing experience were also found to be less compliant with other lens system care procedures. (t = -2.99, df=47, p lens system maintenance steps. Most common non-compliant behaviours were the ones that are crucial for maintaining lens sterility and preventing infection. Despite the low objective compliance rate, self grading was relatively high. Therefore, these results indicate the need for patient

  12. Trends of contact lens prescribing in Jordan.

    Science.gov (United States)

    Haddad, Mera F; Bakkar, May; Gammoh, Yazan; Morgan, Philip

    2016-10-01

    To evaluate contact lens prescribing trends among optometrists in Jordan. Optometrists from 173 practices in Jordan were surveyed about prescribing contact lenses in their practice. Practitioners were required to record information for the last 10 patients that visited their practice. Demographic data such as age and gender was obtained for each patient. In addition, data relating to lens type, lens design, replacement methods and the care regime advised to each patient were recorded. Practitioners were required to provide information relating to their education and years of experience. The influence of education and experience with respect to lens prescribing trends was explored using linear regression models for the proportions of lens types fitted for patients. A total of 1730 contact lens fits were analyzed. The mean (±SD) age of lens wearers was 26.6 (±7.9) years, of whom 65% were female. Conventional hydrogel lenses were the most prescribed lenses, accounting for 60.3% of the fits, followed by silicone hydrogel lenses (31.3%), and rigid lenses (8.4%). In terms of lens design, spherical lenses appeared to be most commonly prescribed on monthly basis. Daily disposable lenses were second most prescribed lens modality, accounting for 20.4% of the study sample. Multi-purpose solution (MPS) was the preferred care regimen, with a prevalence of 88.1% reported in the study sample, compared to hydrogen peroxide (1-step and 2-step), which represented only 2.8% of the patients in this study. A relationship was established between the two educational groups for rigid lens prescribing (F=17.4, p<0.0001), while the experience of the optometrist was not a significant factor (F=0.4, p=0.54). This work has provides an up-to-date analysis of contact lens prescribing trends among optometrists in Jordan. Contact lens prescribing in terms of lens type, lens design, modality of wear and care regimen agree with global market trends with small variations. This report will help

  13. Lens surface roughening for tears invariant contact lens performance

    Science.gov (United States)

    Zalevsky, Zeev; Azogui, Jonathan; Limon, Ofer; Rudnitsky, Arkady

    2014-03-01

    In many extended depth of focus diffractive or interferometry based ophthalmic contact lenses the time varied tears layers affect the ophthalmic functionality of the lens. In this paper we present a new approach involving nano pillars realized inside the grooves of a contact lens aiming to implement any type of extended depth of focus or diffractive optical element for ophthalmic applications in order to solve the micro fluidics layer uncertainty within the micro sag features.

  14. [Contact lens in children: epidemiological aspects].

    Science.gov (United States)

    Salame, André Luiz Alves; Simon, Eduardo José Maidana; Leal, Fernando; Lipener, César; Brocchetto, Daniela

    2008-01-01

    To describe the epidemiology of children submitted to contact lens fit. Retrospective study of 73 children that had been submitted to contact lens fit at the "Universidade Federal de São Paulo". This study analyzed sex distribution, age, diagnosis, indications and contact lens fitted at first examination. 34 children (46.6%) were male and 39 (53.4%) female, aged between 2 and 12 years with mean of 10.2 and standard deviation of 2.42. The most common diagnosis was aphakia, in 16 (21.9%) cases. Keratoconus was present in 14 (19.1%), leucoma in 11 (15%), anisometropia in 10 (13.7%), refractive errors in 9 (12.3%), irregular astigmatism in 7 (9.5%), ectopia lentis in 4 (5.4%), high myopia in one case (1.3%) and one child (1.3%) had no ocular pathology, just wishing to change eye color. 52 (71.2%) had medical indication, 9 (12.3%) had optical indication and 12 (16.4%) had cosmetic indication. Contact lenses were fitted in 103 eyes, the most tested lens was rigid gas permeable in 43 (41.7%), soft lens in 41 (39.8%) and cosmetic soft lens in 11 (10.6%). Aphakia was the most common diagnosis among children in use of contact lens. The incidence of medical indication was higher than the others and the most tested lens was the rigid gas permeable one.

  15. Microbial contamination of contact lens storage cases and domestic tap water of contact lens wearers.

    Science.gov (United States)

    Üstüntürk, Miray; Zeybek, Zuhal

    2012-11-01

    Contact lenses have been widely used as an alternative to spectacles both in developed and developing countries. However, under certain circumstances, adverse responses can occur during contact lens wear and several microorganisms--including bacteria, fungi, and free living amoebae--can cause several eye infections in wearers. Extended wear of contact lenses is the major risk factor of eye infections such as microbial keratitis, besides contaminated contact lens storage case, contaminated lens care solutions, and inaccurate contact lens handling. In this study, we collected contact lens storage case and domestic tap water samples from 50 asymptomatic contact lens wearers. We determined that total aerobic mesophilic bacteria were isolated in 45 (90 %), Gram negative rod bacteria were isolated in 20 (40 %), Pseudomonas spp. were isolated in 2 (4 %) and fungi were isolated in 18 (36 %) out of 50 contact lens storage cases. Free living amoebae were not detected in investigated contact lens storage cases. At the same time, out of 50, total aerobic mesophilic bacteria were isolated in 34 (68 %), fungi were isolated in 15 (30 %) and free living amoebae were isolated in 15 (30 %) domestic tap water samples. No Gram-negative rod bacteria and Pseudomonas spp. were detected in investigated water samples. Two contact lens case samples and two tap water samples were excluded from the analysis for Pseudomonas spp. for technical reasons. According to our findings, inadequate contact lens maintenance during lens wear may result in the contamination of contact lens storage cases. This situation can lead to severe eye infections in contact lens wearers over time.

  16. Contractual considerations in contact lens practice.

    Science.gov (United States)

    Classé, J G

    1986-03-01

    The use of forms in contact lens practice can save time, promote patient education, and reduce the opportunity for legal or economic disputes. The most commonly employed forms are those for contact lens fitting agreements, instructions for care and maintenance of lenses, prepaid service agreements, clinical investigations of investigatory lenses or solutions, and for extended wear patients. Sample forms are utilized for purposes of illustration.

  17. Disposable contact lenses vs. contact lens maintenance for extended wear.

    Science.gov (United States)

    Josephson, J E; Caffery, B E; Campbell, I; Slomovic, A R

    1990-01-01

    We compared a disposable extended wear contact lens modality with conventional extended wear over a 6-week period. To do so, we refit 31 patients who had successfully worn conventional extended wear contact lenses for more than 1 year. One eye was fit with the AcuvueR disposable contact lens, and a new extended wear lens of the type the patient had been wearing was placed on the other eye. At weekly intervals the disposable lens was discarded and a new disposable lens inserted. At the same time, the conventional lens on the fellow eye was cleaned, disinfected, and reinserted. After 6 weeks the ocular response, subjective impressions, and condition of the lenses in the two eyes were compared. Both lenses were then cultured. Three subjects had to discontinue disposable lens wear because of adverse reactions to trapped cellular debris and corneal microcysts. Although the results were not statistically significant, the Acuvue lens appeared to perform better than or equal to the conventional lens in biomicroscopic observation, visual acuity measurement, and subjective patient preference. Eighty-seven percent of patients preferred to continue with the disposable system. There were no differences found in the type or degree of microbial contamination of the lenses.

  18. Multipurpose soft contact lens care in Japan

    Directory of Open Access Journals (Sweden)

    Toshida H

    2012-01-01

    Full Text Available Hiroshi Toshida1,2, Yoshiaki Kadota3, Chikako Suto2, Toshihiko Ohta1, Akira Murakami21Juntendo University Shizuoka Hospital, Department of Ophthalmology, Shizuoka, 2Juntendo University School of Medicine, Department of Ophthalmology, Tokyo, 3Bausch & Lomb Japan Co, Ltd, Research and Development, Tokyo, JapanPurpose: To assess the use of multipurpose lens care products via an online survey conducted among soft contact lens (SCL wearers in Japan.Methods: The subjects were 1000 men and women aged 15–44 years who reported that they cleaned their SCL by using multipurpose solution at least twice a week. Via the internet, they were asked questions about SCL care, the use of a rubbing step when cleaning SCL, cleaning and replacing lens cases, and recommended SCL care methods.Results: Of the 1000 SCL wearers enrolled, 94.3% performed lens care every day lenses were worn, 64.2% reported rubbing the lenses every time, 57.9% rubbed the lenses for at least 10 seconds per side, and 64.7% reported they rubbed the lenses on both sides. Further, 61.2% reported that they had been given an explanation of SCL cleaning at an eye clinic or contact lens store. Only 49.8% of subjects reported that they cleaned the lens case every time and 61.7% replaced the case within 3 months. Only 19.5% had been given an explanation about lens case care. Half of the subjects reported they had been given no recommendation to use specific SCL care products or could not remember whether or not they had. The most common reason for the recommendation was good compatibility with their type of lens.Conclusion: More education is needed in Japan regarding methods of SCL care to ensure correct lens cleaning with inclusion of a rubbing step, as well as sufficient cleaning and replacement of the lens case. Of particular interest is the finding that many subjects were not given an explanation about proper SCL care and lens case cleaning and replacement at the time of lens purchase or

  19. 16 CFR 315.6 - Expiration of contact lens prescriptions.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Expiration of contact lens prescriptions. 315.6 Section 315.6 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS CONTACT LENS RULE § 315.6 Expiration of contact lens prescriptions. (a) In general. A contact lens prescription shall expire: (1) On the date...

  20. Contact lens fitting following corneal graft surgery.

    Science.gov (United States)

    Szczotka, Loretta B; Lindsay, Richard G

    2003-07-01

    Contact lens fitting may be required following keratoplasty for either optical or therapeutic reasons. Optical indications for contact lens fitting include the correction of irregular astigmatism, high regular astigmatism, anisometropia and secondary aniseikonia, as well as simple ametropia, where the patient desires to wear contact lenses in preference to spectacles. Therapeutic lenses are not routinely fitted following keratoplasty, although this management is advised in certain cases, such as when there are protruding sutures or epithelial healing is impaired. Designing a contact lens for a patient who has undergone keratoplasty will require the practitioner to carefully assess all the relevant features of the corneal graft. In this regard, there are many factors that need to be considered including the diameter of the graft zone, the topographical relationship between the host cornea and donor cornea, the corneal (graft) toricity and the location of the graft. Special designs, such as reverse geometry lenses, or more complex contact lens modalities, such as piggyback contact lens systems, may be required to achieve success in fitting.

  1. Acanthamoeba keratitis and contact lens wear.

    Science.gov (United States)

    Lindsay, Richard G; Watters, Grant; Johnson, Richard; Ormonde, Susan E; Snibson, Grant R

    2007-09-01

    Acanthamoeba keratitis is a rare but serious complication of contact lens wear that may cause severe visual loss. The clinical picture is usually characterised by severe pain, sometimes disproportionate to the signs, with an early superficial keratitis that is often misdiagnosed as herpes simplex virus (HSV) keratitis. Advanced stages of the infection are usually characterised by central corneal epithelial loss and marked stromal opacification with subsequent loss of vision. In this paper, six cases of contact lens-related Acanthamoeba keratitis that occurred in Australia and New Zealand over a three-year period are described. Three of the patients were disposable soft lens wearers, two were hybrid lens wearers and one was a rigid gas permeable lens wearer. For all six cases, the risk factors for Acanthamoeba keratitis were contact lens wear with inappropriate or ineffective lens maintenance and exposure of the contact lenses to tap or other sources of water. All six patients responded well to medical therapy that involved topical use of appropriate therapeutic agents, most commonly polyhexamethylene biguanide and propamidine isethionate, although two of the patients also subsequently underwent deep lamellar keratoplasty due to residual corneal surface irregularity and stromal scarring. Despite the significant advances that have been made in the medical therapy of Acanthamoeba keratitis over the past 10 years, prevention remains the best treatment and patients who wear contact lenses must be thoroughly educated about the proper use and care of the lenses. In particular, exposure of the contact lenses to tap water or other sources of water should be avoided.

  2. Recurrence rates of herpes simplex virus keratitis in contact lens and non-contact lens wearers.

    Science.gov (United States)

    Mucci, Joti Juneja; Utz, Virginia M; Galor, Anat; Feuer, William; Jeng, Bennie H

    2009-07-01

    To evaluate the recurrence rates of herpes simplex virus (HSV) keratitis in contact lens wearers compared with non-contact lens wearers. Retrospective cohort study. Charts of patients diagnosed with HSV keratitis seen at the Cleveland Clinic between January 2001 and December 2004 were reviewed. One hundred seventeen patients were included in this study: 21 contact lens wearers and 96 non-contact lens wearers. Contact lens wearers were found to have a higher median recurrence rate (0.4 episodes/year) compared with non-contact lens wearers (0.2 episodes/year) (P=0.02). A multivariate regression evaluating factors predictive of the number of recurrences found that contact lens use remained a significant predictive variable (P=0.02) when accounting for patient demographic and disease factors and variable follow-up time. Patients with a history of HSV keratitis should be counseled about the potential increased risk of recurrence that may be associated with contact lens wear.

  3. Tear Movement through a Contact Lens of Variable Thickness

    Science.gov (United States)

    Gerhart, Matthew; Anderson, Daniel

    2013-11-01

    This work is on a two-dimensional tear film with a movable porous contact lens. The inclusion of a contact lens into a tear film results in three layers: Pre-Lens Tear Film, Contact Lens, and the Post-Lens Tear Film layers. The interfaces between the contact lens and the tear films are modeled as planar interfaces. There is a free surface interface between the tear film and the outside air. The goal is analyze the effects of the spatial variability of thickness on the Post-Lens Tear Film thickness and on the fluid flow through the Contact Lens layer.

  4. Non-compliance in contact lens wear.

    Science.gov (United States)

    Claydon, B E; Efron, N

    1994-10-01

    Non-compliance is emerging as a critical issue in the contact lens field. This problem has been studied at depth in general health care situations and is seen as the responsibility of both practitioner and patient (client) working in a health care partnership. The contact lens practitioner and patient present a specific case for the study of non-compliance in areas such as hygiene, solution use, appointment attendance and wearing times. From 40 to 91% of contact lens patients have been reported as non-complaint in the use of recommended care and maintenance regimens and many of these are confused or ignorant about their behaviour. In order to arrive at a general set of conclusions from the studies published to date, it is important to understand the methodology of each study, it purpose, the definition of non-compliance used and the way the results were analysed and described. This review summarizes the research into non-compliance in the contact lens field to data. A set of general conclusions is drawn and a model for compliance in the context of contact lens practice is proposed.

  5. Contact lens interactions with the tear film.

    Science.gov (United States)

    Mann, Aisling; Tighe, Brian

    2013-12-01

    Biochemical changes brought about by the influence of the contact lens on the tear film are conveniently split into two categories. Firstly, the lens can remove or reduce the levels of specific components in the tear film, and secondly, the lens can augment the tear film, by stimulating the influx of new components or increasing the level of existing components. The most obvious tear film components for study in this context are lipids, proteins, mucins and electrolytes. The interactions are affected by the properties of the lens, the characteristics of the individual wearer and the wear schedule. An additional complicating factor is the fact that the lens is many times thicker than the tear film and any immobilised tear components will be more extensively exposed to oxygen and UV radiation than is the case in the absence of a lens. It is arguably the lipoidal components that are most markedly affected by lens wear, since their immobilisation on the lens surface markedly increases their susceptibility to autoxidative degradation. The limited information that is available highlights the importance of subject specificity and suggests that lipid oxidation phenomena are potentially important in contributing to the 'end of day' discomfort of symptomatic contact lens patients. It is clear that tear lipids, although regarded as relatively inert for many years, are now seen as a reactive and potentially important family of compounds in the search for understanding of contact lens-induced discomfort. The influence of the lens on tear proteins shows the greatest range of complexity. Deposition and denaturation can stimulate immune response, lower molecular weight proteins can be extensively absorbed into the lens matrix and the lens can stimulate cascade or upregulation processes leading either to the generation of additional proteins and peptides or an increase in concentration of existing components. Added to this is the stimulating influence of the lens on vascular

  6. Complications caused by contact lens wearing.

    Science.gov (United States)

    Beljan, Jasna; Beljan, Kristina; Beljan, Zdravko

    2013-04-01

    Complications in wearing contact lenses are very rare and caused by poor maintenance, over-extended wear and wearing of contact lenses in a polluted environment. Regular control by a professional person can efficiently reduce the number of complications. This paper describes the most common risks factors for complications, and complications of wearing contact lenses with the classification according to the anatomic parts of the eye: eyelids, tear film, limbus, corneal epithelium, corneal stroma and corneal endothelium. Every complication has been described by the characteristic signs and symptoms, etiology and pathology, as well as therapy and prognosis. The paper describes how to select adequate customers as contact lens users, with proper education in order to ensure minimal incidence of complications due to contact lens wear, thus attracting a lot of satisfied and healthy customers.

  7. Achromobacter xylosoxidans keratitis after contact lens usage.

    Science.gov (United States)

    Park, Jung Hyun; Song, Nang Hee; Koh, Jae Woong

    2012-02-01

    To report on Achromobacter xylosoxidans keratitis in two healthy patients who had worn contact lenses foran extended period of time. A 36-year-old female and a 21-year-old female visited our hospital with ocular pain and blurred vision. Both patients had a history of wearing soft contact lenses for over fve years with occasional overnight wear. At the initial presentation, a slit lamp examination revealed corneal stromal infiltrations and epithelial defects with peripheral neovascularization in both patients. Microbiological examinations were performed from samples of corneal scrapings, contact lenses, contact lens cases, and solution. The culture resulting from the samples taken from the contact lenses, contact lens cases, and solution were all positive for Achromobacter xylosoxidans. Confrming that the direct cause of the keratitis was the contact lenses, the frst patient was prescribed ceftazidime and amikacin drops sensitive to Achromobacter xylosoxidans. The second patient was treated with 0.3% gatifoxacin and fortifed tobramycin drops. After treatment, the corneal epithelial defects were completely healed, and subepithelial corneal opacity was observed. Two cases of Achromobacter xylosoxidans keratitis were reported in healthy young females who wore soft contact lenses. Achromobacter xylosoxidans should be considered a rare but potentially harmful pathogen for lens-induced keratitis in healthy hosts.

  8. Sterilization potential of contact lens solutions

    Directory of Open Access Journals (Sweden)

    Dada Vijay

    1988-01-01

    Full Text Available In a dynamic field of Contact Lens Solutions maintenance of high standards of anti-microbial activity is a must Resterilization Activity Time′ is a universally accepted yardstick for such an evaluation. In this study eight brands of indigenous popular solutions alongwith two FDA approved solutions were tested for their sterilization efficacy: Standardized suspensions of Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus fumigatus were used for the purpose. It was observed that the contact lens solutions available ir, the domestic market were not upto the mark Suggestions for improvement have also been made.

  9. Spherical aberration in contact lens wear.

    Science.gov (United States)

    Lindskoog Pettersson, A; Jarkö, C; Alvin, A; Unsbo, P; Brautaset, R

    2008-08-01

    The aim of the present studies was to investigate the effect on spherical aberration of different non custom-made contact lenses, both with and without aberration control. A wavefront analyser (Zywave, Bausch & Lomb) was used to measure the aberrations in each subject's right eye uncorrected and with the different contact lenses. The first study evaluated residual spherical aberration with a standard lens (Focus Dailies Disposable, Ciba Vision) and with an aberration controlled contact lens (ACCL) (Definition AC, Optical Connection Inc.). The second study evaluated the residual spherical aberrations with a monthly disposable silicone hydrogel lens with aberration reduction (PureVision, Bausch & Lomb). Uncorrected spherical aberration was positive for all pupil sizes in both studies. In the first study, residual spherical aberration was close to zero with the standard lens for all pupil sizes whereas the ACCL over-corrected spherical aberration. The results of the second study showed that the monthly disposable lens also over-corrected the aberration making it negative. The changes in aberration were statistically significant (plenses. Since the amount of aberration varies individually we suggest that aberrations should be measured with lenses on the eye if the aim is to change spherical aberration in a certain direction.

  10. Mechanical Properties of Contact Lens Materials.

    Science.gov (United States)

    Kim, Eon; Saha, Mou; Ehrmann, Klaus

    2017-11-07

    To evaluate the mechanical properties of commonly available soft contact lens materials and compare results using custom-built MicroTensometer. The Young modulus, parameters for stress relaxation, and toughness of 18 types of single vision soft contact lenses were measured using custom-built MicroTensometer. Five lenses of each type were soaked in standard phosphate buffered saline and measured at a temperature of 35°C. Each lens was flattened and sliced into a rectangular strip sample using two parallel blades. The Acuvue Moist 1-Day and SofLens Daily lenses measured lowest moduli, whereas Air Optix Night & Day Aqua and Premio measured the highest. The measured moduli for silicone hydrogel materials were generally higher compared with the hydrogels except for Dailies AquaComfort Plus. The exponential curve fitted over the decay in stress showed a consistent time constant of approximately 10 sec for most lens types measured. However, the amplitude constant varied from 2.84% for SofLens Daily to 22.39% for Acuvue TruEye 1-Day. The toughness results showed that Dailies AquaComfort Plus is strong but not necessarily tough. The mechanical properties of commonly prescribed soft contact lens materials were measured using a dedicated instrument. Its reliability was demonstrated, and modulus results were compared against published data from manufacturers and other research groups. Agreement was generally good, with only a few exceptions exceeding 15% difference. The more recently released silicone hydrogel lens types have reduced modulus, approaching that of medium or high water content hydrogel materials.

  11. Tear film physiology and contact lens wear. II. Contact lens-tear film interaction.

    Science.gov (United States)

    Holly, F J

    1981-04-01

    The successful fitting of contact lenses requires the practitioner to take into account many properties of the specific lens type used but the practitioner must also understand patient factors including tear properties, use of appropriate solutions, procedures for lens cleaning, and efficiency of blinking. Selection of appropriate patients, selection of lens type, proper fitting, good maintenance, and training and monitoring of patients increase the probability of achieving success.

  12. Risk factors for contact lens-induced papillary conjunctivitis associated with silicone hydrogel contact lens wear.

    Science.gov (United States)

    Tagliaferri, Angela; Love, Thomas E; Szczotka-Flynn, Loretta B

    2014-05-01

    Contact lens-induced papillary conjunctivitis (CLPC) continues to be a major cause of dropout during extended wear of contact lenses. This retrospective study explores risk factors for the development of CLPC during extended wear of silicone hydrogel lenses. Data from 205 subjects enrolled in the Longitudinal Analysis of Silicone Hydrogel Contact Lens study wearing lotrafilcon A silicone hydrogel lenses for up to 30 days of continuous wear were used to determine risk factors for CLPC in this secondary analysis of the main cohort. The main covariates of interest included substantial lens-associated bacterial bioburden and topographically determined lens base curve-to-cornea fitting relationships. Additional covariates of interest included history of adverse events, time of year, race, education level, gender, and other subject demographics. Statistical analyses included univariate logistic regression to assess the impact of potential risk factors on the binary CLPC outcome and Cox proportional hazards regression to describe the impact of those factors on time-to-CLPC diagnosis. Across 12 months of follow-up, 52 subjects (25%) experienced CLPC. No associations were found between the CLPC development and the presence of bacterial bioburden, lens-to-cornea fitting relationships, history of adverse events, gender, or race. Contact lens-induced papillary conjunctivitis development followed the same seasonal trends as the local peaks in environmental allergens. Lens fit and biodeposits, in the form of lens-associated bacterial bioburden, were not associated with the development of CLPC during extended wear with lotrafilcon A silicone hydrogel lenses.

  13. Successful monovision contact lens wearers refitted with bifocal contact lenses.

    Science.gov (United States)

    Situ, Ping; Du Toit, Rènée; Fonn, Desmond; Simpson, Trefford

    2003-07-01

    Should successful monovision contact lens wearers be refitted with bifocal lenses? Fifty current monovision lens wearers were fitted with ACUVUE Bifocal contact lenses (Johnson & Johnson Vision Care, Jacksonville, FL). Visual function and subjective vision ratings were assessed with habitual monovision lenses at the first visit and then were repeated at the end of 6 months while wearing bifocal lenses. Lens preference was determined at the end of the 6-month study, and the subjects were called 1 year later to repeat the lens preference questionnaire. Forty (80%) subjects completed the 6-month study; nine discontinued for visual reasons. At the end of 6 months of wear, 68% preferred bifocal lenses and 25% preferred monovision. Of the subjects who were contacted a year later, 53% were still wearing bifocal lenses. High-contrast visual acuity and letter contrast sensitivity at distance was the same for monovision and bifocal lenses, but low-contrast acuity was better with monovision. Intermediate low- and high-contrast acuity and 3-meter and near stereoscopic acuity were better with bifocal lenses. Near high- and low-contrast acuity were better with monovision. All subjective ratings, except near vision in poor lighting, were significantly greater with bifocal lenses. It is possible to refit successful monovision lens wearers with simultaneous vision bifocal lenses, and these lenses should be considered as an alternative method for the correction of presbyopia. In addition, subjective responses to bifocal lenses may not be reflective of visual function measurements.

  14. Corneal ring infiltration in contact lens wearers

    Directory of Open Access Journals (Sweden)

    Seyed Ali Tabatabaei

    2017-01-01

    Full Text Available To report a case of atypical sterile ring infiltrates during wearing soft silicone hydrogel contact lens due to poor lens care. A 29-year-old woman presented with complaints of pain, redness, and morning discharge. She was wearing soft silicone hydrogel contact lens previously; her current symptoms began 1 week before presentation. On examination, best-corrected visual acuity was 20/40 in that eye. Slit-lamp examination revealed dense, ring-shaped infiltrate involving both the superficial and deep stromal layers with lucid interval to the limbus, edema of the epithelium, epithelial defect, and vascularization of the superior limbus. Cornea-specific in vivo laser confocal microscopy (Heidelberg Retina Tomograph 2 Rostock Cornea Module, HRT 2-RCM, Heidelberg Engineering GmbH, Dossenheim, Germany revealed Langerhans cells and no sign of Acanthamoeba or fungal features, using lid scraping and anti-inflammatory drops; her vision completely recovered. We reported an atypical case of a sterile corneal ring infiltrate associated with soft contact lens wearing; smear, culture, and confocal microscopy confirmed a sterile inflammatory reaction.

  15. Corneal ring infiltration in contact lens wearers.

    Science.gov (United States)

    Tabatabaei, Seyed Ali; Soleimani, Mohammad; Johari, Mohammadkarim

    2017-01-01

    To report a case of atypical sterile ring infiltrates during wearing soft silicone hydrogel contact lens due to poor lens care. A 29-year-old woman presented with complaints of pain, redness, and morning discharge. She was wearing soft silicone hydrogel contact lens previously; her current symptoms began 1 week before presentation. On examination, best-corrected visual acuity was 20/40 in that eye. Slit-lamp examination revealed dense, ring-shaped infiltrate involving both the superficial and deep stromal layers with lucid interval to the limbus, edema of the epithelium, epithelial defect, and vascularization of the superior limbus. Cornea-specific in vivo laser confocal microscopy (Heidelberg Retina Tomograph 2 Rostock Cornea Module, HRT 2-RCM, Heidelberg Engineering GmbH, Dossenheim, Germany) revealed Langerhans cells and no sign of Acanthamoeba or fungal features, using lid scraping and anti-inflammatory drops; her vision completely recovered. We reported an atypical case of a sterile corneal ring infiltrate associated with soft contact lens wearing; smear, culture, and confocal microscopy confirmed a sterile inflammatory reaction.

  16. The corneal stroma during contact lens wear.

    Science.gov (United States)

    Jalbert, Isabelle; Stapleton, Fiona

    2005-03-01

    Recent technological advances have lead to novel descriptions of the microanatomy of the corneal stroma. In the first section of this review, these findings and the role they play in the maintenance of vital properties such as corneal transparency, mechanical strength, homeostasis, wound-healing response and metabolism are described. In the second part, contact lens induced stromal alterations such as acidosis, oedema, striae, thinning and opacities are reviewed as well as the more recently described phenomenon of microdot deposits and keratocyte loss with an emphasis on how lens wearing stromal effects can be minimised.

  17. Subjective assessment of contact lens wear by army aircrew.

    Science.gov (United States)

    Lattimore, M R; Cornum, R L

    1993-07-01

    Because 23% of Army aviators are ametropic, contact lenses have drawn increased attention as a spectacle substitute to solve system compatibility problems. From November 1988 until October 1991, a series of contact lens research protocols were conducted to develop a comprehensive database on contact lens wear in varied environments. Questionnaires were used to assess suitability and acceptability of routine contact lens wear. Responses from 202 subjects were obtained from September 1989 through September 1991. The questions explored operational and safety of flight issues of contact lens wear. Subjects overwhelmingly approved of contact lens use in all settings: 95% expressed greater combat readiness and effectiveness with contact lenses, 98% felt contact lens use (and maintenance) in the cockpit had no adverse impact on safety of flight, and 98% endorsed the routine use of contact lenses. These data highlight Army aircrew acceptance of contact lens use.

  18. Corneal topography and soft contact lens fit.

    Science.gov (United States)

    Young, Graeme; Schnider, Cristina; Hunt, Chris; Efron, Suzanne

    2010-05-01

    To determine which ocular topography variables affect soft contact lens fit. Fifty subjects each wore three pairs of soft lenses in random succession (Vistakon Acuvue 2, Vistakon Acuvue Advance, Ciba Vision Night & Day), and various aspects of lens fit were evaluated. The steeper base curves of each type were worn in one eye and the flatter base curves in the other eye. Corneal topography data were collected using a Medmont E300 corneal topographer (Camberwell, Australia). Corneal curvature, shape factor (SF), and corneal height were measured over a 10 mm chord and also over the maximum measurable diameter. These were measured in the horizontal, vertical, steepest, and flattest meridians. With each lens type, the steeper base curve provided the best fit on the greatest proportion of eyes and the significant differences in various aspects of fit were noted between base curves. For each lens type, there was no significant difference in mean K-reading between those eyes best fit with the steeper base curve and those eyes best fit with the flatter base curve. Two of the lenses showed a positive correlation between centration and horizontal corneal height (maximum), whereas one lens showed a negative correlation between centration and horizontal SF (SF = e). Several lenses showed a positive correlation between post-blink movement and horizontal or vertical corneal SF. The measurement of corneal topography using current Placido disc instrumentation allows a better prediction of soft lens fit than by keratometry, but it is not reliable enough to enable accurate selection of the best fitting base curve. Some correlations are evident between corneal measurements; however, trial fitting remains the method of choice for selection of soft lens base curve.

  19. 21 CFR 886.5420 - Contact lens inserter/remover.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Contact lens inserter/remover. 886.5420 Section 886.5420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5420 Contact lens inserter/remover. (a) Identification. A contact lens inserter...

  20. 1. History, evolution, and evolving standards of contact lens care.

    Science.gov (United States)

    Szczotka-Flynn, Loretta; Ahearn, Donald G; Barr, Joseph; Benjamin, William Joe; Kiang, Tina; Nichols, Jason J; Schein, Oliver D; Stone, Ralph P; Winterton, Lynn

    2013-01-15

    Contact lenses and lens care regimens are an important part of eyecare practices and vital to lens-wearing patients. New contact lens materials and cleaning options continue to come to market and affect how patients wear and care for their lenses. In this section we look at how the contact lens and lens solution revolution started, how it has evolved over the last 40 years, and how standards have evolved and impacted these new offerings. Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  1. Sterilization potential of contact lens solutions

    OpenAIRE

    Dada Vijay; Mehta Manoj

    1988-01-01

    In a dynamic field of Contact Lens Solutions maintenance of high standards of anti-microbial activity is a must Resterilization Activity Time′ is a universally accepted yardstick for such an evaluation. In this study eight brands of indigenous popular solutions alongwith two FDA approved solutions were tested for their sterilization efficacy: Standardized suspensions of Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus fumigatus were used for the purpose. ...

  2. Modeling the evaporation of a pre-lens tear film on a contact lens

    Science.gov (United States)

    Anderson, Daniel; Talbott, Kevin; Xu, Amber; Seshaiyer, Padmanabhan

    2011-11-01

    We develop a model for evaporation of a post-blink pre-lens tear film in the presence of a porous contact lens. The tear film is modeled as a Newtonian fluid and the flow in the contact lens is assumed to obey Darcy's law. The evaporation model treats the contact lens as a wetting surface. Evaporative mass flux thins the pre-lens film down to a nonzero steady thickness at which point evaporation continues by drawing fluid up through the contact lens. Both one and two-dimensional models are explored. The post-lens film (between the contact lens and the corneal surface) is not included explicitly in the model but is assumed to act as a reservoir that supplies fluid drawn up through the contact lens. Supported by NSF CSUMS and REU programs.

  3. Trends in US Contact Lens Prescribing 2002 to 2014.

    Science.gov (United States)

    Efron, Nathan; Nichols, Jason J; Woods, Craig A; Morgan, Philip B

    2015-07-01

    To document contact lens prescribing patterns in the United States between 2002 and 2014. A survey of contact lens prescribing trends was conducted each year between 2002 and 2014, inclusive. Randomly selected contact lens practitioners were asked to provide information relating to 10 consecutive contact lens fits between January and March each year. Over the 13-year survey period, 1650 survey forms were received from US practitioners representing details of 7702 contact lens fits. The mean (±SD) age of lens wearers was 33.6 (±15.2) years, of whom 65.2% were female. Rigid lens new fits decreased from 13.0% in 2002 to 9.4% in 2014. Across this period, silicone hydrogels have replaced mid water contact lens hydrogels as the soft lens material of choice. Toric lenses represented about 25 to 30% of all soft lens fits. Multifocal soft lenses are generally preferred to monovision. Daily disposable lens fits have recently increased, and in 2014, they represented 27.1% of all soft lens fits. Most lenses are prescribed on 1 to 2 weekly or monthly lens replacement regimen. Extended wear remains a minority lens wearing modality. The vast majority of those wearing reusable lenses use multipurpose lens care solutions. Lenses are mostly worn 7 d/wk. This survey has revealed prescribing trends and preferences in the United States over the past 13 years.

  4. Contact lens-related acanthamoeba keratitis.

    Science.gov (United States)

    Stapleton, Fiona; Ozkan, Jerome; Jalbert, Isabelle; Holden, Brien A; Petsoglou, Con; McClellan, Kathy

    2009-10-01

    Acanthamoeba keratitis is a rare but severe disease, with more than 95% of cases occurring in contact lens wearers. With a worldwide resurgence of contact lens-related disease, this report illustrates the clinical characteristics and treatment challenges representative of this disease. This report describes Acanthamoeba keratitis in a 47-year-old female using extended wear silicone hydrogel contact lenses, with a history of swimming in a home pool and failure to subsequently disinfect the contact lenses. The diagnosis was based on clinical signs, disease course, and confocal microscopy results despite a negative result for corneal smear and culture. The corneal signs included an epithelial defect, epithelial irregularities, anterior stromal infiltrates, perineural infiltrates, an anterior stromal ring infiltrate, and hypopyon. The case was diagnosed as an infective keratitis and treated promptly using intensive topical administration of fortified gentamicin and cephalothin. The high likelihood Acanthamoeba prompted immediate use of polyhexamethylbiguanide and chlorhexidine, with propamide and adjunct treatment using atropine and oral diclofenac. Steroids were added on day 3, and the frequency of administration of antibacterial treatment was gradually reduced and ceased by day 10. The analgesia was stopped at 3 months. The frequency of administration of antiamoeba therapy and steroid treatment was slowly reduced and all treatment was ceased after 18 months. Despite considerable morbidity in terms of the treatment duration, hospitalization, outpatient appointments, and associated disease costs, the final visual outcome (6/6) was excellent.

  5. Pitfalls in aphakic contact lens fitting

    Directory of Open Access Journals (Sweden)

    Dada Vijay

    1990-01-01

    Full Text Available We examined 23 consecutive cases of unilateral aphakia reporting to the contact lens office for endothelial count and morphology, corneal thickness and toricity. The fellow eye served as a control in all the cases. It was found that there is a significant drop in the central endothelial cell density, and change in the size and shape of the cells. These observations indicate a thermodynamically unstable state. The aphakic corneas were thicker than the controls but not to a significant extent. The cell count and pachymetry had no statistical correlation. Toricity of the aphakic corneas make successful fitting of a lens difficult. Since prolonged use of extended wear gas permeable as well as hydrogel lenses have a deleterious effect on the endothelium it is suggested that a careful case selection be made and strict monitoting carried out at follow up. These corneas are liable for decompensation with only mild noxious stimuli. This article is intended to acquaint the ophthalmologist with the pitfalls in aphakic contact lens fitting so that a cautious follow up may be planned.

  6. RISK FACTORS FOR CONTACT LENS COMPLICATIONS

    Directory of Open Access Journals (Sweden)

    Mirna Štabuc Šilih

    2016-04-01

    Full Text Available Contact lenses are freely available without professional examination and fitting, as well as without adequate introduction and instructions on handling, disinfection and storage. Contact lenses may have physiological, metabolic and anatomic effect on the eyes, which is manifested both on the eyelids, lacrimal film, conjunctiva and in all layers of the cornea - the epithelium, stroma and the endothelium. We can see these complications too often at our everyday work. The purpose of this paper is to draw attention to the potential complications due to inappropriate use of contact lenses.Contact lenses are otherwise a safe and effective method of correcting visual acuity; they are also useful for therapeutic purposes. Complications related to contact lenses wear could be largely avoided with an appropriate professional approach and the compliance of contact lens wearers. It is important to discuss with patients their medical history, their desires and expectations, their working and living environment; followed by professional examination of patients and appropriate fitting of contact lenses. Patients should receive detailed oral and written instructions and be subscribed to regular checks. But unfortunately, all this is not enough, if patients do not comply every day with given instructions.

  7. The impact of contemporary contact lenses on contact lens discontinuation.

    Science.gov (United States)

    Dumbleton, Kathy; Woods, Craig A; Jones, Lyndon W; Fonn, Desmond

    2013-01-01

    Discontinuation or "dropout" from contact lens (CL) wear continues to afflict the CL industry. This study was conducted to determine whether the advent of new CL materials and designs has impacted the dropout rate and the reasons for discontinuation. Current and lapsed CL wearers residing in Canada were recruited using Facebook to take part in an on line survey investigating CL wearing experiences during 2008 to 2010 and to establish the percentage of participants who temporarily and permanently discontinued CL wear during the period surveyed. Four thousand two hundred seven eligible surveys were received (64% female; median age 27 years). Forty percent had lapsed from lens wear for at least 4 months; however, 62% of the lapsed wearers (LWs) resumed wear. There were no differences between LWs and nonlapsed wearers (NLWs) with respect to gender; however, LWs were older, started lens wear when older, and had not worn lenses for as long as NLWs (all Plenses and hydrogel CLs (24% vs. 19% and 22% vs. 18%, respectively, P≤0.001). Primary reasons for discontinuation were discomfort (24%), dryness (20%), red eyes (7%), and expense (7%). Compliance with lens replacement was no different between LWs and NLWs (48% vs. 45%). About 23% of those surveyed had discontinued CL wear permanently. The primary reasons for dropping out continue to be discomfort and dryness. Dropout rates were lower in silicone hydrogel wearers.

  8. [Contact lens-associated Paecilomyces lilacinus keratitis].

    Science.gov (United States)

    Mihailovic, N; Alnawaiseh, M; Zumhagen, L; Eter, N

    2017-01-01

    We present the case of a 23-year-old otherwise healthy female patient with contact lens-associated Paecilomyces lilacinus keratitis. The clinical findings stabilized after initial local antimycotic and antibacterial treatment; however, in the further course of local therapy an extensive relapse occurred which required treatment by perforating keratoplasty à chaud due to a penetrating corneal ulcer. The patient responded well to subsequent treatment with systemic and local antimycotic medication. After a few months HLA-matched keratoplasty was performed. During the follow-up time of 14 months there were no signs of recurrence of the infection.

  9. Forensic Analysis of a Contact Lens in a Murder Case.

    Science.gov (United States)

    Zwerling, Charles S

    2016-03-01

    Contact lenses have had rare relevance in trials and/or investigations. After 5 years of burial, orbital remnants were retrieved from an exhumed body and subsequently identified as a key piece of material evidence in a murder trial. The exhumed case materials were evaluated under laboratory conditions and were determined to be contact lens remnants. Contact lens fracture and burial simulation studies were performed to provide additional corroboration of the physical findings of the exhumed contact lens remnants. This material evidence was instrumental in providing factual proof refuting the defendant's testimony in the murder trial. A brief history of contact lens composition and use is provided for understanding the methods and observational results. This forensic case study represents the first published documentation of a contact lens from an exhumed body being used in a murder investigation and establishes an operational procedure for future forensic contact lens examinations. © 2016 American Academy of Forensic Sciences.

  10. Prevalence of corneal ulcer among contact lens wearers in Nigeria ...

    African Journals Online (AJOL)

    Corneal Ulceration has been described as the most serious complication of contact lens wear worldwide. The incidence of corneal ulceration in contact lens wearers in Nigeria was determined retrospectively. 1759 case notes of patients who had worn contact lenses for at least one year were obtained from eye clinics in ...

  11. Evolution of a pre and post lens tear film with a contact lens

    Science.gov (United States)

    Gerhart, Matthew; Anderson, Daniel

    2012-11-01

    The work is the development, implementation, and analysis of a two-dimensional tear film model including a porous contact lens. The geometry of the problem is: a pre-lens layer that is a thin tear film between the outside air and contact lens, a contact lens that is a rigid but movable porous substrate, and a post-lens layer that is a thin film layer between the contact lens and the cornea. We are looking at short and long term behavior of the evolution of the thin film in the pre-lens layer coupled with the porous layer and the thin squeeze film in the post-lens layer. We model the different behaviors that arise as the Darcy number, evaporation effects, and boundary flux conditions change.

  12. Comparation of effectiveness of silicone hydrogel contact lens and hydrogel contact lens in patients after LASEK.

    Science.gov (United States)

    Xie, Wen-Juan; Zeng, Jin; Cui, Ying; Li, Juan; Li, Zhong-Ming; Liao, Wei-Xiong; Yang, Xiao-Hong

    2015-01-01

    To conduct a comparative study of effectiveness of silicone hydrogel contact lens and hydrogel contact lens, which are used in patients after laser-assisted subepithelial keratomileusis (LASEK). Sixty-three patients (121 eyes) with a spherical equivalent ≤-5.0 D were chosen after undergoing LASEK in 2012 at Guangdong General Hospital. They were randomly divided into 2 groups. The silicone hydrogel group included 32 cases (61 eyes) that wore silicone hydrogel contact lenses for 4-6d after the operation, while the hydrogel group included 31 cases (60 eyes) who wore hydrogel contact lenses for 4-6d after the operation. Patients' self-reported postoperative symptoms (including pain, photophobia, tears, and foreign body sensation) were evaluated. The healing time of the corneal epithelium, the visual acuity of patients without contact lens after epithelial healing, and the incidence of delayed corneal epithelial shedding were also assessed. The follow-up time was 1mo. Postoperative symptoms were milder in the silicone hydrogel group than in the hydrogel group. There were significant differences in pain, foreign body sensation, and photophobia between the 2 groups (P0.05). The healing time of the corneal epithelium in the silicone hydrogel lens group was markedly shorter than that in the hydrogel group (4.07±0.25 vs 4.33±0.82d, t=2.43, P=0.02). Visual acuity without contact lenses after healing of the corneal epithelium was better in the silicone hydrogel group compared with the hydrogel group (χ (2)=7.76, P=0.02). There was no significant difference in the occurrence of delayed corneal epithelial shedding between the 2 groups (P>0.05). Patients with LASEK using silicon hydrogel contact lenses had less discomfort and shorter corneal epithelial healing time compared with those using hydrogel contact lenses, suggesting that silicon hydrogel contact lenses may be considered to be a better choice of bandage contact lens after LASEK.

  13. Comparation of effectiveness of silicone hydrogel contact lens and hydrogel contact lens in patients after LASEK

    Directory of Open Access Journals (Sweden)

    Wen-Juan Xie

    2015-12-01

    Full Text Available AIM: To conduct a comparative study of effectiveness of silicone hydrogel contact lens and hydrogel contact lens, which are used in patients after laser-assisted subepithelial keratomileusis (LASEK. METHODS: Sixty-three patients (121 eyes with a spherical equivalent ≤-5.0 D were chosen after undergoing LASEK in 2012 at Guangdong General Hospital. They were randomly divided into 2 groups. The silicone hydrogel group included 32 cases (61 eyes that wore silicone hydrogel contact lenses for 4-6d after the operation, while the hydrogel group included 31 cases (60 eyes who wore hydrogel contact lenses for 4-6d after the operation. Patients’ self-reported postoperative symptoms (including pain, photophobia, tears, and foreign body sensation were evaluated. The healing time of the corneal epithelium, the visual acuity of patients without contact lens after epithelial healing, and the incidence of delayed corneal epithelial shedding were also assessed. The follow-up time was 1mo. RESULTS: Postoperative symptoms were milder in the silicone hydrogel group than in the hydrogel group. There were significant differences in pain, foreign body sensation, and photophobia between the 2 groups (P0.05. The healing time of the corneal epithelium in the silicone hydrogel lens group was markedly shorter than that in the hydrogel group (4.07±0.25 vs 4.33±0.82d, t=2.43, P=0.02. Visual acuity without contact lenses after healing of the corneal epithelium was better in the silicone hydrogel group compared with the hydrogel group (χ2=7.76, P=0.02. There was no significant difference in the occurrence of delayed corneal epithelial shedding between the 2 groups (P>0.05. CONCLUSION: Patients with LASEK using silicon hydrogel contact lenses had less discomfort and shorter corneal epithelial healing time compared with those using hydrogel contact lenses, suggesting that silicon hydrogel contact lenses may be considered to be a better choice of bandage contact lens after

  14. Patient compliance during contact lens wear: perceptions, awareness, and behavior.

    Science.gov (United States)

    Bui, Thai H; Cavanagh, H Dwight; Robertson, Danielle M

    2010-11-01

    Patient noncompliance with recommended hygienic practices in contact lens wear is often considered a significant risk factor for microbial keratitis and adverse contact lens-related events. Despite advancements in lens materials and care solutions, noncompliant behavior continues to hinder efforts to maximize contact lens safety. The objective of this pilot study was to assess the relationship between perceived and actual compliance with awareness of risk and behavior. One hundred sixty-two established contact lens wearers were sequentially evaluated after their routine contact lens examination at the Optometry Clinic at the University of Texas Southwestern Medical Center at Dallas, TX. Each patient was questioned by a single trained interviewer regarding his or her lens care practices and knowledge of risk factors associated with lens wear. Eighty-six percent of patients believed they were compliant with lens wear and care practices; 14% identified themselves as noncompliant. Using a scoring model, 32% demonstrated good compliance, 44% exhibited average compliance, and 24% were noncompliant; age was a significant factor (P = 0.020). Only 34% of patients who perceived themselves as compliant exhibited a good level of compliance (Plens case was the only behavior associated with a positive history for having experienced a prior contact lens-related complication (P = 0.002). Perceived compliance is not an indicator for appropriate patient behavior. A large proportion of patients remain noncompliant despite awareness of risk. Education alone is not a sufficient strategy to improve behavior; newer approaches aimed at improving compliance with lens care practices are urgently needed.

  15. High Dk piggyback contact lens system for contact lens-intolerant keratoconus patients.

    Science.gov (United States)

    Sengor, Tomris; Kurna, Sevda Aydin; Aki, Suat; Ozkurt, Yelda

    2011-01-01

    The aim of the study was to examine the clinical success of high Dk (oxygen permeability) piggyback contact lens (PBCL) systems for the correction of contact lens intolerant keratoconus patients. Sixteen patients (29 eyes) who were not able to wear gas-permeable rigid lenses were included in this study. Hyper Dk silicone hydrogel (oxygen transmissibility or Dk/t = 150 units) and fluorosilicone methacrylate copolymer (Dk/t = 100 units) lenses were chosen as the PBCL systems. The clinical examinations included visual acuity and corneal observation by biomicroscopy, keratometer reading, and fluorescein staining before and after fitting the PBCL system. INDICATIONS FOR USING PBCL SYSTEM WERE: lens stabilization and comfort, improving comfort, and adding protection to the cone. Visual acuities increased significantly in all of the patients compared with spectacles (P = 0). Improvement in visual acuity compared with rigid lenses alone was recorded in 89.7% of eyes and no alteration of the visual acuity was observed in 10.3% of the eyes. Wearing time of PBCL systems for most of the patients was limited time (mean 6 months, range 3-12 months); thereafter they tolerated rigid lenses alone except for 2 patients. The PBCL system is a safe and effective method to provide centering and corneal protection against mechanical trauma by the rigid lenses for keratoconus patients and may increase contact lens tolerance.

  16. High Dk piggyback contact lens system for contact lens-intolerant keratoconus patients

    Directory of Open Access Journals (Sweden)

    Tomris Sengor

    2011-03-01

    Full Text Available Tomris Sengor, Sevda Aydin Kurna, Suat Aki, Yelda ÖzkurtFatih Sultan Mehmet Training and Research Hospital, Istanbul, TurkeyBackground: The aim of the study was to examine the clinical success of high Dk (oxygen permeability piggyback contact lens (PBCL systems for the correction of contact lens intolerant keratoconus patients.Methods: Sixteen patients (29 eyes who were not able to wear gas-permeable rigid lenses were included in this study. Hyper Dk silicone hydrogel (oxygen transmissibility or Dk/t = 150 units and fluorosilicone methacrylate copolymer (Dk/t = 100 units lenses were chosen as the PBCL systems. The clinical examinations included visual acuity and corneal observation by biomicroscopy, keratometer reading, and fluorescein staining before and after fitting the PBCL system.Results: Indications for using PBCL system were: lens stabilization and comfort, improving comfort, and adding protection to the cone. Visual acuities increased significantly in all of the patients compared with spectacles (P = 0. Improvement in visual acuity compared with rigid lenses alone was recorded in 89.7% of eyes and no alteration of the visual acuity was observed in 10.3% of the eyes. Wearing time of PBCL systems for most of the patients was limited time (mean 6 months, range 3–12 months; thereafter they tolerated rigid lenses alone except for 2 patients.Conclusion: The PBCL system is a safe and effective method to provide centering and corneal protection against mechanical trauma by the rigid lenses for keratoconus patients and may increase contact lens tolerance.Keywords: piggyback contact lens, keratoconus, irregular astigmatism

  17. Incidence of contact lens-associated microbial keratitis

    NARCIS (Netherlands)

    Cheng, K.H.; Leung, S.L.; Hoekman, J.W.; Beekhuis, W.H.; Mulder, P.G.H.; Geerards, A.J.M.; Kijlstra, A.

    1999-01-01

    Background. The incidence of contact-lens-associated microbial keratitis is uncertain and its related morbidity in the general population of contact-lens wearers is not known. We examined these issues in a prospective epidemiological study. Methods. We surveyed all practising ophthalmologists in the

  18. 21 CFR 800.10 - Contact lens solutions; sterility.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Contact lens solutions; sterility. 800.10 Section 800.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL Requirements for Specific Medical Devices § 800.10 Contact lens solutions; sterility. (a)(1) Informed medical opinion is...

  19. 21 CFR 886.5916 - Rigid gas permeable contact lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rigid gas permeable contact lens. 886.5916 Section 886.5916 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5916 Rigid gas permeable contact lens. (a) Identification. A rigid gas permeable...

  20. 21 CFR 886.5925 - Soft (hydrophilic) contact lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Soft (hydrophilic) contact lens. 886.5925 Section 886.5925 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5925 Soft (hydrophilic) contact lens. (a) Identification. A soft (hydrophilic)...

  1. 21 CFR 886.1385 - Polymethylmethacrylate (PMMA) diagnostic contact lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Polymethylmethacrylate (PMMA) diagnostic contact lens. 886.1385 Section 886.1385 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1385 Polymethylmethacrylate (PMMA) diagnostic contact lens. (...

  2. Contact lens wear and dry eyes: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Markoulli M

    2017-02-01

    Full Text Available Maria Markoulli, Sailesh Kolanu School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia Abstract: The number of contact lens wearers worldwide has remained relatively stable over the past decade, despite the investment that has gone into contact lens technology. This is largely because 10%–50% of wearers dropout of contact lens wear within 3 years of commencement; the most common reason cited being contact lens discomfort (CLD. Of the symptoms reported, sensation of dry eye is the most common. Given the outcome of reduced wearing time, increased chair time, and ultimate contact lens discontinuation, the challenge is to identify the warning signs of CLD early on. Clinically detectable changes such as conjunctival staining, conjunctival indentation, conjunctival epithelial flap formation, lid wiper epitheliopathy, Demodex blepharitis, and meibomian gland dysfunction have been linked to CLD, highlighting the need to perform regular aftercare visits to identify these changes. At a cellular level, conjunctival metaplasia and reduced goblet cell density have been linked to CLD, leading to a downstream effect on the tear film breakup time of contact lens wearers. These factors suggest a strong link between CLD and friction, raising the need to target this as a means of minimizing CLD. The purpose of this review is to identify the clinical signs that relate to CLD as a means of earlier detection and management in order to combat contact lens dropout. Keywords: contact lens discomfort, dry eye disease, lid wiper epitheliopathy, tear film biomarkers, meibomian gland dysfunction

  3. CONTACT LENS WEAR AND THE OXYGEN ISSUE: A REVIEW

    African Journals Online (AJOL)

    increase both the prevalence and severity of all complication . About 33% of the complications encountered with contact lens wear are attributable to hypoxia, and thus the oxygen transmissibility of a contact lens is probably the most important single parameter in terms of maintaining the physiologic integrity of the cornea .

  4. The Risk of Blepharoptosis in Contact Lens Wearers.

    Science.gov (United States)

    Hwang, Kun; Kim, Joo Ho

    2015-07-01

    The aim of this systematic review was to summarize and evaluate the risk of blepharoptosis in contact lens wearers. In a PubMed search, 393 papers were found using the terms "lens and ptosis." The abstracts were read and 16 full text articles were reviewed. Among them, 5 articles were analyzed. Five studies were subgrouped and a meta-analysis of these data suggested there is an increased risk of blepharoptosis in hard contact lens wearers over nonwearers (n = 7426, OR, 17.38, 95% CI = 3.71-81.29, P contact lens wearers over nonwearers (n = 90, OR, 8.12, 95% CI = 2.68-24.87, P contact lenses should be advised of the risk of ptosis, and a history of contact lens use should be sought in all patients who have acquired ptosis as the previous authors have recommended.

  5. Effect of contact lens use on Computer Vision Syndrome.

    Science.gov (United States)

    Tauste, Ana; Ronda, Elena; Molina, María-José; Seguí, Mar

    2016-03-01

    To analyse the relationship between Computer Vision Syndrome (CVS) in computer workers and contact lens use, according to lens materials. Cross-sectional study. The study included 426 civil-service office workers, of whom 22% were contact lens wearers. Workers completed the Computer Vision Syndrome Questionnaire (CVS-Q) and provided information on their contact lenses and exposure to video display terminals (VDT) at work. CVS was defined as a CVS-Q score of 6 or more. The covariates were age and sex. Logistic regression was used to calculate the association (crude and adjusted for age and sex) between CVS and individual and work-related factors, and between CVS and contact lens type. Contact lens wearers are more likely to suffer CVS than non-lens wearers, with a prevalence of 65% vs 50%. Workers who wear contact lenses and are exposed to the computer for more than 6 h day(-1) are more likely to suffer CVS than non-lens wearers working at the computer for the same amount of time (aOR = 4.85; 95% CI, 1.25-18.80; p = 0.02). Regular contact lens use increases CVS after 6 h of computer work. © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.

  6. Force analysis of bacterial transmission from contact lens cases to corneas, with the contact lens as the intermediary

    NARCIS (Netherlands)

    Qu, Wen-wen; Hooymans, Johanna MM; de Vries, Jacob; van der Mei, Henderina; Busscher, Hendrik

    PURPOSE. To determine the probability of transmission of a Staphylococcus aureus strain from a contact lens case, to the contact lens (CL) surfaces, to the cornea, on the basis of bacterial adhesion forces measured by using atomic force microscopy (AFM). METHODS. Adhesion forces between S. aureus

  7. Impact of soft contact lens edge design and midperipheral lens shape on the epithelium and its indentation with lens mobility.

    Science.gov (United States)

    Wolffsohn, James S; Drew, Thomas; Dhallu, Sandeep; Sheppard, Amy; Hofmann, Greg J; Prince, Mark

    2013-09-11

    To evaluate the influence of soft contact lens midperipheral shape profile and edge design on the apparent epithelial thickness and indentation of the ocular surface with lens movement. Four soft contact lens designs comprising of two different plano midperipheral shape profiles and two edge designs (chiseled and knife edge) of silicone-hydrogel material were examined in 26 subjects aged 24.7 ± 4.6 years, each worn bilaterally in randomized order. Lens movement was imaged enface on insertion, at 2 and 4 hours with a high-speed, high-resolution camera simultaneous to the cross-section of the edge of the contact lens interaction with the ocular surface captured using optical coherence tomography (OCT) nasally, temporally, and inferiorly. Optical imaging distortions were individually corrected for by imaging the apparent distortion of a glass slide surface by the removed lens. Apparent epithelial thickness varied with edge position (P design. Horizontal and vertical lens movement did not change with time postinsertion. Vertical motion was affected by midperipheral lens shape profile (P design (P designs. Dynamic OCT coupled with high-resolution video demonstrated that soft contact lens movement and image-corrected ocular surface indentation were influenced by both lens edge design and midperipheral lens shape profiles.

  8. The long and winding road: contact lens-induced ptosis.

    Science.gov (United States)

    Tossounis, Charalambos M; Saleh, George M; McLean, Chris J

    2007-01-01

    Intrapalpebral migration is a rare complication of hard contact lens use. We report a case of a 52-year-old man who presented with right upper eyelid ptosis and requested cosmetic correction. He had no ocular history apart from myopia, which was corrected with the use of hard contact lenses. Prior to the ptosis he recalled losing his right contact lens during a bout of sneezing. He replaced the missing lens and continued to wear contact lenses as usual. After careful clinical examination, an ipsilateral small, mobile eyelid mass was detected, and orbital MRI verified the suspected presence of a hard contact lens. Following surgical removal and ptosis correction, the patient made a full recovery. The phenomenon of hard contact lens migration in the periocular tissues has been reported in the literature before, but most patients experienced symptoms of variable severity. In this patient, however, there were no symptoms to indicate the presence of a contact lens. This case highlights the importance of including intrapalpebral contact lens migration in the differential diagnosis of an eyelid mass or ptosis in patients.

  9. Suction cup/contact lens complications following penetrating keratoplasty.

    Science.gov (United States)

    Ingraham, H J; Perry, H D; Epstein, A B; Donnenfeld, E D; Gwin, T D; Carlson, A N; Moadel, K; Mariani, R E

    1998-01-01

    Rigid gas permeable (RGP) contact lenses facilitate visual rehabilitation in cases of high or irregular corneal astigmatism following penetrating keratoplasty. A variety of plunger-like suction cup devices are available to assist in the removal of these lenses. We report three patients with serious complications associated with the use of a suction cup device for contact lens removal following penetrating keratoplasty. Two patients suffered corneal wound dehiscence following contact lens removal; one contact lens was removed by the patient's spouse and the other was removed by a trained technician. A third patient triggered a graft rejection, and ultimately, graft failure, after a vigorous attempt at lens removal. Forces generated by suction cup devices during removal of RGP contact lenses are sufficient to cause significant trauma. Contact lenses with an apical clearance fit may augment these forces, with the potential for complications following penetrating keratoplasty.

  10. The eyelids and tear film in contact lens discomfort.

    Science.gov (United States)

    Siddireddy, Jaya Sowjanya; Vijay, Ajay Kumar; Tan, Jacqueline; Willcox, Mark

    2017-10-17

    To investigate characteristics of the eyelid margins, meibomian glands and the tear film of contact lens wearers, and to determine whether these characteristics were related to symptoms of contact lens discomfort. A cross sectional study was performed on thirty existing daily wear soft contact lens wearers (6 male; 24 female) with median age of 23 years (range 18-41). Eyelid signs and tear film characteristics were evaluated during a single visit and subjects completed the contact lens and dry eye questionnaire (CLDEQ-8) to evaluate ocular discomfort. Based on the CLDEQ-8 responses, subjects were classified as symptomatic (n=17) or asymptomatic (n=13). Grades of foam at meibomian gland orifices (3±1), expressibility (2±1) and quality of secretions (2±1), tear evaporation rate with (112±54g/m(2)/h) or without (88±45g/m(2)/h) contact lens wear, fluorescein tear breakup time (8±2 seconds) and tear lipid layer thickness (45±17nm) were significantly associated with symptoms of discomfort in symptomatic lens wearers only (r(2)>0.45; p value<0.05). Upper lid-wiper epitheliopathy, meibomian gland acini reflectivity and tear meniscus height showed significant correlations with comfort scores in both symptomatic and asymptomatic contact lens wearers (p<0.05). A greater number of Demodex mites was also observed in the upper eyelid of symptomatic lens wearers (2±1) compared to asymptomatic lens wearers (0±0; p value=0.042). Morphological irregularities of the meibomian glands and alterations to tear film secretions that affect tear evaporative dynamics were associated with symptoms of discomfort amongst the symptomatic lens wearers. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  11. Contact lens and tear film dynamics during blinking

    Science.gov (United States)

    Reid, Timothy; Anderson, Daniel

    2016-11-01

    We develop a mathematical model that couples the dynamics of the tear film and contact lens during blinking. We derive an ordinary differential equation for the motion of the contact lens (parallel to the cornea) driven and retarded by viscous forces in the thin fluid films separating the contact lens from the eyelids and the corneal surface. Using the contact lens motion and tear film dynamics models we calculate a numerical solution of tear film thickness, showing that the lens and lid motion influence the tear film dynamics. The numerical solution uses a mapped Chebyshev spectral method for the spatial derivatives to reduce the model to a system of differential algebraic equations. National Science Foundation Grants (DMS-1407087) and (DMS-1107848).

  12. Further studies of contact lens motion during blinking.

    Science.gov (United States)

    Conway, H D; Knoll, H A

    1986-10-01

    Contact lens motion is felt to be of increasing importance in connection with debris elimination, particularly in extended wear lenses. Thus an improved analysis is made of a simple model for investigating the initial motion of a hard contact lens over the eye during blinking. It is shown that the assumption of constant tear film thickness is a reasonable one. This greatly simplifies the analysis. Various vertical force vs. time variations are considered and lens velocity/time graphs and maximum lens displacement calculated. These are in good agreement with the results of experiment.

  13. Retention Rates in New Contact Lens Wearers.

    Science.gov (United States)

    Sulley, Anna; Young, Graeme; Hunt, Chris; McCready, Sarah; Targett, Marie-Therese; Craven, Ruth

    2017-06-14

    To determine the retention rate (RR) for neophyte patients fitted with contact lenses (CLs) and to identify factors associated with retention and dropout. This multisite, sponsor-masked registry study evaluated the 1-year status of neophyte CL wearers fitted in a representative range of UK practices. A total of 26 UK investigational sites each recruited up to 89 neophyte patients. The participants were requested to complete surveys at 1 month (±1 week from date of fitting), 3 months (±2 weeks), and 12 months (±3 weeks) online or through phone. Participants were contacted by email (or phone) and invited to complete an online survey that asked a range of questions regarding their CL wearing experience. Of the 531 participants recruited, 65.3% (347/531) responded to at least one follow-up survey and 42.3% (225/531) responded to all three surveys. One in four patients showed discontinued CL wear by 12 months. Based on evaluable subjects at 12 months, the RR was 77.6% (194/250, 95% confidence interval: 72.0-82.3). The most common reason for discontinuation was problems with vision (41%), followed by discomfort (36%) and handling problems (25%). The factors affecting first-year RRs: sex, spherical refraction, lens usage (full time or part time), and supply method (collected or posted). In this prospective study, the first-year RR for neophyte CL wearers was 77.6%. This was consistent with that noted in a retrospective study: 74.0%. As with the previous study, the commonly cited reason for discontinuation was visual problems.

  14. Contact lens management of aniseikonia and photophobia induced by trauma.

    Science.gov (United States)

    Migneco, Mary K

    2005-11-01

    To describe a case of a contact lens fitting to relieve aniseikonia and photophobia resulting from trauma. A 61-year-old man suffered a blunt injury to his left eye resulting in glaucoma and a traumatic cataract with a fixed pupil and iris defects. A vitrectomy, lensectomy, and iris repair were performed leaving him with significant anisometropia. The patient was fitted with a prosthetic contact lens. Contact lenses can provide significant visual improvement in cases of aniseikonia and photophobia.

  15. Contact lens compliance among a group of young, university-based lens users in South India.

    Science.gov (United States)

    Noushad, Babu; Saoji, Yeshwant; Bhakat, Premjit; Thomas, Jyothi

    2012-01-01

    To investigate the rate of compliance with the soft contact lens care and maintenance procedures with a focus on contact lens wearing habits, cleaning and disinfecting procedures, and maintenance of lens care accessories in a group of young, university-based contact lens wearers Two hundred and sixteen young soft contact lens wearers with an age range of 18-22 years were selected conveniently from the student population of Manipal University, Manipal, India. After receiving informed consent from the participants, their level of compliance with contact lenses was assessed using a questionnaire. The mean (±SD) age of the participants was 21.86±2.35 years. Out of 216 subjects, only 34% of the lens users were identified to be compliant with the least level of compliance observed in the maintenance of lens care accessories. Conventional users showed significantly (p=0.001) better level of compliance compared to disposable wearers and so did the users who acquired their lenses from clinicians (p=0.001) compared to over-the-counter lens receipt. The gender (p=0.496) and years of experience in contact lens use (p=0.142) did not show any statistically significant difference in the level of compliance. This study demonstrated that non-compliance with lens care procedures among a group of young, university-based soft contact lens wearers is common. The results indicated that all subjects had some degree of non-compliance and the least level of compliance observed in the care of lens accessories.

  16. Evaluation of resources for contact lens practice in private contact lens clinics of Muscat, Oman

    Directory of Open Access Journals (Sweden)

    Rajiv Khandekar

    2009-01-01

    Materials and Methods: This study was conducted between May and July 2006. A team of optometrists and health inspectors visited clinics and collected information about the infrastructure, available human resources, and materials used in the CL practice. We used a pre-tested close-ended questionnaire to collect responses of the practitioners and observations of the field staff. Statistical Method: Univariate parametric type of analysis. Results: The team visited 67 CL clinics and interviewed 75 CL practitioners. Proper hand washing facility was available at 61 clinics. Thirty-nine practitioners had> 10 years of experience in dispensing contact lenses. Only 13 clinics had a bio-microscope. None of the clinics had legal documents signed by both providers and end users of the contact lens. Conclusions: Contact lens has received less attention in areas outside the developed world. The CL practice in the private sectors of Oman needs to be strengthened. Minimum standards, standard operating procedures for CL practice, and its periodic supervision would be useful.

  17. Treatment of contact lens related dry eye with antibacterial honey.

    Science.gov (United States)

    Wong, Daniel; Albietz, Julie M; Tran, Huan; Du Toit, Cimonette; Li, Anita Hui; Yun, Tina; Han, Jee; Schmid, Katrina L

    2017-12-01

    Contact lens induced dry eye affects approximately 50% of contact lens wearers. The aim was to assess the effects of Manuka (Leptospermum sp.) honey eye drops (Optimel, Melcare, Australia) on dry eye in contact lens wearers. The safety of the honey eye drops in contact lens wear and contact lens wearers' compliance were also evaluated. Prospective, randomised, cross over study, examiner masked, pilot treatment trial. Twenty-four participants aged 20 to 55 years with contact lens related dry eye were recruited and randomised to two treatment groups; 20 completed the study. One group used Optimel eye drops twice a day for two weeks followed by conventional lubricant (Systane Ultra, Alcon) therapy for two weeks; the other group completed the treatments in the reverse order. Before and after each treatment dry eye symptomology, ocular surface inflammation, and tear quantity and quality were assessed. Participants completed a daily log detailing their usage of treatments and any issues. Dry eye symptoms improved significantly after Optimel treatment. Patients with more severe symptoms at baseline showed a greater improvement in symptoms. No significant differences were observed in the objective signs of dry eye; presumably because of the short treatment duration. Seventy-five% of contact lens wearers reported good adherence to Optimel treatment and 95% reported no issues using this product. Optimel Eye Drops reduce the symptoms of dry eye in contact lens wearers and are safe to use. A longer treatment period to assess the effect on clinical signs of dry eye is required. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  18. Cytokine changes in tears and relationship to contact lens discomfort.

    Science.gov (United States)

    Willcox, Mark D P; Zhao, Zhenjun; Naduvilath, Thomas; Lazon de la Jara, Percy

    2015-01-01

    To determine the reproducibility of a multiplex bead assay for measuring cytokines in tears and correlations between ocular discomfort with or without contact lens wear and the concentration of cytokines in tears. Ninety participants (divided into two groups) were enrolled in this prospective study. They were asked to rate their ocular comfort and collect their tears in the morning and just before sleep for 10 days with or without contact lenses. The participants collected their tears using a glass microcapillary tube for both stages. Galyfilcon A lenses were worn on a daily disposable basis during the contact lens stage, and comfort scores and tears were collected before lens insertion and prior to lens removal at the end of the day. Tears were analyzed for cytokine concentrations using a 27-plex multibead assay. Correlations were sought between cytokine concentrations and comfort. There was a significant (pocular comfort over the day with or without lens wear. The magnitude of ocular discomfort was significantly greater (p-0.5 Log pg/ml, p-0.2 Log pg/ml, ptears was correlated to ocular comfort, but this was not changed by contact lens wear. Ocular comfort during the day is magnified by contact lens wear. However, the increase in the change in comfort during lens wear was not associated with changes in 15 cytokines in the tear film.

  19. A single-pixel wireless contact lens display

    Science.gov (United States)

    Lingley, A. R.; Ali, M.; Liao, Y.; Mirjalili, R.; Klonner, M.; Sopanen, M.; Suihkonen, S.; Shen, T.; Otis, B. P.; Lipsanen, H.; Parviz, B. A.

    2011-12-01

    We present the design, construction and in vivo rabbit testing of a wirelessly powered contact lens display. The display consists of an antenna, a 500 × 500 µm2 silicon power harvesting and radio integrated circuit, metal interconnects, insulation layers and a 750 × 750 µm2 transparent sapphire chip containing a custom-designed micro-light emitting diode with peak emission at 475 nm, all integrated onto a contact lens. The display can be powered wirelessly from ~1 m in free space and ~2 cm in vivo on a rabbit. The display was tested on live, anesthetized rabbits with no observed adverse effect. In order to extend display capabilities, design and fabrication of micro-Fresnel lenses on a contact lens are presented to move toward a multipixel display that can be worn in the form of a contact lens. Contact lenses with integrated micro-Fresnel lenses were also tested on live rabbits and showed no adverse effect.

  20. Risk factors for contact lens-related microbial keratitis in Singapore

    National Research Council Canada - National Science Library

    Lim, C H L; Carnt, N A; Farook, M; Lam, J; Tan, D T; Mehta, J S; Stapleton, F

    2016-01-01

    .... Community contact lens wearers were recruited as controls. All wearers completed a previously validated questionnaire describing contact lens wear history, hygiene and compliance habits, and demographics...

  1. Smart Reinvention of the Contact Lens with Graphene.

    Science.gov (United States)

    Choi, Kyoungjun; Park, Hyung Gyu

    2017-06-27

    With potential benefits to the 71 million contact lens users worldwide, contact lenses are being reinvented in the form of smart wearable electronics. In this issue of ACS Nano, Lee et al. report on the fascinating functions of a graphene-based smart contact lens that is able to protect eyes from electromagnetic waves and dehydration. Graphene and two-dimensional materials can be exploited in many opportunities in the development of smart contact lenses. Here, we briefly review and describe prospects for the future of smart contact lenses that incorporate graphene in their platforms.

  2. Impact of contact lens materials on multipurpose contact lens solution disinfection activity against Fusarium solani.

    Science.gov (United States)

    Clavet, Charles R; Chaput, Maria P; Silverman, Matthew D; Striplin, Megan; Shoff, Megan E; Lucas, Anne D; Hitchins, Victoria M; Eydelman, Malvina B

    2012-11-01

    To investigate the effects of eight different soft contact lenses on disinfection efficacy of a multipurpose solution (MPS) containing polyhexamethylene biguanide (PHMB) against Fusarium solani. Six silicone hydrogel lenses (galyfilcon A, senofilcon A, comfilcon A, enfilcon A, balafilcon A, and lotrifilcon B) and two conventional hydrogel lenses (polymacon and etafilcon A) were placed in polypropylene lens cases filled with MPS containing 0.0001% PHMB and soaked for 6, 12, 24, 72, and 168 hours. After each interval, depleted MPS from lens cases were removed and assayed for activity against F. solani according to International Organization for Standardization (ISO) 14729 stand-alone procedure. A portion was aliquoted for chemical analysis. Soaking etafilcon A, balafilcon A, and polymacon lenses for 6 hours reduced the concentration of PHMB in MPS by more than half the stated labeled concentration, with concentrations below the limit of detection for etafilcon A-depleted and balafilcon A-depleted solutions after 12 and 72 hours of soaking, respectively. Except for comfilcon A-depleted solutions, all others failed to consistently obtain one log reduction of F. solani. The solutions soaked with etafilcon A, balafilcon A, and polymacon lenses for 24 hours or more lost all or almost all fungicidal activity against F. solani. Over time, the disinfectant uptake by some lenses can significantly reduce the PHMB concentration and the fungicidal activity of the MPS against F. solani. Current ISO methodology does not address the reduction in microbiocidal efficacy when lenses are soaked in MPS. The ISO committee should consider adding "soaking experiments" to quantify the effect that contact lens materials have on the performance of MPSs.

  3. Bacterial Adhesion Forces to Ag-Impregnated Contact Lens Cases and Transmission to Contact Lenses

    NARCIS (Netherlands)

    Qu, Wenwen; Busscher, Henk J.; van der Mei, Henny C.; Hooymans, Johanna M. M.

    Purpose: To measure adhesion forces of Pseudomonas aeruginosa, Staphylococcus aureus, and Serratia marcescens to a rigid contact lens (CL), standard polypropylene, and Ag-impregnated lens cases using atomic force microscopy and determine bacterial transmission from lens case to CL. Methods: Adhesion

  4. Microbial contamination of soft contact lenses & accessories in asymptomatic contact lens users.

    Science.gov (United States)

    Thakur, Deeksha V; Gaikwad, Ujjwala N

    2014-08-01

    With increasing use of soft contact lenses the incidence of contact lens induced infections is also increasing. This study was aimed to assess the knowledge of new and existing contact lens users about the risk of microbial contamination associated with improper use and maintenance of contact lenses, type of microbial flora involved and their potential to cause ophthalmic infections. Four samples each from 50 participants (n=200) were collected from the lenses, lens care solutions, lens care solution bottles and lens cases along with a questionnaire regarding their lens use. The samples were inoculated onto sheep blood agar, Mac Conkey's agar and Sabouraud's dextrose agar. Organisms were identified using standard laboratory protocols. Overall rate of microbial contamination among the total samples was 52 per cent. The most and the least contaminated samples were found to be lens cases (62%) and lens care solution (42%), respectively. The most frequently isolated contaminant was Staphylococcus aureus (21%) followed by Pseudomonas species (19.5%). Majority (64%) of the participants showed medium grade of compliance to lens cleaning practices. Rate of contamination was 100 and 93.75 per cent respectively in those participants who showed low and medium compliance to lens care practices as compared to those who had high level of compliance (43.75%) (PLens care practices amongst the participants were not optimum which resulted into high level contamination. Hence, creating awareness among the users about the lens care practices and regular cleaning and replacements of lens cases are required.

  5. Customer loyalty among daily disposable contact lens wearers.

    Science.gov (United States)

    Patel, Neelam I; Naroo, Shehzad A; Eperjesi, Frank; Rumney, Nicholas J

    2015-02-01

    Optometric practices offer contact lenses as cash sale items or as part of monthly payment plans. With the contact lens market becoming increasingly competitive, patients are opting to purchase lenses from supermarkets and Internet suppliers. Monthly payment plans are often implemented to improve loyalty. This study aimed to compare behavioural loyalty between monthly payment plan members and non-members. BBR Optometry Ltd offers a monthly payment plan (Eyelife™) to their contact lens wearers. A retrospective audit of 38 Eyelife™ members (mean±SD: 42.7±15.0 years) and 30 non-members (mean±SD: 40.8±16.7 years) was conducted. Revenue and profits generated, service uptake and product sales between the two groups were compared over a fixed period of 18 months. Eyelife™ members generated significantly higher professional fee revenue (P<0.001), £153.96 compared to £83.50, and profits (P<0.001). Eyelife™ members had a higher uptake of eye examinations (P<0.001). The 2 groups demonstrated no significant difference in spectacle sales by volume (P=0.790) or value (P=0.369). There were also no significant differences in contact lens revenue (P=0.337), although Eyelife™ members did receive a discount. The Eyelife™ group incurred higher contact lens costs (P=0.037), due to a greater volume of contact lens purchases, 986 units compared to 582. Monthly payment plans improve loyalty among contact lens wearers, particularly service uptake and volume of lens purchases. Additionally the greater professional fees generated, render monthly payment plans an attractive business model and practice builder. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  6. Corneal Biomechanical Findings in Contact Lens Induced Corneal Warpage

    OpenAIRE

    Fateme Alipour; Mojgan Letafatnejad; Amir Hooshang Beheshtnejad; Seyed-Farzad Mohammadi; Seyed Reza Ghaffary; Narges Hassanpoor; Mehdi Yaseri

    2016-01-01

    Purpose. To evaluate the difference in biomechanical properties between contact lens induced corneal warpage and normal and keratoconic eyes. Method. Prospective observational case control study, where 94 eyes of 47 warpage suspicious and 46 eyes of 23 keratoconic patients were included. Warpage suspected cases were followed until a definite diagnosis was made (warpage, normal, or keratoconus). Results. 44 eyes of 22 patients had contact lens related corneal warpage. 46 eyes of 23 people were...

  7. Lost contact lens masquerading as an orbital mass

    OpenAIRE

    Morris, Daniel S; Peter J Dolman

    2009-01-01

    A 30-year-old woman presented to the orbital clinic with a 4-year history of a mass in her left upper eyelid of unknown aetiology. Eyelid eversion revealed an embedded hard contact lens, which was removed under local anaesthesia. The patient made a full recovery but this case highlights the need for a careful history in contact lens wearers and a full examination including double eversion of the upper eyelids.

  8. Outcome following surgery for contact lens-induced ptosis.

    Science.gov (United States)

    de Silva, D Julian; Collin, J Richard O

    2011-01-01

    To assess the outcome of surgery in patients with a history of contact lens wear. Retrospective, comparative interventional case series. A total of 419 patients underwent ptosis surgery during a 1-year period (2005-2006) at Moorfields Eye Hospital. Those included in this study had a diagnosis of aponeurotic ptosis and history of contact lens wear. The outcome was considered a success if the following criteria were met: 1) a margin reflex distance of between 3 and 5 mm, 2) an interlid difference of 1 mm or less, and 3) absence of redo surgery. Thirty patients (7.2%) were identified with a history of contact lens wear and were matched against a control group of 46 patients. The mean margin-reflex distance at presentation was 0.5 ± 2.4 mm. This equated to a ptosis graded as mild (≥1.5 mm) for 32% of patients, moderate (0.5-1.0 mm) for 29%, and severe (≤0.0 mm) for 39%, with similar proportions in the control group (36% mild, 39% moderate, and 25% severe). The power of the refractive correction (p contact lens-related ptosis was related to the degree of myopia and the age of the patient but not to the duration of contact lens wear. There was a higher level of failure and requirement for redo surgery in patients with contact lens-related ptosis compared with matched controls.

  9. Demographic Factors Affect Ocular Comfort Ratings During Contact Lens Wear.

    Science.gov (United States)

    Naduvilath, Thomas; Papas, Eric B; Lazon de la Jara, Percy

    2016-08-01

    To determine if rating of ocular comfort during soft contact lens wear is affected by demographic factors. Retrospective analysis of ocular comfort ratings during soft contact lens wear extracted from 44 nonrandomized similar clinical trials (n = 986). Subjects wore one of seven daily wear silicone hydrogels (SiHy) in combination with one of nine lens care products (LCP), and two daily disposables lenses. The effects on comfort rating of demographic factors were examined after adjusting for lens and LCP effects using general linear model. Males reported lower comfort on insertion than females (7.9 ± 1.6 vs. 8.1 ± 1.6, p = 0.001). Over 45 years old had higher comfort ratings than those between 26 and 45 or gender, lens wear experience, ethnicity, and refractive status can influence the rating of ocular comfort in clinical studies. The confounding effects of such demographic factors can be controlled by implementing randomization and appropriate multivariable statistical analysis.

  10. Microbial contamination of soft contact lenses & accessories in asymptomatic contact lens users

    OpenAIRE

    Deeksha V Thakur; Ujjwala N Gaikwad

    2014-01-01

    Background & objectives: With increasing use of soft contact lenses the incidence of contact lens induced infections is also increasing. This study was aimed to assess the knowledge of new and existing contact lens users about the risk of microbial contamination associated with improper use and maintenance of contact lenses, type of microbial flora involved and their potential to cause ophthalmic infections. Methods: Four samples each from 50 participants (n=200) were collected from the l...

  11. Contact Lens Visual Rehabilitation in Keratoconus and Corneal Keratoplasty

    Directory of Open Access Journals (Sweden)

    Yelda Ozkurt

    2012-01-01

    Full Text Available Keratoconus is the most common corneal distrophy. It’s a noninflammatory progressive thinning process that leads to conical ectasia of the cornea, causing high myopia and astigmatism. Many treatment choices include spectacle correction and contact lens wear, collagen cross linking, intracorneal ring segments implantation and finally keratoplasty. Contact lenses are commonly used to reduce astigmatism and increase vision. There are various types of lenses are available. We reviewed soft contact lenses, rigid gas permeable contact lenses, piggyback contact lenses, hybrid contact lenses and scleral-semiscleral contact lenses in keratoconus management. The surgical option is keratoplasty, but even after sutur removal, high astigmatism may stil exists. Therefore, contact lens is an adequate treatment option to correct astigmatism after keratoplasty.

  12. Contact lens visual rehabilitation in keratoconus and corneal keratoplasty.

    Science.gov (United States)

    Ozkurt, Yelda; Atakan, Mehmet; Gencaga, Tugba; Akkaya, Sezen

    2012-01-01

    Keratoconus is the most common corneal distrophy. It's a noninflammatory progressive thinning process that leads to conical ectasia of the cornea, causing high myopia and astigmatism. Many treatment choices include spectacle correction and contact lens wear, collagen cross linking, intracorneal ring segments implantation and finally keratoplasty. Contact lenses are commonly used to reduce astigmatism and increase vision. There are various types of lenses are available. We reviewed soft contact lenses, rigid gas permeable contact lenses, piggyback contact lenses, hybrid contact lenses and scleral-semiscleral contact lenses in keratoconus management. The surgical option is keratoplasty, but even after sutur removal, high astigmatism may stil exists. Therefore, contact lens is an adequate treatment option to correct astigmatism after keratoplasty.

  13. Dynamic contour tonometry over silicone hydrogel contact lens.

    Science.gov (United States)

    Lam, Andrew K C; Tse, Jimmy S H

    2014-01-01

    This study compared the measurements of intraocular pressure (IOP) and ocular pulse amplitude (OPA) using the Dynamic Contour Tonometry (DCT) over silicone hydrogel contact lenses of different modulus. Corneal biomechanics were also measured using the Ocular Response Analyzer (ORA). Forty-seven young (mean age 22.3 years, standard deviation 1.2 years) subjects had IOP, OPA, corneal hysteresis (CH) and corneal resistance factor (CRF) measured without lens and with two brands of silicone hydrogel contact lenses. Each eye wore one brand followed by another, randomly assigned, and then the lenses switched over. Difference and agreement of IOP and OPA with and without silicone hydrogel contact lens were studied. The right and left eyes had similar corneal curvatures, central corneal thicknesses, IOP, OPA and corneal biomechanics at baseline. No significant difference was found in CH and CRF when they were measured over different contact lenses. IOP demonstrated a greater difference (95% limits of agreement: 2.73mmHg) compared with no lens when it was measured over high modulus silicone hydrogel lenses. Agreement improved over low lens modulus silicone hydrogel lenses (95% limits of agreement: 2.2-2.4mmHg). 95% limits of agreement were within 1.0mmHg for OPA. This study demonstrated the feasibility of DCT over silicone hydrogel lenses. Low lens modulus silicone hydrogel contact lens in situ has no clinical effect on DCT. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  14. An international survey of contact lens prescribing for presbyopia.

    Science.gov (United States)

    Morgan, Philip B; Efron, Nathan; Woods, Craig A

    2011-01-01

      The aim was to determine world-wide patterns of fitting contact lenses for the correction of presbyopia.   Up to 1,000 survey forms were sent to contact lens fitters in each of 38 countries between January and March every year over five consecutive years (2005 to 2009). Practitioners were asked to record data relating to the first 10 contact lens fittings or refittings performed after receiving the survey form.   Data were received relating to 16,680 presbyopic (age 45 years or older) and 84,202 pre-presbyopic (15 to 44 years) contact lens wearers. Females are over-represented in presbyopic versus pre-presbyopic groups, possibly reflecting a stronger desire for the cosmetic benefits of contact lenses among older women. The extent to which multifocal and monovision lenses are prescribed for presbyopes varies considerably among nations, ranging from 79 per cent of all soft lenses in Portugal to zero in Singapore. There appears to be significant under-prescribing of contact lenses for the correction of presbyopia, although for those who do receive such corrections, three times more multifocal lenses are fitted compared with monovision fittings. Presbyopic corrections are most frequently prescribed for full-time wear and monthly replacement.   Despite apparent improvements in multifocal design and an increase in available multifocal options in recent years, practitioners are still under-prescribing with respect to the provision of appropriate contact lenses for the correction of presbyopia. Training of contact lens practitioners in presbyopic contact lens fitting should be accelerated and clinical and laboratory research in this field should be intensified to enhance the prospects of meeting the needs of presbyopic contact lens wearers more fully. © 2010 The Authors. Clinical and Experimental Optometry © 2010 Optometrists Association Australia.

  15. Non-compliance with lens care and maintenance in diabetic contact lens wearers.

    Science.gov (United States)

    O'Donnell, Clare; Efron, Nathan

    2004-11-01

    We hypothesize that diabetic contact lens wearers may represent a special group displaying higher levels of compliance with their lens care regimens as a result of learned behaviour relating to maintenance of their diabetic condition. To test this hypothesis, a prospective, single centre, controlled, masked study was performed whereby 29 diabetic contact lens patients and 29 non-diabetic control subjects were issued with disposable hydrogel contact lenses and a multipurpose lens care regimen. All participants were given identical instruction on lens care and maintenance. Compliance levels were assessed at a 12-month aftercare appointment by demonstration and questionnaire. Twenty-four different aspects of compliance were scored, 12 by observation and 12 by questionnaire report, of which only two showed a significant difference between the diabetic and control groups. Although the combined population of contact lens wearers was generally compliant, there were examples of non-compliance in both groups. Neither the duration of diabetes nor the degree of metabolic control appeared to have a significant effect on compliance. The results suggest that eye care practitioners cannot assume that diabetic patients will be more compliant with contact lens care and maintenance than non-diabetic patients.

  16. Rhizopus Keratitis Associated with Poor Contact Lens Hygiene

    Directory of Open Access Journals (Sweden)

    David B. Warner

    2016-01-01

    Full Text Available We report a case of Rhizopus keratitis in a young woman with poor contact lens hygiene. The mold was highly sensitive to treatment with amphotericin 0.15% drops, after a relatively prompt diagnosis. Obtaining cultures of both corneal infiltrates and presumably infected contact lenses may help to avoid a delay in proper treatment.

  17. Immunoglobulin Concentration in Tears of Contact Lens Wearers

    Directory of Open Access Journals (Sweden)

    Rajendra P Maurya

    2014-01-01

    Conclusion: The relation of immunoglobulin concentration with increasing duration of wear and material of contact lens shows that tear immunoglobulin rise accrues due to mechanical stimulation, hence contact lenses should not be used for a long period and lenses of hard nature should be discouraged. The maintenance, cleaning and deproteinization of the lenses are of high importance to avoid immunostimulation.

  18. The contact lens environment: tear proteins in perspective.

    Science.gov (United States)

    Carney, L G; Hill, R M

    1985-03-01

    Tear protein deposition on contact lenses can lead to interruption or even cessation of lens wear. Yet, there are positive roles that tear proteins play in the maintenance of ocular integrity, with and without contact lenses present. One of these roles, that of tear buffering, is explored here.

  19. Contact Lens Safety (A Minute of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2016-08-18

    Contact lenses are a convenient alternative to glasses, but improper care and use can result in infections which can lead to eye damage. This podcast discusses contact lens safety.  Created: 8/18/2016 by MMWR.   Date Released: 8/18/2016.

  20. Corneal biomechanical changes following toric soft contact lens wear

    Directory of Open Access Journals (Sweden)

    Somayeh Radaie-Moghadam

    2016-01-01

    Conclusion: CH and CRF decreased significantly one month after fitting toric soft contact lenses while CCT and K mean did not change significantly. Corneal biomechanical parameters may alter with toric soft contact lens use and such changes may have implications with long-term use such lenses.

  1. Patient compliance and its influence on contact lens wearing problems.

    Science.gov (United States)

    Collins, M J; Carney, L G

    1986-12-01

    One hundred consecutively presenting patients, fifty from each of two contact lens clinics, were questioned about the procedures encountered in care and maintenance of their contact lenses and asked to demonstrate their use of those procedures. Their clinic records were then analyzed for the occurrence of signs and symptoms that were related potentially to noncompliance with instructions and procedures, and that could not be otherwise explained. Only 26% of patients were fully complaint. Noncompliance with instructions was related strongly to the occurrence of signs and symptoms indicative of potential wearing problems. Improvements in the level of patient compliance with instructions is likely to bring about increased patient success with contact lens wearing.

  2. Immunoglobulin Concentration in Tears of Contact Lens Wearers

    OpenAIRE

    Maurya, Rajendra P.; Bhushan, Prashant; Singh, Virendra P.; Singh, Mahendra K.; Kumar, Prakash; Bhatia, Ravindra P.S.; Singh, Usha

    2014-01-01

    Purpose: To evaluate changes in the concentration of tear immunoglobulins in contact lens wearers. Methods: A total of 45 cases including 23 contact lens wearers (43 eyes) and 22 age and sex matched healthy controls having no ocular pathology were studied for immunoglobulins (IgA, IgG, IgM) in their tears by single radial immunodiffusion method. Results: Most of the cases used soft (56.6%) and semi-soft gas permeable (30.4%) contact lenses. Tear IgM was detected in only 17.4% and tear I...

  3. Factors affecting light scatter in contact lens wearers.

    Science.gov (United States)

    Elliott, D B; Mitchell, S; Whitaker, D

    1991-08-01

    We measured forward light scatter at 3.5, 10, and 28 degrees using a portable stray light meter. Subjects included 66 normal subjects (age range 19 to 79 years), 17 established hydrophilic contact lens wearers, and 15 rigid gas permeable (RGP) contact lens wearers. Contact lens deposits were measured using a modified Rudko procedure and a Leitz/Wild Makroscope M240. Corneal health was assessed using slitlamp biomicroscopy. Results showed a significant increase in light scatter with age, particularly after the age of 40 years. Stray light scores were significantly lower in pigmented non-Caucasian subjects, particularly at larger angles. The stray light scores were significantly greater in contact lens wearers than in age-matched normals, but were not found to correlate with the amount of lens deposits. Scores from hydrophilic lens wearers after removal of their lenses were significantly higher than results from RGP wearers after removal of their lenses and from age-matched normals. This suggests the presence of subclinical corneal edema in some of these subjects.

  4. Self retaining contact lens system for vitreous surgery

    Directory of Open Access Journals (Sweden)

    Chalam Kakarla

    2004-01-01

    Full Text Available We describe the principle and design of a new self-retaining contact lens system for vitreous surgery. The system has three lenses: the plano-concave, prism and magnifying lens. This system is based on the principle of a direct imaging contact lens, designed for a 150-200mm focal length operating microscope. The contact lenses are designed to have an inferior concave surface [radius of curvature (ROC 7.7mm], modified by the addition of four footplates to provide stability and centration during vitreous surgery. The lenses are used with a drop of viscoelastic material placed between the concave surface of the contact lens and cornea. This induces negative suction and helps retain the lens in position during surgery. These specially designed lenses provide a stable, well-centered, high-resolution, magnified view of the fundus. This system eliminates the need for a skilled assistant or for suturing the lens to the sclera during vitreous surgery.

  5. Improved Vision and Contact Lens Wear Time With Piggy-Back Contact Lens Systems in Children After Penetrating Corneal Trauma.

    Science.gov (United States)

    Cromelin, Caroline; Russell, Buddy; Lambert, Scott R

    2017-07-01

    Consecutive case series of children treated successfully with "piggy-back" (PB) contact lens systems after corneal trauma. We reviewed the medical record of all children ages 4 to 14 years treated at the Emory Eye Center between January 11, 2003 and January 11, 2013 with PB contact lens systems. Four children with a history of corneal penetrating trauma were treated with a PB lens system, with a mean age of 7±0.08 (range: 6-8) years. Best-corrected spectacle vision was count fingers in two children and logMAR +0.70 (Snellen equivalent 20/100) and logMAR +0.6 (Snellen equivalent 20/80) in the remaining two. The PB lens system was introduced with a mean of 15.7±6.5 (range: 9-22) months after the injury. All patients were initially fitted with gas-permeable (GP) lenses. Each child achieved 11 or more hours of daily contact lens wear time in PB systems. The mean best-corrected logMAR visual acuity using the PB system was 0.26±0.21 (Snellen equivalent 20/36). The mean improvement in best-corrected logMAR between GP and PB lens systems was +0.21±0.11, which corresponds to an improvement of greater than two lines on the Snellen chart. Piggy-back contact lens systems can be helpful to improve vision and contact lens wearing time in children with irregular astigmatism after corneal trauma, who are intolerant of GP contact lenses.

  6. Immunoglobulin concentration in tears of contact lens wearers.

    Science.gov (United States)

    Maurya, Rajendra P; Bhushan, Prashant; Singh, Virendra P; Singh, Mahendra K; Kumar, Prakash; Bhatia, Ravindra P S; Singh, Usha

    2014-01-01

    To evaluate changes in the concentration of tear immunoglobulins in contact lens wearers. A total of 45 cases including 23 contact lens wearers (43 eyes) and 22 age and sex matched healthy controls having no ocular pathology were studied for immunoglobulins (IgA, IgG, IgM) in their tears by single radial immunodiffusion method. Most of the cases used soft (56.6%) and semi-soft gas permeable (30.4%) contact lenses. Tear IgM was detected in only 17.4% and tear IgG in 43.6% of contact lens wearers, while in controls IgG was detected in 9.1% but none of the controls had IgM. There was a significant rise in total tear IgA (13.17 ± 4.44 mg/dl) in contact lens wearer as compared to controls (8.93 ± 3.79 mg/dl). Rise of tear IgA was more in symptomatic patients (15.38 ± 5.28 mg/dl) and in those wearing hard (19.73 ± 5.43 mg/dl) and semi-soft contact lenses (13.31 ± 5.43 mg/dl). A significant increase in tear IgA was noticed in subjects wearing lenses for >3 years (15.69 ± 5.39 mg/dl). About 43.4% of lens wearers were symptomatic and 80% of their lenses showed deposits and/or haziness. All cases with IgM in tear were symptomatic. The relation of immunoglobulin concentration with increasing duration of wear and material of contact lens shows that tear immunoglobulin rise accrues due to mechanical stimulation, hence contact lenses should not be used for a long period and lenses of hard nature should be discouraged. The maintenance, cleaning and deproteinization of the lenses are of high importance to avoid immunostimulation.

  7. Peripheral corneal infiltrates associated with contact lens wear.

    Science.gov (United States)

    Suchecki, J K; Ehlers, W H; Donshik, P C

    1996-01-01

    We describe the epidemiological and clinical characteristics of peripheral corneal infiltrates associated with contact lens wear. We conducted a retrospective study of 52 patients with contact lens associated peripheral corneal infiltrates. Demographic data, clinical characteristics of the infiltrates, contact lens parameters, treatment modality, and the time to resolution for the infiltrates were analyzed. Forty-four of the 52 patients in this study presented with a single infiltrate, while the remaining 8 patients had multiple infiltrates. Types of contact lenses worn were as follows: 40% of the patients wore disposable extended wear contact lenses; 21% wore conventional extended wear lenses; 19% wore conventional daily wear lenses; 12% used frequent replacement daily wear lenses; 6% wore rigid gas permeable (RGP) contact lenses; and 2% used disposable lenses as daily wear. Although there was no predilection for a specific quadrant of the cornea, when a subgroup of extended wear contact lens patients was analyzed, 19 of their 40 infiltrates were located in the superior quadrant. The epithelium was intact in 42% of the infiltrates, while 58% of the infiltrates had epithelial involvement, either punctate staining or frank defect. Eight of the 16 patients who had corneal cultures performed had positive cultures. All patients who had positive cultures used extended wear contact lenses. Smoking did not appear to have an effect on the associated inflammatory reaction, positive cultures, or time to resolution. Seventy-five percent of patients were treated with topical antibiotics. Antibiotic steroids were prescribed for 23% of patients, and 2% of patients were treated with topical steroids. The mean time to resolution for all infiltrates was 1.74 weeks. Focal peripheral infiltrates with or without epithelial disturbance represent a distinct clinical complication associated with contact lens wear. All patients in this study had resolution of their infiltrates without

  8. History and symptom taking in contact lens fitting and aftercare.

    Science.gov (United States)

    Wolffsohn, James S; Naroo, Shehzad A; Christie, Caroline; Morris, Judith; Conway, Robert; Maldonado-Codina, Carole; Retalic, Neil; Purslow, Christine

    2015-08-01

    To appraise history and symptom taking for contact lens consultations, to determine current practice and to make recommendations for best practice. The peer reviewed academic literature was reviewed and the results informed a survey completed by 256 eye care practitioners (ECPs) on their current practice and influences. The last eye-test date, last contact lens aftercare (for existing wearers) and reason for visit are key questions for most ECPs. Detailed use of contact lens questions are more commonly applied in aftercares than when refitting patients who have previously discontinued wear (87% vs 56% use), whereas questions on ocular and general history, medication and lifestyle were generally more commonly utilised for new patients than in aftercares (72% vs 50%). 75% of ECPs requested patients bring a list of their medication to appointments. Differential diagnosis questioning was thorough in most ECPs (87% of relevant questions asked). Attempts to optimise compliance included oral instruction (95% always) and written patient instructions (95% at least sometimes). Abbreviations were used by 39% of respondents (26% used ones provided by a professional body). There is scope for more consistency in history and symptom taking for contact lens consultations and recommendations are made. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  9. Complications Caused by Contact Lens Wearing

    OpenAIRE

    Beljan, Jasna; Beljan, Kristina; Beljan, Zdravko

    2013-01-01

    Complications in wearing contact lenses are very rare and caused by poor maintenance, over-extended wear and wearing of contact lenses in a polluted environment. Regular control by a professional person can efficiently reduce the number of complications. This paper describes the most common risks factors for complications, and complications of wearing contact lenses with the classification according to the anatomic parts of the eye: eyelids, tear film, limbus, corneal epithelium, corneal stro...

  10. Risk factors for contact lens bacterial contamination during continuous wear.

    Science.gov (United States)

    Szczotka-Flynn, Loretta B; Bajaksouzian, Saralee; Jacobs, Michael R; Rimm, Alfred

    2009-11-01

    Microbial contamination of contact lenses is associated with corneal infection and inflammation. This study determined the microbiological, clinical, and demographic factors that are associated with bacterial contamination of a silicone hydrogel contact lens when worn for continuous wear (CW). Two hundred five healthy subjects were enrolled in the Longitudinal Analysis of Silicone Hydrogel Contact Lens Study and were fitted with lotrafilcon A lenses for monthly CW and followed for 1 year. Lenses were aseptically removed after 1 week and 4 months of wear and cultured using an agar sandwich technique. Lids and conjunctiva were routinely cultured at baseline and after 1 week and 4 months of CW. Lenses and ocular sites were considered to have substantial microbial bioburden when they harbored pathogenic organisms or high levels of commensal organisms. Univariate and multivariate logistic regression analyses were conducted to examine whether substantial conjunctival or lid bioburden, subject demographics, lens-wearing history, symptoms, and biomicroscopic signs were associated with lens bioburden. About one third (32.4%) of subjects had substantial bacterial bioburden in either eye across multiple visits. Over half (53.2%) and about one tenth (11.7%) of subjects had substantial lid and conjunctival bioburden, respectively, and 11.2% discontinued because of discomfort. The adjusted odds ratios (and 95% confidence intervals) for presence of substantial lens bioburden were 2.49 (1.17-5.30), 4.24 (1.45-12.40), and 4.11 (1.17-14.46) for substantial lid bioburden, substantial conjunctival bioburden, and lens discomfort, respectively. Bacterial contamination of silicone hydrogel contact lenses is common during CW. Substantial lens bioburden is associated with discomfort precluding successful CW. The presence of substantial lid and conjunctival bioburden is associated with a 2.5-fold and more than fourfold greater risk of substantial lens bioburden and is likely the major route

  11. Microbial contamination of soft contact lenses & accessories in asymptomatic contact lens users

    Directory of Open Access Journals (Sweden)

    Deeksha V Thakur

    2014-01-01

    Full Text Available Background & objectives: With increasing use of soft contact lenses the incidence of contact lens induced infections is also increasing. This study was aimed to assess the knowledge of new and existing contact lens users about the risk of microbial contamination associated with improper use and maintenance of contact lenses, type of microbial flora involved and their potential to cause ophthalmic infections. Methods: Four samples each from 50 participants (n=200 were collected from the lenses, lens care solutions, lens care solution bottles and lens cases along with a questionnaire regarding their lens use. The samples were inoculated onto sheep blood agar, Mac Conkey′s agar and Sabouraud′s dextrose agar. Organisms were identified using standard laboratory protocols. Results: Overall rate of microbial contamination among the total samples was 52 per cent. The most and the least contaminated samples were found to be lens cases (62% and lens care solution (42%, respectively. The most frequently isolated contaminant was Staphylococcus aureus (21% followed by Pseudomonas species (19.5%. Majority (64% of the participants showed medium grade of compliance to lens cleaning practices. Rate of contamination was 100 and 93.75 per cent respectively in those participants who showed low and medium compliance to lens care practices as compared to those who had high level of compliance (43.75% ( p0 <0.05. Interpretation & conclusions: Lens care practices amongst the participants were not optimum which resulted into high level contamination. Hence, creating awareness among the users about the lens care practices and regular cleaning and replacements of lens cases are required.

  12. Orthoptic indications for contact lens wear.

    Science.gov (United States)

    Evans, Bruce J W

    2006-09-01

    Orthoptic anomalies are prevalent: they are encountered in at least 5% of patients seen in a typical primary eyecare practice. Several cases are reviewed that highlight the role of contact lenses in treating orthoptic anomalies. In particular, contact lenses are the preferred optical approach to the correction of anisometropia, and it is often argued that anisometropia should be corrected as young as possible. However, fitting contact lenses to patients, particularly children, with anisometropic amblyopia has been problematic because there is no immediate binocular acuity improvement when the contact lenses are inserted which reduces patient motivation. Continuous wear with silicone hydrogels represents a breakthrough for these cases and some illustrative case studies are given. The visual deficit in amblyopia can be reduced in some cases solely by fitting contact lenses, without the need for occlusion therapy. Other orthoptic uses of contact lenses are reviewed including: correcting motor deviations, occlusion, and infantile onset nystagmus. It is concluded that there are orthoptic anomalies where contact lenses are the preferred mode of correction. It is in patients' best interest for practitioners to discuss contact lenses in these cases.

  13. [Now soft toric contact lenses; silicone hydrogel lens for astigmatism].

    Science.gov (United States)

    Radu, Simona

    2006-01-01

    Soft toric contact lenses are a good alternative for the optical correction of astigmatism. They provide a wide visual field, quick adaptation process, negligible aniseikonia, together with enhanced comfort and reduced incidence of complications introduced by the lenses for frequent replacement. Still practitioners do not recommend them proactively and the satisfaction obtained by the patients is not high enough. This paper presents two recent studies that investigate the opinions of specialists and contact lens wearers and introduce a new contact lens, with an original design, born after 30 years of domination of only 2 modalities of rotational stabilization: prism ballast and dual thin zones. The lens is manufactured using a silicon-hydrogel material of 2-nd generation that provides sustained comfort and better oxygenation.

  14. Mass spectrometry-based proteomic analyses of contact lens deposition.

    Science.gov (United States)

    Green-Church, Kari B; Nichols, Jason J

    2008-02-08

    The purpose of this report is to describe the contact lens deposition proteome associated with two silicone hydrogel contact lenses and care solutions using a mass spectrometric-based approach. This was a randomized, controlled, examiner-masked crossover clinical trial that included 48 participants. Lenses and no-rub care solutions evaluated included galyfilcon A (Acuvue Advance, Vistakon Inc., Jacksonville, FL), lotrafilcon B (O2 Optix, CIBA Vision Inc., Duluth, GA), AQuify (CIBA Vision Inc.), and ReNu MoistureLoc (Bausch and Lomb Inc., Rochester, NY). After two weeks of daily wear in each lens-solution combination, the left lens was removed by the examiner (using gloves and forceps) and placed in a protein precipitation buffer (acetone). The precipitate was quantitated for total protein concentration (per lens), and proteins were then identified using liquid chromatography tandem mass spectrometry (nano-LC-MS/MS) and peptide sequencing. Between 7.32 and 9.76 microg/lens of protein was observed on average from each lens-solution combination. There were 19 total unique proteins identified across the two lens materials, and six proteins were identified in all four lens-solution combinations including lipocalin, lysozyme, lacritin, lactoferrin, proline rich 4, and Ig Alpha. Lotrafilcon B was associated with 15 individual proteins (across both care solutions), and 53% of these proteins were observed in at least 50% of the analyses. Galyfilcon A was associated with 13 individual proteins, and 38.5% of these proteins were observed in at least 50% of the analyses. There were three unique proteins identified from galyfilcon A and four unique proteins identified from lotrafilcon B. The total amount of proteins identified from silicone hydrogel materials is much less than the amount from traditional soft lens materials. For the most part, the deposition proteome across these lenses is similar, although the different polymer characteristics might be associated with some

  15. Contact lens associated microbial keratitis: practical considerations for the optometrist

    Directory of Open Access Journals (Sweden)

    Zimmerman AB

    2016-01-01

    Full Text Available Aaron B Zimmerman, Alex D Nixon, Erin M Rueff College of Optometry, The Ohio State University, Columbus, OH, USAAbstract: Microbial keratitis (MK is a corneal condition that encompasses several different pathogens and etiologies. While contact lens associated MK is most often associated with bacterial infections, other pathogens (fungi, Acanthamoeba species, etc may be responsible. This review summarizes the risk factors, microbiology, diagnostic characteristics, and treatment options for all forms of contact lens-related MK.Keywords: corneal ulcer, fungal keratitis, bacterial keratitis, Acanthamoeba, Fusarium, Pseudomonas

  16. Twenty years and twenty thousand contact lens patients.

    Science.gov (United States)

    Dixon, J M

    1981-01-01

    A self contained non commercial private office laboratory staffed by office personnel has been used to prepare contact lenses for private office patients. These lenses include hard contact lenses of various materials and various designs. During the past ten years extended wear hydrophilic soft lenses have been prepared in the same manner as hard lenses, all custom made with lens powers, base curves, diameters, and thickness designed according to the needs of each patient. This has provided strict medical supervision and lens maintenance with maximum convenience for patients and the ophthalmologist.

  17. RISK FACTORS FOR CONTACT LENS COMPLICATIONS

    OpenAIRE

    Mirna Štabuc Šilih

    2016-01-01

    Contact lenses are freely available without professional examination and fitting, as well as without adequate introduction and instructions on handling, disinfection and storage. Contact lenses may have physiological, metabolic and anatomic effect on the eyes, which is manifested both on the eyelids, lacrimal film, conjunctiva and in all layers of the cornea - the epithelium, stroma and the endothelium. We can see these complications too often at our everyday work. The purpose of this paper i...

  18. Achromobacter xylosoxidans Keratitis after Contact Lens Usage

    OpenAIRE

    Park, Jung Hyun; Song, Nang Hee; Koh, Jae Woong

    2012-01-01

    To report on Achromobacter xylosoxidans keratitis in two healthy patients who had worn contact lenses foran extended period of time. A 36-year-old female and a 21-year-old female visited our hospital with ocular pain and blurred vision. Both patients had a history of wearing soft contact lenses for over fve years with occasional overnight wear. At the initial presentation, a slit lamp examination revealed corneal stromal infiltrations and epithelial defects with peripheral neovascularization ...

  19. Not only hard contact lens wear but also soft contact lens wear may be associated with blepharoptosis.

    Science.gov (United States)

    Bleyen, Isabel; Hiemstra, Coen A; Devogelaere, Thibaut; van den Bosch, Willem A; Wubbels, Rene J; Paridaens, Dion A

    2011-08-01

    The authors attempt to establish an association between prolonged hard and soft contact lens wear and ptosis. Single-center retrospective consecutive series. All patients between 18 and 50 years of age who were diagnosed with unilateral or bilateral ptosis between January 2002 and December 2005 (35 patients). In a retrospective consecutive series, we included all patients between 18 and 50 years of age, with unilateral or bilateral ptosis between January 2002 and December 2005. Patients with congenital ptosis, ophthalmic surgery or disease, trauma, giant papillary conjunctivitis, unknown duration of contact lens wear, or muscular or neurologic disorders were excluded. We compared this study group to a Dutch reference population (the total underlying population from which the ptosis cases derive). The group included 35 patients: 20 (57%) (ages 18 to 50 years, average 37 years) had been wearing hard contact lenses for, on average, 17.6 years (range 6 to 27 years); 9 (26%) (ages 18 to 45 years, average 30 years) had been wearing soft contact lenses for, on average, 9 years (range 1.5 to 20 years); and 6 (17%) (ages 23 to 39 years, average 33 years) had no history of contact lens wear. The odds ratio for soft contact lenses was 14.7 (4.2 to 50.7; CI = 95) and for hard contact lenses 97.8 (22.5 to 424). This study suggests that not only hard contact lens wear but also soft contact lens wear may be associated with ptosis. Copyright © 2011 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  20. [Contact lens related corneal ulcers: clinical, microbiological and therapeutic features].

    Science.gov (United States)

    Benhmidoune, L; Bensemlali, A; Bouazza, M; Karami, R; El Mansouri, H; El Belhadji, M; Rachid, R; Chakib, A; Amraoui, A

    2013-09-01

    Corneal ulcers in contact lens wearers are becoming more common, and can sometimes lead to severe complications. The purpose of this study is to define the epidemiological, clinical, microbiological and therapeutic considerations of these ulcers within the above context. We conducted an uncontrolled, descriptive, retrospective study of 51 patients presenting with contact lens related corneal ulcers to the ophthalmology department of the August 20, 1953 Hospital in Casablanca between January 2009 and January 2012. The average age of our patients was 22 years, with a gender ratio of 7.5 female to male. General risk factors (diabetes and tuberculosis) were found in 17.5% of cases. The average length of hospital stay was 15 days. Of our patients, 58.8% wore cosmetic contact lenses and 41.18% wore therapeutic contact lenses. Mean duration prior to consultation was 5 days. The predominant clinical signs were eye pain and redness, with a decrease in visual acuity worse than 1/10 in 82.3% of patients. In 70.6% of cases, the ulcer was central. The average size was 4.3mm. An anterior chamber reaction was found in 47.1%. Corneal bacterial cultures were positive in 47.8%. Pathogens found were Staphylococcus aureus, Pseudomonas aeruginosa and Acanthamœba. Contact lens and solution cultures were positive in 73.6% of cases. Outcomes were favorable with local and systemic antibiotic treatment adapted to microbiological results in only 41.2% of cases. In the remaining patients, significant secondary opacities persisted. Cosmetic and therapeutic contact lens wear is a major cause of corneal ulcer. Delayed consultation results in severe sequelae with persistently decreased visual acuity. The ophthalmologist plays an important role in preventing complications of contact lens wear, through better hygiene instruction and follow-up of his or her patients. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  1. Evaluated Conjunctival Blood Flow Velocity in Daily Contact Lens Wearers.

    Science.gov (United States)

    Shi, Yingying; Hu, Liang; Chen, Wan; Qu, Dongyi; Jiang, Hong; Wang, Jianhua

    2017-04-13

    This study examined conjunctival microvasculature development in long-term habitual contact lens (HCL) wearers after a night of sleep. Twenty HCL wearers (15 women and 5 men, aged 28.6±6.9 years, mean age±standard deviation) who had worn contact lenses on a daily basis for at least 3 years and 40 noncontact lens (NCL) wearers (23 women and 17 men, aged 36.5±6.6 years, mean age±standard deviation) participated in the study. A functional slitlamp biomicroscopy imaging system was used to image the temporal bulbar conjunctiva. Imaging was performed in the morning while the contact lens wearers were not wearing their lenses after a night of sleep. The conjunctival vessel diameters, blood flow velocities, and flow rates were measured. In addition, fractal analyses were performed to obtain the vessel network density (Dbox) and complexity (D0). The average blood flow velocity in HCL wearers after a night of sleep was 0.59±0.19 mm/s, which was significantly higher than that in NCL wearers (0.48±0.17 mm/s, P<0.05). The microvessel network density and complexity levels (Dbox=1.64±0.05 and D0=1.71±0.05, respectively) in the HCL wearers were significantly higher than those in NCL wearers (Dbox=1.61±0.05 and D0=1.69±0.04, both P<0.05). The blood flow velocity was positively correlated with the duration of contact lens wear (r=0.46, P<0.05) and with the daily number of lens-wearing hours (r=0.49, P<0.05) in HCL wearers. This study identified microvascular alterations in the conjunctiva in response to daily contact lens wear after a night of sleep in long-term daily contact lens wearers. The unrecovered changes may indicate that para-inflammation occurs on ocular surfaces because of contact lens wear and that overnight sleeping with no lenses may not sufficiently restore the ocular surface to an intact state.

  2. Microbial Keratitis: Could Contact Lens Material Affect Disease Pathogenesis?

    Science.gov (United States)

    Evans, David J.; Fleiszig, Suzanne M. J.

    2012-01-01

    Microbial keratitis is a sight-threatening complication associated with contact lenses. The introduction of silicone hydrogel lens materials with increased oxygen transmission to the ocular surface has not significantly altered the incidence of microbial keratitis. These data suggest that alternate, or additional, predisposing factors involving lens wear must be addressed to reduce or eliminate these infections. The contact lens can provide a surface for microbial growth in situ, and can also influence ocular surface homeostasis through effects on the tear fluid and corneal epithelium. Thus, it is intuitive that future contact lens materials could make a significant contribution to preventing microbial keratitis. Design of the “right” material to prevent microbial keratitis requires understanding the effects of current materials on bacterial virulence in the cornea, and on ocular surface innate defenses. Current knowledge in each of these areas will be presented, with a discussion of future directions needed to understand the influence of lens material on the pathogenesis of microbial keratitis. PMID:23266587

  3. Epidemiology of contact lens-induced infiltrates: an updated review.

    Science.gov (United States)

    Steele, Kelsy R; Szczotka-Flynn, Loretta

    2017-09-01

    Corneal infiltrative events (CIEs) are well established as a risk associated with soft contact lens wear. The incidence of symptomatic CIEs during extended soft lens wear ranges from 2.5 to six per cent; when asymptomatic CIEs are included, the incidence can be as high as 20-25 per cent. In daily soft lens wear, the annual incidence of symptomatic CIEs is about three per cent. There are various accepted methods of categorising CIEs, and a scoring system based on clinical signs and symptoms is a good approach to grade severity. Lens-related risk factors include extended wear, silicone hydrogel material, the use of multipurpose solutions, bacterial bioburden and reusable lenses. Recent studies report that daily disposable lenses reduce the risk of CIEs. © 2017 Optometry Australia.

  4. Care solution effects on contact lens in vivo wettability.

    Science.gov (United States)

    Fagehi, Raied; Pearce, E Ian; Oliver, Katherine; Abusharha, Ali A; Tomlinson, Alan

    2017-11-01

    The aim of the study was to evaluate the effect of care solutions on contact lens in vivo wettability using Doane's interferometric technique. Thirteen subjects (aged 26.6 ± 6.3 years) participated for contact lens wettability evaluation after soaking in five care solutions namely Opti-Free EverMoist (now called puremoist), Opti-Free Express (Alcon), COMPLETE (AMO), ReNu and Biotrue (Bausch & Lomb). A new pair of lenses was soaked in the solutions for eight hours (prior to wear) or taken directly from pack solutions (as control) and worn by the subjects. The total number of pairs of lenses tested was 13 by six (78 lenses; 13 pairs of lenses wetted in five care solutions plus the pack solution). Doane's interferometer was used to capture images of the pre-lens film on a single type of contact lens, Acuvue Oasys (Johnson & Johnson). The lens in vivo wettability was evaluated after 15 minutes and eight hours of wear by each subject. Four parameters: onset latency, drying duration, maximum speed and peak latency were used to assess the lens wettability. After eight hours, the solutions showing significant reduction in contact lens wettability were the following. For onset latency: Pack solution, Biotrue Opti-Free EverMoist and Express; for drying duration: pack solution, ReNu and Opti-Free EverMoist; for peak latency; pack solution, Biotrue and Opti-Free EverMoist. Regarding the maximum speed, lenses soaked in Pack solution, ReNu and Opti-Free EverMoist showed a significant increase (worsening). The comparative study showed that there were significant differences among the performance of the care solutions. This novel thin film interferometric technique was able to measure, objectively, contact lens in vivo wettability, following the use of care solutions. COMPLETE was the only solution that showed no significant change in the lens wettability (with the all parameters) between the initial and the end of day. © 2017 Optometry Australia.

  5. Oxygen transport through soft contact lens and cornea: Lens characterization and metabolic modeling

    Science.gov (United States)

    Chhabra, Mahendra

    The human cornea requires oxygen to sustain metabolic processes critical for its normal functioning. Any restriction to corneal oxygen supply from the external environment (e.g., by wearing a low oxygen-permeability contact lens) can lead to hypoxia, which may cause corneal edema (swelling), limbal hyperemia, neovascularization, and corneal acidosis. The need for adequate oxygen to the cornea is a major driving force for research and development of hypertransmissible soft contact lenses (SCLs). Currently, there is no standard technique for measuring oxygen permeability (Dk) of hypertransmissible silicone-hydrogel SCLs. In this work, an electrochemistry-based polarographic apparatus was designed, built, and operated to measure oxygen permeability in hypertransmissible SCLs. Unlike conventional methods where a range of lens thickness is needed for determining oxygen permeabilities of SCLs, this apparatus requires only a single lens thickness. The single-lens permeameter provides a reliable, efficient, and economic tool for measuring oxygen permeabilities of commercial hypertransmissible SCLs. The single-lens permeameter measures not only the product Dk, but, following modification, it measures separately diffusivity, D, and solubility, k, of oxygen in hypertransmissible SCLs. These properties are critical for designing better lens materials that ensure sufficient oxygen supply to the cornea. Metabolism of oxygen in the cornea is influenced by contact-lens-induced hypoxia, diseases such as diabetes, surgery, and drug treatment, Thus, estimation of the in-vivo corneal oxygen consumption rate is essential for gauging adequate oxygen supply to the cornea. Therefore, we have developed an unsteady-state reactive-diffusion model for the cornea-contact-lens system to determine in-vivo human corneal oxygen-consumption rate. Finally, a metabolic model was developed to determine the relation between contact-lens oxygen transmissibility (Dk/L) and corneal oxygen deficiency. A

  6. Healthy Contact Lens Wear and Care

    Centers for Disease Control (CDC) Podcasts

    2014-02-04

    In this podcast, CDC’s Dr. Jennifer Cope explains some basic steps for proper wear and care of soft contact lenses.  Created: 2/4/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/4/2014.

  7. Contact Lens-Related Eye Infections

    Science.gov (United States)

    ... and preserving your vision. Privacy Policy Related 27 Contact Lenses Found in Woman’s Eye Jul 17, 2017 Eye Muscle Stimulation May Delay the Need For Reading Glasses Nov 22, 2016 PEARL: A Promising New Treatment for Presbyopia Nov 21, 2016 Studies Show Zika Virus May ...

  8. Reverse geometry contact lens fitting after corneal refractive surgery.

    Science.gov (United States)

    Martin, Raul; Rodriguez, Guadalupe

    2005-01-01

    To describe reverse geometry rigid gas permeable (RGP) contact lens fitting in eyes with irregular surface induced by complications after myopic corneal refractive surgery. Reverse geometry RGP contact lenses were fit in nine eyes that underwent myopic corneal refractive surgery and experienced a reduction in best spectacle-corrected visual acuity (BSCVA) Snellen lines postoperatively. Comparing the BSCVA with contact lenses, 5 (55.6%) eyes improved > or = 2 lines of BSCVA, 2 (22.2%) eyes improved 1 line, and 2 (22.2%) eyes maintained the same BSCVA as the one eye with spectacles (P RGP contact lens fitting is effective in correcting surgically induced irregular surfaces with improved visual acuity and comfortable wear. These lenses may be the best choice in cases in which surgical retreatment is unfeasible or undesirable.

  9. Can Binocular Vision Disorders Contribute to Contact Lens Discomfort?

    Science.gov (United States)

    Rueff, Erin M; King-Smith, P Ewen; Bailey, Melissa D

    2015-09-01

    To determine the relationship between binocular vision (BV) disorder and dry eye symptoms and the frequency of BV disorders in subjects with contact lens-induced dry eye symptoms. Subjects recruited for a larger dry eye study (n = 104) completed the Ocular Surface Disease Index (OSDI) and Convergence Insufficiency Symptom Survey (CISS) to determine if symptoms assessed on these two surveys were related. Also, myopic soft contact lens wearers (n = 29) with self-reported dry eye symptoms were recruited. Subjects completed the OSDI and CISS to assess severity of dry eye and BV disorder symptoms. Basic BV and dry eye testing was performed on each subject. Severity of symptoms assessed on the OSDI and CISS was found to be significantly correlated in the larger subject group (ρ = 0.68, p = 0.0001). This significant correlation warranted further investigation of both symptoms and clinical signs. In the group of myopic soft contact lens wearers, 48.3% had a BV disorder. This proportion appeared to be higher than previously reported prevalence estimates of BV disorders. Accommodative lag greater than or equal to 1.00 diopter was the most common BV disorder sign encountered (48.3%), and pseudo-convergence insufficiency was the most common BV disorder (31.0%). Symptoms related to dry eye and BV disorders overlap. Subjects with symptoms of discomfort while wearing soft contact lenses may be experiencing a concurrent or stand-alone BV disorder. Accommodative insufficiency and pseudo-convergence insufficiency were common in the sample of myopic soft contact lens wearers. Clinicians should screen symptomatic contact lens-induced dry eye patients for BV disorders. Dry eye studies should assess basic BV function.

  10. Contact lens prescribing in the Australian states and territories 2001.

    Science.gov (United States)

    Woods, Craig A; Morgan, Philip B

    2002-09-01

    This study was conducted to ascertain current preferences for contact lens prescribing in the Australian states and territories. One thousand questionnaires were randomly distributed to proportionate samples of optometrists in each state of Australia. We requested details of the first 10 patients fitted with contact lenses after receipt of the questionnaire. One hundred and seventy-eight completed questionnaires were returned, detailing contact lens fits to 1,611 patients. The mean age of the patient group was 32.1 +/- 13.0 yrs (65 per cent female). For Australia as a whole: 53 per cent of patients were existing wearers, the remainder were new fits; 93 per cent of new fits were with soft lenses, of which seven per cent were for extended wear. Of the refits, 89 per cent were soft lenses and 18 per cent for extended wear. The lens material of first choice was mid-water-content (62 per cent of all soft lens fits). Only eight per cent of all soft fits were for lenses that were not replaced on a planned basis, with two weeks being the replacement interval of choice in all states and territories. The majority of rigid lenses were prescribed using mid-Dk materials (50 per cent). Analysis of solution prescribing indicates that multi-purpose products were the most common regimens for planned replacement soft lenses. The percentage of hydrogen peroxide prescribed increased as lens replacement became less frequent. By state or territory: practitioners in Tasmania prescribed more extended wear than those in any other state (p = 0.007) and practitioners in Queensland prescribed more daily disposable contact lenses than those in any other state (p = 0.009). Non-planned replacement lenses are now rarely prescribed to patients. Extended-wear lenses and rigid lenses continue to be prescribed more to existing contact lens wearers than to new patients. The impact of soft multifocal lens designs on contact lens prescribing is very small, ranging from 2.6 per cent in Queensland to 4

  11. Cytokine changes in tears and relationship to contact lens discomfort

    OpenAIRE

    Willcox, Mark D.P.; Zhao, Zhenjun; Naduvilath, Thomas; Lazon de la Jara, Percy

    2015-01-01

    Purpose To determine the reproducibility of a multiplex bead assay for measuring cytokines in tears and correlations between ocular discomfort with or without contact lens wear and the concentration of cytokines in tears. Methods Ninety participants (divided into two groups) were enrolled in this prospective study. They were asked to rate their ocular comfort and collect their tears in the morning and just before sleep for 10 days with or without contact lenses. The participants collected the...

  12. Twenty years and twenty thousand contact lens patients.

    OpenAIRE

    Dixon, J M

    1981-01-01

    A self contained non commercial private office laboratory staffed by office personnel has been used to prepare contact lenses for private office patients. These lenses include hard contact lenses of various materials and various designs. During the past ten years extended wear hydrophilic soft lenses have been prepared in the same manner as hard lenses, all custom made with lens powers, base curves, diameters, and thickness designed according to the needs of each patient. This has provided st...

  13. Mass spectrometry-based proteomic analyses of contact lens deposition

    OpenAIRE

    Green-Church, Kari B.; Nichols, Jason J.

    2008-01-01

    Purpose The purpose of this report is to describe the contact lens deposition proteome associated with two silicone hydrogel contact lenses and care solutions using a mass spectrometric-based approach. Methods This was a randomized, controlled, examiner-masked crossover clinical trial that included 48 participants. Lenses and no-rub care solutions evaluated included galyfilcon A (Acuvue Advance, Vistakon Inc., Jacksonville, FL), lotrafilcon B (O2 Optix, CIBA Vision Inc., Duluth, GA), AQuify (...

  14. Corneal Biomechanical Changes Following Toric Soft Contact Lens Wear.

    Science.gov (United States)

    Radaie-Moghadam, Somayeh; Hashemi, Hassan; Jafarzadehpur, Ebrahim; Yekta, Abbas Ali; Khabazkhoob, Mehdi

    2016-01-01

    To determine the effect of using toric soft contact lenses on corneal biomechanical properties. We enrolled 33 healthy patients with mean age of 23.18 ± 4.06 and minimal cylinder power of 1 D (-1.98 ± 0.808 SD) and negative history of contact lens use; keratoconic patients were excluded from the study. Toric soft contact lenses (BIOFINITY, Comfilcon A, Coopervision, Southampton, UK) were fitted in all participants. The Ocular Response Analyzer (Reichert Ophthalmic Instruments, Depew, New York, USA) was used to measure corneal hysteresis (CH), corneal resistance factor (CRF), and the Pentacam HR (Oculus, Inc., Lynnwood, WA, USA) was used to measure central corneal thickness (CCT) and mean keratometry (K mean) before and one week, one month, and three months after using the toric soft contact lenses. CH and CRF were decreased significantly one month after using the contact lens; mean CH decreased from 9.99 ± 1.44 to 9.59 ± 1.54 mmHg, and mean CRF decreased from 9.96 ± 1.71 to 9.63 ± 1.73 mmHg (P = 0.013 and P = 0.017, respectively). Mean CCT and K mean did not show a significant change during the period of toric soft contact lens use. CH and CRF decreased significantly one month after fitting toric soft contact lenses while CCT and Kmean did not change significantly. Corneal biomechanical parameters may alter with toric soft contact lens use and such changes may have implications with long-term use such lenses.

  15. Polymicrobial Infection of the Cornea Due to Contact Lens Wear

    OpenAIRE

    Selçuk Sızmaz; Filiz Kibar; Soner Koltaş

    2016-01-01

    A 38-year-old male presented with pain and redness in his left eye. He had a history of wearing contact lenses. His ophthalmic examination revealed a large corneal ulcer with surrounding infiltrate. Cultures were isolated from the contact lenses, lens solutions, storage cases, and conjunctivae of both eyes and also corneal scrapings of the left eye. Fortified vancomycin and amikacin drops were started hourly. Culture results of conjunctivae of each eye and left cornea were positive f...

  16. Contact lens-related bilateral and simultaneous Acremonium keratitis

    Directory of Open Access Journals (Sweden)

    Patrícia Cortez Bona Doliveira

    Full Text Available Abstract This is a case of bilateral and simultaneous Acremonium keratitis related to intermittent and alternating eye soft contact lens use, which has a delayed diagnose, presented amphotericin B resistance with persistent hypopyon and had a positive response to topical natamycin. Besides the unusual presentation, there was no history of trauma or contact with vegetable matter, usually associated to the majority of cases of keratomicosys by filamentous fungi.

  17. Task Analysis in Optical & Contact Lens Dispensing. Dispensing Opticians.

    Science.gov (United States)

    Hrushowy, Eugene; Stanley, Dale

    A task force of opticians and educators in British Columbia was assembled to determine the knowledge and skills required of dispensing opticians and contact lens specialists. The ideas generated by the task force were analyzed and distilled into the standardized tasks listed in this document, using Krathwohl's taxonomy. The document contains 36…

  18. Biofilm formation of Achromobacter xylosoxidans on contact lens.

    Science.gov (United States)

    Konstantinović, Neda; Ćirković, Ivana; Đukić, Slobodanka; Marić, Vesna; Božić, Dragana D

    2017-09-01

    Achromobacter spp. may contaminate lenses, lens cases, and contact lens solutions and cause ocular infections. The aim of this study was to investigate the possibility of isolated strain of Achromobacter xylosoxidans to form biofilm on the surface of soft contact lenses (CL), to quantify the production of the formed biofilm, and compare it with the reference strains (Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae). Bacterial strain isolated from one contact lens case was identified as A. xylosoxidans using Vitek2 Automated System. Biofilm forming capacity of isolated strain of A. xylosoxidans and reference strains of P. aeruginosa, S. aureus, and H. influenzae on soft CL were analyzed by commonly used microtitre plate method. Our results showed that isolated strain of A. xylosoxidans was capable to form biofilm on the surface of soft contact lens. A. xylosoxidans was strong biofilm producer while all examined reference strains were moderate biofilm producers. A. xylosoxidans appears to be superior biofilm producer on soft CL compared to reference strains.

  19. Opaque contact lens treatment for older children with amblyopia.

    Science.gov (United States)

    Anderson, Justin E; Brown, Sandra M; Mathews, Taryn A; Mathews, Steven M

    2006-03-01

    To investigate the usefulness of daily-wear opaque contact lens treatment for older children with amblyopia. A retrospective chart review of all children undergoing opaque contact lens therapy for amblyopia between 2000 and 2003 was performed. All patients were included except for those younger than 5 years of age, those undergoing maintenance treatment only, those lost to follow-up, or those unable to cooperate with Snellen visual acuity testing. Thirteen children were identified, and seven met the inclusion criteria. The seven patients had a mean age of 7.5 years (range, 5.7-8.7 years). The causes of amblyopia were anisometropia (five patients), cataract (one patient), and strabismus (one patient). For all seven patients, the mean logMAR improvement in visual acuity was 0.52 (range, 0.26-1.22). The average duration of opaque contact lens use was 9.3 months (range, 2-21 months). Compliance problems were encountered in three patients. No major complications occurred, but one patient had an episode of mild superficial punctate keratitis. Daily-wear opaque contact lens treatment is a useful occlusion method for amblyopia treatment in older children with various practical and social impediments to skin patching. Meaningful improvement in visual acuity can be obtained, even in children older than 8 years of age.

  20. Contact lens disinfection by ultraviolet light

    Energy Technology Data Exchange (ETDEWEB)

    Dolman, P.J.; Dobrogowski, M.J. (Univ. of British Columbia, Vancouver (Canada))

    1989-12-15

    A 253.7-nm ultraviolet light with an intensity of 1,100 microW/cm2 was tested for its germicidal activity against contact lenses and storage solutions contaminated with various corneal pathogens. The exposure time necessary to reduce a concentration of organisms from 10(6)/ml to less than 10/ml was 30 seconds for Staphylococcus aureus, 60 seconds for Pseudomonas aeruginosa, and 84 seconds for Candida albicans. The time necessary to sterilize a suspension of 10(4)/ml Acanthamoeba polyphaga was less than three minutes with this technique. Four brands of soft contact lenses were exposed to ultraviolet light for over eight hours without changing their appearance, comfort, or refraction.

  1. A new ceramics approach for contact lens

    OpenAIRE

    Carpena DDS, MS, PhD, Guilherme; Ballarin DDS, Andressa; Aguiar, José

    2015-01-01

    Nowadays the field of dentistry is focusing into a new aesthetic area in the light of an minimal invasive dentistry approach. Aesthetic treatments with dental porcelain veneers without any preparation (ceramic contact lenses) have gained popularity in recent years. Thus, the need for constant improvement and knowledge of innovative techniques and ceramics is fundamental.   This article point out about the essential criteria to promote a clinical succeed of the technique over the years.   A...

  2. Contact lens management following corneal refractive surgery.

    Science.gov (United States)

    Ward, Michael A

    2003-09-01

    Corneal refractive surgery has enjoyed considerable success and popularity in recent years; LASIK has become the surgical procedure of choice. The incidence of visually significant complications varies widely, but is inversely related to surgeon experience. Visual complaints include multifocal images, shadows, ametropias, anisometropia, night vision difficulties, decreased contrast sensitivity and loss of BCVA. Contact lenses offer an option to rehabilitate patients when visually symptomatic following refractive surgery. RGP lenses provide the best postoperative visual rehabilitation following refractive surgery.

  3. Frequency of and factors associated with contact lens dissatisfaction and discontinuation.

    Science.gov (United States)

    Richdale, Kathryn; Sinnott, Loraine T; Skadahl, Elisa; Nichols, Jason J

    2007-02-01

    To determine the frequency of and factors associated with contact lens dissatisfaction and discontinuation. A cross-sectional survey of 730 subjects was conducted using a self-administered survey instrument. The survey collected information about present age and sex, history of contact lens wear, types of lenses worn, age at starting wear, current wearing schedule (hours per day, days per week), self-perceived contact lens satisfaction, and contact lens-related problems. A variety of statistical analyses including analysis of variance, logistic regression, and repeated-measures logistic regression were used to model the data. Current or previous experience with contact lenses was reported by 453 (62%) of the subjects. Of these subjects, 119 (26.3%) reported that contact lenses were not the ideal form of visual correction for them (contact lens dissatisfaction) and another 109 (24.1%) had permanently discontinued contact lens wear. Dissatisfied contact lens wearers had reduced self-reported wearing times compared with satisfied contact lens wearers. Previous lens wearers were more likely than current lens wearers to be men, older (by approximately 9.5 years), have started contact lens wear at a later age (approximately 4-5 years later), and have tried either rigid or both soft and rigid lenses. The primary self-reported reason for both contact lens dissatisfaction and discontinuation was ocular symptoms (dryness and discomfort), followed by preference for another corrective modality. A significant number of contact lens wearers are not satisfied with contact lenses and are at risk for discontinuation.

  4. Review on prevention of bacterial adhesion on contact lens using plasma treatment

    Science.gov (United States)

    Ramli, N. A. H.; Zaaba, S. K.; Mustaffa, M. T.; Zakaria, A.; Shahriman A., B.

    2017-03-01

    Many researches had been conducted to enhance the properties of contact lens. Most of the research conducted discussed on the factors that affect the adhesion process to contact lenses, rate of contact lens contamination, and type of microbe that adhere on the contact lens surface and contact lens casing. Studies on the proposed strategies or technology that can be used to slower down the formation of bacteria on contact lens are being explored. New technologies or strategies to prevent or slow down the adhesion of bacteria on contact lens have become a priority in this area. This review paper covers two main aspects, namely factor that affect the bacteria adhesion on contact lens and also the introduction of plasma treatment as a potential method for contact lens treatment.

  5. A novel rat contact lens model for Fusarium keratitis.

    Science.gov (United States)

    Abou Shousha, Mohamed; Santos, Andrea Rachelle C; Oechsler, Rafael A; Iovieno, Alfonso; Maestre-Mesa, Jorge; Ruggeri, Marco; Echegaray, Jose J; Dubovy, Sander R; Perez, Victor L; Miller, Darlene; Alfonso, Eduardo C; Bajenaru, M Livia

    2013-01-01

    The aim of this study was to develop and characterize a new contact lens-associated fungal keratitis rat model and to assess the ability of non-invasive spectral-domain optical coherence tomography (SD-OCT) to detect pathological changes in vivo in fungal keratitis. We used SD-OCT to image and measure the cornea of Sprague Dawley rats. Fusarium infection was initiated in the rat eye by fitting Fusarium solani-soaked contact lenses on the experimental eye, while the control animals received contact lenses soaked in sterile saline. The fungal infection was monitored with periodic slit-lamp examination and in vivo SD-OCT imaging of the rat eye, and confirmed by histology, counting of viable fungi in the infected rat cornea, and PCR with specific primers for Fusarium sp. We imaged and measured the rat cornea with SD-OCT. Custom-made contact lenses were developed based on the OCT measurements. Incubation of contact lenses in a F. solani suspension resulted in biofilm formation. We induced contact lens-associated Fusarium keratitis by fitting the rat eyes for 4 h with the Fusarium-contaminated contact lenses. The SD-OCT images of the cornea correlated well with the slit-lamp and histopathological results and clearly defined clinical signs of infection, namely, increased corneal thickening, loss of epithelial continuity, hyper-reflective areas representing infiltrates, and endothelial plaques characteristic of fungal infection. Moreover, in three cases, SD-OCT detected the infection without any clear findings on slit-lamp examination. Infection was confirmed with histological fungal staining, PCR, and microbiological culture positivity. We developed a highly reproducible rat contact lens model and successfully induced contact lens-associated Fusarium keratitis in this model. The clinical presentation of contact lens-associated Fusarium keratitis in the rat model is similar to the human condition. SD-OCT is a valuable tool that non-invasively revealed characteristic signs

  6. Curative effect assessment of bandage contact lens in neurogenic keratitis

    Directory of Open Access Journals (Sweden)

    Yu-Zhao Sun

    2014-12-01

    Full Text Available AIM:To observe the curative effect of bandage contact lens in neurogenic keratitis.METHODS:Twenty cases of neurogenic keratitis were studied attheDepartment of Ophthalmology, the first Affiliated Hospital of China Medical University, between October 2012 and June 2013. These included 13 males and 7 females, aged from 35 to 88y. Patients were voluntarily divided into an experimental group (lens wearing group, n=10 and control group (drug therapy, n=10. In experimental group patients wore silicone hydrogel bandage soft contact lens. Both groups used the following eyedrops:0.5% levofloxacin TID; 0.5% Sodium carboxymethyl cellulose QID; fibroblast growth factor BID; ganciclovir BID [cases complicated with herpes simplex virus (HSV]; compound tropicamide BID (cases concurrent hypopyon. The healing time of corneal ulcer and complication rates were observed in the two groups.RESULTS: The healing time of corneal ulcer in the experimental group was 10.80±4.44d versus 46.70±13.88d in the control group (P<0.05. No complications occurred in the experimental group, except for the lens falling off twice in one case, the patient recovered eight days after rewearing the lens. While in the control group, all cases vascularized, 2 cases were complicated with descemetocele that recovered with amniotic membrane transplantation and 1 case was complicated with corneal perforation that recovered by autologous conjunctival flap covering.CONCLUSION: Bandage contact lens is a safe and effective method of treating neurogenic keratitis and significantly shortened the healing time of corneal ulcer.

  7. Not only hard contact lens wear but also soft contact lens wear may be associated with blepharoptosis

    NARCIS (Netherlands)

    I. Bleyen (Isabel); C.A. Hiemstra; T. Devogelaere (Thibaut); W.A. van den Bosch (Willem); R.J. Wubbels (René J.); A.D.A. Paridaens (Dion)

    2011-01-01

    textabstractObjective: The authors attempt to establish an association between prolonged hard and soft contact lens wear and ptosis. Design: Single-center retrospective consecutive series. Participants: All patients between 18 and 50 years of age who were diagnosed with unilateral or bilateral

  8. Polymicrobial Infection of the Cornea Due to Contact Lens Wear.

    Science.gov (United States)

    Sızmaz, Selçuk; Bingöllü, Sibel; Erdem, Elif; Kibar, Filiz; Koltaş, Soner; Yağmur, Meltem; Ersöz, Reha

    2016-04-01

    A 38-year-old male presented with pain and redness in his left eye. He had a history of wearing contact lenses. His ophthalmic examination revealed a large corneal ulcer with surrounding infiltrate. Cultures were isolated from the contact lenses, lens solutions, storage cases, and conjunctivae of both eyes and also corneal scrapings of the left eye. Fortified vancomycin and amikacin drops were started hourly. Culture results of conjunctivae of each eye and left cornea were positive for Pseudomonas aeruginosa; cultures from the contact lenses, lens solution and storage case of both eyes revealed Pseudomonas aeruginosa and Alcaligenes xylosoxidans. Polymerase chain reaction of the corneal scraping was positive for Acanthameoba. The topical antibiotics were changed with ones that both bacteria were sensitive to and anti-amoebic therapy was added. The patient had two recurrences following initial presentation despite intensive therapy. Keratitis occurred due to multiple pathogens; the relapsing course despite adequate therapy is potentially associated with this polymicrobial etiology.

  9. Changes in the Eye Microbiota Associated with Contact Lens Wearing

    Directory of Open Access Journals (Sweden)

    Hakdong Shin

    2016-03-01

    Full Text Available Wearing contact lenses has been identified as a risk factor for the development of eye conditions such as giant papillary conjunctivitis and keratitis. We hypothesized that wearing contact lenses is associated with changes in the ocular microbiota. We compared the bacterial communities of the conjunctiva and skin under the eye from 58 subjects and analyzed samples from 20 subjects (9 lens wearers and 11 non-lens wearers taken at 3 time points using a 16S rRNA gene-based sequencing technique (V4 region; Illumina MiSeq. We found that using anesthetic eye drops before sampling decreases the detected ocular microbiota diversity. Compared to those from non-lens wearers, dry conjunctival swabs from lens wearers had more variable and skin-like bacterial community structures (UniFrac; P value = 3.0. The results indicate that wearing contact lenses alters the microbial structure of the ocular conjunctiva, making it more similar to that of the skin microbiota. Further research is needed to determine whether the microbiome structure provides less protection from ocular infections.

  10. The dangers of distilled water in contact lens maintenance.

    Science.gov (United States)

    Josephson, J E; Caffery, B E

    1988-03-01

    The reports of serious corneal infection associated with hydrogel lens wear prompted us to explore the level of sterility of the distilled water used by lens wearers in our practice. Fifty patients supplied samples of their partially-used distilled water for testing. Of the samples, 12% were found to be contaminated. Five samples of previously unopened distilled water were tested and no growth was found. We recommend that patients do not use distilled water for the care of hydrogel contact lenses. Rather, sterile unit dose or multi-dose (aerosol) nonpreserved, or preserved salines can be used.

  11. Imaging Approaches for Contact Lens Deposition.

    Science.gov (United States)

    Panthi, Shyam; Nichols, Jason J

    2017-07-01

    Deposition on contact lenses (CLs) starts quickly after their application to the ocular surface. Deposits may be composed of tear film components or other extraneous substances. These deposits have been related to various adverse conditions of the eye, leading to reduced biocompatibility between the CLs and the ocular surface. Analysis of these deposits is essential to better elucidate the relationship between these deposits and their adverse reactions so that better methods of increasing biocompatibility can be developed. Although methods such as enzymatic assays are available for quantitative analysis, they do not provide a complete picture of the deposition (e.g., lack of morphological details), and therefore, the use of imaging methods that can provide both qualitative and quantitative information about the deposits may be more preferable. Therefore, a search of the peer-reviewed literature that focused on imaging methods in the analysis of deposits on CLs was conducted. Various methods of imaging deposits in-vitro, in-vivo, or ex-vivo have been described along with the associated results. Imaging methods using fluorescence-based techniques and scanning electron microscopy appear to be the most frequently used methods. Some of the described methods not only provided morphologies but also identified the types of various deposits that were attached to the CLs. Various CL materials possessed different deposition morphologies and different quantities of the attached deposits. Further imaging studies performed in conjunction with other methods that could identify and quantify the deposits at a molecular level are recommended.

  12. [Water-cushion contact lens for pars plana vitrectomy].

    Science.gov (United States)

    Klöti, R

    1983-01-01

    Our water-cushion contact lens satisfies same requirements as the lenses we used previously: stabilization of the anterior segment, perfect attachment to the eye, freedom of movement of the eye in all directions. A rather important additional advantage is achieved by virtue of the fact that the lens floats on a constantly renewed fluid layer in a ring-shaped pool. Even in diabetic patients postoperative damage to the corneal epithelium no longer occur. A planoconcave or prismatic quartz lens may be placed into the pool. The lenses are scratch-resistant and have an antireflective coating. Direct observation of the equatorial area in phakic and of the oraserrata area in aphakic eyes is possible with this perfect optical system.

  13. Non-contact lens related Acanthamoeba keratitis.

    Science.gov (United States)

    Garg, Prashant; Kalra, Paavan; Joseph, Joveeta

    2017-11-01

    The purpose of the study is to describe epidemiology, clinical features, diagnosis, and treatment of Acanthamoeba keratitis (AK) with special focus on the disease in nonusers of contact lenses (CLs). This study was a perspective based on authors' experience and review of published literature. AK accounts for 2% of microbiology-proven cases of keratitis. Trauma and exposure to contaminated water are the main predisposing factors for the disease. Association with CLs is seen only in small fraction of cases. Contrary to classical description experience in India suggests that out of proportion pain, ring infiltrate, and radial keratoneuritis are seen in less than a third of cases. Majority of cases present with diffuse infiltrate, mimicking herpes simplex or fungal keratitis. The diagnosis can be confirmed by microscopic examination of corneal scraping material and culture on nonnutrient agar with an overlay of Escherichia coli. Confocal microscopy can help diagnosis in patients with deep infiltrate; however, experience with technique and interpretation of images influences its true value. Primary treatment of the infection is biguanides with or without diamidines. Most patients respond to medical treatment. Corticosteroids play an important role in the management and can be used when indicated after due consideration to established protocols. Surgery is rarely needed in patients where definitive management is initiated within 3 weeks of onset of symptoms. Lamellar keratoplasty has been shown to have good outcome in cases needing surgery. Since the clinical features of AK in nonusers of CL are different, it will be important for ophthalmologists to be aware of the scenario wherein to suspect this infection. Medical treatment is successful if the disease is diagnosed early and management is initiated soon.

  14. Non-contact lens related Acanthamoeba keratitis

    Directory of Open Access Journals (Sweden)

    Prashant Garg

    2017-01-01

    Full Text Available The purpose of the study is to describe epidemiology, clinical features, diagnosis, and treatment of Acanthamoeba keratitis (AK with special focus on the disease in nonusers of contact lenses (CLs. This study was a perspective based on authors' experience and review of published literature. AK accounts for 2% of microbiology-proven cases of keratitis. Trauma and exposure to contaminated water are the main predisposing factors for the disease. Association with CLs is seen only in small fraction of cases. Contrary to classical description experience in India suggests that out of proportion pain, ring infiltrate, and radial keratoneuritis are seen in less than a third of cases. Majority of cases present with diffuse infiltrate, mimicking herpes simplex or fungal keratitis. The diagnosis can be confirmed by microscopic examination of corneal scraping material and culture on nonnutrient agar with an overlay of Escherichia coli. Confocal microscopy can help diagnosis in patients with deep infiltrate; however, experience with technique and interpretation of images influences its true value. Primary treatment of the infection is biguanides with or without diamidines. Most patients respond to medical treatment. Corticosteroids play an important role in the management and can be used when indicated after due consideration to established protocols. Surgery is rarely needed in patients where definitive management is initiated within 3 weeks of onset of symptoms. Lamellar keratoplasty has been shown to have good outcome in cases needing surgery. Since the clinical features of AK in nonusers of CL are different, it will be important for ophthalmologists to be aware of the scenario wherein to suspect this infection. Medical treatment is successful if the disease is diagnosed early and management is initiated soon.

  15. Insurgence of Fusarium keratitis associated with contact lens wear.

    Science.gov (United States)

    Alfonso, Eduardo C; Cantu-Dibildox, Jorge; Munir, Wuqaas M; Miller, Darlene; O'Brien, Terrence P; Karp, Carol L; Yoo, Sonia H; Forster, Richard K; Culbertson, William W; Donaldson, Kendall; Rodila, Jill; Lee, Yunhee

    2006-07-01

    To describe the clinical presentation and course of patients who developed keratitis due to Fusarium while wearing nontherapeutic soft contact lenses. A retrospective review of microbiologic records from January 1, 2004, through April 15, 2006, was performed, identifying all patients with corneal ulceration and a culture positive for Fusarium species. Medical records of 34 patients were reviewed for clinical characteristics, treatment regimens, and microbiologic features. The most common antimicrobial medications administered prior to Fusarium diagnosis were antibacterials in 31 of 34 patients. No distinct preponderance of any one brand of either contact lens or solution was identified. The microbiologic corneal cultures found Fusarium oxysporum in 20 cases, Fusarium solani in 3 cases, Fusarium species not further identifiable in 10 cases, and no growth in 1 case. Patients with a delayed onset of treatment had a tendency for prolonged treatment until cure. Fusarium has previously been an unusual organism in the etiology of infectious keratitis in the setting of nontherapeutic soft contact lens wear. A delay in proper diagnosis and intervention may contribute to a prolonged treatment course. The microbial spectrum of contact lens-related keratitis may be evolving with higher participation of Fusarium species compared with prior reports.

  16. Assessing Scleral Contact Lens Satisfaction in a Keratoconus Population.

    Science.gov (United States)

    Bergmanson, Jan P G; Walker, Maria K; Johnson, Leah A

    2016-08-01

    To assess perceived comfort and related experiences of adapted keratoconic scleral contact lens (17-18.2 mm) wearers with a history of wearing other contact lens modalities and to compare these subjective clinical effects with previous experiences. Twenty-four keratocones were recruited, signed an informed consent approved by the University Internal Review Board, and were asked to complete a survey and a dry eye questionnaire. Previous lens wearing experience included soft, piggy back, and hybrid lenses but predominantly was corneal gas permeable. An overwhelming majority strongly preferred the comfort and vision with the scleral contact lenses. This cohort of keratoconus patients were on average dry eye suspects according to a dry eye questionnaire but contained individuals with either normal or significantly dry eye scores. However, patients stated that they experienced less dryness with their scleral lenses, but slightly more than half of these patients experienced, at least occasionally, midday fogging. The scleral contact lenses are extremely well accepted by keratoconic patients because of comfort and vision these devices provide. For many patients, they offer further relief from dryness symptoms. However, midday fogging remains a limitation for many wearers.

  17. Management and treatment of contact lens-related Pseudomonas keratitis

    Directory of Open Access Journals (Sweden)

    Willcox MD

    2012-06-01

    Full Text Available Mark DP WillcoxSchool of Optometry and Vision Science, University of New South Wales, Sydney, AustraliaAbstract: Pubmed and Medline were searched for articles referring to Pseudomonas keratitis between the years 2007 and 2012 to obtain an overview of the current state of this disease. Keyword searches used the terms "Pseudomonas" + "Keratitis" limit to "2007–2012", and ["Ulcerative" or "Microbial"] + "Keratitis" + "Contact lenses" limit to "2007–2012". These articles were then reviewed for information on the percentage of microbial keratitis cases associated with contact lens wear, the frequency of Pseudomonas sp. as a causative agent of microbial keratitis around the world, the most common therapies to treat Pseudomonas keratitis, and the sensitivity of isolates of Pseudomonas to commonly prescribed antibiotics. The percentage of microbial keratitis associated with contact lens wear ranged from 0% in a study from Nepal to 54.5% from Japan. These differences may be due in part to different frequencies of contact lens wear. The frequency of Pseudomonas sp. as a causative agent of keratitis ranged from 1% in Japan to over 50% in studies from India, Malaysia, and Thailand. The most commonly reported agents used to treat Pseudomonas keratitis were either aminoglycoside (usually gentamicin fortified with a cephalosporin, or monotherapy with a fluoroquinolone (usually ciprofloxacin. In most geographical areas, most strains of Pseudomonas sp. (≥95% were sensitive to ciprofloxacin, but reports from India, Nigeria, and Thailand reported sensitivity to this antibiotic and similar fluoroquinolones of between 76% and 90%.Keywords: Pseudomonas, keratitis, contact lens

  18. Increased numbers of Demodex in contact lens wearers.

    Science.gov (United States)

    Jalbert, Isabelle; Rejab, Shazana

    2015-06-01

    The aim of this study was to determine if Demodex infestation is more frequent in contact lens wearers than in nonwearers. Secondary aims were to evaluate the effects of Demodex on the ocular surface (symptoms and signs) and to evaluate the ability of confocal laser scanning microscopy to detect and quantify the Demodex infestation compared with the conventional light microscopic technique. Forty Asian female participants (20 nonwearers, 20 lens wearers) with a mean (± SD) age of 27 (± 9) years were recruited. Ocular comfort scores (Ocular Surface Disease Index, Ocular Comfort Index, and Dry Eye Questionnaire), vital staining (corneal, conjunctival, and lid wiper), tear osmolarity, tear breakup time, and meibomian gland evaluation were evaluated. Demodex was detected using in vivo confocal microscopy and conventional light microscopy. The number of Demodex was higher in lens wearers than in nonwearers (7.6 [± 5.8] vs. 5.0 [± 3.1]; p = 0.02). Demodex was observed in a large majority (90%) of lens wearers and in 65% of nonwearers using confocal microscopy (p = 0.06). The detection rate was lower in both groups using conventional light microscopy (p = 0.003) where Demodex could only be confirmed in 70% and 60% of lens wearers and nonwearers, respectively. The number of Demodex tended to increase with age (ρ = 0.28, p = 0.08), but Demodex did not appear to affect ocular comfort or any clinical signs (p > 0.05). Contact lens wearers harbor Demodex as frequently as nonwearers and in higher numbers, which is best detected using in vivo confocal microscopy. The significance of these findings is uncertain because no associations were found with any symptoms and signs of dry eye disease.

  19. National Apprenticeship and Training Standards for Optical Technician (Contact Lens Technician).

    Science.gov (United States)

    Manpower Administration (DOL), Washington, DC. Bureau of Apprenticeship and Training.

    A statement of policy of the Contact Lens Society of America regarding contact lens filters is followed by national apprenticeship and training standards for optical technicians approved and adopted by the Contact Lens Society of America in accordance with the basic standards recommended by the Bureau of Apprenticeship and Training of the…

  20. 16 CFR 315.3 - Availability of contact lens prescriptions to patients.

    Science.gov (United States)

    2010-01-01

    ... to patients. 315.3 Section 315.3 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS CONTACT LENS RULE § 315.3 Availability of contact lens prescriptions to patients... not requested by the patient, shall provide to the patient a copy of the contact lens prescription...

  1. Effect of contact lens surface properties on comfort, tear stability and ocular physiology.

    Science.gov (United States)

    Vidal-Rohr, Maria; Wolffsohn, James S; Davies, Leon N; Cerviño, Alejandro

    2017-09-15

    Retrospective analysis of different contact lens wearing groups suggests lens surface lubricity is the main factor influencing contact lens comfort. However, the examined commercially available contact lenses differ in material and design as well as surface properties. Hence this study isolates the contribution of lens surface properties using an ultra-thin coating technology. Nineteen habitual contact lens wearers (21.6±1.7years) wore formofilcon B soft monthly disposable contact lenses with and without coating technology modified surface properties for a month each in a randomised double-masked cross-over study. OBJECTIVE NON-INVASIVE: breakup time (NIKBUT), NIKBUT average and ocular redness (Jenvis grading scale) were evaluated (Keratograph 5M) after 1 week and 1 month of wear. Symptoms were assessed using the Contact Lens Dry Eye Questionnaire (CLDEQ-8); perceived vision quality and subjective lens comfort at insertion, mid-day and end of the day were rated with four Visual Analog Scales. Perceived visual quality (F=5.049,p=0.037), contact lens dry eye symptoms (F=14.408,p=0.001) and subjective lens comfort (F=28.447,p0.05). Lens surface wettability and ocular redness were not correlated to changes in symptoms (p>0.05). As previously hypothesised, enhancing the physical surface properties of a soft contact lens improves subjectively rated wearer comfort, which, in turn, should result in reduced contact lens discontinuation. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  2. Hard contact lens-induced metabolic changes in rabbit corneas.

    Science.gov (United States)

    Tsubota, K; Kenyon, K R; Cheng, H M

    1989-11-01

    The biochemistry of contact lens-cornea interaction is not well understood, although previous studies have suggested that corneal metabolic changes may be the underlying factor in morphological alterations. Using a rabbit model, this interaction has been examined with 31P nuclear magnetic resonance (NMR) spectroscopy, which detects signals principally from the epithelium. The examination was supplemented with electron microscopy and histochemistry. Polymethylmethacrylate lenses caused reversible changes, including activation of anaerobic glycolysis and disturbance of membrane metabolite levels. These changes were far more severe than those occurring during prolonged eye closure. There appears to be an association between cellular deterioration and loss of membrane metabolites. On the other hand, oxygen-permeable silicone lenses allowed maintenance of nearly normal metabolic patterns. These results show multifaceted corneal response to hard contact lens wear.

  3. A Two-Dimensional Model for Tear Flow through a Permeable Contact Lens

    Science.gov (United States)

    Gerhart, Matthew; Anderson, Daniel

    2011-11-01

    This is an investigation into the flow of an incompressible fluid in a thin pre-lens, contact lens, and post-lens system. The pre-lens and post-lens layers are coupled through the middle layer being a thin permeable contact lens. Included in this system are the effects of evaporation of the pre-lens film and the settling of the contact lens over time. This analysis is done through the nondimensionalization of the governing equations which include the Navier-Stokes equations for the pre- and post-lens tear film and Darcy's equations for the contact lens layer along with heat equations for temperature. Lubrication theory is then applied to the resulting system leaving a reduced coupled system of equations whose properties we explore. Supported by NSF-DMS.

  4. Contact lens associated microbial keratitis: practical considerations for the optometrist

    OpenAIRE

    Zimmerman AB; Nixon AD; Rueff EM

    2016-01-01

    Aaron B Zimmerman, Alex D Nixon, Erin M Rueff College of Optometry, The Ohio State University, Columbus, OH, USAAbstract: Microbial keratitis (MK) is a corneal condition that encompasses several different pathogens and etiologies. While contact lens associated MK is most often associated with bacterial infections, other pathogens (fungi, Acanthamoeba species, etc) may be responsible. This review summarizes the risk factors, microbiology, diagnostic characteristics, and treatment options for a...

  5. [Contact lens-related Fusarium keratitis: a case report].

    Science.gov (United States)

    Amadasi, Silvia; Pelliccioli, Giovanni Federico; Colombini, Paolo; Bonomini, Annalisa; Farina, Claudio; Pietrantonio, Filomena; Pedroni, Palmino

    2017-06-01

    We aim to highlight the key factors for a good outcome of fungal keratitis. We describe a case of contact lens-related Fusarium keratitis in a young girl. After identification of Fusarium spp under direct microscopic examination and in culture, a prolonged treatment with topic natamycin 5% was started and administered for five months with restitutio ad integrum of the eye. Prompt microbiological diagnosis and a specific and prolonged treatment are essential for correct management of Fusarium keratitis.

  6. Aspergillus tamarii keratitis in a contact lens wearer

    Directory of Open Access Journals (Sweden)

    Juan Cuadros

    2018-03-01

    Full Text Available Keratitis produced by Aspergillus tamarii has been previously described associated to an ocular injury. We report a case in a contact lens wearer with a history of previous bilateral myopic LASIK ablation, bilateral intracorneal rings and vitrectomy and scleral buckling in his left eye. The fungus could be quickly identified combining phenotype, microscopy and mass spectrometry. Treatment with intravenous amphotericin, oral voriconazole, and topical amphotericin and natamycin and voriconazole was needed for corneal preservation.

  7. Scleral contact lens management of bilateral exposure and neurotrophic keratopathy.

    Science.gov (United States)

    Grey, Fiona; Carley, Fiona; Biswas, Susmito; Tromans, Cindy

    2012-12-01

    We report an interesting case of therapeutic scleral lens management of bilateral exposure and neurotrophic keratopathy resulting from bilateral cranial nerve (CN) palsies including V, VI and VII, which caused lagophthalmos and anaesthetic corneas. Subsequent development of severe exposure keratitis with vascularisation and keratinisation of the inferior cornea was previously treated with intensive ocular lubrication, botulinum toxin injections to the upper eyelid levator muscle, temporary tarsorrhophies, bilateral amniotic membrane grafts, punctal plugs, lid taping, gold eyelid weights and soft bandage contact lenses. Corneal integrity was re-established but visual acuity remained significantly compromised by corneal vascularisation, scarring and keratin deposits. Visions on presentation to the contact lens department were R 1.90 logMAR, L 1.86 logMAR. Therapeutic, high Dk, non-fenestrated, saline filled, scleral lenses were fitted. Daily wear of these lenses have protected and hydrated the cornea, enabling corneal surface recovery whilst retaining visual and social function. The visual acuities 6 months post-scleral fitting with lenses in situ are R 0.90 logMAR and L logMAR 0.70. Copyright © 2012 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  8. MICROBIAL EVALUATION OF NORMAL SALINE USED BY CONTACT LENS WEARERS

    Directory of Open Access Journals (Sweden)

    CHUA SIEW SIANG

    2006-01-01

    Full Text Available Contact lens solutions should only be used for four weeks after first opening but this practice is not always followed. Therefore, the present study was conducted to determine the duration that contact lens wearers could use their normal saline without microbial contamination. Two brands of normal saline, OpticareTM and Klean & KareTM, were used by 30 contact lens wearers on alternate days. Samples were collected weekly for microbial evaluation. On an average, the duration of use without microbial contamination was four weeks. Half of the participants were able to use both bottles of their normal saline without microbial contamination for at least four weeks after first opening and this included nine participants who were able to use for at least eight weeks. The brands of normal saline, the frequency of use, the place where the normal saline was stored or used were not significantly related to the duration of contamination-free period. Of the 27 samples tested, 11 grew gram-positive bacteria and 16, gram-negative bacteria. The most common bacteria found were Staphylococcus aureus and Pseudomonas species. None of the samples had Acanthamoeba spp. and no eye infection or irritation was reported. It was concluded that on an average, a bottle of sterile normal saline can be used for at least four weeks after first opening. Some users may be able to extend this expiry date to eight weeks, depending on the way the solution was used.

  9. Association between multifocal soft contact lens decentration and visual performance

    Directory of Open Access Journals (Sweden)

    Fedtke C

    2016-06-01

    Full Text Available Cathleen Fedtke,1 Klaus Ehrmann,1,2 Varghese Thomas,1 Ravi C Bakaraju1,2 1The Brien Holden Vision Institute, Clinical Trial Research Centre, 2School of Optometry and Vision Science, The University of New South Wales, Sydney, NSW, Australia Purpose: The aim of this study was to assess the association between decentration of several commercial multifocal soft contact lenses (MFCLs and various objective and subjective visual performance variables in presbyopic and non-presbyopic participants. Materials and methods: All presbyopic (age >40 years, near add ≥+1.25 D and non-presbyopic (age ≥18 years, no near add requirements, spherical equivalent ≤-0.50 D participants were each fitted bilaterally with six and two MFCLs (test lens, respectively, and with one single vision lens (control lens. Lens decentration, ie, the x- and y-differences between the contact lens and pupil centers, was objectively determined. Third-order aberrations were measured and compared. Visual performance (high- and low-contrast acuities and several subjective variables was analyzed for any associations (Pearson’s correlation, r with MFCL decentration. Results: A total of 17 presbyopic (55.1±6.9 years and eight non-presbyopic (31.0±3.3 years participants completed the study. All lenses displayed a temporal–inferior decentration (x=-0.36±0.29 mm, y=-0.28±0.28 mm, mean ± SD. Compared to the control, a significant inferior decentration was found for the Proclear® MFCL Near lens in both groups (ypresbyopic =-0.26 mm, ynon-presbyopic =-0.70 mm and for the Proclear® MFCL Distance lens in the non-presbyopic group (ynon-presbyopic =-0.69 mm. In both groups, lens-induced vertical coma (C(3, -1 was, by at least tenfold, significantly more positive for the Proclear® MFCL Distance lens and significantly more negative for the Proclear® MFCL Near lens. In the presbyopic group, the correlation of total MFCL decentration with vision variables was weak (r<|0

  10. Bacterial transmission from lens storage cases to contact lenses - Effects of lens care solutions and silver impregnation of cases

    NARCIS (Netherlands)

    Vermeltfoort, Pit B. J.; Hooymans, Johanna M. M.; Busscher, Henk J.; van der Mei, Henny C.

    2008-01-01

    The killing efficacies of multipurpose lens care solutions on planktonic and biofilm bacteria grown in polypropylene contact lens storage cases with and without silver impregnation and effects on bacterial transmission from storage cases to silicone hydrogel contact lenses were investigated. For

  11. Fluctuation in visual acuity during soft toric contact lens wear.

    Science.gov (United States)

    Chamberlain, Paul; Morgan, Philip B; Moody, Kurt J; Maldonado-Codina, Carole

    2011-04-01

    To quantify changes in visual acuity (VA) with soft toric contact lenses as a result of lens movement and/or rotational instability caused by versional eye movements. A novel chart for vision assessment at near (40 cm) for soft toric contact lenses (VANT chart),consisting of a central, color-coded logMAR panel and eight peripheral letter targets set on a white background measuring 60 × 40 cm was constructed. In the developmental phase of the work, 10 subjects (20 eyes) wore 2 toric lenses in random order, and the impact of rapid and delayed eye versions in 8 directions of gaze on VANT acuity was investigated. In phase 2, 35 subjects (68 eyes) wore 4 toric lenses in random order, and a streamlined clinical protocol using the VANT chart was implemented. Standard assessments of toric lens fit and distance VA were also performed. Testing in the first phase showed no difference for change in VA for rapid vs. delayed version movements, (p = 0.17) but acuity reduction was greater for diagonal compared with horizontal/vertical versions (p = 0.06). As such, testing in phase 2 proceeded using rapid, diagonal versions only. In this second phase, there were differences for low-contrast distance VA measures between lens types (p = 0.02) and for both VANT baseline acuity (p = 0.03) and postversion acuity (p = 0.04), but no differences were found between lenses for magnitude of vision loss (p = 0.91), which was about one line. No relationship was established between the magnitude of vision loss and measured rotational stability (p = 0.75). This work has demonstrated that conventional approaches to measuring VA do not fully replicate the "real world" experience of soft toric lens wearers. The VANT chart has shown that VA is reduced immediately after versional eye movements and suggests that more dynamic methods of assessing visual performance should be considered for soft toric contact lens wearers, especially given the apparent inability of lens stability measurements to predict

  12. Fusarium and Candida albicans biofilms on soft contact lenses: model development, influence of lens type and susceptibility to lens care solutions

    Science.gov (United States)

    Fungal keratitis is commonly caused by Fusarium species, while cases of Candida-associated keratitis are less frequent. Recent outbreaks of Fusarium keratitis were associated with contact lens wear and with MoistureLoc contact lens care solution, and biofilm formation on contact lens/lens cases was...

  13. Conjunctival epithelial flap in continuous contact lens wear.

    Science.gov (United States)

    Graham, Andrew D; Truong, Tan N; Lin, Meng C

    2009-04-01

    Composed of sheets of cells detached from the underlying conjunctiva, conjunctival epithelial flap (CEF) is a recently reported phenomenon associated with contact lens wear with potential consequences for ocular health. Although CEF is generally asymptomatic, it is not known to what extent it might increase the longer-term risk of discomfort, inflammatory response, or infection. In this study, we use survival analysis methods to obtain unbiased estimates of the probability of developing CEF, the mean survival time free of CEF, and the effects of age, gender, ethnicity, and contact lens type. Two hundred four subjects were recruited for a continuous wear (CW) study of silicone hydrogel (SiH) and gas permeable (GP) contact lenses. Subjects were examined by optometrists throughout contact lens adaptation and CW periods. Statistical methods included the Kaplan-Meier nonparametric estimator of the survival function and the Cox proportional hazards model for estimating the relative effects of covariates. Of the 204 subjects, 72 (35%) developed CEF. In 64% of cases, CEFs were observed bilaterally. The majority of cases (90.3%) presented with CEF in the superior conjunctiva. Mean survival time free of CEF was longer for GP lenses (94.3 days) than for SiH lenses (76.5 days), and the probability of developing CEF was significantly greater for SiH lenses (p = 0.002). Although there was some evidence that women and non-Asians remain free of CEF longer, the effects of age, gender, and ethnicity were not statistically significant. There was a significantly increased risk of CEF in subjects wearing SiH lenses, compared with GP lenses. Subjects wearing SiH lenses remained free of CEF for a shorter time on average. Further study is needed to determine whether the increased incidence of CEF in CW with SiH lenses poses an increased risk of adverse ocular response or infection.

  14. Citation parameters of contact lens-related articles published in the ophthalmic literature.

    Science.gov (United States)

    Cardona, Genís; Sanz, Joan P

    2014-09-01

    This study aimed at exploring the citation parameters of contact lenses articles published in the Ophthalmology thematic category of the Journal Citation Reports (JCR). The Thompson Reuters Web of Science database was accessed to record bibliometric information and citation parameters of all journals listed under the Ophthalmology area of the 2011 JCR edition, including the journals with main publication interests in the contact lens field. In addition, the same database was used to unveil all contact lens-related articles published in 2011 in the same thematic area, whereupon differences in citation parameters between those articles published in contact lens and non-contact lens-related journals were explored. Significant differences in some bibliometric indicators such as half-life and overall citation count were found between contact lens-related journals (shorter half-life and fewer citations) and the median values for the Ophthalmology thematic area of the JCR. Visual examination of all Ophthalmology journals uncovered a total of 156 contact lens-related articles, published in 28 different journals, with 27 articles each for Contact Lens & Anterior Eye, Eye & Contact Lens, and Optometry and Vision Science. Significant differences in citation parameters were encountered between those articles published in contact lens and non-contact lens source journals. These findings, which disclosed contact lenses to be a fertile area of research, may be of interest to researchers and institutions. Differences in bibliometric indicators are of relevance to avoid unwanted bias when conducting between- and within-discipline comparisons of articles, journals, and researchers.

  15. Theoretical fitting characteristics of typical soft contact lens designs.

    Science.gov (United States)

    Sulley, Anna; Osborn Lorenz, Kathrine; Wolffsohn, James S; Young, Graeme

    2017-08-01

    To calculate theoretical fitting success rates (SR) for a range of typical soft contact lens (SCL) designs using a mathematical model. A spreadsheet mathematical model was used to calculate fitting SR for various SCL designs. Designs were evaluated using ocular topography data from 163 subjects. The model calculated SR based on acceptable edge strain (within range 0-6%) and horizontal diameter overlap (range 0.2-1.2mm). Where lenses had multiple base curves (BCs), eyes unsuccessful with the steeper BC were tested with the flatter BC and aggregate SR calculated. Calculations were based on typical, current, hydrogel and silicone hydrogel SCLs and allowed for appropriate on-eye shrinkage (1.0-2.3%). Theoretical results were compared with those from actual clinical trials. Theoretical success rates for one-BC lenses ranged from 60.7% (95% CI 7.2%) to 90.2% (95% CI 3.7%). With two-BC designs, most combinations showed a SR increase with a second BC (84.0%-90.2%). However, one of the two-BC combinations showed only negligible increase with a second BC (72.4%-73.0%). For designs with lower SR, the greatest contributor to failure was inadequate lens diameter. For a given design, differences in shrinkage (i.e. on-eye bulk dehydration) had a significant effect on success rate. In comparison with historical clinical data, there was a positive correlation between small lens fitting prevalence and discomfort reports (r=+0.95, P=<0.001) with a poor correlation between theoretical and actual tight/loose fittings. Mathematical modelling is a useful method for testing SCL design combinations. The results suggest that judicious choice of additional fittings can expand the range of fitting success. Copyright © 2017 British Contact Lens Association. All rights reserved.

  16. Rat silicone hydrogel contact lens model: effects of high- versus low-Dk lens wear.

    Science.gov (United States)

    Zhang, Yunfan; Gabriel, Manal M; Mowrey-McKee, Mary F; Barrett, Ronald P; McClellan, Sharon; Hazlett, Linda D

    2008-11-01

    This study used a rat contact lens (CL) model to test if high- versus low-Dk lens wear caused changes in (1) conjunctival Langerhans cell (LC) number or location; (2) Bcl-2 expression; and (3) infection risk. Female, Lewis rats wore a high- or low-Dk CL continuously for 2 weeks. Afterward, corneas were harvested and processed for ADPase activity to identify LCs, for immunostaining and for real time-polymerase chain reaction. Contact lens-wearing rats also were challenged with Pseudomonas aeruginosa by placing a bacterial-soaked CL on the eye followed by topical delivery of bacteria. After 48 hrs, slit lamp examination and real time-polymerase chain reaction were used to evaluate the corneal response. Conjunctival LC were significantly increased after low- versus high-Dk CL wear (PDk lens wearing group. Bcl-2 mRNA levels were significantly decreased in low- versus high-Dk CL wearing rats, while Bax, FasL, caspase 3, and caspase 9 levels were unchanged. Immunostaining for Bcl-2 showed fewer positively stained epithelial cells in the low- versus high-Dk lens wearing group. After bacterial challenge, 30% of low- versus none of the high-Dk CL wearing corneas became infected and showed increased mRNA levels for several proinflammatory cytokines/chemokines, inducible nitric oxide synthase and matrix metalloproteinase-9. Low- versus high-Dk or non-CL wear led to an increased number of conjunctival LC, decreased Bcl-2 levels, and increased the risk of bacterial infection.

  17. Contact lens management of patients who have had unsuccessful refractive surgery.

    Science.gov (United States)

    Zadnik, K

    1999-08-01

    The advent of corneal refractive surgery has, inevitably, resulted in the occasional need for contact lens fitting after surgery. For each new, developing procedure, new contact lens fitting challenges arise. The literature on contact lens use after radial keratotomy is rich and well known, but reports on the use of contact lenses after photorefractive keratectomy or laser-assisted in situ keratomileusis are few and far between. This review summarizes the prevailing clinical opinions on the contact lenses and contact lens fitting methods that are most effective after refractive surgery that results in high refractive error, irregular astigmatism, or anisometropia.

  18. Comparation of effectiveness of silicone hydrogel contact lens and hydrogel contact lens in patients after LASEK

    National Research Council Canada - National Science Library

    Wen-Juan Xie Jin Zeng Ying Cui Juan Li Zhong-Ming Li Wei-Xiong Liao Xiao-Hong Yang

    2015-01-01

    .... They were randomly divided into 2 groups. The silicone hydrogel group included 32 cases(61 eyes) that wore silicone hydrogel contact lenses for 4-6d after the operation, while the hydrogel group included 31 cases(60 eyes...

  19. Inhibition of Lens Photodamage by UV-Absorbing Contact Lenses

    Science.gov (United States)

    Malone, James P.; Townsend, R. Reid

    2011-01-01

    Purpose. To determine whether class 1 UV-blocking contact lenses protect against UVB radiation–induced damage in a human lens epithelial cell line (HLE B-3) and postmortem human lenses using a proteomics approach. Methods. HLE B-3 cells were exposed to 6.4 mW/cm2 UVB radiation at 302 nm for 2 minutes (768 mJ/cm2) with or without covering by senofilcon A class 1 UV-blocking contact lenses or lotrafilcon A non–UV-blocking (lotrafilcon A has some UV-blocking ability, albeit minimal) contact lenses. Control cells were not exposed to UVB radiation. Four hours after treatment, cells were analyzed by two-dimensional difference gel electrophoresis and tandem mass spectrometry, and changes in protein abundance were quantified. F-actin and microtubule cytoskeletons were examined by fluorescence staining. In addition, human donor lenses were exposed to UVB radiation at 302 nm for 4 minutes (1536 mJ/cm2). Cortical and epithelial cell proteins were scraped from lens surfaces and subjected to the same protein analyses. Results. Senofilcon A lenses were beneficial for protecting HLE B-3 cells against UVB radiation–induced changes in caldesmon 1 isoform, lamin A/C transcript variant 1, DEAD (Asp-Glu-Ala-Asp) box polypeptide, β-actin, glyceraldehyde 3-phosphate dehydrogenase (G3PDH), annexin A2, triose phosphate isomerase, and ubiquitin B precursor. These contact lenses also prevented actin and microtubule cytoskeleton changes typically induced by UVB radiation. Conversely, non–UV-blocking contact lenses were not protective. UVB-irradiated human lenses showed marked reductions in αA-crystallin, αB-crystallin, aldehyde dehydrogenase 1, βS-crystallin, βB2-crystallin, and G3PDH, and UV-absorbing contact lenses significantly prevented these alterations. Conclusions. Senofilcon A class 1 UV-blocking contact lenses largely prevented UVB-induced changes in protein abundance in lens epithelial cells and in human lenses. PMID:21873653

  20. Polymicrobial Infection of the Cornea Due to Contact Lens Wear

    Directory of Open Access Journals (Sweden)

    Selçuk Sızmaz

    2016-04-01

    Full Text Available A 38-year-old male presented with pain and redness in his left eye. He had a history of wearing contact lenses. His ophthalmic examination revealed a large corneal ulcer with surrounding infiltrate. Cultures were isolated from the contact lenses, lens solutions, storage cases, and conjunctivae of both eyes and also corneal scrapings of the left eye. Fortified vancomycin and amikacin drops were started hourly. Culture results of conjunctivae of each eye and left cornea were positive for Pseudomonas aeruginosa; cultures from the contact lenses, lens solution and storage case of both eyes revealed Pseudomonas aeruginosa and Alcaligenes xylosoxidans. Polymerase chain reaction of the corneal scraping was positive for Acanthameoba. The topical antibiotics were changed with ones that both bacteria were sensitive to and anti-amoebic therapy was added. The patient had two recurrences following initial presentation despite intensive therapy. Keratitis occurred due to multiple pathogens; the relapsing course despite adequate therapy is potentially associated with this polymicrobial etiology.

  1. Contact lens fitting post-laser-in situ keratomileusis (LASIK).

    Science.gov (United States)

    Steele, Chris; Davidson, John

    2007-05-01

    Despite recent advances in refractive surgical procedures a small proportion of patients still achieve sub-optimal results for a variety of reasons. In such cases, contact lenses may provide the only option for visual rehabilitation and restoration of binocular vision post-refractive surgery. The indications for contact lenses post-LASIK may be one, or a combination of the following: *Initial bandage lens for corneal protection. *Residual ametropia--over and under correction. *Irregular astigmatism. * Anisometropia. * Decentred ablation zones. In low powered corrections conventional soft lenses can be fitted in the normal way, giving good levels of acuity. Where there is astigmatism (>0.75 DC) then toric soft contact lenses may appropriate. Rigid lenses may prove to be the only viable option in a number of cases where visual correction is required post-refractive surgery, or in the presence of high levels of astigmatism. Fitting can be more complex however, since a conventional rigid lens cannot follow the shape of both the flattened central cornea and the relatively steeper periphery in higher corrections, as the amount of laser ablation increases. Reverse geometry lenses are indicated where there is a significant difference between the flat central ablated zone and the relatively steeper peripheral cornea. On rare occasions scleral lenses may also be indicated.

  2. Acanthamoeba keratitis and contact lens wear: static or increasing problem?

    Science.gov (United States)

    Foulks, Gary N

    2007-11-01

    The occurrence of Acanthamoeba keratitis is increasing in the United States because of an expanding population at risk of infection and sporadic outbreaks of infection. Such outbreaks are the result of lapses in contact lens wear and care and of alterations in water quality and water treatment procedures. Although improved techniques in diagnosis are available, better identification of infection alone does not explain an increase in the observed occurrence of the disease. Likewise, there does not appear to be an increase in the virulence or infectivity of the amoebae. Strategies for prevention, including patient education, improved decontaminating agents, maintenance of water treatment standards, and possible immunization of subjects at risk, are needed.

  3. Knowledge, usage and barriers associated with contact lens wear in Ghana.

    Science.gov (United States)

    Abokyi, Samuel; Manuh, George; Otchere, Heinz; Ilechie, Alex

    2017-10-01

    Despite findings that contact lens wear for vision correction provides better quality of life than spectacles, contact lens use in developing countries is low. This study evaluated knowledge, usage and barriers associated with contact lens wear among spectacle wearers in Cape Coast, Ghana. A cross-sectional survey using a structured questionnaire was conducted on an adult population of spectacle wearers to assess their knowledge of contact lens wear for vision correction. The participants were proportionately sampled from three eye clinics in the Cape Coast Metropolis, Ghana. Questionnaires were either self-administered or completed with the help of a research assistant. Of the 422 participants, only 147 (34.8%) knew of contact lens wear for vision correction. The proportion of spectacle wearers reporting history of contact lens wear was 14 (3.3%). Barriers to contact lens wear reported were satisfaction with vision through spectacles 102 (25.0%), lack of adequate information 111 (27.2%), fear of side effects 94 (23.0%) and cost 78 (19.1%). The younger adults and those with higher number of changes of spectacles were more likely to know of contact lenses. Knowledge and usage of contact lenses among spectacle wearers was low. Contact lens education and demonstration of visual performance through fitting of trial contact lenses on potential candidates may help overcome barriers to contact lens wear. Published by Elsevier Ltd.

  4. Characterizing contact lens-related dryness symptoms in a cross-section of UK soft lens wearers.

    Science.gov (United States)

    Young, Graeme; Chalmers, Robin L; Napier, Leslie; Hunt, Chris; Kern, Jami

    2011-04-01

    To estimate the prevalence of and factors associated with contact lens-related dryness symptoms in a large population of soft contact lens patients in the UK. Soft contact lens (CL) wearers (n=932) from 12 UK clinical sites were queried regarding CL history and wearing experience by a self-administered questionnaire. A new score using Contact Lens Dry Eye Questionnaire (CLDEQ) items was used where CL-related dry eye (CL-DE)=frequency of 'sometimes', 'frequently', or 'constantly' plus intensity 3-5; NoCL-DE=frequency of 'never' or 'rarely' and intensity 0-1; Marginal CL-DE, all other categories. Data were analyzed across categories, P-values lens wearers (n=129) compared to spherical lens wearers (43% vs. 30%, P=0.04). Lens material class, lens care system and gender were not significantly related to CL-DE status. Of the CL-DE group, only 38% had been diagnosed with dry eye and 47% self-assessed as dry eye. Use of artificial tears, CLs for dryness, ointments/gels and warm compresses differed between groups according to CL-DE status (PContact Lens Association. Published by Elsevier Ltd. All rights reserved.

  5. Impact of Contact Lens Material, Design, and Fitting on Discomfort.

    Science.gov (United States)

    Stapleton, Fiona; Tan, Jacqueline

    2017-01-01

    To review the effect of contact lens (CL) material, design, and fitting characteristics on CL discomfort. A PubMed search identified publications describing subjective comfort and CL material, fitting, and design parameters. The review included clinical signs associated with discomfort that may be a consequence of these parameters. Reduced lens movement or more CL tightness were associated with improved comfort. Increased lens-induced paralimbal conjunctival staining and indentation, considered as quasi-indicators of CL fitting or edge design, were also associated with better comfort. No recent studies have evaluated varying CL design parameters and subjective comfort. Silicone hydrogel CLs are no different in comfort compared with hydrogel CLs. Lower equilibrium water content is associated with improved comfort in hydrogel CL wear. Coefficient of friction shows promise as a material factor potentially associated with comfort. Lid wiper epitheliopathy and lid-parallel conjunctival folds have been linked with comfort in established wearers. Recent studies have confirmed the association between more mobile CLs and more discomfort, whereas closer conformity of the CL to the bulbar conjunctiva improved subjective comfort. There is no evidence to support the perceived comfort difference between silicone hydrogel and hydrogel CL. There has been limited progress in understanding the impact of varying specific CL design parameters. Although specific clinical signs may be predictive of discomfort, their role in the natural history of discomfort remains unclear. A better understanding of the relationship between coefficient of friction and comfort and strategies to improve lubricity may hold promise for limiting CL discomfort.

  6. Severe pseudomonal keratitis in an infrequent daily disposable contact lens wearer.

    Science.gov (United States)

    Batta, Priti; Goldstein, Michael H

    2010-05-01

    To report an unusual case of contact lens-associated pseudomonal keratitis in a compliant daily disposable contact lens wearer. A case report is presented of a compliant daily disposable contact lens wearer who developed culture-positive pseudomonal keratitis. A 38-year-old woman who reported compliant and infrequent use of daily disposable contact lenses presented with rapid-onset, severe keratitis consistent with pseudomonal infection. Corneal cultures were positive for Pseudomonas aeruginosa. She had no identifiable risk factors, although notably had a remote history of contact lens-associated keratitis in the fellow eye. Although extremely rare, pseudomonal keratitis should still be considered in the differential diagnosis of severe keratitis in daily disposable contact lens wearers. Given the history of a previous contact lens-related bacterial keratitis in this compliant patient, it is possible that host susceptibility factors played a role in the case of pseudomonal keratitis described here.

  7. Shack-Hartmann and Interferometric Hybrid Wavefront Sensor

    Science.gov (United States)

    2011-03-24

    detector area Ad (or, equivalently, the intensity integrated over the detector solid angle) and integration time Td of the detector, and σ 2 W is the...Reprinted photographically in 1937, 1946 by Lowe & Brydone, Printers, LTD., London from sheets of the third edi - tion. 49. Noll, R.J. “Zernike polynomials and

  8. Retrospective analysis of vision correction and lens tolerance in keratoconus patients prescribed a contact lens with dual aspherical curves.

    Science.gov (United States)

    Yanai, Ryoji; Ueda, Kiichi; Nishida, Teruo

    2010-03-01

    To determine whether Aphex KC, a newly designed rigid gas-permeable (RGP) contact lens with dual aspherical base curves, improves visual acuity and lens wear time in patients with keratoconus. We performed a retrospective analysis of a noncomparative case series of 29 eyes of 24 patients with keratoconus who were intolerant of spherical RGP contact lenses and were fitted with Aphex KC at Yamaguchi University Hospital. Visual acuity and lens wear time were recorded as primary outcome measures at follow-up visits. Six patients with a follow-up period of RGP contact lens (P = 1 x 10). The numbers of eyes wearing Aphex KC or the previously prescribed RGP contact lens for >12 hr/day were 26 and 0, respectively (P = 1 x 10). No serious complications of Aphex KC wear were observed. Fitting of an Aphex KC lens improved visual acuity and increased lens wear time in keratoconus patients who were intolerant of a spherical RGP contact lens. Aphex KC thus provides a viable alternative for management of such patients.

  9. Risk Behaviors for Contact Lens-Related Eye Infections Among Adults and Adolescents - United States, 2016.

    Science.gov (United States)

    Cope, Jennifer R; Collier, Sarah A; Nethercut, Hannah; Jones, Jefferson M; Yates, Kirsten; Yoder, Jonathan S

    2017-08-18

    Contact lens-related eye infections, which can lead to serious outcomes, including blindness, are associated with several risk factors, including sleeping in lenses, exposing lenses to water, not adhering to replacement schedules, and reusing disinfecting solution (1). In some studies, adolescent and young adult contact lens wearers have been reported to be more likely than older adult contact lens wearers to develop eye infections (2,3) and more likely to have poor contact lens hygiene practices (2). In 2015, CDC reported the number and demographics of adult contact lens wearers in the United States to define the population at risk for contact lens-related eye infections (4); however, this estimate did not include adolescents. To better understand this group of younger contact lens wearers and guide prevention efforts, a population-based survey was used to assess contact lens wear, care behaviors, risk factors, and demographics among persons aged 12-17 years (referred to as adolescents in this report), young adults aged 18-24 years, and older adults aged ≥25 years in the United States. In 2016, an estimated 3.6 million adolescents (14.5%) wore contact lenses. Of the adolescents who wore contact lenses, 85% reported at least one behavior that put them at risk for a contact lens-related eye infection, compared with 81% of young adults, and 88% of older adults. These findings can inform the creation of age-specific targeted prevention messages aimed at contact lens wearers and establish a baseline for evaluating trends in contact lens wear, care habits, and contact lens-related risk behaviors.

  10. A Survey of Presbyopic Contact Lens Wearers in a University Setting.

    Science.gov (United States)

    Rueff, Erin M; Varghese, Robin Joy; Brack, Taylor M; Downard, Danica E; Bailey, Melissa D

    2016-08-01

    To determine why presbyopic patients discontinue contact lens wear and describe their opinions of comfort and visual quality with contact lenses. A survey assessing current age, gender, contact lens material/design, and opinions of contact lens comfort and visual quality was mailed to 2400 presbyopic patients (age 40 years and older) that have had eye exams in the Ohio State University College of Optometry's Contact Lens Services over the last 4 years. A total of 496 surveys were analyzed. The mean age of survey respondents was 57 ± 9 years, and 68% of the sample was female. Permanent discontinuation of contact lens wear was reported by 15%. No association was found between contact lens discontinuation and age (p = 0.7), gender (p = 0.2), age of beginning contact lens wear (p = 0.1), or contact lens material (p = 0.1). Poor vision (38%), discomfort (34%), convenience (20%), and cost (6%) were the primary reported reasons for discontinuation. There was no difference between the proportion of subjects reporting "poor vision" as their primary discontinuation reason and those reporting "discomfort" (p = 0.7). Discontinued wearers had a worse overall opinion of their distance (p = 0.03), intermediate (p = 0.01), and near vision (p = 0.002) compared to subjects who were still wearing their contact lenses. Discomfort has been reported as the primary reason for contact lens discontinuation. In this presbyopic population, dissatisfaction with vision and discomfort were reported equally as often as primary reasons for discontinuation. As well, subjects who ceased contact lens wear had worse overall opinions of their vision at all distances than current contact lens wearers. The results of this survey suggest that presbyopes have unique demands and opinions related to contact lens wear.

  11. Elemental Composition at Silicone Hydrogel Contact Lens Surfaces.

    Science.gov (United States)

    Rex, Jessica; Knowles, Timothy; Zhao, Xueying; Lemp, Jessie; Maissa, Cecile; Perry, Scott S

    2018-01-15

    The outermost surface composition of 11 silicone hydrogel (SiHy) lenses was measured using X-ray photoelectron spectroscopy (XPS) to understand differences in wettability and potential interactions within an ocular environment. The SiHy lenses tested included balafilcon A, lotrafilcon A, lotrafilcon B, senofilcon A, comfilcon A, and somofilcon A reusable 2-week or monthly replacement lenses and delefilcon A, samfilcon A, narafilcon A, stenfilcon A, and somofilcon A daily disposable lenses. All lenses were soaked for 24 hr in phosphate-buffered saline to remove all packaging solution and dried under vacuum overnight before analysis. X-ray photoelectron spectroscopy measurements were performed at 2 take-off angles, 55° and 75°, to evaluate changes in elemental composition as a function of depth from the surface. Detailed analysis of the XPS data revealed distinct differences in the chemical makeup of the different lens types. For all lenses, carbon, oxygen, and nitrogen were observed in varying quantities. In addition, fluorine was detected at the outermost surface region of comfilcon A (3.4%) and lotrafilcon A and B (silicon content of the near-surface region analyzed varied among lens types, ranging from a low of 1.6% (lotrafilcon B) to a high of 16.5% (comfilcon A). In most instances, silicon enrichment at the outermost surface was observed, resulting from differences in lens formulation and design. Lenses differed most in their surface silicon concentration, with lotrafilcon B and delefilcon A exhibiting the lowest silicon contents and comfilcon A lens exhibiting the highest. Silicon has hydrophobic properties, which, when found at the surface, may influence the wettability of the contact lenses and their interaction with the tear film and ocular tissues. Higher surface silicon contents have been previously correlated with adverse effects, such as enhanced lipid uptake, thus underscoring the importance of monitoring their presence.

  12. Reduced aniseikonia in axial anisometropia with contact lens correction.

    Science.gov (United States)

    Winn, B; Ackerley, R G; Brown, C A; Murray, F K; Prais, J; St John, M F

    1988-01-01

    Aniseikonia, although present in isometropia, is associated principally with anisometropia and is widely thought to be the result of differences in the retinal image size presented to each eye. This assumes that equating retinal image size results in congruous cortical images. To test this assumption 1 refractive and 17 axial anisometropic subjects were examined to determine the aniseikonia present when corrected with spectacles and contact lenses. Contrary to many previous predictions, based upon Knapp's Law, the presence of equal retinal images resulted in larger aniseikonias than observed when the eyes were presented with unequal retinal images. This suggests that non-optical components have a significant role in the production of the cortical image, and this therefore requires a shift in the way the management of anisometropia is considered clinically. Contact lens correction maintains the aniseikonia at a minimum level in axial as well as refractive anisometropia and offers the clinician an acceptable practical alternative when prescribing for these patients.

  13. A study of corneal endothelial changes in soft contact lens wearers using non-contact specular microscopy

    Directory of Open Access Journals (Sweden)

    Renu M Magdum

    2013-01-01

    Full Text Available Aim: To study the corneal endothelial changes after soft contact lens wear, to correlate these changes with the duration of soft contact lens wear, and to study the pattern of use and preferences of contact lens among young adults. Materials and Methods: This observational study was carried out in 100 eyes of 50 soft contact lens users aged between 19 and 27 years. Both eyes of 50 medical students who had never worn contact lenses served as controls. Data from each subject were collected using a structured questionnaire of 24 items that included demographic profile, pattern of contact lens use, symptoms, brand name, number of years worn, and hours of daily wear. These data were analyzed using Chi square for association. Specular microscopy was done using TOPCON SP-3000P. Computerized morphometry was used to evaluate central corneal thickness, size, shape, mean cellular density, hexagonality, coefficient of variation, and polymegathism of the corneal cells . Results: It was found that central corneal thickness was 0.532 ± 0.0309 mm in lens users and 0.514 ± 0.03 mm in controls, cell density was 2570.91 ± 432.06 cells/mm 2 in lens users and 2723.17 ± 327.64 cells/mm 2 in controls, while hexagonality was 54.81 ± 39.72% in lens users and 67.65 ± 36.49% in controls. Conclusion: Despite the known effects of long duration of soft contact lens use on corneal endothelial cell morphology, this study could not draw a significant correlation between them. However, a significant difference was found in the corneal endothelial thickness, cell density, and hexagonality. Among the soft contact lens users, 62% used soft disposable type while 38% used soft extended wear contact lens. Contact lenses were preferred over spectacles for better cosmetic appearance, comfort, and wider visual field.

  14. A contact-lens-shaped IC chip technology

    Science.gov (United States)

    Liu, Ching-Yu; Yang, Frank; Teng, Chih-Chiao; Fan, Long-Sheng

    2014-04-01

    We report on novel contact-lens-shaped silicon integrated circuit chip technology for applications such as forming a conforming retinal prosthesis. This is achieved by means of patterning thin films of high residual stress on top of a shaped thin silicon substrate. Several strategies are employed to achieve curvatures of various amounts. Firstly, high residual stress on a thin film makes a thin chip deform into a designed three-dimensional shape. Also, a series of patterned stress films and ‘petal-shaped’ chips were fabricated and analyzed. Large curvatures can also be formed and maintained by the packaging process of bonding the chips to constraining elements such as thin-film polymer ring structures. As a demonstration, a complementary metal oxide semiconductor transistor (CMOS) image-sensing retina chip is made into a contact-lens shape conforming to a human eyeball 12.5 mm in radius. This non-planar and flexible chip technology provides a desirable device surface interface to soft tissues or non-planar bio surfaces and opens up many other possibilities for biomedical applications.

  15. Potentially pathogenic free-living amoebae in contact lenses of the asymptomatic contact lens wearers.

    Directory of Open Access Journals (Sweden)

    Maryam Niyyati

    2014-03-01

    Full Text Available Free-living amoebae (FLA including Acanthamoeba spp. and Hartmannella spp. are the causative agents of serious corneal infection especially within contact lens wearers. Thus contact lenses and their storage case could be a suitable niche for potentially pathogenic amoebae. The main objective of the present study was to evaluate the contamination of contact lenses to free living amoebae using morphological and sequencing based methods.Overall, 90 volunteers provided their contact lenses. All volunteers wore soft contact lenses. Both lenses were cultured in the same plate. Forty-eight of the volunteers were medical and dentistry student and 42 were ophthalmology attendees of hospitals in Tehran, Iran. All of the samples were inoculated to non-nutrient medium and monitored daily for the outgrowth of the amoebae. PCR and sequencing were performed using various primer pairs.Of the 90 volunteers, 9 (10% were positive for free-living amoebae outgrowth. Morphological analysis revealed that 3 isolates were belonged to Hartmannella genus according to small round cysts and 6 isolates were belonged to Acanthamoeba genus based on the star shape of endocysts. Sequencing revealed that Acanthamoeba belonged to T4, T3 and T5 genotype. Hartmannella were also belonged to vermiformis species.The presence of potentially pathogenic free living amoebae including Acanthamoeba and Hartmannella could be a high risk for people using soft contact lenses. These results revealed that improved clarification and professional recommendations for contact lens wearers is of utmost importance.

  16. In situ visualization of tears on contact lens using ultra high resolution optical coherence tomography.

    Science.gov (United States)

    Wang, Jianhua; Jiao, Shuliang; Ruggeri, Marco; Shousha, Mohamed Abou; Shousha, Mohammed Abou; Chen, Qi

    2009-03-01

    To demonstrate the capability of directly visualizing the tear film on contact lenses using optical coherence tomography (OCT). Six eyes of three healthy subjects wearing PureVision and ACUVUE Advance soft and Boston RGP hard contact lenses were imaged with a custom built, high speed, ultra-high resolution spectral domain optical coherence tomograph. Refresh Liquigel was used to demonstrate the effect of artificial tears on the tear film. Ultra high resolution images of the pre- and post-lens films were directly visualized when each lens was inserted onto the eye. After the instillation of artificial tears during lens wear, the tear film was thicker. The post-lens tear film underneath the lens edge was clearly shown. Interactions between the lens edges and the ocular surface were obtained for each of the lens types and base curves. With a contrast enhancement agent, tear menisci on the contact lenses around the upper and lower eyelids were highlighted. With hard contact lenses, the tear film was visualized clearly and changed after a blink when the lens was pulled up by the lid. Ultra-high resolution OCT is a potentially promising technique for imaging tears around contact lenses. This successful demonstration of in situ post-lens tear film imaging suggests that OCT could open a new era in studying tear dynamics during contact lens wear. The novel method may lead to new ways of evaluating contact lens fitting.

  17. A New Model for the Suction Pressure Under the Contact Lens

    Science.gov (United States)

    Maki, Kara; Ross, David; Holz, Emily

    2013-11-01

    We study the dynamics of the contact lens to better understand how the design of the lens can be optimized for patient comfort and ocular fit. When a contact lens is inserted on an eye, it is subjected to forces from both the tear film in which it is immersed and the blinking eyelid. In response, the lens bends and stretches. These forces center the lens, and they produce the suction pressure that keeps the lens on the cornea. In this presentation, we couple fluid and solid mechanics to determine the most prominent forces acting on the lens. We present a mathematical model that predicts the suction pressure. We explore the influence of contact lens properties on the suction pressure. This work is supported by the Economic Development Administration and Bausch + Lomb.

  18. Accommodative Behavior of Eyes Wearing Aspheric Single Vision Contact Lenses.

    Science.gov (United States)

    Altoaimi, Basal H; Almutairi, Meznah S; Kollbaum, Pete; Bradley, Arthur

    2017-10-01

    Wearing aspheric contact lenses adds significant amounts of negative spherical aberration (SA). Also, when accommodated and converged to near targets, pupil size shrinks and SA shift from positive to more negative direction. Interestingly, in this study, pupil miosis was fully or partially able to compensate for the additional accommodation-induced negative SA. The present study aims to examine the accommodative response characteristics of young eyes fit with aspheric single vision contact lenses (SVCLs) that add significant negative SA to the eye responding to a wide range of accommodation stimuli. Using a Shack-Hartmann aberrometer, the accommodation behavior in eight young adult eyes (mean age and spherical equivalent is 27.25 ± 2.05 years and -1.75 ± 1.80D, respectively) was measured while subjects fixated binocularly and monocularly 20/40 letter E, which were moved from 2 m to 20 cm (0.5 to 5D) in 0.25D steps. Using natural pupils, refractive state was defined using three standard criteria: the dioptric power that (1) minimized the root mean square error (minRMS), (2) best-fit paraxial, and (3) provided the peak image quality (peak IQ). Wearing aspheric lenses with negative SA shifts the mean SA of the unaccommodated eyes from +0.05 μm (eyes only) to -0.029 μm (eyes + SVCL) and increases the negative SA for the eye + lens when accommodating from -0.029 to -0.07 μm for natural pupils. Aberration changes with accommodation were attenuated by the accommodative pupil miosis, which reduced binocular viewing pupil diameters from 3.9 to 3.3 mm. This alteration of the typical SA levels by the aspheric SVCL did not prevent accurate accommodation (mean ± standard deviation accommodative lag under binocular viewing were -0.08 ± 0.12D, -0.38 ± 0.12D, and -0.26 ± 0.08D for paraxial, minRMS, and peak IQ, respectively). These data clearly show that aspheric contact lenses designed to correct some or all of the unaccommodated eye's positive SA do not interfere with

  19. Antimicrobial Efficacy of Contact Lens Care Solutions Against Neutrophil-Enhanced Bacterial Biofilms.

    Science.gov (United States)

    Hinojosa, Jorge A; Patel, Naiya B; Zhu, Meifang; Robertson, Danielle M

    2017-04-01

    Neutrophil-derived extracellular debris has been shown to accelerate bacterial biofilm formation on hydrogel and silicone hydrogel contact lens surfaces compared to lenses inoculated with bacteria alone. The purpose of this study was to evaluate the disinfection efficacy of four standard commercial contact lens cleaning regimens against neutrophil-enhanced bacterial biofilms formed on silicone hydrogel contact lenses. Four reference strains were used: Pseudomonas aeruginosa, Serratia marcescens, Stenotrophomonas maltophilia, and Staphylococcus aureus. Human neutrophils were isolated from peripheral blood by venipuncture. Unworn Lotrafilcon B lenses were incubated overnight in each respective strain with stimulated neutrophils. Contact lenses were then cleaned using one of four contact lens care solutions according to manufacturer instructions. Bacterial viability was assessed by colony counts and confocal microscopy. Volume of residual debris on lens surfaces after cleaning was quantified using IMARIS software. All four solutions tested showed effective antimicrobial activity against each bacterial strain; however, substantial amounts of nonviable bacteria and cellular debris remained on the lens surface despite concomitant digital cleaning. Necrotic cellular debris that accumulates under the posterior lens surface during wear of an inoculated contact lens is not fully removed during routine cleaning and disinfection. The accumulation of residual cellular debris on the contact lens surface may contribute to new colonization of the lens and represents a significant risk factor for a contact lens-related adverse event. Additional studies are needed to correlate these findings with risk for corneal infiltrative and/or infectious events in a standard animal model.

  20. Tear film evaluation and management in soft contact lens wear: a systematic approach.

    Science.gov (United States)

    Downie, Laura E; Craig, Jennifer P

    2017-09-01

    The human tear film is a highly ordered structure consisting of a thin layer of lipid on the surface and a thicker aqueous-mucin phase, which increases in mucin concentration toward the corneal epithelial cell layer. The health of the tear film and ocular surface influences the likelihood of being able to achieve successful contact lens wear. Contact lens discomfort and dryness are the most frequent reasons why contact lens wearers experience reduced wearing times, which can eventually lead to contact lens discontinuation. Comprehensive clinical assessment of tear film integrity and ocular surface health is therefore essential prior to commencing contact lens wear, to enable the ocular surface environment to be optimised to support lens wear. These parameters should also be evaluated over the course of contact lens wear, in order to identify any aspects requiring clinical management and ensure maintenance of optimal lens-wearing conditions. This review summarises current knowledge relating to the effects of soft contact lens wear on the tear film and ocular surface. It also provides a systematic approach to evaluating tear film and ocular surface integrity, in order to guide the clinical management of tear film anomalies with respect to contact lens wear. © 2017 Optometry Australia.

  1. Development of the Contact Lens User Experience: CLUE Scales.

    Science.gov (United States)

    Wirth, R J; Edwards, Michael C; Henderson, Michael; Henderson, Terri; Olivares, Giovanna; Houts, Carrie R

    2016-08-01

    The field of optometry has become increasingly interested in patient-reported outcomes, reflecting a common trend occurring across the spectrum of healthcare. This article reviews the development of the Contact Lens User Experience: CLUE system designed to assess patient evaluations of contact lenses. CLUE was built using modern psychometric methods such as factor analysis and item response theory. The qualitative process through which relevant domains were identified is outlined as well as the process of creating initial item banks. Psychometric analyses were conducted on the initial item banks and refinements were made to the domains and items. Following this data-driven refinement phase, a second round of data was collected to further refine the items and obtain final item response theory item parameters estimates. Extensive qualitative work identified three key areas patients consider important when describing their experience with contact lenses. Based on item content and psychometric dimensionality assessments, the developing CLUE instruments were ultimately focused around four domains: comfort, vision, handling, and packaging. Item response theory parameters were estimated for the CLUE item banks (377 items), and the resulting scales were found to provide precise and reliable assignment of scores detailing users' subjective experiences with contact lenses. The CLUE family of instruments, as it currently exists, exhibits excellent psychometric properties.

  2. Retained soft contact lens masquerading as a chalazion: A case report

    OpenAIRE

    Pankaj Kumar Agarwal; Taha Y Ahmed; Diaper, Charles J M

    2013-01-01

    A misplaced contact lens is a common ocular emergency presenting to the eye casualty. We report a case of lost soft contact lens which migrated in the lid and presented 13 years later with symptomatic eye lid swelling. Authors in the past have reported migration and subsequent retention of lost hard lenses in locations such as the superior fornix and eyelid. To the best of our knowledge, misplaced soft contact lens masquerading as a chalazion has not been reported in the literature. Considera...

  3. Reducing dropout of contact lens wear with Biotrue multipurpose solution

    Directory of Open Access Journals (Sweden)

    Rah MJ

    2014-01-01

    Full Text Available Marjorie J Rah, Mohinder M Merchea, Marianne Q DoktorBausch & Lomb Incorporated, Rochester, NY, USAPurpose: To evaluate whether the use of Biotrue multipurpose solution (MPS could significantly reduce the likelihood with which patients drop out of using daily wear contact lenses (CLs amongst 18–44-year-old frequent replacement CL wearers.Methods: Daily wear CL subjects habitually using MPSs (other than Biotrue MPS who reported an intent to imminently drop out of CL wear because of comfort and dryness complaints were recruited to participate in this investigation. Subjects were switched to Biotrue MPS and continued to use habitual CL types with the new MPS for 2 weeks. Subjects completed an online satisfaction questionnaire at baseline and after 2 weeks to assess the change in symptoms and the intent to drop out of CL wear. Six months after completion of the initial study, a follow-up survey was administered to a subset of the initial participants.Results: A total of 153 daily wear (silicone hydrogel and hydrogel subjects completed this 2-week study with Biotrue MPS. When measuring those with the highest propensity to drop out of lens wear (n=93 after switching to Biotrue MPS, 90% of subjects significantly reduced their likelihood of dropping out of CL wear (P<0.0001. Online interviews were conducted with 73 of the study participants 6 months after completion of the initial study. A total of 93% of participants responded that they were still wearing CLs at least once per week. Of the 7% of respondents who were not currently wearing lenses 6 months after the initial study, two had dropped out of lens wear completely, and three still wore lenses less than once per week.Conclusion: Patients intending to drop out of CL wear due to discomfort and dryness significantly reduced their propensity of discontinuing lens wear following use of Biotrue MPS. Six months after completion of the study, 93% of patients were still wearing CLs at least once per

  4. Wettability conundrum: Discrepancies of soft contact lens performance in vitro and in vivo

    Science.gov (United States)

    Svitova, T. F.; Lin, M. C.

    2011-08-01

    The recognition and appreciation of soft contact lenses as simple, efficient and aesthetically gratifying vision-correction devices is ever growing, especially among younger population. Stable thin tear film uniformly spread over corrective lens surface is essential for acute vision, and also for comfortable and safe contact lens wear. The significant efforts have been invested by the contact lens industry to develop soft lens surface that is completely wet by tear aqueous in the ocular environment. Number of the publications dedicated to the wettability properties of the soft hydrogel lenses is on the steady rise. However, the clinical results show that no unambiguous correlation emerges when lens surface wettability in vitro is judged against tear film stability evaluated in vivo. This paper assesses and compares the modern techniques used for evaluation of soft contact lens surface wettability and reports some findings regarding relations between lens surface wettability in vitro and in vivo.

  5. Miniaturized high-resolution wide-field contact lens for panretinal photocoagulation

    Directory of Open Access Journals (Sweden)

    Koushan K

    2014-04-01

    Full Text Available Keyvan Koushan, KV Chalam Department of Ophthalmology, University of Florida College of Medicine, Jacksonville, FL, USA Background and objective: We describe a miniaturized lightweight high-refractive-index panretinal contact lens for diagnostic and therapeutic visualization of the peripheral retina. Instrument design: The miniaturized high-resolution wide-field contact lens includes three optical elements in a light (15 g and miniaturized (16 mm footplate, 24 mm external aperture, and 21 mm vertical height casing contributing to a total dioptric power of +171 diopters. This lens provides up to 165° visualization of the retina for diagnostic and therapeutic applications while allowing easier placement due to its miniaturization. Conclusion: This new lens (50% lighter and 89% smaller improves upon earlier contact lenses for visualization of the peripheral retina. Keywords: contact lens, panretinal photocoagulation, retinal examination, peripheral retina, high resolution view, wide-angle lens, lens

  6. Thin Film Evolution Over a Thin Porous Layer: Modeling a Tear Film on a Contact Lens

    Science.gov (United States)

    Anderson, Daniel; Nong, Kumnit

    2010-11-01

    We examine a mathematical model that describes the behavior of the pre-contact lens tear film of a human eye. Our work examines the effect of contact lens thickness and lens permeability and slip on the film dynamics. A mathematical model for the evolution of the tear film is derived using a lubrication approximation applied to the hydrodynamic equations of motion in the fluid film and the porous layer. The model is a nonlinear fourth order partial differential equation subject to boundary conditions and an initial condition for post-blink film evolution. We find that increasing the lens thickness, permeability and slip all contribute to an increase in the film thinning rate although for parameter values typical for contact lens wear these modifications are minor. The presence of the contact lens can, however, fundamentally change the nature of the rupture dynamics as the inclusion of the porous lens leads to rupture in finite time rather than infinite time.

  7. Contact lens surface changes after exposure to surfactant and abrasive cleaning procedures.

    Science.gov (United States)

    Doell, G B; Palombi, D L; Egan, D J; Huff, J W

    1986-06-01

    Proper lens maintenance is required if contact lens wear is to be successful. Poor compliance or inadequate cleaning may lead to contact lens failures and potentially damage to the eye. With phase contrast microscopy, we addressed the effect of cleaning systems on the physical integrity of a surface-modified lens--the Silcon contact lens. Several cleaners were evaluated for their ability to clean Silcon lenses with minimal damage to the lens surface. The data demonstrated that: all cleaning techniques alter the surface appearance; scratches develop more readily on lenses received with surface irregularities; wettability does not correlate with the extent of surface scratching; recommended cleaning procedures do not directly alter the wettability of the contact lens material; and phase contrast microscopy may be a useful addition to laboratory quality control.

  8. Associations with Meibomian Gland Atrophy in Daily Contact Lens Wearers.

    Science.gov (United States)

    Pucker, Andrew D; Jones-Jordan, Lisa A; Li, Wing; Kwan, Justin T; Lin, Meng C; Sickenberger, Wolfgang; Marx, Sebastian; Srinivasan, Sruthi; Jones, Lyndon W

    2015-09-01

    To determine associations for contact lenses (CLs) and meibomian gland atrophy in a matched-pair study. Contact lens wearers (case) and age- and sex-matched non-contact lens (NCL) wearers with no history of CL use (control) were recruited for a multicenter study. All subjects were administered the Ocular Surface Disease Index questionnaire and a comprehensive battery of clinical tests (e.g., tear breakup time, bulbar and limbal redness, meibography, etc.) were performed. Upper and lower eyelid meibomian gland atrophy were graded with both digital meibography (percent gland atrophy) and visual meiboscore methods. Conditional logistic regression analyses were then used to determine relationships among CL use, meibomian gland atrophy, and ocular surface signs and symptoms. A total of 70 matched pairs were analyzed. The mean (± SD) age of the CL group was 30.6 (± 12.4) years, and that of the NCL group was 30.1 (± 12.2) years. The subjects were 63% female. The association between CL wear and meiboscore was not significant univariately, but the best-fitting multivariate regression model showed that higher meiboscores were associated with being a CL wearer (odds ratio [OR], 2.45) in a model that included eyelid margin erythema (OR, 0.25) and lissamine green staining (OR, 1.25). Percent gland atrophy was not associated with CL wear in regression analysis (p = 0.31). This study determined inconclusive associations with CLs and meibomian gland atrophy. This study also provided a comprehensive assessment of differences between CL and NCL wearers.

  9. Lens material and formulation of multipurpose solutions affects contact lens disinfection.

    Science.gov (United States)

    Santos, Lívia; Oliveira, Rosário; Oliveira, M Elisabete C D Real; Azeredo, Joana

    2011-08-01

    To assess the disinfection efficacy of multipurpose solutions (MPS) against different bacterial species adhered either to silicon hydrogel or to conventional hydrogel contact lenses (CLs). The influences of the MPS formulation and the chemical composition of the lens material were investigated. This investigation followed the standard 14729, which establishes the guidelines for assessing CL disinfecting solutions. Two commercially available (Opti-Free(®) Express(®) and Renu(®) Multiplus) solutions and one recalled solution (Complete(®) MoisturePlus™) were used in this study. After disinfection, the number of survivors was estimated by the colony forming units' method. The lens material appears to influence disinfection. The conventional hydrogel polymacon exhibited the highest disinfection scores, a fact that should be related with the lack of electrostatic attraction towards the biocides and its hydrophilicity. The MPS formulation appears to have influence in disinfection efficacy as well. For most adhered bacteria, Opti-Free(®) was capable of reducing cell concentration in 4-log. Disinfection results from multivariate factors and this study confirmed that the lens material and the MPS play a very important role in the disinfection efficacy of CL. Copyright © 2011. Published by Elsevier Ltd.

  10. A novel rat contact lens model for Fusarium keratitis

    Science.gov (United States)

    Abou Shousha, Mohamed; Santos, Andrea Rachelle C.; Oechsler, Rafael A.; Iovieno, Alfonso; Maestre-Mesa, Jorge; Ruggeri, Marco; Echegaray, Jose J.; Dubovy, Sander R.; Perez, Victor L.; Miller, Darlene; Alfonso, Eduardo C.

    2013-01-01

    Purpose The aim of this study was to develop and characterize a new contact lens–associated fungal keratitis rat model and to assess the ability of non-invasive spectral-domain optical coherence tomography (SD-OCT) to detect pathological changes in vivo in fungal keratitis. Methods We used SD-OCT to image and measure the cornea of Sprague Dawley rats. Fusarium infection was initiated in the rat eye by fitting Fusarium solani–soaked contact lenses on the experimental eye, while the control animals received contact lenses soaked in sterile saline. The fungal infection was monitored with periodic slit-lamp examination and in vivo SD-OCT imaging of the rat eye, and confirmed by histology, counting of viable fungi in the infected rat cornea, and PCR with specific primers for Fusarium sp. Results We imaged and measured the rat cornea with SD-OCT. Custom-made contact lenses were developed based on the OCT measurements. Incubation of contact lenses in a F. solani suspension resulted in biofilm formation. We induced contact lens–associated Fusarium keratitis by fitting the rat eyes for 4 h with the Fusarium-contaminated contact lenses. The SD-OCT images of the cornea correlated well with the slit-lamp and histopathological results and clearly defined clinical signs of infection, namely, increased corneal thickening, loss of epithelial continuity, hyper-reflective areas representing infiltrates, and endothelial plaques characteristic of fungal infection. Moreover, in three cases, SD-OCT detected the infection without any clear findings on slit-lamp examination. Infection was confirmed with histological fungal staining, PCR, and microbiological culture positivity. Conclusions We developed a highly reproducible rat contact lens model and successfully induced contact lens–associated Fusarium keratitis in this model. The clinical presentation of contact lens–associated Fusarium keratitis in the rat model is similar to the human condition. SD-OCT is a valuable tool that

  11. Folded bandage contact lens retention in a patient with bilateral dry eye symptoms: a case report.

    Science.gov (United States)

    Ho, Derek K-H; Mathews, John P

    2017-07-04

    Bandage contact lenses are commonly used by ophthalmic practitioners to protect the patient's cornea. We report a case of folded bandage contact lens retained for six and a half years in the upper subtarsal space. To our knowledge, no other cases of retained bandage contact lens have previously been reported in the literature. A patient was applied a pair of bandage contact lenses due to persistent ocular pain secondary to dry eye symptoms. At her subsequent visit, bandage contact lens was removed from her left eye, but none was found in the right eye. Documentation from further visit stated that the bandage contact lenses were no longer in situ. 6.5 years since the lens insertion, lid eversion revealed a 'foreign body' retained beneath her right upper eyelid, which was noted to be a folded, discoloured bandage contact lens. The 'upper fornix trap', where the contact lens may be retained by the upper tarsal edge, presents an anatomical hazard for contact lens users. Moreover, soft contact lenses may be more likely to retain asymptomatically and to fold onto itself compared to hard lenses. Our case report highlights the importance of performing a thorough eye examination, which includes double eversion of the upper eyelids and sweeping of the fornices with cotton buds, and maintaining clinical suspicion of contact lens retention.

  12. [Current quality management situation and administration countermeasure study of enterprises marketing corneal contact lens].

    Science.gov (United States)

    Liu, Yungui; Yao, Ying; Shangguan, Shihao; Gu, Qun; Gao, Wuming; Chen, Yaoshui

    2014-05-01

    Study the current quality management situation of enterprises marketing corneal contact lens via systemic investigations and explore effective administration countermeasures in the future. The quality management indicators of sixty-two corneal contact lens marketing enterprises in Xuhui district of Shanghai were systematically investigated and enterprises of different operation models was compared and analyzed. Wholesale enterprises and retail chain enterprises are apparently better than independent enterprises almost in all facets. Facilitate market accession of corneal contact lens marketing enterprises, encourage the business model of retail chain, enhance supervision of corneal contact lens marketing enterprises, especially independent franchisors.

  13. Contact Lens Compliance With Ophthalmologists and Other Health Professionals.

    Science.gov (United States)

    Taslipinar Uzel, Ayse Guzin; Uzel, Mehmet Murat; Yuksel, Nilay; Akcay, Emine Kalkan

    2017-09-29

    To assess the compliance with contact lens (CL) use among ophthalmologists and other health professionals, and to identify the main noncompliant behaviors. A cross-sectional, comparative study was designed for soft CL wearers. Twenty-five ophthalmologists, 24 medical doctors other than ophthalmologists, 20 nurses (health professionals), and 52 lay people (members of the public) subjects were included in the interview. The compliance rate for each behavior were determined and compared. Users were asked to rate their subjective use to calculate self-evaluation scores. The compliance rate was found to be the highest among ophthalmologists; however, the difference was not significant (P=0.083). Although the level of compliance was not associated with the subjects' age, duration of lens wear, or wearing days per week (P>0.05), an association was found with the number of wearing hours per day (P=0.010). Increased wearing hours per day was found to increase the rate of poor compliance (P=0.010). Significant differences were found between the groups in storing lenses in fresh solution, lens wearing time according to the ophthalmologist recommendation, and follow-up visits according to ophthalmologist recommendation (P<0.001, P=0.036, P=0.001, respectively). Self-evaluation scores among ophthalmologists, health professionals, and the lay people were 7.56±0.86, 7.59±1.29, and 7.67±1.60, respectively, and no significant differences existed between the groups (P=0.930). No differences were evident between the groups in terms of good compliance with CL wear and care practices. As this result shows that compliance with CL wear and care practices is not only related to the level of knowledge, different methods should be developed to increase compliance.

  14. Effects of Contact Lens Wear on Biometry Measurements for Intraocular Lens Calculations.

    Science.gov (United States)

    Meyer, Jay J; Kim, Michelle J; Kim, Terry

    2017-09-21

    To determine the effects of contact lens (CL) wear on biometry measurements for cataract surgery and whether a CL hiatus can reduce the prediction error of intraocular lens (IOL) calculations. Retrospective, interventional case series of eyes that received repeat biometry measurements for IOL calculations after discontinuing hard or soft CLs for at least 14 days. intersession change in axial length, average keratometry, astigmatism, and axis. change in recommended IOL power and toricity, postoperative refraction prediction error. Thirty-two eyes of 16 patients had a mean duration of CL wear (12 hard and 20 soft) of 39.5 years (range, 29-55 years) and mean CL hiatus duration of 25 days (range, 14-56 days). Mean absolute intersession change in axial length was 0.016 mm (range, 0-0.05 mm), average keratometry 0.31 D (range, 0.02-1.01 D), astigmatism 0.41 D (range, 0.01-1.10 D), and axis 6.3° (range, 0-28°). The IOL power predicting the lowest postoperative spherical equivalent changed for 17 of 32 eyes (by 0.5 D for 12 eyes and 1.0 D for five eyes). Recommended IOL toricity changed for nine of 14 eyes (by 0.75 D for six eyes and 1.50 D for three eyes). The median absolute prediction error of IOL calculations was 0.69 D (range, 0.19-2.93 D) before and 0.57 D (range, 0.01-2.82 D) after the CL hiatus (P=0.16). Contact lens wear may affect biometry measurements and subsequent IOL power and toricity selection. For some eyes, repeating biometry measurements after a CL hiatus may improve the accuracy of IOL calculations.

  15. Keratitis Due to Achromobacter xylosoxidans in a Contact Lens User.

    Science.gov (United States)

    Almenara Michelena, Cristina; Del Buey, María Ángeles; Ascaso, Francisco Javier; Cristóbal, Jose Ángel

    2017-03-27

    Ocular infections due to Achromobacter xylosoxidans are extremely uncommon; their diagnosis is a challenge and the optimal treatment remains controversial. We present a case of A. xylosoxidans in a contact lens user and a review of the literature to facilitate diagnostic suspicion and empirical therapeutic management. Review of the literature in PubMed and MEDLINE. We also document a case diagnosed in our department in January 2016. Hospital Clínico Universitario Lozano Blesa, Zaragoza, Spain. According to the literature, clinical manifestations and antibiotic sensitivity of A. xylosoxidans varied greatly. Our patient with no history of keratopathy presented three risk factors that made the diagnosis suspicious. The infection was resolved with topical moxifloxacin and fluorometholone. A. xylosoxidans is an uncommon cause of infection, but must be suspected in atypical keratitis, reported contact with warm or still waters, use of contact lenses, or previous corneal damage. In these cases, microbiological studies and antibiotic sensitivity testing are particularly important.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

  16. Contact lens surveillance cultures in Boston type 1 keratoprosthesis patients.

    Science.gov (United States)

    Rai, Ruju; Shorter, Ellen; Cortina, Maria S; McMahon, Timothy; de la Cruz, Jose

    2013-03-01

    To describe surveillance cultures of bandage contact lenses (BCL) in patients with a history of Boston type 1 keratoprosthesis (KPro) surgery. An institutional review board-approved retrospective review of patients with a history of Boston type 1 KPro surgery and BCL cultures between July 2008 and June 2010. Data on demographics, preoperative diagnosis, topical corticosteroid and antibiotic use, duration of BCL wear, clinical diagnosis of microbial keratitis or endophthalmitis, and culture results were recorded. There were 14 patients (15 eyes) who underwent Boston type 1 KPro between July 2008 and June 2010 with BCL culture data. Ten eyes showed positive growth and one eye developed an infection. Thirty-four cultures were performed and 12 were positive. The most common organism cultured was coagulase-negative staphylococcus (CoNS). Positive cultures, colonization by non-CoNS pathogens, and infection occurred more frequently in patients with an ocular history of autoimmune disease or chemical burn. The growth of 15 or more CoNS colonies occurred only in patients not on vancomycin. An antibiotic was added to the regimen in response to positive cultures for three patients. Contact lens surveillance cultures may provide valuable information on the characteristics of microbial colonization, particularly in highlighting inflammatory disease and disuse of vancomycin as possible risk factors. Bandage contact lenses cultures also have the potential to be useful adjuncts in the clinical management of antibiotic therapy.

  17. Continuous wear contact lens surface chemistry and wearability.

    Science.gov (United States)

    Nicolson, Paul C

    2003-01-01

    Continuous wear (CW) contact lenses are defined as lenses composed of hydrogel polymers containing elements other than carbon, hydrogen, oxygen, and nitrogen that enhance oxygen permeability to an extent greater than water alone. Those elements are silicon and fluorine. Silicon is incorporated as siloxanes, and fluorine is used as fluoroalkyl. Despite the water present in CW lenses, they are not wearable without surface modification because of the tendency of siloxanes and fluoroakyls to move in the soft polymers, orient, and become enriched at the surface. Various methods of surface modification are discussed, with emphasis on the plasma technologies used by the two commercial CW lens products, Focus Night & Day and PureVision. Speculation about future directions in surface chemistry are also presented.

  18. Survival of Acanthamoeba in contact lens rinse solutions.

    Science.gov (United States)

    Nauheim, R C; Brockman, R J; Stopak, S S; Turgeon, P W; Keleti, G; Roat, M I; Thoft, R A

    1990-10-01

    Acanthamoeba may cause a severe keratitis in contact lens wearers. Since most sterilization techniques require rinsing the lenses prior to insertion, contaminated solutions represent a potential vector for transmission of Acanthamoeba. The ability of rinse solutions to sustain an inoculum of Acanthamoeba polyphaga was investigated. A. polyphaga was exposed to 0.1% benzalkonium chloride, 0.001% thimerosal/0.1% edetate disodium, 0.1% edetate disodium, saline, tap water, and distilled water. The status of the organism was evaluated with direct microscopic counts and cultures to confirm viability. Incubation with 0.1% edetate disodium, saline, tap water, and distilled water resulted in the maintenance of reduced populations of viable organisms for 7 days. Benzalkonium chloride preserved saline and solutions containing thimerosal with edetate rendered the Acanthamoeba nonviable.

  19. A comparison of spectacle and contact lens wearing times in the ACHIEVE study.

    Science.gov (United States)

    Jones-Jordan, Lisa A; Chitkara, Monica; Coffey, Bradley; Jackson, John Mark; Manny, Ruth E; Rah, Marjorie J; Walline, Jeffrey J

    2010-05-01

    The aim was to compare vision correction wearing time between myopic children and teenagers in a clinical trial of contact lenses and spectacles. Parents of subjects in the Adolescent and Child Health Initiative for Vision Empowerment (ACHIEVE) study provided wearing times for spectacle and contact lens wear. Hours wearing primary correction and total correction were compared between the two treatment groups. Other factors hypothesised to be associated with wearing time were analysed. The average wearing time of the primary correction differed significantly with the wearing time for the spectacles group being 91.5 hours per week compared to 80.3 hours per week for the contact lens wearers (p lenses less than young spectacle wearers and older contact lens wearers. Low scores on an appearance quality-of-life scale were associated with longer wearing time in spectacle wearers compared to the low- and high-scoring contact lens wearers. Gender, spectacle satisfaction and activities were not related to wearing time. While contact lens wearers, on average, wear their contact lenses less than spectacle wearers, they spend roughly the same amount of time wearing a refractive correction. Higher refractive error resulted in longer wearing times for both spectacle and contact lens wearers. Younger contact lens wearers wore their contact lenses for shorter periods than the spectacle wearers, but still wore them, on average, 74.4 hours per week (about 10 hours per day), suggesting that contact lenses are a viable alternative mode of correction for children.

  20. An Evaluation of the Softperm Contact Lens in the Simulated Aircraft Environment

    Science.gov (United States)

    1991-01-01

    anisometropia , or irregular corneal topography. 148 TABLE 2 Disadvantages of Contact Lenses 1. Not tolerated by all individuals. Adjustment period required...215 iv LIST OF TABLES TABLE PAGE 1. Advantages of contact lenses ..................... 147 2. Disadvantages of contact ...more complex, contact lens wear by military aviators has become a more attractive option for the correction of refractive error. Contact lenses are

  1. Clinical research on high oxygen permeable contact lens used after photorefractive keratectomy surgery

    Directory of Open Access Journals (Sweden)

    Hao-Jiang Yang

    2013-07-01

    Full Text Available AIM: To evaluate the outcome of high oxygen permeable contact lens used after photorefractive keratectomy(PRKsurgery.METHODS: Totally 95 patients(190 eyesafter PRK were included. Patients were randomly assigned to wear high oxygen permeable contact lens in one eye and normal lens in the fellow eye after surgery. The subjective symptoms and corneal epithelial status after PRK were evaluated. Uncorrected visual acuity(UCVAand haze were assessed at 6 months after PRK.RESULTS: Complaints of blurred vision, pain and photophobia were statistically more among the normal lens group than high oxygen permeable contact lens group(PPP=0.35. There was no difference in UCVA and haze 6 months after surgery(P=0.55. CONCLUSION: High oxygen permeable contact lens can significantly produce less the corneal irritated symptoms, reduce the discomfort feeling and promote healing of corneal epithelium after PRK.

  2. [Feasibility Research of Determined Oxygen Permeability of Finished Soft Contact Lens].

    Science.gov (United States)

    Wen, Yan; Zheng, Jian; Fang, Honqping; Jia, Xiaohang; He, Tao; Qi, Weiming

    2015-03-01

    A method for determined oxygen permeability (Dk) of finished soft contact lens. Oxygen permeability(Dk) of 10 group finished soft contact lens was determined by polarographic method, and the values were linearly calibrated using the measured and established Dk values of the specified reference materials. Only one Dk value fell outside of the requirement of GB 11417.3-2012 tolerance for Dk (± 20%). It is great practicability when determined the oxygen permeability (Dk) of finished soft contact lens by polarographic method which were linearly calibrated using the measured and established Dk values of the specified equal thickness reference materials without the measured lens customized 4 different thickness.

  3. Non-compliance with contact lens wear and care practices: a comparative analysis.

    Science.gov (United States)

    Robertson, Danielle M; Cavanagh, H Dwight

    2011-12-01

    To compare the effects of existing patient awareness of lens-related complications and underlying risk factors on actual patient behavior during contact lens wear and care practices in two different clinical study populations. Established contact lens wearers (n = 281) completed an anonymous written questionnaire on presenting to their habitual eye care practitioner in the Dallas-Fort Worth metroplex. Data were analyzed and compared against a second study population, which comprised established contact lens wearers (n = 152) who were sequentially evaluated after their routine contact lens examination at the University of Texas Southwestern Medical Center at Dallas, TX (UTSW). All patients were questioned regarding his or her lens care practices and knowledge of complications and risk factors associated with contact lens wear. Fifty-eight percent of patients in the general community could identify by name a complication associated with lens wear compared with 91% within the medical center. The most frequent complications reported were related to comfort and handling (72%, Dallas-Fort Worth) and infection (47%, UTSW). The majority of patients could correctly identify risk factors associated with lens-related complications; awareness for topping-off solutions, tap water exposure, and hygiene varied between groups. Overall, 85% of patients perceived themselves as compliant with their lens wear and care practices. Using a standard scoring model to determine actual compliance, 2% of patients demonstrated good compliance; however, only 0.4% of patients were fully compliant with contact lens wear and care practices. The data reveal some study bias in complication and risk awareness between populations; however, despite this limitation, a significant proportion of patients exhibited actual non-compliant behavior despite acknowledged awareness of risk. Although most patients consider themselves to be complying with standard practitioner guidelines for lens wear and care

  4. Giant papillary conjunctivitis in frequent-replacement contact lens wearers: a retrospective study.

    OpenAIRE

    Donshik, P C; Porazinski, A D

    1999-01-01

    PURPOSE: A retrospective study was done of 47 patients who wore frequent-replacement contact lenses on a daily basis and replaced them every 1 day to 12 weeks. The incidence of giant papillary conjunctivitis (GPC) was determined, and potential risk factors that may predispose frequent-replacement contact lens wearers to develop GPC were assessed. METHODS: The records of patients who were fitted with frequent-replacement contact lenses with no prior contact lens experience (September 1993 to F...

  5. Folded bandage contact lens retention in a patient with bilateral dry eye symptoms: a case report

    OpenAIRE

    Ho, Derek K.-H.; Mathews, John P.

    2017-01-01

    Background Bandage contact lenses are commonly used by ophthalmic practitioners to protect the patient?s cornea. We report a case of folded bandage contact lens retained for six and a half years in the upper subtarsal space. To our knowledge, no other cases of retained bandage contact lens have previously been reported in the literature. Case presentation A patient was applied a pair of bandage contact lenses due to persistent ocular pain secondary to dry eye symptoms. At her subsequent visit...

  6. Efficacy of Toric Contact Lenses in Fitting and Patient-Reported Outcomes in Contact Lens Wearers.

    Science.gov (United States)

    Cox, Stephanie M; Berntsen, David A; Bickle, Katherine M; Mathew, Jessica H; Powell, Daniel R; Little, B Kim; Lorenz, Kathrine Osborn; Nichols, Jason J

    2017-09-21

    To assess whether patient-reported measures are improved with soft toric contact lenses (TCLs) compared with soft spherical contact lenses (SCLs) and whether clinical time needed to fit TCL is greater than SCL. Habitual contact lens wearers with vertexed spherical refraction +4.00 to +0.25 D or -0.50 to -9.00 D and cylinder -0.75 to -1.75 DC were randomly assigned to be binocularly fitted into a TCL or SCL, and masked to treatment assignment. Time to successful fit was recorded. After 5 days, the National Eye Institute Refractive Error Quality of Life Instrument (NEI-RQL-42) and modified Convergence Insufficiency Symptom Survey (CISS) were completed. After washout, subjects were fit into the alternative lens design (TCL or SCL). Outcomes were evaluated using linear mixed models for the time to fit and CISS score, generalized linear model for the successful fit, and Wilcoxon tests for the NEI-RQL-42. Sixty subjects (71.7% women, mean age [±SD] = 27.5±5.0 years) completed the study. The mean time to fit the TCL was 10.2±4.3 and 9.0±6.5 min for the SCL (least square [LS] mean difference (TCL-SCL)=1.2, P=0.22). Toric contact lens scored better than SCL in global NEI-RQL-42 score (P=0.006) and the clarity of vision (P=0.006) and satisfaction with correction subscales (P=0.006). CISS showed a 15% reduction in symptoms (LS mean difference [TCL-SCL]=-2.20, P=0.02). TCLs are a good option when trying to improve the vision of patients with low-to-moderate astigmatism given the subjective improvements in outcomes.

  7. Surface thermodynamics and adhesion forces governing bacterial transmission in contact lens related microbial keratitis

    NARCIS (Netherlands)

    Qu, Wenwen; Busscher, Henk J.; Hooymans, Johanna M. M.; van der Mei, Henny C.

    2011-01-01

    Contact lens induced microbial keratitis results from bacterial transmission from one surface to another. We investigated the adhesion forces of Pseudomonas aeruginosa, Staphylococci and Serratia to different contact lenses, lens cases and corneal surfaces using AFM, and applied a Weibull analysis

  8. 21 CFR 800.12 - Contact lens solutions and tablets; tamper-resistant packaging.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Contact lens solutions and tablets; tamper-resistant packaging. 800.12 Section 800.12 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL Requirements for Specific Medical Devices § 800.12 Contact lens solutions and tablets; tampe...

  9. 21 CFR 886.5918 - Rigid gas permeable contact lens care products.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rigid gas permeable contact lens care products. 886.5918 Section 886.5918 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5918 Rigid gas permeable contact lens care products. (a)...

  10. 21 CFR 886.5928 - Soft (hydrophilic) contact lens care products.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Soft (hydrophilic) contact lens care products. 886.5928 Section 886.5928 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5928 Soft (hydrophilic) contact lens care products. (a)...

  11. Presumed corneal intraepithelial neoplasia associated with contact lens wear and intense ultraviolet light exposure.

    OpenAIRE

    Guex-Crosier, Y.; Herbort, C P

    1993-01-01

    Corneal intraepithelial neoplasia (CIN) is a rare dysplastic process affecting mostly elderly fair-skinned people. A variant of the disease associated with contact lens wear was recently described. The three cases reported here had a history of contact lens wear together with strong ultraviolet light exposure. These two conditions may represent a serious risk factor for the development of CIN.

  12. Incidental discovery of circle contact lens by MRI: you can't scan my poker face, circle contact lens as a potential MRI hazard.

    Science.gov (United States)

    Tokue, Hiroyuki; Taketomi-Takahashi, Ayako; Tokue, Azusa; Tsushima, Yoshito

    2013-03-25

    Circle contact lenses, also known as color contact lenses and big eye contact lenses, are a type of cosmetic contact lens. It is not generally known that a circle contact lens usually contains iron oxide and other metals, which means their use during magnetic resonance imaging (MRI) is a potential hazard. We present a rare case of incidental discovery of circle contact lenses by MRI and MRI images of circle lenses in vitro. Circle contact lenses usually contain iron oxide, which is a known source of susceptibility artifact on MRI. Not only radiologists and radiographers but also referring physicians should be familiar with the imaging findings and potential risk of scanning circle contact lenses by MRI.

  13. Incidental discovery of circle contact lens by MRI: you can’t scan my poker face, circle contact lens as a potential MRI hazard

    Science.gov (United States)

    2013-01-01

    Background Circle contact lenses, also known as color contact lenses and big eye contact lenses, are a type of cosmetic contact lens. It is not generally known that a circle contact lens usually contains iron oxide and other metals, which means their use during magnetic resonance imaging (MRI) is a potential hazard. Case presentation We present a rare case of incidental discovery of circle contact lenses by MRI and MRI images of circle lenses in vitro. Conclusions Circle contact lenses usually contain iron oxide, which is a known source of susceptibility artifact on MRI. Not only radiologists and radiographers but also referring physicians should be familiar with the imaging findings and potential risk of scanning circle contact lenses by MRI. PMID:23530981

  14. Self-evaluation of contact lens wearing and care by college students and health care workers.

    Science.gov (United States)

    de Oliveira, Paulo Ricardo; Temporini-Nastari, Edméa Rita; Ruiz Alves, Milton; Kara-José, Newton

    2003-07-01

    To identify perceptions related to the wear and care and of contact lenses and self-evaluation of the knowledge regarding their cleaning and disinfection. A survey was conducted by interviewing contact lens wearers among health care workers at a university hospital. Two hundred one contact lens wearers were interviewed. The average age was 23.5 years; 69.2% were female and 71.1% were college students. Approximately 55% did not consider themselves good wearers and declared as the main reason the inadequate maintenance of the contact lenses and their cases. Regarding contact lens care, 79.1% of respondents admitted not performing it correctly. Although the interviewees were health care workers, their self-evaluation regarding contact lens care showed unsatisfactory knowledge and practices related to the use and care of contact lenses.

  15. Success of Rigid Gas Permeable Contact Lens Fitting.

    Science.gov (United States)

    Ortiz-Toquero, Sara; Martin, Mario; Rodriguez, Guadalupe; de Juan, Victoria; Martin, Raul

    2017-05-01

    To assess the percentage of successful rigid gas permeable (GP) contact lenses (CLs) fit for both refractive and therapeutic reasons. New CLs (soft or GP) fittings were retrospectively analyzed and divided into refractive and therapeutic prescriptions. A standardized fitting protocol that included complete CLs information after a first eye examination, a diagnostic fitting visit, a dispensing visit, and a prescribing visit was used in all fittings. A GP fitting was defined as successful if full-time wear and optimal ocular surface physiology were both achieved at the review assessment 2 to 3 weeks after lens dispensing. Of 232 new CLs fittings analyzed, 166 were refractive fittings (71.6%) and 66 were therapeutic (28.4%). Of the refractive fittings, 88 subjects (53%) were initially fitted with GP CLs and 61 (69.3%) of these met the criteria for successful GP fitting. Within this group, a different percentage of successful fits were found for neophyte (72%), previous soft lens wearers (62%), and previous GP wearers (92.3%). Of the therapeutic fittings, 61 subjects (92.4%) were initially fitted with GP CLs and 59 (96.7%) of these met the criteria for successful GP fitting. Following a standardized CLs fitting protocol, a relatively high percentage of successful GP fits was achieved for refractive (7/10 subjects) and therapeutic (9/10 subjects) prescriptions. These results will improve the information available to patients and aid in their CL choices by providing them with a realistic attitude. It will also help eye care practitioners in their clinical activities by providing evidence-based information.

  16. Comparison of corneal thickness of long-term contact lens wearers for different types of contact lenses.

    Science.gov (United States)

    Iskeleli, Guzin; Onur, Umut; Ustundag, Can; Ozkan, Sehirbay

    2006-09-01

    To compare the central corneal thickness (CCT) values of long-term wearers of different types of contact lenses with those of each other and a normal control group. Twenty-three healthy eyes with no history of contact lens wear were used for the control group. Forty-eight eyes were evaluated in four different groups according to the type of contact lens worn; each group comprised 12 eyes. Group 1 (SofLens 38) and group 2 (Contact Day 30) had worn daily-wear frequent-replacement soft contact lenses with a 38% and 55% water content, respectively, and they had worn their lenses for an average of 4.28 +/- 1.70 years and 3.71 +/- 1.11 years, respectively. Group 3 (Wöhlk A90) and group 4 (Conflex-air) had worn daily-wear rigid gas-permeable (RGP) contact lenses with a Dk/t value of 68 and 22, respectively, and they had worn their lenses for an average of 3.00 +/- 0.63 years and 3.25 +/- 1.17 years, respectively. CCT values in micrometers were measured by optical coherence tomography. When comparing the CCT between the control group and the contact lens groups, the CCT was significantly thinner in the group wearing Conflex-air RGP contact lenses with a low Dk/t value (P = 0.010). In comparing the CCT among the four contact lens groups, the CCT was significantly thinner in the group wearing SofLens 38 contact lenses with a water content of 38% than in the group wearing Contact Day 30 contact lenses with a water content of 55% (P = 0.004). There was also significant thinning in the group wearing Conflex-air RGP contact lenses versus the group wearing Contact Day 30 soft contact lenses (P = 0.0005). CCT was significantly thinner in patients wearing long-term low-Dk/t RGP contact lenses compared to no contact lens wear and soft contact lenses with a water content of 55%. CCT was also decreased significantly in long-term soft contact lens wear with a water content of 38% compared to 55%.

  17. [Study and prevention of contact lens-related microbial keratitis with a standardized questionnaire].

    Science.gov (United States)

    Sauer, A; Abry, F; Berrod, J-P; Bron, A; Burillon, C; Chiquet, C; Colin, J; Creuzot-Garcher, C; Delbosc, B; Hoffart, L; Kodjikian, L; Labetoulle, M; Malet, F; Merle, H; Robert, P-Y; Vabres, B; Beynat, J; Brisard, M; Combey de Lambert, A; Donnio, A; Gendron, G; Pagot, R; Saleh, M; Gaucher, D; Speeg-Schatz, C; Bourcier, T

    2010-12-01

    microbial keratitis is a significant health concern for the one million wearers of contact lenses and their ophthalmologists, with some potentially modifiable risk factors. The number of risk factors for contact lens-related microbial keratitis has been described, but many of them still remain assumed or unknown. a multicenter prospective case-control study was conducted in 12 French university hospitals (Besançon, Bordeaux, Dijon, Fort-de-France, Grenoble, Limoges, Lyon, Nancy, Nantes, Paris, Marseille and Strasbourg) beginning in July 2007 on contact lens wearers presenting with microbial keratitis and on healthy contact lens wearers. Patients and healthy wearers were interviewed using a 51-item anonymous standardized questionnaire to determine subject demographics and contact lens wear history. two hundred and fifty-six patients with microbial keratitis were included. One hundred and thirteen healthy contact lenses wearers were surveyed. Cosmetic contact lens wear highly increased the relative risk (RR) of microbial keratitis (RR, 16.5). Time since the last visit to an ophthalmologist longer than 1 year (RR, 3.4) or prescription by someone other than an ophthalmologist (RR, 7.6) also increased the risk of microbial keratitis. Education on lens care and handling was deficient (hand washing: RR, 2.2; rub and rinse: RR, 2.7). a standardized questionnaire is a powerful tool to determine risk factors for contact lens-related microbial keratitis, but also to analyze individual mistakes in contact lenses use and care. 2010 Elsevier Masson SAS. All rights reserved.

  18. Status of the effectiveness of contact lens disinfectants in Malaysia against keratitis-causing pathogens.

    Science.gov (United States)

    Abjani, Farhat; Khan, Naveed Ahmed; Jung, Suk Yul; Siddiqui, Ruqaiyyah

    2017-09-15

    The aim of this study was (i) to assess the antimicrobial effects of contact lens disinfecting solutions marketed in Malaysia against common bacterial eye pathogens and as well as eye parasite, Acanthamoeba castellanii, and (ii) to determine whether targeting cyst wall would improve the efficacy of contact lens disinfectants. Using ISO 14729 Stand-Alone Test for disinfecting solutions, bactericidal and amoebicidal assays of six different contact lens solutions including Oxysept(®), AO SEPT PLUS, OPTI-FREE(®) pure moist(®), Renu(®) fresh™, FreshKon(®) CLEAR and COMPLETE RevitaLens™ were performed using Manufacturers Minimum recommended disinfection time (MRDT). The efficacy of contact lens solutions was determined against keratitis-causing microbes, namely: Pseudomonas aeruginosa, Methicillin-resistant Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, and Acanthamoeba castellanii. In addition, using chlorhexidine as an antiamoebic compound and cellulase enzyme to disrupt cyst wall structure, we determined whether combination of both agents can enhance efficacy of marketed contact lens disinfectants against A. castellanii trophozoites and cysts, in vitro. The results revealed that all contact lens disinfectants tested showed potent bactericidal effects exhibiting 100% kill against all bacterial species tested. In contrast, none of the contact lens disinfectants had potent effects against Acanthamoeba cysts viability. When tested against trophozoites, two disinfectants, Oxysept Multipurpose and AO-sept Multipurpose showed partial amoebicidal effects. Using chlorhexidine as an antiamoebic compound and cellulase enzyme to disrupt cyst wall structure, the findings revealed that combination of both agents in contact lens disinfectants abolished viability of A. castellanii cysts and trophozoites. Given the inefficacy of contact lens disinfectants tested in this study, these findings present a significant concern to public health. These

  19. Exploring the links between contact lens comfort, osmolarity and lid wiper staining.

    Science.gov (United States)

    Stahl, Ulrike; Jalbert, Isabelle

    2017-09-19

    Contact lens discomfort remains poorly understood, not least due to lack of associations between clinical signs and symptoms. This study aimed to explore the relationships between osmolarity, comfort and lid wiper epitheliopathy in contact lens wear. Twenty subjects participated in a randomized, cross-over study where comfilcon A and lotrafilcon A lenses were each worn for 10days separated by a 7days washout period. Tear and contact lens osmolarity, ocular symptoms including comfort, tear stability and production, and lid wiper epitheliopathy were measured. Comfort and tear stability decreased and upper lid wiper staining and foreign body sensation increased with lens wear. These were not affected by lens type. A reduction in tear production was seen after 10days of comfilcon A lens wear. High proportions of lid wiper epitheliopathy were observed at the upper (range 65%-85%) and lower (range 90%-100%) lid margins. Tear and contact lens osmolarity were unaffected by lens wear or type. Contact lens osmolarity was associated with comfort (r=0.45, p=0.009). Tear osmolarity moderately correlated with tear stability (r=-0.53, p=0.014) and tear production (r=-0.44, p=0.012) but not with lid wiper staining. A relationship between comfort and contact lens osmolarity and between tear osmolarity and tear stability and production were found, however, this study was unable to demonstrate an association between comfort and tear osmolarity or lid wiper epitheliopathy. Further studies using contact lenses with a wider range of comfort responses are warranted to investigate these associations further. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  20. Bacterial and fungal biofilm formation on contact lenses and their susceptibility to lens care solutions.

    Science.gov (United States)

    Kackar, Siddharth; Suman, Ethel; Kotian, M Shashidhar

    2017-01-01

    Microbial biofilm formation on contact lenses and lens storage cases may be a risk factor for contact lens-associated corneal infections. Various types of contact lens care solutions are used to reduce microbial growths on lenses. The present study aimed at comparing the growths of biofilms on the different contact lenses and lens cases. The study also aimed at determining the effect of lens care solutions and bacteriophage on these biofilms. One type of hard lens and two types of soft lenses were used for the study. The organisms used were Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Candida albicans ATCC 60193 and Escherichia coli ATCC 25922. Biofilm production was performed by modified O'Toole and Kolter method and effect of lens cleaning solutions and a crude coliphage on biofilms was also studied. Results were visualised using scanning electron microscopy and quantitated by colony counting method and spectrophotometric measurement of optical density (OD). Statistical analysis was done by SPSS 11.5, Kruskal-Wallis test and Chi-square test. Soft lens cleaning solutions had a significant inhibitory effect (P = 0.020) on biofilm formation on soft lenses and also lens cases (P contact lenses.

  1. Risk factors for contact lens-related microbial keratitis in Singapore.

    Science.gov (United States)

    Lim, C H L; Carnt, N A; Farook, M; Lam, J; Tan, D T; Mehta, J S; Stapleton, F

    2016-03-01

    To investigate independent risk factors for contact lens-related microbial keratitis in Singapore and estimate their impact on disease load. Cases were contact lens wearers presenting to Singapore National Eye Centre with microbial keratitis between 2008 and 2010. Community contact lens wearers were recruited as controls. All wearers completed a previously validated questionnaire describing contact lens wear history, hygiene and compliance habits, and demographics. Risk factors significant in univariate analysis (Pcontact lens wear (less often than one night per week) was associated with a 4 × higher risk (95% CI: 1.2-15.4, P=0.03) compared with daily use. Not washing hands before handling was associated with a 13 × increased risk (95% CI: 1.9-84.8, P=0.008). Use of multipurpose solution A carried a 16 × higher risk compared with hydrogen peroxide (95% CI: 1.5-174.0, P=0.02). The combined PAR% for modifiable risk factors (occasional overnight wear, not washing of hands, and MPS A) was 82%. Consistent with previous findings, independent risk factors for contact lens-related microbial keratitis include poor hand hygiene, occasional overnight wear, and type of lens care solution. Prolonged overnight or extended contact lens use was infrequent in this population.

  2. The Risk of Contact Lens Wear and the Avoidance of Complications

    Directory of Open Access Journals (Sweden)

    Farihah Tariq

    2013-11-01

    Full Text Available Contact lenses are lenses placed on the surface of the cornea to correct refractive errors such as myopia (short-sightedness, hypermetropia (far-sightedness and astigmatism. Lens-related complications are becoming a greater health concern as increasing number of individuals are using them as an alternative to spectacles. Contact lenses alter the natural ocular environment and reduce the efficacy of the innate defences. Although many complications are minor, microbial keratitis is potentially blinding and suspected cases should be rapidly diagnosed and referred to an ophthalmologist for treatment. Several risk factors have been identified with extended wear, poor hand hygiene, inadequate lens and lens-case care being the most significant. Promotion of good contact lens hygiene and practices are essential to reduce the adverse effects of contact lens wear.

  3. Retained soft contact lens masquerading as a chalazion: A case report

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Agarwal

    2013-01-01

    Full Text Available A misplaced contact lens is a common ocular emergency presenting to the eye casualty. We report a case of lost soft contact lens which migrated in the lid and presented 13 years later with symptomatic eye lid swelling. Authors in the past have reported migration and subsequent retention of lost hard lenses in locations such as the superior fornix and eyelid. To the best of our knowledge, misplaced soft contact lens masquerading as a chalazion has not been reported in the literature. Consideration should be given to the possibility of a retained contact lens in a patient with a history of a lost or misplaced lens, and examination of the ocular surface with double eversion of the upper lid should be performed.

  4. Retained soft contact lens masquerading as a chalazion: a case report.

    Science.gov (United States)

    Agarwal, Pankaj Kumar; Ahmed, Taha Y; Diaper, Charles J M

    2013-02-01

    A misplaced contact lens is a common ocular emergency presenting to the eye casualty. We report a case of lost soft contact lens which migrated in the lid and presented 13 years later with symptomatic eye lid swelling. Authors in the past have reported migration and subsequent retention of lost hard lenses in locations such as the superior fornix and eyelid. To the best of our knowledge, misplaced soft contact lens masquerading as a chalazion has not been reported in the literature. Consideration should be given to the possibility of a retained contact lens in a patient with a history of a lost or misplaced lens, and examination of the ocular surface with double eversion of the upper lid should be performed.

  5. Corneal epithelial and aqueous humor acidification during in vivo contact lens wear in rabbits.

    Science.gov (United States)

    Giasson, C; Bonanno, J A

    1994-03-01

    Based on contact lens-induced stromal acidification of the cornea, it has been suggested that the corneal epithelial and endothelial cells also become acidotic during contact lens wear. This alleged acidification may have a role in altered cell appearance and metabolism during contact lens wear. This study investigated the effects of anoxia, carbon dioxide retention, and contact lens gas transmissibility on the epithelial and aqueous humor pH in living rabbits. Epithelial intracellular pH (pHi) and aqueous humor pH were fluorophotometrically measured with a pH sensitive-dye (BCECF) during contact lens wear or exposure to various gas mixtures. Polymethylmethacrylate (PMMA) lens wear acidified epithelial cells by preventing CO2 efflux and by inducing hypoxia. Increasing lens oxygen transmissibility decreased epithelial acidification. After initiation of rigid, gas-permeable (RGP) lens wear or CO2-air exposure, pHi dropped transiently and then recovered partially. This recovery of pHi was not observed during anoxia, whether induced by PMMA lens wear or exposure to 100% N2. The aqueous humor also acidified during PMMA lens wear, a phenomenon not observed during RGP lens wear. Changes in aqueous pH were smaller, slower, and delayed when compared to their epithelial counterparts. Hypoxic contact lens wear acidifies the corneal epithelium and aqueous humor. The aqueous humor pH change indicates a probable endothelial acidification during hypoxic contact lens wear; the pH changes are caused by two separate and additive effects, CO2 retention and hypoxic acidosis. Increases in the oxygen transmissibility of the lens decrease the cellular acidosis, which might minimize cellular complications arising from contact lens wear. We estimate that a lens with an oxygen transmissibility (Dk/L) of 300 x 10(-11) (cm/sec)(ml O2/ml x mm Hg) is needed to prevent epithelial pHi changes in the open eye. In contrast, lenses with Dk/L as low as 18 x 10(-9) (cm/sec)(ml O2/ml x mm Hg) can

  6. Complexity of contact lens fitting following penetrating keratoplasty.

    Science.gov (United States)

    Ho, S K.; Andaya, L; Weissman, B A.

    1999-11-01

    The aim of this study was to quantify the complexity of contact lens (CL) fitting following penetrating keratoplasty (PKP).The CL care of 40 eyes following PKP was analyzed retrospectively and compared to that of 40 age-matched and gender-matched controls. We evaluated the numbers of diagnostic and ordered rigid gas permeable (RGP) CLs, office visits for 6-month follow-up, best spectacle and RGP CL-corrected logMar visual acuities (VAs), and RGP CL success and complication rates. Post-PKP corneas required more diagnostic CLs (p = 0.009), ordered CLs (p = 0.0003), and office visits (p = 0.001) than did controls. Corrected logMAR VAs post-PKP improved from 0.31 +/- 0.31 (mean +/- SD) with spectacles (20/41) to 0.076 +/- 0.19 (20/24) with RGP CLs (p complications; these differences did not reach statistical significance.Post-PKP eyes require more diagnostic CLs, ordered CLs, and professional office visits. They also have greater improvement of VAs with RGPs than normals compared to spectacles. CL wear post-PKP does not statistically increase the rate of CL complications or alter the success rate of CL wear.

  7. Presbyopic and non-presbyopic contact lens opinions and vision correction preferences.

    Science.gov (United States)

    Rueff, Erin M; Bailey, Melissa D

    2017-10-01

    To compare vision correction preferences, refractive error, and gender of non-presbyopes and presbyopes. Adults who wear spectacles or contact lenses completed a survey about refractive correction opinions and refractive error was measured. Of the 304 subjects, 38.2% were presbyopic (≥40 years) and 59.2% were female. Spectacles were the primary vision correction for 78.0% of subjects. Compared to contact lens wearers, the proportion of presbyopes was higher (p=0.006) in spectacle wearers. There was no difference in the proportion of presbyopes and non-presbyopes who have tried contact lenses (p=0.2) or who would prefer to wear contact lenses (p=0.2). In contact lens wearers, there was no difference in the proportion of presbyopes and non-presbyopes with a history of temporary discontinuation (p=0.9). Within the contact lens wearing group, there was no refractive error difference between presbyopes and non-presbyopes (spherical equivalent p=0.6; power vector J0 p=0.5; power vector J45 p=0.4; anisometropia p=0.2). Overall, contact lens wearers were more likely to be female (p=0.004). There was no difference in gender in presbyopic and non-presbyopic contact lens wearers (p=0.5). Presbyopes and non-presbyopes have similar opinions about spectacles and contact lenses. Presbyopes of all refractive errors prefer contact lens correction when good vision and comfort can be achieved. Eye care providers should not assume that presbyopia, refractive error, or gender are factors that preclude a patient from being interested in contact lens wear. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  8. Sunglasses- and photochromic lens-wearing patterns in spectacle and/or contact lens-wearing individuals.

    Science.gov (United States)

    Glavas, Ioannis P; Patel, Sarit; Donsoff, Irene; Stenson, Susan

    2004-04-01

    To determine differences in wearing patterns of sunglasses and/or photochromic lenses in spectacle and contact lens wearers, to assess patient awareness of the indications for the use of tinted lenses, and to identify wearers' lens tint preferences. A total of 100 individuals wearing some combination of contact lenses and spectacles participated in a survey questionnaire composed of 14 questions. Participants were asked if they used sunglasses/photochromic lenses, why they used them, their preferred lens tints, and temporal and seasonal patterns of use. They were also queried on their awareness of the potential adverse effects of ultraviolet radiation (UVR) exposure on the health of the eye and appropriate protective measures. Participants were categorized based on their use of spectacles and/or contact lenses. Demographic characteristics of sex and age were taken into account for the analysis. The data were imported and analyzed using commercial statistical analysis software. A total of 52% of the participants wore spectacles exclusively, while 48% wore some combination of spectacles and contact lenses. In the spectacle group, 36% and 20% wore sunglasses and photochromic lenses, respectively. In the contact lens group, 20% and 10% wore sunglasses and photochromic lenses, respectively. Overall gray was the preferred lens tint, especially in the younger age groups. Summer was the primary season for use of tinted lenses. Approximately one-third of the sample were not aware of the UVR protective properties of their eyewear. A total of 77% believed that UVR could be harmful to the eyes, but only a small percentage of the participants wore sunglasses or photochromic lenses specifically for UVR protection. There was no statistically significant difference (P = 0.07) for preference between sunglasses versus photochromic lenses and in seasonal patterns for tinted lens use among spectacles and contact lens wearers. Spectacle wearers (as well as contact lens wearers) used

  9. Optical quality for keratoconic eyes with conventional RGP lens and simulated, customised contact lens corrections: a comparison.

    Science.gov (United States)

    Jinabhai, Amit; Neil Charman, W; O'Donnell, Clare; Radhakrishnan, Hema

    2012-05-01

    To compare monochromatic aberrations of keratoconic eyes when uncorrected, corrected with spherically-powered RGP (rigid gas-permeable) contact lenses and corrected using simulations of customised soft contact lenses for different magnitudes of rotation (up to 15°) and translation (up to 1mm) from their ideal position. The ocular aberrations of examples of mild, moderate and severe keratoconic eyes were measured when uncorrected and when wearing their habitual RGP lenses. Residual aberrations and point-spread functions of each eye were simulated using an ideal, customised soft contact lens (designed to neutralise higher-order aberrations, HOA) were calculated as a function of the angle of rotation of the lens from its ideal orientation, and its horizontal and vertical translation. In agreement with the results of other authors, the RGP lenses markedly reduced both lower-order aberrations and HOA for all three patients. When compared with the RGP lens corrections, the customised lens simulations only provided optical improvements if their movements were constrained within limits which appear to be difficult to achieve with current technologies. At the present time, customised contact lens corrections appear likely to offer, at best, only minor optical improvements over RGP lenses for patients with keratoconus. If made in soft materials, however, these lenses may be preferred by patients in term of comfort. Ophthalmic & Physiological Optics © 2012 The College of Optometrists.

  10. Bacterial and fungal biofilm formation on contact lenses and their susceptibility to lens care solutions

    Directory of Open Access Journals (Sweden)

    Siddharth Kackar

    2017-01-01

    Full Text Available Background: Microbial biofilm formation on contact lenses and lens storage cases may be a risk factor for contact lens-associated corneal infections. Various types of contact lens care solutions are used to reduce microbial growths on lenses. Objectives: The present study aimed at comparing the growths of biofilms on the different contact lenses and lens cases. The study also aimed at determining the effect of lens care solutions and bacteriophage on these biofilms. Materials and Methods: One type of hard lens and two types of soft lenses were used for the study. The organisms used were Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Candida albicans ATCC 60193 and Escherichia coli ATCC 25922. Biofilm production was performed by modified O'Toole and Kolter method and effect of lens cleaning solutions and a crude coliphage on biofilms was also studied. Results were visualised using scanning electron microscopy and quantitated by colony counting method and spectrophotometric measurement of optical density (OD. Statistical analysis was done by SPSS 11.5, Kruskal–Wallis test and Chi-square test. Results: Soft lens cleaning solutions had a significant inhibitory effect (P = 0.020 on biofilm formation on soft lenses and also lens cases (P < 0.001. Soft lens cleaning solution 2 was more efficient than solution 1. However, no such inhibitory effect was observed with regard to hard lens cleaning solution, but for a significant reduction in the OD values (P < 0.001. There was no significant inhibitory effect by bacteriophages. Conclusion: This study showed the importance of selecting the appropriate lens cleaning solution to prevent biofilm production on contact lenses.

  11. Topographic stability and safety of contact lens use after penetrating keratoplasty.

    Science.gov (United States)

    Gomes, J A; Rapuano, C J; Cohen, E J

    1996-01-01

    We evaluated long-term corneal topographic stability and the safety of contact lens use after penetrating keratoplasty (PK). Over a period of 3 years, we followed 18 patients who had been fit with rigid gas permeable (RGP) contact lenses after PK on the basis of computerized topographic measurements 1.5 mm superior to the visual axis. Computerized corneal topography, keratometry, refraction, visual acuity, slit-lamp examination, and contact lens parameters were recorded at the time of lens fitting and at 3 years follow-up. Comparison between the two times was performed using the paired Student's t test. The ten patients (55.5%) that did not undergo suture removal after initial contact lens fitting and who did not change contact lens type during the follow-up period were considered eligible for topographic and keratometric evaluation. Absolute keratometric astigmatism, average keratometric values, computerized corneal topography measurements 1.5 mm superior to the visual axis, and inferior minus superior measurements did not reveal significant differences over time. Keratometric vector analysis showed a significant change in astigmatism during the study period. Complications observed in the 18 patients included suture infiltrates (two patients), corneal neovascularization (six patients), graft rejection (five patients), transitory punctate epithelial keratitis (eight patients), and giant papillary conjunctivitis (three patients). All were successfully treated topically and with temporary cessation of contact lens wear. RGP contact lens use after PK is safe provided patients are properly fit and followed by the ophthalmologist. Although corneal topographic changes occur, stability remains acceptable.

  12. Prevalence of contact lens related complications in a tertiary eye centre in India.

    Science.gov (United States)

    Nagachandrika, Tumati; Kumar, Uday; Dumpati, Srikanth; Chary, Swathi; Mandathara, Preeji S; Rathi, Varsha M

    2011-12-01

    To determine the prevalence of contact lens related complications in a tertiary eye care centre in India. A retrospective review of the charts of 1255 patients who visited our contact lens clinic during 2001-2004 was conducted. The inclusion criteria included patients of at least 18 years of age, having refractive errors and keratoconus. Exclusion criteria included previous corneal surgeries and pediatric patients. 190 subjects with lens related complications were identified from among 923 patients who were using lenses. The prevalence of contact lens complications was 20.58%. Females with complications were more common (59.47%). The complications were more common in students. The most common complications were contact lens induced papillary conjunctivitis (CLPC) (6.39%), corneal vascularisation (4%), and superficial punctate keratitis (SPK) (3.5%). The total complications were less prevalent in patients wearing rigid gas permeable (RGP) lenses as compared to soft contact lenses. Infectious keratitis was noted in 8 eyes. Pseudomonas aeuroginosa was the most common organism isolated. The average daily wear with RGP lenses was 11.04±3.7h and 10.96±3h with soft contact lens. The highest number of complications was noted in 47.89% patients who were wearing lenses for excess of 11h. The number of patients with complications arising due to sleeping with the lenses was 74 (38.95%). Prevalence of contact lens complications was more in soft contact lens wearers compared to RGP wearers. CLPC was the most common complication followed by vascularisation and SPK. 2011 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  13. Comparison of Contact Lens Corrected Quality of Vision and Life of Keratoconus and Myopic Patients.

    Science.gov (United States)

    Lee, Sunghoon; Jung, Gangwook; Lee, Hyung Keun

    2017-08-26

    To compare and analyze changes in vision quality, subjective symptoms, and psycho-social satisfaction in keratoconus and myopic patients following the wearing of contact lenses. This study enrolled 25 keratoconus and 25 myopic patients with corrected vision over 0.8 according to the Snellen chart due to treatment with contact lenses. Patients were surveyed prior to the wearing of contact lenses, and again after three months of contact lens usage with a questionnaire about quality of vision and life. The changes in visual function, visual symptoms, and psycho-social well-being before and after contact lens usage were analyzed. The keratoconus patients' overall degree of satisfaction was higher than the overall degree of satisfaction of myopic patients, and the motivation for contact lens usage and purpose of contact lens treatment were different in the two groups. Keratoconus patients experienced greater changes in satisfaction, particularly in satisfaction during night activities, short-distance work, and the reading of fine print. Furthermore, they experienced fewer dry eye symptoms but greater foreign body sensations than patients with myopia following treatment with contact lenses. No statistically significant differences in social role functions existed between the two groups. Keratoconus patients had a lower expectation of visual acuity recovery before treatment with contact lenses (Mann-Whitney U-test, p = 0.049) compared to myopic patients, and more anxiety about vision loss following treatment (Wilcoxon signed-rank test, p = 0.018) compared to their level of anxiety about vision loss before treatment with contact lenses. Although the same treatment was applied, keratoconus and myopic patients experienced different types of discomfort and areas of improvement in contact lens corrected vision. Therefore, not only corrected vision, but also subsequent improvement and discomfort outcomes should be considered by patients when choosing contact lens treatment. For

  14. Corneo-scleral limbal changes following short-term soft contact lens wear.

    Science.gov (United States)

    Consejo, Alejandra; Bartuzel, Maciej M; Iskander, D Robert

    2017-10-01

    To assess whether short-term soft contact lens wear alters the anterior eye surface. Twenty-two neophyte subjects wore soft contact lenses for a period of five hours. Topography based corneo-scleral limbal radius estimates were derived from height measurements acquired with a corneo-scleral profilometer. Additionally, central corneal thickness (CCT), anterior chamber depth (ACD), corneal curvature radius (R) and white-to-white (WTW) diameter were acquired with an OCT-assisted biometer. Measurements were obtained without lens wear (baseline), immediately after lens removal following five hours of wear and three hours after lens removal. Short-term soft contact lens wear significantly modifies corneo-scleral limbal radius (mean±SD: 130±74μm, p < 0.001) and the changes are repeatable. In contrast, the WTW diameter and R were not modified. ACD and CCT were significantly affected but no significant correlations were found between the increment of the limbal radius and the decrease in ACD and CCT. Limbal radius increment was reversed three hours after lens removal for 68% of the subjects but the time course of this reversal was not uniform. It is possible to accurately quantify limbal radius changes as a consequence of soft contact lens wear. The increment in the limbal diameter could reach over 0.5mm but that alteration does not correspond to changes in WTW diameter and it was not observable to the examiner using a slit lamp. Assessing topographical limbus after contact lens wear could be a tool to optimize the selection of the contact lens, from the perspective of anterior eye surface changes. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  15. Acanthamoeba keratitis in a non-contact lens wearer with human immunodeficiency virus

    DEFF Research Database (Denmark)

    Hansen, Birgitte Rønde; Kronborg, Gitte

    2003-01-01

    Acanthamoeba keratitis is potentially blinding and often associated with contact lens wearing. A human immunodeficiency virus (HIV)-positive patient, a non-contact lens wearer, presented with keratitis. She experienced a protracted course of disease, characterized by exacerbations and remissions......, and was treated with various topical antibiotics and steroids. 13 months after symptom onset the eye was removed owing to serious scarring of cornea and unbearable pain. Microbiological and histopathological examination of the cornea showed Acanthamoeba. In non-contact lens wearers suffering from Acanthamoeba...

  16. A single-lens polarographic measurement of oxygen permeability (Dk) for hypertransmissible soft contact lenses.

    Science.gov (United States)

    Chhabra, Mahendra; Prausnitz, John M; Radke, Clayton J

    2007-10-01

    A novel polarographic apparatus is described that requires only a single soft contact lens (SCL) to ascertain oxygen permeabilities of hypertransmissible lenses. Unlike conventional methods where a range of lens thickness is needed for determining oxygen permeabilities of SCLs, the apparatus described here requires only a single-lens thickness. This is accomplished by minimizing (or completely eliminating) edge effects, boundary-layer resistances, and lens desiccation in the polarographic apparatus. By taking these effects into account, we measure reliable oxygen permeabilities of hypertransmissible SCLs (i.e., above 100 barrer). Results are reported for nine commercial SCLs ranging in permeability from 9 to 180 barrer. Measured single-lens oxygen permeabilities are in excellent agreement with those claimed by commercial manufacturers. Our new single-lens permeameter provides a reliable, efficient, and economical method for measuring oxygen permeabilities of commercial SCLs. The single-lens method offers a potential international standard for measuring oxygen permeabilities of SCLs up to 250 barrer.

  17. Effect of Three Interventions on Contact Lens Comfort in Symptomatic Wearers: A Randomized Clinical Trial.

    Directory of Open Access Journals (Sweden)

    Maria Navascues-Cornago

    Full Text Available To investigate whether carrying out various interventions part way through the day influences comfort in symptomatic daily disposable (DD contact lens wearers.A subject-masked, randomized, controlled clinical trial was conducted in thirty symptomatic soft lens wearers who wore their habitual DD contact lenses bilaterally for 12 h on two separate days. Five hours after lens application, one of the following three interventions or a control was performed on each eye: replacing the existing lens with a new lens; removing and reapplying the same lens; performing a 'scleral swish'; and no action (control. Comfort scores were recorded using SMS text messages every hour following lens application using a 0 (causes pain to 100 (excellent comfort scale. Comfort scores before lens application, at 6 mins post-application, and at 6 mins post-intervention were also recorded.There was a significant reduction in comfort from pre-lens application to 6 mins post-application for all groups (all p0.05. After the intervention, comfort continued to decline (p<0.0001 with slightly lower mean scores for the control group compared to the new lens group (p = 0.003. Change in comfort relative to pre-intervention (5 h was similar for all groups (p = 0.81. There was no difference in comfort at 12 h between groups (p = 0.83.This work has confirmed that comfort shows a continual and significant decline over a 12-h wearing period in symptomatic DD contact lens wearers. None of the interventions investigated had any significant impact on end-of-day comfort. These data suggest discomfort in lens wearers is more heavily influenced by changes to the ocular environment rather than to the lens itself.Controlled-Trials.com ISRCTN10419752 http://www.controlled-trials.com/ISRCTN10419752.

  18. Compliance and hygiene behaviour among soft contact lens wearers in the Maldives.

    Science.gov (United States)

    Gyawali, Rajendra; Nestha Mohamed, Fathimath; Bist, Jeewanand; Kandel, Himal; Marasini, Sanjay; Khadka, Jyoti

    2014-01-01

    Significant levels of non-compliance and poor hygiene among contact lens wearers have been reported previously from different parts of the world. This survey aimed at identifying the scope of hygiene and non-compliant behaviour of soft contact lens wearers in the Maldives. Established soft lens wearers attending two eye clinics in Male' city, were interviewed in office or via telephone. A set of interviewer-administered questions was used to access the subjective response on compliance and hygiene behaviour (hand and lens case hygiene, water exposure, adherence to lens replacement schedule, dozing and overnight wear, awareness of aftercare visits and reuse of disinfecting solution). Participants were also asked to rate themselves as a contact lens user based on their perceived compliance and hygiene practices. Out of 107 participants, 79 (74.8 per cent) were interviewed in the office and the rest via telephone. The majority of lens wearers were female, office workers and students, with a mean age of 20.64 ± 4.4 years. Mean duration of lens wear was 28.04 ± 8.36 months. Most of them were using spherical lenses (86.9 per cent) on a daily wear basis (96.3 per cent). Major reported forms of non-compliance were poor hand hygiene (60.7 per cent), lack of aftercare awareness (39.3 per cent), water exposure (35.5 per cent) and over-use of lenses (24.3 per cent). While females were more likely to overuse their lenses than males (p hygienic behaviour. A significant number of Maldivian contact lens wearers exhibited poor levels of hygiene and compliance with contact lenses and lens care systems. An effective educational reinforcement strategy needs to be developed to modify lens wearers' non-compliance. © 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.

  19. Tear Cytokine Levels in Contact Lens Wearers With Acanthamoeba Keratitis.

    Science.gov (United States)

    Carnt, Nicole; Montanez, Vicente M; Galatowicz, Grazyna; Veli, Neyme; Calder, Virginia

    2017-07-01

    To determine differences in key tear film cytokines between mild and severe cases of acanthamoeba keratitis (AK) and control contact lens (CL) wearers. This was a prospective study of CL wearers with AK attending Moorfields Eye Hospital and control CL wearers from the Institute of Optometry, London. Basal tear specimens were collected by 10-μL capillary tubes (BLAUBRAND intraMark, Wertheim, Germany), and tear protein levels were measured with a multiplex magnetic bead array (Luminex 100; Luminex Corporation, Austin, TX) for cytokines interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-17A, IL-17E, IL-17F, IL-22, and interferon gamma and with enzyme-linked immunosorbent assay (Abcam, Cambridge, United Kingdom) for CXCL2. Severe cases of AK were defined as having active infection for over 12 months and at least 1 severe inflammatory event. One hundred and thirty-two tear samples were collected from a total of 61 cases (15 severe and 46 mild-moderate) and 22 controls. IL-8, part of the Toll-like receptor 4 cytokine cascade, was found to be expressed at a detectable level more often in cases of AK than in control CL wearers (P = 0.003) and in higher concentrations in severe cases than in milder forms of the disease (z = -2.35). IL-22, part of the IL-10 family, and a proinflammatory Th17 cytokine, was detected more often in severe cases than in milder forms of AK (P < 0.02). Profiling patients with AK during disease shows differences in cytokine levels between severe and milder disease that may inform clinical management. The Toll-like receptor 4 and IL-10/Th17 inflammatory pathways should be included in further investigations of this disease.

  20. Reliability of Blotting Techniques to Assess Contact Lens Water Content.

    Science.gov (United States)

    Cañadas, Pilar; López-Miguel, Alberto; Gómez, Alba; López-de la Rosa, Alberto; Fernández, Itziar; González-García, María J

    2018-02-15

    To determine the reliability of wet and modified dry blotting techniques used in the gravimetric method to assess contact lens (CL) water content (WC), the accuracy of both techniques in comparison with the nominal WC, and also their agreement. We evaluated hydrated and dry CL mass values and WC using the gravimetric method in 440 daily disposable CLs. Samples assessed corresponded to Dailies Total 1, Dailies AquaComfort Plus, 1-Day Acuvue TruEye, and Biotrue ONEday. Back vertex power ranged from +3.00 diopters (D) to -6.00 D. Within-subject coefficient of variation (CVw) and intraclass correlation coefficients were calculated. Bland-Altman analysis was also performed. The modified dry blotting technique yielded significantly (P≤0.0001) higher hydrated CL mass values. The wet blotting technique provided significantly (P≤0.04) better consistency than the modified dry one. Values of CVw for wet and modified dry blotting techniques ranged from 1.2% to 2.1% and from 3.7% to 5.4%, respectively. As for dry CL mass values, CVw values were not significantly different (P≥0.05) between wet (range: 1.1%-1.9%) and dry (range: 1.0%-5.1%) blotting techniques, except for Dailies AquaComfort Plus (P=0.03). Bland-Altman analysis showed poor agreement between the techniques. The wet blotting technique yielded WC values close (around 1%) to nominal ones, in contrast to modified dry blotting technique (≥2.5%). The wet blotting technique is not only more reliable than the modified dry one when obtaining hydrated CL mass but also provides more accurate nominal WC measurements. Agreement between the techniques was poor.

  1. Objective and subjective evaluation of the performance of medical contact lenses fitted using a contact lens selection algorithm

    NARCIS (Netherlands)

    Visser, Esther-Simone; Wisse, Robert P L; Soeters, Nienke; Imhof, Saskia M; van der Lelij, Allegonda

    PURPOSE: To evaluate the performance of medical contact lenses (CLs) for a wide range of clinical indications. DESIGN: Prospective cross-sectional study. METHODS: A total of 281 eyes were evaluated in 281 consecutive patients (≥18 years of age; CL use ≥3 months) who visited the contact lens service

  2. TU-E-201-03: Eye Lens Dosimetry in Radiotherapy Using Contact Lens-Shaped Applicator

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. [Seoul National University Hospital (Korea, Republic of)

    2015-06-15

    . These actions should be considered when they are consistent with the clinical task and patient anatomy. Learning Objectives: To become familiar with method of eye dose estimation for patient in specific situation of brain perfusion CT To become familiar with level of eye lens radiation doses in patients undergoing brain perfusion MDCT To understand methods for reducing eye lens dose to patient Jong Min Park, Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea Eye lens dosimetry in radiotherapy using contact lens-shaped applicator Dose calculation accuracy of commercial treatment planning systems is relatively low at shallow depths. Therefore, in-vivo measurements are often performed in the clinic to verify delivered doses to eye lens which are located at shallow depth. Current in-vivo dosimetry for eye lens during radiotherapy is generally performed with small in-vivo dosimeters on the surface of patient eyelid. Since this procedure potentially contains considerable uncertainty, a contact lens-shaped applicator made of acrylic (lens applicator) was developed for in-vivo measurements of eye lens dose during radiotherapy to reduce uncertainty. The lens applicator allows the insertion of commercially available metal oxide semiconductor field effect transistor (MOSFET) dosimeters. Computed tomography (CT) images of an anthropomorphic phantom with and without the lens applicator were acquired. A total of 20 VMAT plans were delivered to an anthropomorphic phantom and the doses with the lens applicator and the doses at the surface of the eyelid were measured using both micro and standard MOSFET dosimeters. The differences in measured dose at the surface of the eyelid from the calculated lens dose were acquired. The differences between the measured and the calculated doses at the lens applicator, as well as the differences between the measured and the calculated doses at the surface of the eyelid were acquired. The statistical significance of the

  3. Contact lens trends over three decades in a hospital-based practice in India.

    Science.gov (United States)

    Rajan, Rajni; Mahadevan, Rajeswari; Thomas, Ann Mary; Bhattacharjee, Pradipta

    2017-09-26

    Contact lens fittings in a hospital-based practice are different from those in private practices because of specialised conditions. Few studies have been published on material preferences of such wearers, especially in long-term wearers. The aim of this study is to document contact lens prescribing trends in a hospital-based practice among long-term lens wearers and to identify their demographic profile. Subjects reporting to a contact lens clinic of a tertiary eye-care centre in India from 1 January 2014 to 31 December 2014, with a minimum of five years of lens wear, were included in the study. Data were collected retrospectively from the electronic medical charts of these subjects. Three hundred and sixty subjects were included in the study. The average duration of contact lens wear among the subjects was 9 ± 5 years (range: 5-35 years). The average age of the subjects was 31.38 ± 11.75 years (age range: 5-78 years). Hydrogel material and soft spherical type were preferred by most of the soft lens wearers (53 per cent). Eighty per cent of subjects followed hand hygiene and cleaning regimen practices. The preference for monthly replacement lenses and silicone hydrogel material increased over the years. Regular after-care consultations could enforce the need for compliance with hand hygiene and cleaning regimens among lens wearers. © 2017 Optometry Australia.

  4. Corneal cell adhesion to contact lens hydrogel materials enhanced via tear film protein deposition.

    Directory of Open Access Journals (Sweden)

    Claire M Elkins

    Full Text Available Tear film protein deposition on contact lens hydrogels has been well characterized from the perspective of bacterial adhesion and viability. However, the effect of protein deposition on lens interactions with the corneal epithelium remains largely unexplored. The current study employs a live cell rheometer to quantify human corneal epithelial cell adhesion to soft contact lenses fouled with the tear film protein lysozyme. PureVision balafilcon A and AirOptix lotrafilcon B lenses were soaked for five days in either phosphate buffered saline (PBS, borate buffered saline (BBS, or Sensitive Eyes Plus Saline Solution (Sensitive Eyes, either pure or in the presence of lysozyme. Treated contact lenses were then contacted to a live monolayer of corneal epithelial cells for two hours, after which the contact lens was sheared laterally. The apparent cell monolayer relaxation modulus was then used to quantify the extent of cell adhesion to the contact lens surface. For both lens types, lysozyme increased corneal cell adhesion to the contact lens, with the apparent cell monolayer relaxation modulus increasing up to an order of magnitude in the presence of protein. The magnitude of this increase depended on the identity of the soaking solution: lenses soaked in borate-buffered solutions (BBS, Sensitive Eyes exhibited a much greater increase in cell attachment upon protein addition than those soaked in PBS. Significantly, all measurements were conducted while subjecting the cells to moderate surface pressures and shear rates, similar to those experienced by corneal cells in vivo.

  5. Effect of soft contact lens curvature on dry eye of flight attendants

    Directory of Open Access Journals (Sweden)

    Chang-Liang Meng

    2014-10-01

    Full Text Available AIM: To discuss the effect of wearing customized curvature soft corneal contact lens to dry eye degree of flight attendants.METHODS: Eighty cases(160 eyesof flight attendants from China Southern were divided into two groups: control group 40 cases(80 eyeswearing ready-made Bausch soft corneal contact lens(curvature 8.4; the experiment group 40 cases(80 eyes, wearing Bausch soft corneal contact lens with customized curvature. Tear break-up time(BUT, Schirmer Ⅰ test(SⅠtand fluorescein(FLstaining were as dry eye evaluation index. The results was statistically analyzed.RESULTS: BUT, SⅠt average shortening value of the experimental group were less than that of the control group, there was statistical significance(PPCONCLUSION: Wearing customized curvature soft corneal contact lens can prevent the flight dry eye more effectively than fixed curvature product.

  6. Corneal aberration changes after rigid gas permeable contact lens wear in keratokonic patients

    Directory of Open Access Journals (Sweden)

    Fereshteh Shokrollahzadeh

    2016-12-01

    Conclusion: In this study, corneal aberrations remained unchanged 3 months after wearing RGP contact lens. Further studies with sufficient samples in different groups of keratoconus severity or baseline aberrations are needed to obtain more accurate results.

  7. The Sensimed Triggerfish contact lens sensor: efficacy, safety, and patient perspectives

    National Research Council Canada - National Science Library

    Dunbar GE; Shen BY; Aref AA

    2017-01-01

    .... The Sensimed Triggerfish contact lens sensor (CLS), which has recently gained approval for marketing in the USA, is designed to detect intraocular pressure-related changes in an eye over a 24-hour period...

  8. Contact lens-related polymicrobial keratitis from Pantoea agglomerans and Escherichia vulneris

    Directory of Open Access Journals (Sweden)

    Vincent D. Venincasa

    2016-04-01

    Conclusions: This is the first report of P. agglomerans and E. vulneris keratitis in association with contact lens wear. Both strains of P. agglomerans and E. vulneris were pansensitive to all tested antibiotics.

  9. Impact of Lens Care Solutions on Protein Deposition on Soft Contact Lenses.

    Science.gov (United States)

    Babaei Omali, Negar; Heynen, Miriam; Subbaraman, Lakshman N; Papinski, Dominik; Lakkis, Carol; Smith, Sarah L; Morgan, Philip B; Berntsen, David A; Nichols, Jason J; Jones, Lyndon W

    2016-08-01

    To evaluate the effect of four contemporary lens care solutions on total protein, total lysozyme, and active lysozyme extracted from three contact lens materials. Adapted contact lens wearers were recruited at three sites, and all subjects were randomly assigned to daily wear of either etafilcon A, galyfilcon A, or senofilcon A for 2 weeks. Four lens care solutions (Biotrue, OPTI-FREE PureMoist, RevitaLens OcuTec, and ClearCare) were used by each subject in random order with a new pair of lenses after a washout period between solutions of at least 4 days. After 2 weeks of daily wear, contact lenses were collected for analysis. Proteins were extracted from a subset of contact lenses (n = 568) and total protein, total lysozyme, and lysozyme activity were quantified using a modified Bradford assay, an enzyme-linked immunosorbent assay, and a micrococcal assay, respectively. Higher levels of total protein were extracted from etafilcon A when used with Biotrue compared to other solutions (p = 0.0001). There were higher levels of total lysozyme extracted from galyfilcon A lenses when used with PureMoist than with Biotrue or ClearCare (p lenses with RevitaLens OcuTec when compared to all other care solutions (all p lenses varies depending upon the care solution composition and also the polymeric make-up of the contact lens material.

  10. Dark secrets behind the shimmer of contact lens: the Indian scenario

    Directory of Open Access Journals (Sweden)

    Singh Deepak

    2009-05-01

    Full Text Available Abstract Background We studied the bacteriological profile of soft contact lens and its accessories among the asymptomatic subjects and monitored the compliance level with the lens use and its cleaning protocol. Findings A total of 115 (104 daily wear and 11 extended wear subjects using contact lens were studied. Data regarding the duration of use and frequency and method of cleaning were recorded. Contact lens, lens cases, preserving solutions and tips of solution bottles were the samples collected. The isolates were identified on the basis of their phenotypic characters. Samples from 24 subjects (21 daily wear and 3 extended wear were found contaminated. Of the 24 contaminated cases, 23 showed medium adherence to the cleaning protocol. Contamination rate was higher among the 56 daily wear lens users who used same lens for 2 years and more, than the 48 users who used their lenses for less than 2 years. Lens case contamination was found in all the 24 cases. The bacteria isolated were Citrobacter freundii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus epidermidis and Streptococcus pneumoniae. In extended wear lens users, there was no change in microbial flora on repeating the cultures on day 7 and 14. Conclusion Non-compliance with contact lens use may lead to invitation of microbial flora. The accumulation of these bacteria may act as a precursor to biofilm formation, thus colonizing the lens accessories as well. The bacteria isolated in this study were similar to the ones causing microbial keratitis thus, predisposing the otherwise asymptomatic subjects to permanent visual damage.

  11. Alterations in contact lens fitting parameters following cross-linking in keratoconus patients of Indian ethnicity.

    Science.gov (United States)

    Singh, Kirti; Bhattacharyya, Mainak; Arora, Ritu; Dangda, Sonal; Mutreja, Ankush

    2017-06-23

    Most studies have either excluded patients using contact lens or not taken their effect while analyzing post-collagen cross-linkage (CXL) changes. This study aims to study impact of CXL on lens fit in both quantitative and qualitative manner. To evaluate changes in CL fit post-CXL and to correlate these changes with alterations in corneal topographic parameters. Prospective intervention study on 20 keratoconic eyes of 14 patients (age > 18 years), with mean follow-up of 6 months. Preoperative evaluation included UCVA, BCVA, corneal topography, AS-OCT and contact lens fit. Patients were evaluated at 2 weeks, 1, 3, 4 and 6 months post-CXL; contact lens trial with standard rigid gas permeable (RGP) lens performed at 3 and 6 months. Changes in objective and subjective parameters of lens fit. Over 6-month follow-up post-CXL, improvement in visual acuity by one Snellen line, both UCVA and BCVA, and decrease in flat/mean/apical K by 0.8 D, 0.8 D and 1.3 D, respectively, resulted in significant improvement in RGPCL fit. Almost 20% increase in near-ideal fit, 100% acceptable fit, 65% improved subjective comfort with 8 h/day increase in duration of comfortable CL wear were observed. Despite no statistically significant change in objective parameters of lens fit, a tendency for flatter lens fit along with contact lens induced further flattening of the ectatic cornea which resulted in marked improvement in both objective and subjective contact lens fit.

  12. Acanthamoeba keratitis in a non-contact lens wearer with human immunodeficiency virus

    DEFF Research Database (Denmark)

    Hansen, Birgitte Rønde; Kronborg, Gitte

    2003-01-01

    Acanthamoeba keratitis is potentially blinding and often associated with contact lens wearing. A human immunodeficiency virus (HIV)-positive patient, a non-contact lens wearer, presented with keratitis. She experienced a protracted course of disease, characterized by exacerbations and remissions...... keratitis the diagnosis is delayed, pathognomonic features are often not seen and visual outcome is usually poor. There is no known relation between HIV infection and Acanthamoeba keratitis....

  13. Genetic analyses of Acanthamoeba isolates from contact lens storage cases of students in Seoul, Korea

    OpenAIRE

    Yu, Hak-Sun; Choi, Kyung-Hee; Kim, Hyo-Kyung; Kong, Hyun-Hee; Chung, Dong-Il

    2001-01-01

    We conducted both the small subunit ribosomal DNA (SSU rDNA) polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and mitochondrial (mt) DNA RFLP analyses for a genetic characterization of Acanthamoeba isolates from contact lens storage cases of students in Seoul, Korea. Twenty-three strains of Acanthamoeba from the American Type Culture Collection and twelve clinical isolates from Korean patients were used as reference strains. Thirty-nine isolates from contact lens ...

  14. Hard contact lens migration into the upper lid: an unexpected lid lump.

    OpenAIRE

    Jones, D; Livesey, S.; Wilkins, P

    1987-01-01

    Contact lens migration into the upper lid is a rare complication of wearing a hard contact lens. We present a case in which the only complaint was the cosmetically unacceptable appearance of a lump in the upper lid. The 76-month duration of the lesion is, we believe, the longest so far described. The histology and possible natural history of the cyst are also discussed.

  15. Performance evaluation of delefilcon a water gradient daily disposable contact lenses in first-time contact lens wearers.

    Science.gov (United States)

    Marx, Sebastian; Lauenborg, Bo; Kern, Jami R

    2018-02-06

    To evaluate the tolerability of and subject and investigator satisfaction with delefilcon A (DAILIES TOTAL1 ® ) daily disposable contact lenses in first-time contact lens wearers. This European multicenter, open-label, single-arm, two-week trial enrolled first-time contact lens wearers and fitted them with delefilcon A contact lenses. Assessments were made at dispensing and at Weeks 1 and 2. Subject-reported outcomes included comfort, quality of vision, convenience, and intent to purchase, which were ranked by agreement responses. Investigator-reported outcomes included slit-lamp biomicroscopy findings and lens fit satisfaction. Ninety-two subjects were included in the per protocol dataset. Mean scores at Weeks 1 and 2 for subject-reported quality of vision and ocular comfort were significantly higher with delefilcon A contact lenses than with the subjects' habitual spectacles during the day, at the end of the day, and overall (all p ≤ 0.02). Ninety-one percent of subjects reported that their study lenses were more comfortable than expected, 98% agreed that they were convenient to use, and 92% were interested in purchasing the lenses (all p lenses had an acceptable fit in at least 97% of subjects. Practitioners can expect favorable outcomes when transitioning first-time contact lens wearers from spectacles to delefilcon A daily disposable contact lenses. Copyright © 2017. Published by Elsevier Ltd.

  16. Organoselenium Polymer Inhibits Biofilm Formation in Polypropylene Contact Lens Case Material.

    Science.gov (United States)

    Tran, Phat L; Huynh, Eric; Pham, Patrick; Lacky, Blake; Jarvis, Courtney; Mosley, Thomas; Hamood, Abdul N; Hanes, Rob; Reid, Ted

    2017-03-01

    Contact lens-acquired bacterial infections are a serious problem. Of the reported cases, inadequate cleaning of the lens case was the most common cause of lens contamination. Organoselenium has been shown to inhibit bacterial attachment to different polymer materials. This study evaluates the ability of an organoselenium monomer, incorporated into the polymer of a polypropylene contact lens case coupon, to block the formation of biofilms in a lens case. The bacteria tested were Pseudomonas aeruginosa, Staphylococcus aureus, Stenotrophomonas maltophilia, and Serratia marcescens. For this study, the bacteria were allowed to grow overnight, in trypticase soy broth media, in the presence of the selenium-containing polymer or the same polymer without organoselenium. The material was studied by both colony-forming unit determination and by confocal laser scanning microscopy. The results showed that the organoselenium polymer versus the control polymer resulted in the following effect on biofilm formation: (1) a reduction in P. aeruginosa of 7.3 logs (100%); (2) a reduction in S. aureus of 7.3 logs (100%); (3) a reduction in S. maltophilia of 7.5 logs (100%); and (4) a reduction in S. marcescens reduction of 3.3 logs (99.9%). To test the stability of the organoselenium polypropylene contact lens coupon, the coupon was soaked in PBS for eight weeks at room temperature. It was found that when these soaked coupons were tested against S. aureus, complete inhibition (8.1 logs) was obtained. Because organoselenium cannot leach from the polymer, this would imply that the organoselenium polypropylene contact lens case coupon would be inhibitory toward bacterial biofilm for the life of the case. The organoselenium polypropylene contact lens case coupon shows the ability to inhibit biofilm formation. The use of organoselenium copolymer should play an important role in protecting against contact lens case-acquired infection.

  17. The physical and chemical properties of polymerization reaction for contact lens irradiated by electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Sin, Junghyeok; Jun, Jin [Dongshin Univ., Naju (Korea, Republic of)

    2010-07-01

    Can EB irradiation be possible the polymerization of HEMA without the cross-linker and initiator? The physical and chemical properties of the polymers are compared between the two polymerization methods Discuss the effects of the EB irradiation on the polymerization for having a good physical properties for the both hard and soft contact lens. EB irradiation can be used to the polymerization reaction and the EB polymerization take place at a very short period of time without any cross-linker and initiator and initiator above 100 kGy of EB dose. The polymer synthesized by EB irradiation can improve the physical properties of contact lens {yields} increase of the OH group on the surface by EB irradiation, resulting in increase o the water content and oxygen permeability of the contact lens The contact lens synthesized by EB irradiation could improve the physical properties of the contact lens, and specially can apply to a disposable soft contact lens with high water content and oxygen permeability.

  18. Impact of contact lens material and design on the ocular surface.

    Science.gov (United States)

    Ruiz-Alcocer, Javier; Monsálvez-Romín, Daniel; García-Lázaro, Santiago; Albarrán-Diego, César; Hernández-Verdejo, José Luis; Madrid-Costa, David

    2017-10-11

    To evaluate the impact on the ocular surface of a daily disposable hydrogel contact lens with high water content compared with two silicone hydrogel daily disposable lenses of lower water content. The hydrogel lens assessed was made from nesofilcon A and the silicone hydrogel lenses were made of delefilcon A and stenfilcon A. Contact lens thickness was measured to assess material stability during daily wear, and ocular surface parameters such as tear film osmolarity, tear meniscus area and central corneal thickness were also assessed. Optical quality was analysed for all cases by means of wavefront aberrometry. The nesofilcon A was shown to be the thinnest lens (p  0.05). In spite of having the thinnest lens and the highest water content, the hydrogel does not significantly impact on tear film and corneal swelling after one day of use in first-time wearers. © 2017 Optometry Australia.

  19. Preinflammatory Signs in Established Reusable and Disposable Contact Lens Wearers.

    Science.gov (United States)

    Chao, Cecilia; Stapleton, Fiona; Willcox, Mark D P; Golebiowski, Blanka; Richdale, Kathryn

    2017-11-01

    Established reusable contact lens (CL) wearers show higher tear inflammatory cytokine concentrations and greater conjunctival metaplasia in the region covered by standard soft CLs. The balance of proinflammatory to anti-inflammatory cytokines, but not individual tear cytokine concentrations, was associated with self-reported CL discomfort. Daily disposable (DD) lenses are often used to improve CL discomfort, but the effect on ocular inflammatory responses has not been fully investigated. This study aimed to compare the concentrations of tear cytokines and conjunctival cell morphology in healthy habitual DD and reusable soft CL wearers. Thirty-six established daily CL wearers, including 14 DD and 24 reusable wearers, were enrolled. Symptoms and ocular surface integrity were evaluated. The concentration of tear cytokines (interleukin 1β [IL-1β], IL-6, IL-10, IL-12(p70), IL-17A, and tumor necrosis factor α) were determined using Multiplex assays. The ratios of proinflammatory and anti-inflammatory cytokines were calculated. Impression cytology was performed on the conjunctiva, and goblet cell density and epithelial squamous metaplasia were quantified. Differences in variables by CL replacement schedules and the associations between variables were analyzed. Reusable CL wearers had higher concentrations (in pg/mL) of IL-1β (26 ± 7 vs. 16 ± 11), IL-6 (42 ± 14 vs. 25 ± 20), IL-10 (83 ± 23 vs. 49 ± 36), IL-12(p70) (145 ± 44 vs. 91 ± 68), IL-17A (93 ± 26 vs. 54 ± 44), and tumor necrosis factor α (312 [171 to 468] vs. 189 [6 to 447]) (all P < .01) and greater conjunctival metaplasia in the region covered by CLs (0.7 [0.2 to 1.6] vs. 0.4 [0.04 to 1.2], P = .01) compared with DD wearers. There was a positive association between CL discomfort and ratios of IL-1β to IL-10 and IL-12(p70) to IL-10 (ρ = 0.42 and ρ = 0.33, P < .05). Higher ocular inflammatory responses, as indicated by higher tear cytokine concentrations and higher conjunctival epithelial

  20. Myopia, contact lens use and self-esteem.

    Science.gov (United States)

    Dias, Lynette; Manny, Ruth E; Weissberg, Erik; Fern, Karen D

    2013-09-01

    To evaluate whether contact lens (CL) use was associated with self-esteem in myopic children originally enrolled in the Correction of Myopia Evaluation Trial (COMET), that after 5 years continued as an observational study of myopia progression with CL use permitted. Usable data at the 6-year visit, one year after CL use was allowed (n = 423/469, age 12-17 years), included questions on CL use, refractive error measurements and self-reported self-esteem in several areas (scholastic/athletic competence, physical appearance, social acceptance, behavioural conduct and global self-worth). Self-esteem, scored from 1 (low) to 4 (high), was measured by the Self-Perception Profile for Children in participants under 14 years or the Self-Perception Profile for Adolescents, in those 14 years and older. Multiple regression analyses were used to evaluate associations between self-esteem and relevant factors identified by univariate analyses (e.g., CL use, gender, ethnicity), while adjusting for baseline self-esteem prior to CL use. Mean (±S.D.) self-esteem scores at the 6-year visit (mean age = 15.3 ± 1.3 years; mean refractive error = -4.6 ± 1.5 D) ranged from 2.74 (± 0.76) on athletic competence to 3.33 (± 0.53) on global self-worth. CL wearers (n = 224) compared to eyeglass wearers (n = 199) were more likely to be female (p self-esteem or CL use. COMET participants who chose to wear CLs after 5 years of eyeglass use had higher self-esteem compared to those who remained in glasses both preceding and following CL use. This suggests that self-esteem may influence the decision to wear CLs and that CLs in turn are associated with higher self-esteem in individuals most likely to wear them. © 2013 The Authors Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

  1. The nature and consequence of vitronectin interaction in the non-compromised contact lens wearing eye.

    Science.gov (United States)

    Cooner, Manpreet; Mann, Aisling; Tighe, Brian

    2017-08-01

    The aim of this work was to investigate the locus and extent of vitronectin (Vn) deposition on ex vivo contact lenses and to determine the influence of wear modality together with surface and bulk characteristics of the lens material. The quantity and location of Vn deposition on the surfaces of contact lens materials was investigated using a novel on-lens cell attachment assay technique. Vn mapping showed that deposition resulted from lens-corneal interaction rather than solely from the tear film. Higher cell counts on the posterior surface of the lenses were determined in comparison to the anterior surface. Overall gross Vn deposition was greater for high water content-low modulus materials (117±4 average cell count per field) than low water content-high modulus materials (88±6 average cell count per field). The role of Vn in plasmin regulation and upregulation is widely recognised. The findings in this paper suggest that the locus of Vn on the contact lens surface, which is affected by material properties such as modulus, is potentially an important factor in the generation of plasmin in the posterior tear film. Consequently, the potential for materials to affect Vn deposition will influence lens-induced inflammatory processes. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  2. Improving contact lens compliance by explaining the benefits of compliant procedures.

    Science.gov (United States)

    McMonnies, Charles W

    2011-10-01

    To increase compliance with instructions for safe and successful contact lens wear by helping patients understand the advantages and consequences of compliant and non-compliant behavior respectively. A series of explanations which elucidate the practical and scientific basis for many of the instructions given at lens delivery and aftercare have been prepared as a means of extending patient education beyond simply being instructed on what to do. The summary versions of these explanations have been prepared at an easier level of readability (age 10-12 years) to assist young patients and adults with reading disabilities, including those for whom English is their second language. Patients may be non-compliant because they do not understand the practical and/or scientific basis for procedures and the potential consequences of aberrant behavior. Delay in the onset of symptoms associated with non-compliance may allow them to assume that compliance is not important. Explanations which describe why instructions given for lens use are consistent with sustained comfortable and safe lens wear, appear to have the potential to strengthen or change patient attitudes toward being compliant. Behavior modification which reduces the prevalence of non-compliance appears likely to also help sustain better contact lens performance and reduce the prevalence of contact lens failure. These explanations could be modified for use in different practices according to the preferences of individual practitioners and to include new research findings as they become available. Copyright © 2011 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  3. Artificial pupil versus contralateral balanced contact lens fit for presbyopia correction

    Directory of Open Access Journals (Sweden)

    Santiago García-Lázaro

    2014-04-01

    Full Text Available Purpose: To assess and compare the effects of contact lens-based artificial pupil design and contralateral balanced multifocal contact lens combination (CBMCLC on visual performance. Methods: This randomized crossover study conducted at the University of Valencia, Spain included 38 presbyopic patients using an artificial pupil contact lens in the nondominant eye and a CBMCLC. After a month of lens wear, the binocular distance visual acuity (BDVA, binocular near visual acuity (BNVA, defocus curve, binocular distance, and near contrast sensitivity and near stereoacuity (NSA were measured under photopic conditions (85 cd/m2. Moreover, BDVA and binocular distance contrast sensitivity were examined under mesopic conditions (5 cd/m2. Results: Visual acuity at an intermediate distance and near vision was better with the CBMCLC than with the artificial pupil (p<0.05. Statistically significant differences were found in contrast sensitivity between the two types of correction for distance (under mesopic conditions and for near vision, with the CBMCLC exhibiting better results in both cases (p<0.05. The mean NSA values obtained for the artificial pupil contact lens were significantly worse than those for the CBMCLC (p=0.001. Conclusion: The CBMCLC provided greater visual performance in terms of intermediate and near vision compared with the artificial pupil contact lens.

  4. Spectral optical coherence tomography in video-rate and 3D imaging of contact lens wear.

    Science.gov (United States)

    Kaluzny, Bartlomiej J; Fojt, Wojciech; Szkulmowska, Anna; Bajraszewski, Tomasz; Wojtkowski, Maciej; Kowalczyk, Andrzej

    2007-12-01

    To present the applicability of spectral optical coherence tomography (SOCT) for video-rate and three-dimensional imaging of a contact lens on the eye surface. The SOCT prototype instrument constructed at Nicolaus Copernicus University (Torun, Poland) is based on Fourier domain detection, which enables high sensitivity (96 dB) and increases the speed of imaging 60 times compared with conventional optical coherence tomography techniques. Consequently, video-rate imaging and three-dimensional reconstructions can be achieved, preserving the high quality of the image. The instrument operates under clinical conditions in the Ophthalmology Department (Collegium Medicum Nicolaus Copernicus University, Bydgoszcz, Poland). A total of three eyes fitted with different contact lenses were examined with the aid of the instrument. Before SOCT measurements, slit lamp examinations were performed. Data, which are representative for each imaging mode, are presented. The instrument provided high-resolution (4 microm axial x 10 microm transverse) tomograms with an acquisition time of 40 micros per A-scan. Video-rate imaging allowed the simultaneous quantitative evaluation of the movement of the contact lens and assessment of the fitting relationship between the lens and the ocular surface. Three-dimensional scanning protocols further improved lens visualization and fit evaluation. SOCT allows video-rate and three-dimensional cross-sectional imaging of the eye fitted with a contact lens. The analysis of both imaging modes suggests the future applicability of this technology to the contact lens field.

  5. Recent Outbreaks of Atypical Contact Lens-Related Keratitis: What Have We Learned?

    Science.gov (United States)

    Tu, Elmer Y.; Joslin, Charlotte E

    2010-01-01

    Purpose To examine the public health implications of two recent outbreaks of atypical contact lens-related infectious keratitis. Design A perspective based on the literature and authors’ experience. Results The contact lens-related fusarium and acanthamoeba keratitis outbreaks were both detected by dramatic rises seen in tertiary care centers in Singapore and the US, respectively. Case control studies in both outbreaks each were able to identify a strong association with the use of different contact lens disinfection solutions. Their respective recalls resulted in a steep decline of fusarium keratitis, but not of acanthamoeba keratitis. Early investigations into each solution association implicate components not directly related to their primary disinfectant, but the true pathogenesis remains unknown. However, the number of Acanthamoeba cases individually attributed to each of almost all available disinfection systems exceeds previously understood total US incidence, suggesting other risk factors. Current standards do not require demonstration of anti-acanthamoebal activity. Yet, despite the inclusion of fusarium in mandatory testing for solutions, current pre-market testing was not predictive of the outbreak. Conclusions The two recent outbreaks of atypical contact-lens related keratitis have reinforced the value of tertiary care eye care centers in detecting early rises in rare infections and the power of adaptable, well-designed epidemiologic investigations. While fusarium keratitis has significantly declined with the recall of Renu with Moistureloc, the persistence of Acanthamoeba keratitis begs fundamental changes in contact lens hygiene practices, inclusion of acanthamoeba as a test organism and contact lens disinfectant test regimens for all contact lens–related pathogens which are verifiably reflective of end user contact lens wear complications. PMID:21036209

  6. Corneal confocal microscopy and dry eye findings in contact lens discomfort patients.

    Science.gov (United States)

    Dogan, Aysun Sanal; Gurdal, Canan; Arslan, Nese

    2017-08-16

    To evaluate the corneal confocal microscopy and dry eye findings in patients with contact lens discomfort. The study included 3 groups of participants: Contact lens wearers using silicone hydrogel soft contact lenses who are symptomatic (CLD, n=15) or asymptomatic (ACL, n=11) and non-wearers as controls (n=14). Duration of contact lens wear, Ocular Surface Disease Index (OSDI) questionnaire responses, fluorescein tear break-uptime (FBUT), and corneal confocal microscopy findings were recorded. Mean age was 25.7±8.2 years and male/female ratio was 7/33. Demographic findings were similar regarding the groups. CLD patients had a longer lens use history than ACL (median 5 vs 2 years, p<0.001). OSDI scores were higher in CLD group than ACL or controls (p<0.001, p=0.002). FBUT was significantly lowest in CLD group, compared to controls and ACL (p<0.001, p=0.039). FBUT was also lower in ACL patients compared to controls (p=0.036). There was no difference between basal epithelium cell counts between all 3 groups. Anterior stromal activated keratocyte numbers were similar between contact lens using groups but was lower in controls (p=0.005). However, dendritiform cells in the sub-basal nerve layer were higher in CLD group compared to controls but similar to ACL (p<0.001, p=0.058). Graded sub-basal nerve tortuosity was more prominent in CLD group than the ACL (p=0.014). Patients with CLD had been wearing contact lenses for longer than those without symptoms. OSDI and FBUT scores were worse in CLD patients. In contact lens discomfort patients, there were increased dendritiform cells, indicating intensified inflammatory status of the cornea. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  7. Objective and subjective assessment of a new diffractive trifocal contact lens

    Science.gov (United States)

    Fulga, Valentine; Schroeder, Shlomo; Avraham, Gaby; Belkin, Michael

    1997-05-01

    We tested the objective and subjective performance of the Holo-Or rigid gas permeable multifocal contact lens, a new trifocal diffractive contact lens. Eleven experienced and two non-experienced rigid gas permeable contact lens wearers participated in the study. Eleven patients were presbyopic (age 40 - 57) and two aphakic (age 12 and 14). All patients were tested both with their best spectacle correction for distance and near and the trifocal diffractive contact lenses. The follow up period was 3 - 8 months. Subjective opinion was also assessed. Statistical analysis was performed using Student's T-test. We did not find any significant difference in visual acuity measured at 6 m, 80 cm and 40 cm, between best spectacle correction and Holo-Or diffractive contact lenses. Depth of focus improved to a statistically significant extent when using trifocal contact lenses. A small reduction in contrast sensitivity was observed when the patients used the multifocal contact lenses. Overall satisfaction and comfort was good to excellent in ten of the thirteen patients. Two other patients who used a bifocal model of the same contact lens design showed similar results. Holo-Or trifocal diffractive contact lenses are a satisfactory means of optical correction for patients with presbyopia or accommodative problems.

  8. Opaque contact lens color choices among women of different ethnic groups.

    Science.gov (United States)

    Gaume, Amber; Prager, Thomas C; Bergmanson, Jan P G; Quintero, Sam; Harden, John; Perrigin, Judith; Piccolo, Marc

    2003-04-01

    The opaque contact lens (OCL) market is profitable and expanding. This pilot study sought to identify OCL color preferences among women of three ethnic groups, African American (A), white (W), and Hispanic Americans (H). Sixty-three brown-eyed female subjects (19 A; 22 W; 22 H), 18 to 35 years of age, with uncorrected near visual accuity of at least 20/50 were recruited. Each subject was presented with OCLs of three different color pattern designs in each of four colors (blue, green, gray, and hazel). The subjects viewed their appearance in a mirror while wearing each lens. Once all lenses had been observed, the subjects chose their lens color preference. Using the nonparametric Kruskal-Wallis test, an ethnic preference was shown for all but the gray contact lenses. In group A 47.4% rated the hazel lens as their first choice whereas 0% chose the blue lens. In contrast, 45.5% of group C chose the blue lens over the other colors but did not favor the hazel lens, which was their first choice only 4.5% of the time. Group H demonstrated the most diversity in color preference, however, 36.4% chose green as their overall lenscolor preference. Distinct differences exist in OCL color preferences among the three ethnic groups studied. Improved understanding of this ethnic difference could increase the efficiency of the trial lens process while possibly decreasing inventory costs when one ethnic group dominates a practice patient base.

  9. Water Exposure is a Common Risk Behavior Among Soft and Gas-Permeable Contact Lens Wearers.

    Science.gov (United States)

    Zimmerman, Aaron B; Richdale, Kathryn; Mitchell, Gladys Lynn; Kinoshita, Beth T; Lam, Dawn Y; Wagner, Heidi; Sorbara, Luigina; Chalmers, Robin L; Collier, Sarah A; Cope, Jennifer R; Rao, Maya M; Beach, Michael J; Yoder, Jonathan S

    2017-08-01

    To understand soft contact lens (SCL) and gas-permeable (GP) lens wearers' behaviors and knowledge regarding exposure of lenses to water. The Contact Lens Risk Survey (CLRS) and health behavior questions were completed online by a convenience sample of 1056 SCL and 85 GP lens wearers aged 20 to 76 years. Participants were asked about exposing their lenses to water and their understanding of risks associated with these behaviors. Chi-square analyses examined relationships between patient behaviors and perceptions. GP lens wearers were more likely than SCL wearers to ever rinse or store lenses in water (rinsing: 91% GP, 31% SCL, P lenses in water. Showering while wearing lenses was more common in SCL wearers (86%) than GP lens wearers (67%) (P lenses was reported by 62% of SCL wearers and 48% of GP lens wearers (P = 0.027). Wearers who rinsed (SCL; P lenses in water (SCL; P water was safer than tap water for storing or rinsing lenses. Despite previously published evidence of Acanthamoeba keratitis' association with water exposure, most SCL, and nearly all GP lens wearers, regularly expose their lenses to water, with many unaware of the risk.

  10. Application of bandage contact lens in pterygium excision combined with conjunctival transplantation

    Directory of Open Access Journals (Sweden)

    Zheng-Hua Xu

    2017-09-01

    Full Text Available AIM: To evaluate the application and effect of bandage contact lens in pterygium excision combined with conjunctival transplantation(CAT.METHODS: In a prospective, randomized, controlled clinical study, 110 patients(110 eyesdiagnosed with primary pterygium were collected in PLA NO.474 Hospital from January 2015 to January 2016. The 110 patients enrolled in the study in turn, and divided into two groups by the odd and even number. The odd number divided into bandage contact lens group(CAT + bandage contact lens, n=55, while the even number divided into control group(CAT, n=55. Visual analog scale(VASand corneal irritation were evaluated on 1, 3 and 7d after operation. Cornea fluorescent staining testing was carried out on 3d after operation. Following-up all the patients with 1a at least observed the recurrence of pterygium. RESULTS:The score of VAS in bandage contact lens group less than that in control group on 1d(4.13±2.06 vs 5.80±1.93, t=4.391, Pvs 3.65±1.65, t=5.422, Pt=1.295, P=0.198after operation. The corneal irritation in bandage contact lens group less than that in control group on 1d and 3d after operation(PP=0.052. Cornea fluorescent staining testing area in bandage contact lens group was less than that in control group on 7d after operation(0.33±0.37mm2 vs 2.73±2.21mm2, t=7.921, PP=1.000. CONCLUSION:Bandage contact lens could significantly release pain and corneal irritation, promote the healing of the corneal epitheliums in the defected area, and increase the postoperative comfort level in patients after operation.

  11. Comparison of multifocal and monovision soft contact lens corrections in patients with low-astigmatic presbyopia.

    Science.gov (United States)

    Richdale, Kathryn; Mitchell, G Lynn; Zadnik, Karla

    2006-05-01

    The purpose of this study was to assess visual performance and patient satisfaction with two presbyopic soft contact lens modalities. A crossover study of 38 patients with presbyopia was conducted. Patients were randomized first into either multifocal (Bausch & Lomb SofLens Multifocal) or monovision (SofLens 59) for 1 month. Visual performance was measured with high- and low-contrast visual acuity at distance and near and near stereoacuity. Patients' satisfaction was measured by the National Eye Institute Refractive Error Quality of Life Instrument questionnaire and by recording the patient's final lens preference. Patients maintained at least 20/20 binocular vision with both multifocal (MF) and monovision (MV) contact lenses under high-contrast conditions at distance and near. Under low-contrast conditions, patients lost less than a line of vision from the best spectacle correction to either multifocal or monovision contact lens correction at distance (pMF = 0.001, pMV = 0.006). Under low-contrast conditions at near, multifocal wearers lost five to six letters and monovision wearers lost two letters of vision (pMF contact lenses (p = 0.002). On the NEI-RQL, patients reported worse clarity of vision (pMF = 0.01, pMV contact lens wear (pMF contact lenses, and 24% preferred monovision contact lenses (p = 0.001). The majority of our patients preferred multifocals to monovision, most likely because the Bausch & Lomb SofLens Multifocal provides excellent visual acuity without compromising stereoacuity to the same degree as monovision.

  12. Investigating the utility of clinical assessments to predict success with presbyopic contact lens correction.

    Science.gov (United States)

    Sivardeen, Ahmed; Laughton, Deborah; Wolffsohn, James S

    2016-10-01

    To determine the utility of a range of clinical and non-clinical indicators to aid the initial selection of the optimum presbyopic contact lens. In addition, to assess whether lens preference was influenced by the visual performance compared to the other designs trialled (intra-subject) or compared to participants who preferred other designs (inter-subject). A double-masked randomised crossover trial of Air Optix Aqua multifocal, PureVision 2 for Presbyopia, Acuvue OASYS for Presbyopia, Biofinity multifocal and monovision was conducted on 35 presbyopes (54.3±6.2years). Participant lifestyle, personality, pupil characteristics and aberrometry were assessed prior to lens fitting. After 4 weeks of wear, high and low contrast visual acuity (VA) under photopic and mesopic conditions, reading speed, Near Activity Visual Questionnaire (NAVQ) rating, subjective quality-of-vision scoring, defocus curves, stereopsis, halometry, aberrometry and ocular physiology were quantified. After trialling all the lenses, preference was mixed (n=12 Biofinity, n=10 monovision, n=7 Purevision, n=4 Air Optix Aqua, n=2 Oasys). Lens preference was not dependent on personality (F=1.182, p=0.323) or the hours spent working at near (p=0.535) or intermediate (p=0.759) distances. No intersubject or strong intrasubject relationships emerged between lens preference and reading speed, NAVQ rating, halo size, aberrometry or ocular physiology (p>0.05). Participant lifestyle and personality, ocular optics, contact lens visual performance and ocular physiology provided poor indicators of the preferred lens type after 4 weeks of wear. This is confounded by the wide range of task visual demands of presbyopes and the limited optical differences between current multifocal contact lens designs. Copyright © 2016 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  13. The clinical and cellular basis of contact lens-related corneal infections

    Directory of Open Access Journals (Sweden)

    Danielle M Robertson

    2008-08-01

    Full Text Available Danielle M Robertson, H Dwight CavanaghDepartment of Ophthalmology, The University of Texas Southwestern Medical Center, Dallas, TX, USAAbstract: Microbial keratitis (MK is the most visually devastating complication associated with contact lens wear. Pseudomonas aeruginosa (PA is highly invasive in the corneal epithelium and is responsible for more than half of the reported cases of contact lens-related MK. To protect against Pseudomonas-mediated MK, the corneal epithelium has evolved overlapping defense mechanisms that function to protect the ocular surface from microbial invasion. Research has shown that contact lens wear disrupts these protective mechanisms through breakdown of normal homeostatic surface renewal as well as damaging the corneal surface, exposing underlying cell membrane receptors that bind and internalize PA through the formation of lipid rafts. Human clinical trials have shown that initial adherence of PA with resulting increased risk for microbial infection is mediated in part by contact lens oxygen transmissibility. Recently, chemical preserved multipurpose solutions (MPS have been implicated in increasing PA adherence to corneal epithelial cells, in addition to inducing significant levels of toxic staining when used in conjunction with specific silicone hydrogel lenses. This review summarizes what is currently known about the relationship between contact lenses, the corneal epithelium, MPS, and infection.Keywords: cornea, epithelium, contact lens, microbial keratitis

  14. Effect of Soft Contact Lens Materials on Tear Film Stability and ...

    African Journals Online (AJOL)

    NIBUT) were assessed with the Bausch and Lomb Keratometer H-135A (Bausch and Lomb Corp., USA). The subjects were categorised into two groups: Polymacon (conventional soft contact lens) group (n = 17) and lotrafilcon B (O2 optix contact ...

  15. Adhesion of Pseudomonas aeruginosa to contact lenses after exposure to multi-purpose lens care solutions

    NARCIS (Netherlands)

    Bruinsma, GM; Van der Mei, HC; Busscher, HJ; de Vries, Jacob

    2001-01-01

    Elemental surface compositions of contact lenses were measured after exposure to different lens care solutions (LCS) using X-ray photoelectron spectroscopy and were related to adhesion and detachment of Pseudomonas aeruginosa. Etafilcon A and polymacon contact lenses, prior to and after exposure to

  16. [Pediatric contact lens users in public and private services: comparative analysis].

    Science.gov (United States)

    Toscano, Daniela Araújo; Florêncio, Ana Cláudia Tabosa; Sales, Maria da Conceição; Cavalcanti, Márcia Trovão Duarte; Antunes, Daniela Almeida Lyra

    2009-01-01

    To analyze the indications, type and complications of contact lens use and visual acuity in children, in ophthalmological, public and private, services. The information from the medical records of 59 contact lens users at a private service (Hospital de Olhos de Pernambuco - Recife - PE- Brazil - group 1), and 43 at public service (Fundação Altino Ventura - Recife - PE - Brazil - group 2), was analyzed. The collected data included: demographic information; age at first examination; indication of lens use; contact lens type; complications and visual acuity. The most common indications of contact lenses in group 1 were: ametropia (55.9%), anisometropia (18.6%) and esotropia (16.9%). In this group leukoma and phthisis were not present. In group 2 the most common indications were: anisometropia (23.2%), ametropia (18.6%), leukoma (18.6%) and phthisis (16.3%). Esotropia was not found in group 2. The most prescribed contact lens was soft and of permanent use in group 1 (45.8%) and in group 2 (32.6%). The most frequent complication in group 1 was discomfort (33.3%) and in group 2 was the loss of the lens (60%). The most frequent indication in private services was ametropia and anisometropia in the public ones. The type of lens mostly prescribed in both groups was soft and of permanent use. The most frequent complication in group 1 was discomfort and in group 2 loss of the lens. The visual acuity was the same in the majority of the patients.

  17. Contact lens wear and the development of squamous metaplasia of the surface cells of the conjunctiva.

    Science.gov (United States)

    Doughty, Michael J

    2011-09-01

    To review the reported effects of contact lens wear on the surface epithelial cells of the human conjunctiva as assessed by conjunctival impression cytology (CIC). A literature search was undertaken to identify reports on the conjunctival health after contact lens wear, principally as assessed using CIC. Of 26 reports identified, 22 examined the bulbar conjunctiva, and 2 examined the tarsal conjunctiva. Just 16 reports provided data from which mean squamous metaplasia grades could be calculated, with the overall grade being just 0.7 on a 0 to 3 scale. Only 13 of these studies provided unambiguous data on the duration of contact lens wear, and only an apparent trend was evident in that grades of squamous metaplasia increased over early years of lens wear. Such a trend was not statistically significant either up to 6 years of average lens wear (P>0.05) or over all studies (P>0.5). The estimated variability in squamous metaplasia was substantially greater when low grades were reported, an observation that either reflects the heterogeneity in the cell response or highlights the difficulty in assigning low grades to cell samples. Based on subjective grading, CIC studies reveal no clearly definable relationship between the duration of contact lens wear and the extent of development of conjunctival squamous metaplasia. Logically, therefore, objective methods to assess squamous metaplasia are needed. Various options for quantitative CIC are discussed, including the use of in vivo confocal microscopy.

  18. Surface modification of fluorosilicone acrylate RGP contact lens via low-temperature argon plasma

    Energy Technology Data Exchange (ETDEWEB)

    Yin Shiheng [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Analytical and Testing Center, South China University of Technology, Guangzhou 510640 (China); Wang Yingjun [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Ren Li [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China)], E-mail: psliren@scut.edu.cn; Zhao Lianna [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Kuang Tongchun [Analytical and Testing Center, South China University of Technology, Guangzhou 510640 (China); Chen Hao [Wenzhou Medical College, Wenzhou 325035 (China)], E-mail: chenhao823@mail.wz.zj.cn; Qu Jia [Wenzhou Medical College, Wenzhou 325035 (China)

    2008-11-15

    A fluorosilicone acrylate rigid gas permeable (RGP) contact lens was modified via argon plasma to improve surface hydrophilicity and resistance to protein deposition. The influence of plasma treatment on surface chemical structure, hydrophilicity and morphology of RGP lens was investigated by X-ray photoelectron spectrometer (XPS), contact angle measurements and scanning electron microscope (SEM), respectively. The contact angle results showed that the hydrophilicity of the contact lens was improved after plasma treatment. XPS results indicated that the incorporation of oxygen-containing groups on surface and the transformation of silicone into hydrophilic silicate after plasma treatment are the main reasons for the surface hydrophilicity improvement. SEM results showed that argon plasma with higher power could lead to surface etching.

  19. Herpes Simplex epithelial keratitis associated with daily disposable contact lens wear.

    Science.gov (United States)

    Hamroush, Ahmed; Welch, James

    2014-06-01

    To report a case of epithelial Herpes Simplex keratitis in a patient wearing daily disposable contact lenses. Case report. A 30-year-old female contact lens wearer presented to the emergency clinic with a painful, red left eye associated with an acute reduction of vision over 48 h. On examination, confluent dendritic ulcers were present on the cornea. Neither pertinent ocular nor medical history was obtained to explain such a dramatic clinical presentation. Contact lens wear was the only risk factor identified, perhaps resulting in deviation of the immune response at the ocular surface, with consequent extensive dendritic ulceration. Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  20. In-vitro analysis of the microbicidal activity of 6 contact lens care solutions

    Directory of Open Access Journals (Sweden)

    Hildebrandt Claudia

    2012-10-01

    Full Text Available Abstract Background Contact lens-related infections are often associated with inadequate contact lens hygiene, and therefore, contact lens care products should be able to sufficiently minimise the amount of pathogens that are responsible for these infections. In 2001, the EN ISO 14729 was introduced to ensure adequate disinfection efficacy of contact lens care solutions, but this norm has recently been criticised. Methods In this study, six frequently used contact lens care solutions were retested according to the Stand Alone Test of the EN ISO 14729 (2001. The Stand Alone Test is a quantitative suspension test. In addition, the products were tested in a modified setting adding an organic load. The load was a mixture of human blood serum, lysozyme, and mucine, which resembles tear fluid. Results The criteria of the Stand Alone Test recommended in EN ISO 14729 were only met by Aosept Plus. This 3% hydrogen-peroxide-based contact lens care solution attained a reduction factor of > 5 log units for bacteria and > 4 for fungi in all cases. Two further contact lens care solutions, Blue Vision and Optifree Replenish, met the criteria of a reduction factor of > 3 log units for bacteria and > 1 log unit for fungi, but only in the presence of artificial tear fluid. The three remaining products did not exhibit adequate disinfecting efficacy, at least against one of the tested microorganisms. Conclusions Through the observation that the artificial tear fluid used in this study influences the disinfecting efficacy of contact lens care solutions, especially that of multi-purpose solutions, in a different way than does albumin, mucine, or even the organic load suggested in EN ISO 14729, it becomes obvious that the test conditions in the EN ISO 14729 should be revised in order to create more realistic conditions, e.g., by using a more realistic artificial tear fluid. Furthermore, we suggest adapting the EN ISO 14729 to the European test hierarchy for chemical

  1. Clinical Presentation and Antibiotic Susceptibility of Contact Lens Associated Microbial Keratitis

    Directory of Open Access Journals (Sweden)

    Hesam Hedayati

    2015-01-01

    Full Text Available Introduction. In recent years, the number of contact lens wearers has dramatically increased in Iran, particularly in youngsters. The purpose of current study was to assess the clinical presentation and antibiotic susceptibility of contact lens related microbial keratitis in Ahvaz, southwest of Iran. Methodology. A cross-sectional investigation of 26 patients (33 eyes with contact lens induced corneal ulcers who were admitted to Imam Khomeini Hospital, Ahwaz City, from June 2012 to June 2013 was done. In order to study microbial culture and susceptibility of corneal ulcers, all of them were scraped. Results. Eight samples were reported as sterile. Pseudomonas aeruginosa (80% in positive cultures was the most widely recognized causative organism isolated. This is followed by Staphylococcus aureus 12% and Enterobacter 8%. The results showed that 84% of the microorganism cases were sensitive to ciprofloxacin, while imipenem, meropenem, and ceftazidime were the second most effective antibiotics (76%. Conclusion. Results of current study show the importance of referring all contact lens wearers with suspected corneal infection to ophthalmologists for more cure. The corneal scraping culture and contact lens solution should be performed to guide antibiotic therapy.

  2. Daily disposable vs. disposable extended wear: a contact lens clinical trial.

    Science.gov (United States)

    Nichols, J J; Mitchell, G L; Zadnik, K

    2000-12-01

    The purpose of this work was to compare traditional standards of contact lens success and patient-reported preferences in the daily-disposable and disposable extended-wear contact lens modalities. This study was a randomized, cross-over contact lens clinical trial involving 50 patients. After the baseline examination, two outcome examinations were performed including the self-administration of the Refractive Status and Vision Profile (RSVP) survey, an additional survey, and masked visual acuity and slit-lamp assessments. No differences were noted on the RSVP when comparing treatment modalities. Patients were considered equally successful in terms of wearing time, overall comfort, visual acuity, and ocular health criteria. In terms of patient preferences, a significant number of patients preferred the disposable extended-wear modality over the daily-disposable modality (chi2(1) = 4.08, p = 0.04). Patients preferred disposable extended-wear over daily-disposables due to convenience (odds ratio = 30.33). Disposable extended-wear represents a convenient contact lens option for contact lens patients.

  3. Strategies for the prevention of contact lens-related Acanthamoeba keratitis: a review.

    Science.gov (United States)

    Carnt, Nicole; Stapleton, Fiona

    2016-03-01

    Acanthamoeba keratitis is a severe, often sight threatening, corneal infection which in Western countries is predominantly seen in daily wear of contact lenses. This review aims to summarise the pathobiology and epidemiology of contact lens-related Acanthamoeba keratitis, and to present strategies for prevention, particularly with respect to modifiable risk factors in contact lens wear. The virulence of Acanthamoeba and resistance to treatment in keratitis appears to be linked with the production of a low molecular weight protease MIP133 by the organism, in response to binding to corneal epithelial cells through a mannose binding protein, and to the ability of the organism to convert from the trophozoite to the resistant cyst form. Recent epidemiological studies in contact lens relate disease have confirmed the link between solution topping up and Acanthamoeba keratitis and have reinforced the importance of avoidance of tap water, either as part of the care for the contact lens or storage case, handling lenses with wet hands or showering while wearing lenses. In the most recent analysis from the USA, there were no strong effects for solution type, water source or water disinfection process. Wearer age, lens wear time and history to appear to be linked with Acanthamoeba keratitis. Daily disposable contact lens use would be expected to reduce the prevalence of Acanthamoeba disease although this is unproven. While Acanthamoeba keratitis remains challenging to diagnose and manage, strategies to limit the disease severity in contact lens wearers should include attention to recently identified risk factors, particularly those related to water contact. Public health awareness measures, the use of daily disposable contact lenses, a better understanding of the contribution of the host immunity and the development of standardised methods for culture of amoeba and testing of contact lens care systems against Acanthamoeba in the licensing process may be of value. Alternative

  4. Application of geometric dimensioning and tolerancing for sharp corner and tangent contact lens seats

    Science.gov (United States)

    Hopkins, C. L.; Burge, J. H.

    2011-10-01

    This paper outlines methods for dimensioning and tolerancing lens seats that mate with spherical lens surfaces. The two types of seats investigated are sharp corner and tangent contact. The goal is to be able to identify which seat dimensions influence lens tilt and displacement and develop a quantifiable way to assign tolerances to those dimensions to meet tilt and displacement requirements. After looking at individual seats, methods are then applied to multiple lenses with examples. All geometric dimensioning and tolerancing is according to ASME Y14.5M - 1994.

  5. [Risk factors for contact lens-related microbial keratitis: A multicenter case-control study].

    Science.gov (United States)

    Becmeur, P H; Abry, F; Bourcier, T; Meyer, N; Sauer, A

    2017-03-01

    Currently, the most feared complication by ophthalmologists of contact lens (CL) wear is microbial keratitis (MK), even though its incidence remains low. It is also a significant financial burden for society. This study aimed to identify the risk factors for CL-related MK especially with regard to hygiene and pattern of use, in a large, prospective, multicenter, case-control study. A multicenter retrospective case-control study was designed. The CL-related MK subpopulation (case) was compared with healthy CL wearers (control) using a 52-item anonymous questionnaire designed to determine subject demographics, lens wear history, lens type and disinfection solution, fitting, patient education, hygiene and maintenance of contact lenses, and patient history. Univariate logistic regression analysis was performed to compare both groups. The study included 497 cases and 364 controls. The risk factors associated with the greatest increased odds of CL-related MK were as follows: extended wear (OR=2.96 [1.65-5.33], Plens use (OR=6.37 [4,55-8.90], Pcontact lens (OR=4.47 [2.27-8.77], Pcontact lens wear, fitting by an ophthalmologist, written and verbal instruction, and daily case maintenance. The knowledge of these risks factors incentivizes action at all levels to reduce the incidence of MK, from the prescriber to the patient, including the type of CL, case and contact lens solution. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. Level of compliance in contact lens wearing medical doctors in Nepal.

    Science.gov (United States)

    Sapkota, Kishor

    2015-12-01

    To determine the level of compliance and major non-compliant behaviors in contact lens (CL) wearing medical doctors (MDs) and to compare it with age matched CL wearing normal subjects with no medical background (NS). Thirty-nine current CL wearing MDs, who were prescribed CLs in Nepal Eye Hospital, Kathmandu, Nepal, between 2007 and 2011, were interviewed on ten modifiable compliant behaviors regarding lens care and maintenance. The level of compliance and the rate of non-compliance for each behavior were determined and compared with NS. Level of compliance was good, average and poor in 35.9%, 48.7% and 15.4% of MDs, respectively. There was no significant difference in compliance between MDs and NS (p=0.209). Level of compliance was not associated with age, gender and duration of lens wear (p>0.05). Compliance rate varied according to different behaviors, achieving a good compliance level of 95% for hand hygiene, avoidance of water contact and not sleeping with lenses. There was poor compliance for topping up solution (53.8%) and lens case replacement (15.4%). About one third of MDs had a good level of compliance. Level of compliance and compliance rate of different behaviors were similar in MDs and NS. Periodic lens case replacement was the most neglected behavior in CL wearers for this region. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  7. Contact lens induced Pseudomonas keratitis following descemet stripping automated endothelial keratoplasty.

    Science.gov (United States)

    Dhiman, Rebika; Singh, Archita; Tandon, Radhika; Vanathi, M

    2015-10-01

    To report a case of bandage contact lens induced infectious keratitis caused by Pseudomonas aeruginosa following DSAEK. A 56-year-old female who underwent DSAEK at our institute for pseudophakic bullous keratopathy, developed contact lens induced keratitis in the fifth post operative week. Best corrected visual acuity (BCVA) reduced to perception of light in the left eye. Slit lamp examination revealed an epithelial ulcer measuring 4.7mm×6mm with surrounding infiltrates in the anterior stroma with hypopyon. The interface was clear. The corneoscleral rim culture of the donor tissue showed no growth on bacterial and fungal culture ruling out the possibility of donor-to-host transmission of infection. Microbiological evaluation identified the causative agent to be Pseudomonas aeruginosa. Based on culture and sensitivity report patient was started on hourly instillation of topical polymyxin B 20,000IU and fortified ceftazidime 5%. A response to treatment was noted and there was a complete resolution of keratitis with residual scarring. There have been case reports suggesting a host to donor transmission of infection which manifests during the postoperative period. To the best of our knowledge there are no reports of bandage contact lens associated Pseudomonas keratitis in a case that has undergone DSAEK. The prolonged use of bandage contact lens, lens contamination, stagnation of tear film behind the lens, compromised ocular surface and post operative use of topical steroids can contribute to infectious keratitis in DSAEK cases. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  8. Contact Lens Safety (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2016-08-18

    Contact lenses are a convenient and effective alternative to traditional eye glasses, but improper care and use can result in severe damage to the eyes. In this podcast, Dr. Jennifer Cope discusses the importance of proper care and use of contact lenses.  Created: 8/18/2016 by MMWR.   Date Released: 8/18/2016.

  9. Cutoff score and responsiveness of the 8-item Contact Lens Dry Eye Questionnaire (CLDEQ-8) in a Large daily disposable contact lens registry.

    Science.gov (United States)

    Chalmers, Robin L; Keay, Lisa; Hickson-Curran, Sheila B; Gleason, William J

    2016-10-01

    To report (1) results of the 8-item Contact Lens Dry Eye Questionnaire (CLDEQ-8) among a large sample of SCL wearers before and during 1 year after fitting with one of 2 daily disposable (DD) lenses (etafilcon A or narafilcon B) in the TEMPO Registry, (2) the cut-off score to identify highly symptomatic SCL wearers and (3) the clinically important difference (CID) in the CLDEQ-8 score. Demographics, CL history and patterns of SCL use were documented. Construct validity of the CLDEQ-8 was tested versus overall opinion (OO) of habitual SCLs, eye dryness and eye sensitivity at baseline. Responsiveness to change in OO was tested. Cutoff score, CID, and predictive accuracy were analyzed with general linear mixed models, adjusting for clustering by site with Bonferoni correction for multiple comparisons. Baseline CLDEQ-8 data from 977 habitual SCL wearers showed significant association with OO, eye dryness and sensitivity (pContact Lens Association. Published by Elsevier Ltd. All rights reserved.

  10. The influence of contact lens wear on the corneal response to ultraviolet radiation.

    Science.gov (United States)

    Ahmedbhai, N; Cullen, A P

    1988-01-01

    One eye of each of 15 male pigmented rabbits was fitted with a gas-permeable rigid contact lens. Lenses were worn on a daily basis for an initial period of 7 days with the other eye serving as a control. After this initial period the lenses were removed and both eyes were irradiated with UV-B (305 nm +/- 9 full width half maximum) using either 0.03 J cm-2 or 0.12 J cm-2 which were approximately the epithelial and endothelial damage thresholds for this waveband respectively. The responses of the cornea were followed by microscopy and pachometry. Biomicroscopically there was a dramatic difference in response between contact lens wearing and non-wearing eyes for the higher radiant exposure, whereas little difference was observed at the lower level. For both levels of radiant exposure there was a significantly less corneal thickness increase in contact lens wearing eyes after UV-B irradiation. Recovery patterns were similar.

  11. Current and potential applications of anterior segment optical coherence tomography in contact lens fitting.

    Science.gov (United States)

    Luo, Zhonghui K; Jacobs, Deborah S

    2012-01-01

    Optical coherence tomography (OCT) is a non-invasive, high-resolution and high-speed imaging modality that has enjoyed rapid growth in ophthalmology since its development 20 years ago. Contact lens fitting is traditionally based on trial lenses, which is expensive and time-consuming. Modern anterior segment OCT is capable of generating three-dimensional ocular surface maps of the cornea and sclera with potential application in contact lens fitting. This paper reviewed the history, the ophthalmic applications, and the most recent advancement in three-dimensional anterior segment OCT. There is very limited literature of OCT in contact lens fitting to date. This review anticipates an increase in this application in the near future.

  12. The TFOS International Workshop on Contact Lens Discomfort: report of the subcommittee on neurobiology.

    Science.gov (United States)

    Stapleton, Fiona; Marfurt, Carl; Golebiowski, Blanka; Rosenblatt, Mark; Bereiter, David; Begley, Carolyn; Dartt, Darlene; Gallar, Juana; Belmonte, Carlos; Hamrah, Pedram; Willcox, Mark

    2013-10-18

    This report characterizes the neurobiology of the ocular surface and highlights relevant mechanisms that may underpin contact lens-related discomfort. While there is limited evidence for the mechanisms involved in contact lens-related discomfort, neurobiological mechanisms in dry eye disease, the inflammatory pathway, the effect of hyperosmolarity on ocular surface nociceptors, and subsequent sensory processing of ocular pain and discomfort have been at least partly elucidated and are presented herein to provide insight in this new arena. The stimulus to the ocular surface from a contact lens is likely to be complex and multifactorial, including components of osmolarity, solution effects, desiccation, thermal effects, inflammation, friction, and mechanical stimulation. Sensory input will arise from stimulation of the lid margin, palpebral and bulbar conjunctiva, and the cornea.

  13. A new technique for rigid gas permeable contact lens fitting following penetrating keratoplasty.

    Science.gov (United States)

    Eggink, F A; Nuijts, R M

    2001-06-01

    To evaluate a new, rigid gas permeable contact lens fitting technique following penetrating keratoplasty. For the correction of postoperative anisometropia or astigmatism, a rigid gas permeable, tetra-curve contact lens with an overall diameter of 12.0 mm and a back optic zone diameter of 8.5 mm was fitted in 36 eyes of 33 patients, 7 months after penetrating keratoplasty. The contact lens back optic zone radius was selected using the videokeratography values over the elevated edges of the transplant wound (with the sutures in place). Graft clarity, visual outcome, and corneal topography were evaluated up to 3 years after surgery at intervals of 6 months. Throughout the follow-up period (range 6-36, mean 19.3+/-sd 11.8 months), all grafts remained clear. Mean contact lens daily wearing time averaged 13.6 (+/- sd 4.7) hours. Mean best-corrected visual acuity improved from +0.36 (+/- sd 0.18) LogMAR with spectacles to +0.11 (+/- sd 0.11) LogMAR with contact lenses (p contact lenses with a tetra-curve design were well tolerated in all patients for more than 13 hours daily.

  14. The role of Serratia marcescens in soft contact lens associated ocular infections. A review.

    Science.gov (United States)

    Parment, P A

    1997-02-01

    Serratia marcescens is a Gram negative rod which for a century and a half was considered a harmless saphrophyte. However, medical technology and the use of antibacterial agents have created ecological niches for this bacterium, which is now a medical problem. The bacterium is encountered in connection with contact lens keratitis, often associated with contaminated contact lens solutions. The concentrations of chlorhexidin and thiomersal required in contact lens solution to suppress the bacterium have been proved toxic to the eye. Modern contact lens solutions with biguanids have rapid killing kinetics, while in solutions with polyquaternium S. marcescens can survive in reduced numbers for up to 72 hours. The adherence of a specific isolate of Serratia to hydrogel lenses increased with decreased water content of the lenses. However, there has been no correlation between hydrophobicity markers or hemagglutinins and adherence to contact lenses or urinary tract epithelium. When handling medical plastic devices, such as contact lenses, strictly enforced hygiene remains the most important method to combat environmental bacteria such as Serratia marcescens.

  15. Quantitative assessment of bandage soft contact lens wear immediately after LASIK.

    Science.gov (United States)

    Orucov, Faik; Frucht-Pery, Joseph; Raiskup, Frederick D; Strasman, Eyal; Landau, David; Solomon, Abraham

    2010-10-01

    To evaluate the efficacy and tolerability of overnight bandage soft contact lenses applied immediately after LASIK. Bandage soft contact lenses were applied immediately following bilateral simultaneous LASIK in 161 consecutive patients. Signs and symptoms associated with contact lens wear were prospectively recorded at 1 hour, 4 hours, and the following morning, using a standardized questionnaire. Contact lenses were removed at 1 hour if patients were symptomatic of intolerance. If no signs of contact lens intolerance appeared at 1 hour, the lenses were removed the following morning. No contact lenses were applied in 61 patients after LASIK. One hour after the procedure, contact lenses were removed from 47 patients due to intolerance. In these patients, contact lens removal was associated with a significant decrease of the total score the next morning (0.31±0.55) compared to 1 hour (5.65±1.60, Pcontact lenses (0.20±0.52 vs 1.30±1.78) and those in whom the contact lenses were not applied (0.76±1.19 vs 3.24±1.93). Mucoid discharge at the lid margins was noted in 52.6% of patients and mild corneal edema was noted in 28.8% of patients with bandage soft contact lenses at 12 to 18 hours. Bandage soft contact lens application after LASIK is associated with significant reduction of symptoms during the immediate postoperative period. However, removal of these lenses may be necessary shortly after the procedure. Copyright 2010, SLACK Incorporated.

  16. Migration of rigid gas permeable contact lens into the upper eyelid after trauma: a case report.

    Science.gov (United States)

    Kang, Hyera; Takahashi, Yasuhiro; Kakizaki, Hirohiko

    2016-06-01

    Migration of a rigid gas permeable (RGP) contact lens after trauma is rare, and its clinical characteristics have not been fully discussed. A 36-year-old female showed mild swelling in the right upper eyelid. She lost her RGP contact lens seven months prior to her first visit, from trauma by her child's kick to the right eye. At the first examination, we felt a firm lump inferior to the right brow. Eversion of the upper eyelid also revealed a firm subconjunctival mass superior to the upper tarsus. After incising the conjunctiva, the RGP contact lens was found without a fibrous capsule and granulation tissue in the subconjunctival space. Three years after removal of the lens, the patient did not show any complications, including ptosis. The RGP contact lens in the present case migrated into the subconjunctival space superior to the upper tarsus without a fibrous capsule and granulation tissue. These findings are similar to those in previously reported traumatic cases but are different from those in some spontaneous migration cases. This difference may be caused by differences in the migration mechanisms.

  17. A silicone hydrogel contact lens after 7 years of continuous wear.

    Science.gov (United States)

    Yesilirmak, Nilufer; Altınors, Dilek D

    2013-08-01

    To report an unusual case with a bandage silicone hydrogel lens that was applied over cyanoacrylate glue application for corneal perforation. Retrospective, interventional case report. A 67-year-old woman with a history of corneal trauma experienced spontaneous corneal perforation in her left eye. Upon arrival, her anterior chamber was flat and Seidel test was positive. After initial treatment with cyanoacrylate adhesive and a bandage silicone hydrogel contact lens, there was no leakage and the anterior chamber was formed at the follow-up period. She was started topical antibiotics. After 7 years, she came back with the complaint of permanent redness in her left eye with the same silicone hydrogel lens in her eye. Corneal healing may occur under cyanoacrylate adhesive glue with therapeutic contact lenses and with proper antibiotic application. Silicone hydrogel contact lenses exhibit good efficacy and safety when utilized as a continuous wear therapeutic lens with antibiotics. Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  18. Comparison of Development of Dry Eye in Conventional Hydrogel and Silicone Hydrogel Contact Lens Users

    Directory of Open Access Journals (Sweden)

    Rukiye Aydın

    2013-01-01

    Full Text Available Pur po se: To compare the level and severity of dry eye between conventional hydrogel and silicone hydrogel contact lens users by using dry eye questionnaires and clinical tests. Ma te ri al and Met hod: Forty-two contact lens users who attended the Cornea and Contact Lens Unit, Department of Ophthalmology at Dokuz Eylül University, were included in this study. The first group consisted of subjects who have used conventional hydrogel (CHL contact lens for minimum one year and maximum five years. The second group consisted of subjects who have used silicone hydrogel (SHL contact lens for minimum one year and maximum 5 years. Twenty healthy individuals with no history of contact lens use were included in the control group. OSDI (Ocular Surface Disease Index questionnaire was performed to all patients. The tear function was determined by Schirmer’s test and tear break-up time in all three groups. Re sults: There was no statistically significant OSDI score differences between CHL and SHL users. Nevertheless, it was noted that OSDI score in both groups was statistically higher than in the control group. There was no statistically significant difference in tear break-up time between CHL and SHL users. On the other hand, tear break-up time was significantly lower in both groups when compared to the control group. There was no significant difference among the groups for Schirmer scoring. Dis cus si on: The use of conventional hydrogel and silicone hydrogel lenses causes a decline in tear break-up time leading to dry eye symptoms. However, no differences were determined between CHL and SHL users with regard to the severity of dry eye symptoms. (Turk J Ophthalmol 2013; 43: 7-14

  19. Contact Lens Use in Patients With Boston Keratoprosthesis Type 1: Fitting, Management, and Complications.

    Science.gov (United States)

    Thomas, Merina; Shorter, Ellen; Joslin, Charlotte E; McMahon, Timothy J; Cortina, M Soledad

    2015-11-01

    The Boston type 1 keratoprosthesis (KPro) is the most commonly used artificial cornea worldwide. Long-term bandage contact lenses are the standard of care for patients with these devices. The goal of bandage contact lenses is to maintain hydration and to protect the corneal tissue that surrounds the anterior plate of the keratoprosthesis which is vulnerable to desiccation, epithelial breakdown, dellen formation, and corneal melt. Contact lenses can also improve comfort, correct refractive errors, and improve the cosmesis of patients with artificial corneas. However, the continuous use of contact lenses places these patients at risk for complications such as lens loss, lens deposits, chronic conjunctivitis, and infection. In addition, obtaining an adequate fit in a patient with a compromised ocular surface and history of multiple surgeries including glaucoma drainage devices can present a challenge. This review discusses the types of contact lenses used, special fitting considerations, and common complications in patients with previous KPro surgery.

  20. Keratitis with Elizabethkingia meningoseptica occurring after contact lens wear: a case report.

    Science.gov (United States)

    Yang, Young Seong; Chun, Ji Woong; Koh, Jae Woong

    2013-04-01

    To report keratitis with Elizabethkingia meningoseptica, which occurred in a healthy patient after wearing contact lenses for 6 months. A 24-year-old male patient visited our hospital with ocular pain. This patient had a history of wearing soft contact lenses for 6 months, about 10 hours per day. At initial presentation, slit lamp examination showed corneal stromal infiltrations and small epithelial defect. Microbiological examinations were performed from corneal scrapings, contact lenses, and the contact lens case and solution. The culture results from contact lenses, contact lens case and solution were all positive for Elizabethkingia meningoseptica. Thus, we could confirm that the direct cause of keratitis was contamination of the contact lenses. The patient was treated with 0.3% gatifloxacin. After treatment, the corneal epithelial defect was completely healed, and a slight residual subepithelial corneal opacity was observed. We diagnosed keratitis with Elizabethkingia meningoseptica in a healthy young male wearing soft contact lenses. We conclude that Elizabethkingia meningoseptica should be considered as a rare but potential pathogen for lens-related keratitis in a healthy host.

  1. Evaluation of RGP Contact Lens Fitting in Keratoconus Patients Using Hierarchical Fuzzy Model and Genetic Algorithms.

    Science.gov (United States)

    Falahati Marvast, Fatemeh; Arabalibeik, Hossein; Alipour, Fatemeh; Sheikhtaheri, Abbas; Nouri, Leila; Soozande, Mehdi; Yarmahmoodi, Masood

    2016-01-01

    Keratoconus is a progressive non-inflammatory disease of the cornea. Rigid gas permeable contact lenses (RGPs) are prescribed when the disease progresses. Contact lens fitting and assessment is very difficult in these patients and is a concern of ophthalmologists and optometrists. In this study, a hierarchical fuzzy system is used to capture the expertise of experienced ophthalmologists during the lens evaluation phase of prescription. The system is fine-tuned using genetic algorithms. Sensitivity, specificity and accuracy of the final system are 88.9%, 94.4% and 92.6% respectively.

  2. Acanthamoeba Species Keratitis in a Soft Contact Lens Wearer Molecularly Linked to Well Water

    Directory of Open Access Journals (Sweden)

    Samira Mubareka

    2006-01-01

    Full Text Available Acanthamoeba species keratitis has been associated with soft contact lens wear. In the present report, an epidemiological link was established between the patient's isolate and well water from the home using molecular methods. To the authors' knowledge, this is the first case in Canada where such a link has been established. Primary care practitioners and specialists, including ophthalmologists and infectious diseases specialists, must maintain a high degree of clinical suspicion in soft contact lens wearers with keratitis unresponsive to conventional topical and systemic treatment.

  3. Clinician interpersonal communication skills and contact lens wearers' motivation, satisfaction, and compliance.

    Science.gov (United States)

    Thompson, B; Collins, M J; Hearn, G

    1990-09-01

    The relation between the practitioner and patient may have important effects upon the safety and success of contact lens wear. In this study we investigated the interrelations among clinicians' interpersonal communication skills and patients' motivation, satisfaction, and compliance with care and maintenance instructions. These variables were measured through questionnaires and interviews. Significant associations were found among many aspects of the clinicians' interpersonal skills and aspects of the patients' motivation and satisfaction. These findings are consistent with those from other health care settings and indicate that the quality of the contact lens practitioner's interpersonal skills can substantially influence patient outcomes and perceptions.

  4. Stretchable Electronic Platform for Soft and Smart Contact Lens Applications

    OpenAIRE

    Vasquez Quintero, Andrés Felipe; Verplancke, Rik; De Smet, Herbert; Vanfleteren, Jan

    2017-01-01

    A stretchable platform with spherical-shaped electronics based on thermo- plastic polyurethane (TPU) is introduced for soft smart contact lenses. The low glass transition temperature of TPU, its relatively low hardness, and its proven biocompatibility (i.e., protection of exterior body wounds) fulfill the essential requirements for eye wearable devices. These requirements include optical transparency, conformal fitting, and flexibility comparable with soft contact lense...

  5. Steady-State Diffusion of Water through Soft-Contact LensMaterials

    Energy Technology Data Exchange (ETDEWEB)

    Fornasiero, Francesco; Krull, Florian; Radke, Clayton J.; Prausnitz, JohnM.

    2005-01-31

    Water transport through soft contact lenses (SCL) is important for acceptable performance on the human eye. Chemical-potential gradient-driven diffusion rates of water through soft-contact-lens materials are measured with an evaporation-cell technique. Water is evaporated from the bottom surface of a lens membrane by impinging air at controlled flow rate and humidity. The resulting weight loss of a water reservoir covering the top surface of the contact-lens material is recorded as a function of time. New results are reported for a conventional hydrogel material (SofLens{trademark} One Day, hilafilcon A, water content at saturation W{sub 10} = 70 weight %) and a silicone hydrogel material (PureVision{trademark}, balafilcon A, W{sub 10} = 36 %), with and without surface oxygen plasma treatment. Also, previously reported data for a conventional HEMA-SCL (W{sub 10} = 38 %) hydrogel are reexamined and compared with those for SofLens{trademark} One Day and PureVision{trademark} hydrogels. Measured steady-state water fluxes are largest for SofLens{trademark} One Day, followed by PureVision{trademark} and HEMA. In some cases, the measured steady-state water fluxes increase with rising relative air humidity. This increase, due to an apparent mass-transfer resistance at the surface (trapping skinning), is associated with formation of a glassy skin at the air/membrane interface when the relative humidity is below 55-75%. Steady-state water-fluxes are interpreted through an extended Maxwell-Stefan diffusion model for a mixture of species starkly different in size. Thermodynamic nonideality is considered through Flory-Rehner polymer-solution theory. Shrinking/swelling is self-consistently modeled by conservation of the total polymer mass. Fitted Maxwell-Stefan diffusivities increase significantly with water concentration in the contact lens.

  6. The use of contact lens telescopic systems in low vision rehabilitation.

    Science.gov (United States)

    Vincent, Stephen J

    2017-06-01

    Refracting telescopes are afocal compound optical systems consisting of two lenses that produce an apparent magnification of the retinal image. They are routinely used in visual rehabilitation in the form of monocular or binocular hand held low vision aids, and head or spectacle-mounted devices to improve distance visual acuity, and with slight modifications, to enhance acuity for near and intermediate tasks. Since the advent of ground glass haptic lenses in the 1930's, contact lenses have been employed as a useful refracting element of telescopic systems; primarily as a mobile ocular lens (the eyepiece), that moves with the eye. Telescopes which incorporate a contact lens eyepiece significantly improve the weight, comesis, and field of view compared to traditional spectacle-mounted telescopes, in addition to potential related psycho-social benefits. This review summarises the underlying optics and use of contact lenses to provide telescopic magnification from the era of Descartes, to Dallos, and the present day. The limitations and clinical challenges associated with such devices are discussed, along with the potential future use of reflecting telescopes incorporated within scleral lenses and tactile contact lens systems in low vision rehabilitation. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  7. Analysis on multifocal contact lens design based on optical power distribution with NURBS.

    Science.gov (United States)

    Vu, Lien T; Chen, Chao-Chang A; Shum, Patrick Joi-Tsang

    2017-10-01

    This paper aims to develop and analyze the design method of multifocal contact lenses to obtain curvature continuity in the optical surfaces with the high addition (Add) powers by adjusting non-uniform rational B-spline (NURBS) curves. The paper has developed mathematical formulae to generate the optical power distributions in which the powers continuously change from either near or distant center to the opposite focal length in the periphery of the optical region with different change rates and Add power values. This developed method can efficiently adjust and optimize three parameters, including control points, weight, and knots of the NURBS, to be anterior optical lens surface profiles to adapt for these given power profiles. The result shows that the proposed contact lenses not only achieve smooth and continuous anterior optical surfaces, but also satisfy various optical power distributions with high Add power values for different pupil diameters. Then, these designs of contact lenses can be feasibly converted to the computer-aided design format for analysis and manufacture for molding or single-point diamond turning. Experimental results of this method have been tested and proven when both the power distributions of simulation of lenses and the actual machined samples match the original specified powers provided by clinical demands of a multifocal contact lens. Future integration with variant clinical demands and optimization rules of lens design can be explored for a progressive contact lens.

  8. Change in refractive anisometropia in presbyopic adults wearing monovision contact lens correction.

    Science.gov (United States)

    Wick, B; Westin, E

    1999-01-01

    Researchers studying the refractive development of infant monkeys suggest that monocular refractive error changes in response to induced ametropia; specifically, slightly blurring one eye may cause a difference to develop between each eye's correction (anisometropia) when none existed before wearing the correction. The important question of whether similar changes occur in humans has not been addressed. We compared premonovision correction and the correction after at least 12 months of monovision soft contact lens wear (artificially induced anisometropia prescribed to focus one eye for near and the other for distance so that bifocal glasses are not needed) for 62 healthy predominantly female soft contact lens wearers and (a) 62 age- and sex-matched spectacle wearers and (b) 62 age- and generally sex-matched contact lens wearers. Control patients wore corrections of like power and had similar follow-up periods. Development of anisometropia occurred significantly more frequently among monovision wearers than among spectacle (p = 0.043) or contact lens wearing controls (p = 0.025). Changes in anisometropia greater than or equal to 0.50 D, with amounts up to 1.25 D, occurred in 29% of monovision wearers. Changes in refractive correction occur for adults who have monocular blur intentionally induced with monovision contact lenses. Similar changes may also occur after refractive surgery if one eye is corrected for a different distance than the other. Care should be taken when counseling presbyopic patients so that they are aware of the possibility of inducing refractive changes after monovision correction.

  9. Hard contact lens wear and the risk of acquired blepharoptosis: a case-control study.

    Science.gov (United States)

    Kitazawa, Takeshi

    2013-01-01

    Since there are increasing numbers of patients with blepharoptosis who have a history of wearing contact lenses, we attempted to estimate the risk of developing ptosis from wearing hard contact lenses. In an age-matched case-control study that was performed in a hospital in Japan, we compared the rate of hard contact lens users in ptosis cases with that in a control group and then estimated the odds ratio. The history of wearing hard contact lenses was significantly higher in patients (90.2%) versus controls (31.6%). Hard contact lens wearers had a 20 times increased risk of ptosis (odds ratio: 19.9; 95% confidence interval: 6.32-62.9) compared with the nonwearing subjects. This study indicated that there was a significant association between hard contact lenses and blepharoptosis. Because of both the prevalence of use and the aging of the population, contact lens-induced blepharoptosis is no longer just a problem for young and middle-aged people with myopia but also for the elderly population.

  10. Objective assessment of squamous metaplasia of conjunctival epithelial cells as associated with soft contact lens wear versus non-lens wearers.

    Science.gov (United States)

    Doughty, Michael J

    2014-10-01

    To objectively assess the morphology of superficial conjunctival surface cells showing squamous metaplasia as seen in contact lens wearers. Impression cytology samples were taken from interpalpebral bulbar conjunctiva from 23 young adult white European women with an average of 6 years of successful daily soft contact lens wear and 23 non-contact-lens-wearing women of the same age. Cell images were graded, and cell and nuclear dimensions and areas were measured by planimetry. The contact lens wearers had a mean squamous metaplasia grade (Nelson) of 2.74 versus 0.35 for the non-lens wearers, with the cell longest dimension (LONG) being 54.4 ± 5.6 μm versus 22.4 ± 2.9 μm, respectively (P cell shortest dimension (SHORT) and cell area values (P cell nuclei in the contact lens wearers, based on measures of cell nuclear length (NUCLONG), were 12.7 ± 1.7 μm versus 10.0 ± 1.1 μm (P metaplasia develops, at least in long-term soft contact lens wearers, the conjunctival surface cells become considerably enlarged, but the nuclear size of these cells also increases, rather than showing signs of pyknosis.

  11. Blefaroptose em usuários de lentes de contato Blepharoptosis in contact lens wearers

    Directory of Open Access Journals (Sweden)

    Tiana Gabriela Burmann

    2006-10-01

    Full Text Available OBJETIVO: Investigar a freqüência de blefaroptose adquirida em usuários de lentes de contato. MÉTODOS: Avaliação prospectiva de 50 pacientes, usuários de lentes de contato, do Setor de Lentes de Contato do Serviço de Oftalmologia do Complexo Hospitalar Santa Casa de Porto Alegre, durante o período de abril a novembro de 2004. A distância reflexo-margem (MRD foi avaliada em 99 pálpebras de usuários de lentes de contato e para as 52 pálpebras de controle. Pacientes cuja medida da distância reflexo-margem se apresentou inferior a 2 mm ou com assimetria de distância reflexo-margem maior ou igual a 2 mm foram considerados portadores de blefaroptose. Foram avaliados o tipo de lente de contato utilizada e o tempo de uso das mesmas. RESULTADOS: Cinco pacientes apresentaram ptose, todos eles eram usuários de lentes de contato rígidas, um com ptose bilateral e quatro, unilateral. A distância reflexo-margem dos pacientes usuários de lentes de contato foi, em média, 0,88 mm inferior aos não usuários. Os valores de distância reflexo-margem foram progressivamente decrescentes nos grupos estudados: controles, usuários de lentes gelatinosas e de lentes rígidas. CONCLUSÃO: O estudo sugere que os usuários de lentes de contato possuem alteração dos valores de distância reflexo-margem, principalmente os que usam lentes rígidas.PURPOSE: To investigate the occurrence of acquired blepharoptosis in contact lens wearers. METHODS: Prospective analysis of 50 contact lens wearers being followed at the Contact Lenses Section of the Ophthalmology Service at the "Complexo Hospitalar Santa Casa de Porto Alegre" between April and November 2004. The margin reflex distance (MRD was evaluated for the 99 eyelids of contact lens wearers and for the 52 eyelids of controls. A patient whose measurement was less than 2 mm or with an assymetry of margin reflex distance greater or equal to 2 mm were considered with blepharoptosis. The contact lens type and

  12. Soft Contact Lens Wear During +G(Z) Acceleration.

    Science.gov (United States)

    1985-12-01

    of ocular disease and had ocular parameters within normal limits. The soft lenses were fitted by accepted standards, and a minimum of one month’s...and offer lower specific gravities than polymethylmethacrylate ( PMMA ) hard lenses. Soft contact lenses have overall diameters in the range of 13.5-15.0

  13. Hard Contact Lens Wear and the Risk of Acquired Blepharoptosis: A Case-Control Study

    OpenAIRE

    Kitazawa, Takeshi

    2013-01-01

    Objectives: Since there are increasing numbers of patients with blepharoptosis who have a history of wearing contact lenses, we attempted to estimate the risk of developing ptosis from wearing hard contact lenses. Methods: In an age-matched case-control study that was performed in a hospital in Japan, we compared the rate of hard contact lens users in ptosis cases with that in a control group and then estimated the odds ratio. Results: The history of wearing hard contact lenses was significan...

  14. Proteoglycan 4 and hyaluronan as boundary lubricants for model contact lens hydrogels.

    Science.gov (United States)

    Samsom, Michael; Iwabuchi, Yuno; Sheardown, Heather; Schmidt, Tannin A

    2017-07-07

    Clinical data show that in vitro contact lens friction is related to in vivo comfort. Solutions of biological lubricants hyaluronan (HA) and proteoglycan 4 (PRG4, also known as lubricin) reduce friction at a cornea-polydimethylsiloxane (PDMS) interface. The purpose of this study was to (1) determine if PRG4 can sorb to and lubricate model contact lens materials and (2) assess the boundary lubricating ability of PRG4 and HA compared to saline on model contact lens materials. PRG4 was obtained from bovine cartilage culture and suspended in saline at 300 µg/mL. N,N-Dimethylacrylamidetris (trimethylsiloxy) silane, (DMAA/TRIS) and methacryloxypropyltris (trimethylsiloxy) silane (pHEMA/TRIS) silicone hydrogels were prepared. A previously described in vitro eyelid-hydrogel and cornea-hydrogel biomechanical friction test was used to determine boundary lubricant effect. PRG4 sorption to the hydrogels was assessed using a soak-rinse protocol and western blotting. PRG4 effectively lubricated both silicone hydrogel materials and HA effectively lubricated pHEMA/TRIS, as indicated by a statistically significant reduction in friction compared to the saline control lubricant. An HA and PRG4 combination showed a synergistic effect for pHEMA/TRIS and effectively lubricated DMAA/TRIS. Biological boundary lubricants HA and PRG4 were shown to effectively lubricate silicone hydrogels when in solution. Additionally, HA and PRG4 showed synergistic lubrication for pHEMA/TRIS. The purpose of this study was not to replicate the friction coefficients of contact lenses, but rather to investigate lubricant-surface interactions for common contact lens constituents. These findings contribute to the potential development of biomolecule based lubricant drops for contact lens wearers. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

  15. Publication analysis of the contact lens field: what are the current topics of interest?

    Science.gov (United States)

    Cardona, Genís; Sanz, Joan P

    2015-01-01

    To determine the main current research interests of scientists working in the contact lens field. All articles published in the 2011 issues of all journals included in the Journal Citation Reports subject category Ophthalmology were inspected to expose those papers related to the contact lens field. Information regarding source journal was obtained and authorship details were recorded to determine the top most prolific authors, institutions and countries. A comprehensive list of key words was compiled to generate a two-dimensional term map in which the frequency of occurrence of a particular term is defined by label size and the distance between two terms is an indication of the relatedness of these terms, based on their co-occurrences within groups of key words. Clusters of related terms were also identified. Visual examination of all articles uncovered a total of 156 papers, published in 28 different journals. Contact Lens & Anterior Eye, Eye & Contact Lens and Optometry and Vision Science had 27 articles each. The most prolific authors and institutions revealed the predominance of countries with long research tradition in the contact lens field. Ten different word clusters or areas of interest were identified, including both traditional, yet unresolved issues (e.g., comfort or dry eye), and the latest research efforts (e.g., myopia control). These findings, which revealed contact lenses to be a fertile area of research, may be of relevance to new researchers as well as to those interested in exploring the latest research trends in this scientific discipline. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  16. The Effect of Fluctuating +G sub z Exposure on Rigid Gas-Permeable Contact Lens Wear

    Science.gov (United States)

    1989-11-01

    environment. Although there are visual, logistical, and economic disadvantages as well as ocular risks associated with contact lens wear, the advantage of...Medicine (USAFSAM) and found them to be remarkably stable on the cornea. Polymethyl methacrylate ( PMMA ) hard contact lenses did not fare as well under...visual acuity. However, the lenses used in this study had small diameters (8.2 mm) and were made of PMMA which is relatively heavy, with a specific

  17. Higher risk taking propensity of contact lens wearers is associated with less compliance.

    Science.gov (United States)

    Carnt, Nicole; Keay, Lisa; Willcox, Mark; Evans, Vicki; Stapleton, Fiona

    2011-10-01

    To determine whether risk taking personality is associated with compliance in contact lens wear, and how practitioner perception of compliance compares with wearer risk taking and non-compliant behaviour. Optometrists in Australia, recruited through professional organizations, were asked to enroll up to 10 current contact lens wearers each. Wearers completed a questionnaire assessing risk-taking propensity (20-item instrument), non-compliant behaviour and demographics. Non-compliance was scored on four components (maximum score 40, lens disinfection, 20; hand hygiene, 8; case hygiene, 6; case replacement, 6). Independently, practitioners ranked each wearer's non-compliance on a 1-5 scale. Associations between wearer risk taking propensity, non-compliant behaviour and practitioner perceived non-compliance were investigated using Pearson correlation. Significant associations were entered into a linear regression model predicting overall non-compliant behaviour. Seventy-three wearers were recruited by 18 optometrists (mean 4, range 1-10). Wearer risk taking was associated with less compliance (plens wear was not associated with non-compliant behaviour (p=0.8), nor was practitioner perception of compliance (p>0.6) Linear regression indicated that risk taking was the only independent significant factor predicting non-compliance, explaining 24% of the variation in behaviour. A higher risk taking personality style of contact lens wearers in Australia is associated with less compliant behaviour. Risk taking is a better predictor of compliance than age, gender and practitioner perception and helps explain the individual characteristics of wearers that may influence lens care and maintenance. Copyright © 2010 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  18. Randomized Trial of the Effect of Contact Lens Wear on Self-Perception in Children

    NARCIS (Netherlands)

    Walline, J.J.; Jones, L.A.; Sinnott, L.; Chitkara, M.; Coffey, B.; Jackson, J.M.; Manny, R.E.; Rath, M.J.; Prinstein, M.J.

    2009-01-01

    Purpose. To determine whether contact lens wear affects children's self-perceptions. Methods. The Adolescent and Child Health Initiative to Encourage Vision Empowerment Study was a randomized, single-masked trial conducted at five clinical centers in the United States. Subjects were 8- to

  19. National Apprenticeship and Training Standards for Optical Technician (Contact Lens Technician). Revised.

    Science.gov (United States)

    Employment and Training Administration (DOL), Washington, DC. Bureau of Apprenticeship and Training.

    These national standards are intended to serve as a guide for the establishment of thorough and complete apprenticeship programs to produce trained optical technicians (contact lens technicians). Covered in the individual sections are the following topics: definitions, qualifications for apprenticeship, credit for previous experience, continuity…

  20. Trichosporon asahii keratitis in a patient with a type I Boston keratoprosthesis and contact lens.

    Science.gov (United States)

    Keating, Anne; Pineda, Roberto

    2012-03-01

    The aim of the study was to report a case of Trichosporon asahii in a patient with a type I Boston keratoprosthesis and contact lens with review of the literature. A case report and literature review are provided. A 70-year-old monocular South Asian man with light perception vision and dense corneal scarring from previously failed amniotic membrane grafting and one failed corneal transplant was evaluated for a keratoprosthesis for visual rehabilitation. Three months after undergoing uneventful implantation of a type I Boston keratoprosthesis and placement of a therapeutic contact lens, he was found on routine follow-up to have a corneal infiltrate that was culture positive for T. asahii. The fungal keratitis was successfully treated with topical amphotericin B and oral ketoconazole. Contact lens wear is a known risk factor for fungal keratitis. Trichosporon is an uncommon agent of fungal keratitis. We report the first known case of fungal keratitis caused by T.asahii in a patient with a keratoprosthesis and contact lens.

  1. Image analysis of contact lens grading scales for objective grade assignment of ocular complications

    Science.gov (United States)

    Perez-Cabre, Elisabet; Millan, Maria S.; Abril, Hector C.; Valencia, Edison

    2005-06-01

    Ocular complications in contact lens wearers are usually graded by specialists using visual inspection and comparing with a standard reference. The standard grading scales consist of either a set of illustrations or photographs ordered from a normal situation to a severe complication. Usually, visual inspection based on comparison with standards yields results that may differ from one specialist to another due to contour conditions or personal appreciation, causing a lack of objectiveness in the assessment of an ocular disorder. We aim to develop a method for an objective assessment of two contact lens wear complications: conjunctiva hyperemia and papillary conjunctivitis. In this work, we start by applying different image processing techniques to two standard grading scales (Efron and Cornea and Contact Lens Research Unit-CCLRU grading scales). Given a set of standard illustrations or pictures, image pre-processing is needed to compare equivalent areas. Histogram analysis allows segmenting vessel and background pixel populations, which are used to determine features, such as total area of vessels and vessel length, in the measurement of contact lens effects. In some cases, the colour content of standard series can be crucial to obtain a correct assessment. Thus, colour image analysis techniques are used to extract the most relevant features. The procedure to obtain an automatic grading method by digital image analysis of standard grading scales is described.

  2. A Management Dilemma: Infectious Keratitis Associated with Soft Contact Lens Use and Dubious Treatment Compliance

    Directory of Open Access Journals (Sweden)

    Konstantinos T. Tsaousis

    2010-01-01

    Full Text Available Purpose. To present a case of infectious keratitis caused by the microorganism Serratia marcescens in a contact lens user and further to confer on the most advantageous management of comparable situations. Case. After altering the routine that she used for contact lens disinfection, a 24-year-old patient presented with pain and conjunctival redness in both eyes. Slit-lamp examination revealed two infiltrates in the inferior part of the cornea in the right eye and five smaller infiltrates in the superior half of the left cornea. Appropriate treatment, after hospitalization, improved the symptoms while culture of the contact lens material revealed Serratia marcescens as the responsible infectious factor. Conclusion. Enhancing the availability of information with respect to contact lens users and customized analysis regarding treatment for a particular complication could be beneficial in order to reduce the frequency of admission to the eye clinic due to infectious keratitis. In addition, rapid laboratory testing of the infected materials should be a priority for selection of the optimal treatment regimen.

  3. A Case of Non-Contact Lens related Acanthamoeba keratitis in Malaysia

    Directory of Open Access Journals (Sweden)

    Mohamed Kamel, A. G.

    2005-01-01

    Full Text Available Acanthamoeba is a ubiquitous free-living amoeba and is responsible for an uncommon yet increasingly diagnosed keratitis in humans. Acanthamoeba keratitis is perhaps the most challenging ocular infection to manage successfully and it can result in permanently impaired vision or blindness. Although contact lens use is the principal risk factor, about 10% of cases occur following trauma and exposure to contaminated soil or water. Cases of Acanthamoeba keratitis involving contact lens wearers have previously been reported in Malaysia but this is the first time, a non-contact lens relatedAcanthamoeba keratitis is reported. The case involved a 28 year old Indonesian male construction worker who had a trauma of the right eye. While working his eye was struck by some sand and dust particles and he quickly washed his eye with water from an open tank at the construction site. He then experienced pain, redness, glaring and blurring of vision of the right eye. The diagnosis was missed at the initial presentation but subsequent culture of the corneal scraping demonstrated Acanthamoeba as the aetiological agent. The history, clinical findings, diagnosis and treatment of non-contact lens related Acanthamoeba keratitis are briefly discussed in this communication. We hope to create awareness especially among the medical and paramedical staff about the existence of this infection in the country and fully support the consideration of Acanthamoeba keratitis as part of the differential diagnosis of most cases of presumed microbial keratitis.

  4. Objective and subjective evaluation of the performance of medical contact lenses fitted using a contact lens selection algorithm.

    Science.gov (United States)

    Visser, Esther-Simone; Wisse, Robert P L; Soeters, Nienke; Imhof, Saskia M; Van der Lelij, Allegonda

    2016-08-01

    To evaluate the performance of medical contact lenses (CLs) for a wide range of clinical indications. Prospective cross-sectional study. A total of 281 eyes were evaluated in 281 consecutive patients (≥18 years of age; CL use ≥3 months) who visited the contact lens service in a tertiary academic clinic for a scheduled follow-up visit. The main outcome measured were clinical indications for CL wear; CL type; change in corrected distance visual acuity (CDVA) with CL use; CL wearing duration; CL wearing time; subjective performance measured using a visual analog scale (VAS) questionnaire (score range: 0-100); and effectiveness of the lens-selection algorithm. Wearing CLs significantly improved CDVA compared to wearing spectacles (median change: -0.15 logMAR, range: 1.00 to -2.10; Plenses and users of soft lenses. These results underscore the importance of prescribing scleral lenses and the need for tertiary eye clinics to offer patients a variety of CL types. Copyright © 2016 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  5. Application of fresh amniotic membrane transplantation combined therapeutic soft corneal contact lens in pterygium

    Directory of Open Access Journals (Sweden)

    Han-Yuan Ye

    2014-09-01

    Full Text Available AIM:To evaluate the clinical effect of therapeutic soft corneal contact lens in combination with fresh amniotic membrane transplantation in the treatment of pterygium and its clinical value.METHODS:This study was a retrospective analysis of 200 pterygium excision patients(200 cases, 220 eyesin hospital from January 2010-June 2011. The patients were divided into two groups. Group 1(100 cases, 110 eyeswere patients treated with fresh amniotic membrane transplantation and therapeutic soft corneal contact lens while group 2(control group, 100 cases, 110 eyesdid not use corneal contact lens. The clinical outcomes in these two groups were compared in a 6-18mo postoperative follow-up observation.RESULTS:In control group using corneal contact lens the epithelium repair time ranged from 2-7d with an average time of 3.8d; in group 1 the epithelial repair time ranged from 1-5d with an average time of 2.5d. The patients were followed up for 6-18mo, 9 recurrent eyes were found in control group, the recurrence rate was 8.2%; 5 recurrent eyes were found in experimental group the recurreat rate was 4.5%. There were significant differences in the 2 groups comparing treatment outcomes(PCONCLUSION:The therapeutic effect of fresh amniotic membrane transplantation after pterygium excision is enhanced by the therapeutic application of corneal contact lens. The epithelial repair time is shortened, the recurrence rate is reduced after pterygium excision and stimulative symptoms including photophobia, tearing, foreign body sensation and ophthalmodynia caused by corneal epithelial defect can be relieved.

  6. Non-contact optical measurement of lens capsule thickness during simulated accommodation

    Science.gov (United States)

    Ziebarth, Noel; Manns, Fabrice; Acosta, Ana-Carolina; Parel, Jean-Marie

    2005-04-01

    Purpose: To non-invasively measure the thickness of the anterior and posterior lens capsule, and to determine if it significantly changes during accommodation. Methods: Anterior and posterior capsule thickness was measured on post-mortem lenses using a non-contact optical system using a focus-detection technique. The optical system uses a 670nm laser beam delivered to a single-mode fiber coupler. The output of the fiber coupler is focused on the tissue surface using an aspheric lens (NA=0.68) mounted on a translation stage with a motorized actuator. Light reflected from the sample surface is collected by the fiber coupler and sent to a photoreceiver connected to a computer-controlled data acquisition system. Optical intensity peaks are detected when the aspheric lens is focused on the capsule boundaries. The capsule thickness is equal to the distance traveled between two peaks multiplied by the capsule refractive index. Anterior and posterior lens capsule thickness measurements were performed on 18 cynomolgus (age average: 6+/-1 years, range: 4-7 years) eyes, 1 rhesus (age: 2 years) eye, and 12 human (age average: 65+/-16, range: 47-92) eyes during simulated accommodation. The mounted sample was placed under the focusing objective of the optical system so that the light was incident on the center pole. Measurements were taken of the anterior lens capsule in the unstretched and the stretched 5mm states. The lens was flipped, and the same procedure was performed for the posterior lens capsule. Results: The precision of the optical system was determined to be +/-0.5um. The resolution is 4um and the sensitivity is 52dB. The human anterior lens capsule thickness was 6.0+/-1.2um unstretched and 4.9+/-0.9um stretched (p=0.008). The human posterior lens capsule was 5.7+/-1.2um unstretched and 5.7+/-1.4um stretched (p=0.974). The monkey anterior lens capsule thickness was 5.9+/-1.9um unstretched and 4.8+/-1.0um stretched (p=0.002). The monkey posterior lens capsule was 5

  7. Complementary treatment of contact lens-induced corneal ulcer using honey: a case report.

    Science.gov (United States)

    Majtanova, Nora; Vodrazkova, Erika; Kurilova, Veronika; Horniackova, Miroslava; Cernak, Martin; Cernak, Andrej; Majtan, Juraj

    2015-02-01

    The aim of this study was to report the complementary use of honey for treatment of a contact lens-induced corneal ulcer. A 23-year-old contact lens user presented with a corneal ulcer in her left eye. She had visual acuity reduced to hand movement. There was a history of wearing contact lenses while swimming in a lake seven days before presentation. The cultures from corneal scrapings and contact lenses were positive for Klebsiella oxytoca, Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Pseudomonas spp. The treatment with topical levofloxacin and 25% (w/v) γ-irradiated honeydew honey solution was effective and the patient achieved final best corrected visual acuity of affected eye. In addition to positive clinical outcome, honeydew honey was shown to be highly effective in vitro against ocular isolates, in particular S. maltophilia. The minimal inhibitory concentrations for honeydew honey ranged from 5% to 10%. These results demonstrate that honey is a promising antibacterial agent in management of corneal ulcers. Moreover, honey exhibits anti-biofilm and anti-inflammatory properties, and thus becomes an interesting ophthalmologic agent. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  8. Clinical performance of Rose K2 soft contact lens for keratoconus

    Directory of Open Access Journals (Sweden)

    Ihsan Yilmaz

    2017-08-01

    Full Text Available AIM: To evaluate the comfort and visual performance of Rose K2 soft contact lenses in patients with keratoconus.METHODS: Fifty eyes of 50 participants were included in this cross-sectional study. Each participant received a full ophthalmologic examination involving refraction, uncorrected visual acuity(UCVA, best spectacle corrected visual acuity(BCVA, slit-lamp biomicroscopy-fundoscopy, break-up time(BUT, corneal topography, and contrast sensitivity. After contact lens was fitted best contact lens corrected visual acuity(BCLCVA, contrast sensitivity, and comfort rating via visual analogue scales(VASwere performed.RESULTS: The mean age was 26.2±6.0(range: 16 to 39y. The mean logMAR UCVA, BCVA, and BCLCVA with Rose K2 soft(in orderwere 0.61±0.37(range: 0.15-1.3, 0.42±0.32(range: 0-1.3, and 0.18±0.20(range: 0-1.3. There were significant increases in visual acuities with contact lenses(P P CONCLUSION: Rose K2 soft contact lens can improve visual acuity, contrast sensitivity with comfort in patients with keratoconus.

  9. Contact lens-induced corneal endothelial polymegathism: functional significance and possible mechanisms.

    Science.gov (United States)

    Connor, C G; Zagrod, M E

    1986-07-01

    The corneal endothelium is principally responsible for maintenance of corneal deturgescence. Therefore, compromise of corneal endothelial functional integrity can result in corneal swelling and opacification. Contact lenses constitute a potential insult to the cornea because their wear reduces the oxygen available to that tissue. It has been reported that contact lens wear induces transient as well as permanent morphologic changes in the corneal endothelium. One of the permanent changes reported is referred to as polymegathism, which is a variation in cell size within the endothelial monolayer. Several investigators have suggested that polymegathism reflects a compromised endothelial functional status. Mechanisms proposed to explain contact lens-induced polymegathism include lactate accumulation, changes in pH, and elevation in CO2 content. We discuss these possibilities as well as speculate that these polymegathous shape changes may be a result of decreased endothelial ATP (adenosine triphosphate) levels and disturbed calcium homeostasis due to corneal endothelial hypoxia.

  10. Mottled cyan opacification of the posterior cornea in contact lens wearers.

    Science.gov (United States)

    Holland, E J; Lee, R M; Bucci, F A; Janda, A M; Doughman, D J; Harris, J K; Krachmer, J H

    1995-05-01

    We studied patients who had mottled cyan-colored opacities of the cornea to better understand the cause and prognosis of this entity. We reviewed examinations of patients who had a mottled cyan opacification of the cornea. Risk factors, including contact lens wear and exposure to heavy metals, were analyzed. Clinical findings, pachymetry specular microscopy, and progression of the abnormality were noted. Six patients who had a mottled cyan opacification at the level of Descemet's membrane were identified. These opacities were located in the peripheral and midperipheral cornea. All patients had bilateral findings, had visual acuities of 20/20 or better, and were asymptomatic. All patients had worn soft contact lenses bilaterally for periods ranging from seven to 14 years. All patients had the similar clinical appearance of a mottled cyan opacification at the level of Descemet's membrane in the peripheral cornea. Long-term contact lens wear appears to be associated; however, the exact cause is unclear.

  11. The Effect of Contact Lens Usage on Corneal Biomechanical Parameters in Keratoconus Patients

    Directory of Open Access Journals (Sweden)

    Ali Bülent Çankaya

    2012-05-01

    Full Text Available Pur po se: To determine and compare the corneal biomechanical properties in keratoconus patients using rigid gas permeable contact lenses and keratoconus patients who do not use contact lenses. Ma te ri al and Met hod: The study consisted of 70 healthy controls (Group A, 27 ketatoconus subjects who do not use contact lens (Group B and 36 rigid gas permeable contact lens using keratoconic patients (Group C. Corneal viscoelastic parameters were measured with an Ocular response analyzer (ORA. Central corneal thickness was measured with an ultrasonic pachymeter. The differences in ORA parameters between the groups were compared. Re sults: The mean corneal hysteresis (CH in Groups A, B, and C were 10.3±1.5 mm Hg, 7.8±1.4 mm Hg, and 7.4±1.2 mm Hg, respectively. The differences in mean CH between Group A and the other two groups were statistically significant (p<0.01 for both comparisons, but no statistically significant difference was found between groups B and C in terms of mean CH (p=0.61. The mean corneal resistance factor (CRF was 10.7±1.9 in Group A compared with 6.6±1.6 in Group B and 6.1±1.5 in Group C. The differences in mean CRF between Group A and the other two groups were statistically significant (p<0.01 for both comparisons. There was no significant difference in CRF between the keratoconus eyes with or without rigid gas permeable contact lens usage (p=0.57. Dis cus si on: Our results suggest that ORA-generated parameters may be different in subjects with keratoconus. Corneal biomechanical parameters did not demonstrate a clear trend of change with rigid gas permeable contact lens usage. (Turk J Ophthalmol 2012; 42: 197-201

  12. Clinical Presentation and Microbial Analyses of Contact Lens Keratitis; an Epidemiologic Study

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    Seyed Ahmad Rasoulinejad

    2014-09-01

    Full Text Available Introduction: Microbial keratitis is an infective process of the cornea with a potentially and serious visual impairments. Contact lenses are a major cause of microbial keratitis in the developed countries especially among young people. Therefore, the purpose of the present study was to evaluate the frequency and microbiological characteristic of CLK in patients referred to the emergency department (ED of teaching hospitals, Babol, Iran. Methods: This is a cross-sectional study of all patients with contact lens induced corneal ulcers admitted to the teaching hospitals of Babol, Iran, from 2011- 2013. An ophthalmologist examined patients with the slit-lamp and clinical features of them were noted (including pain, redness, foreign body sensation, chemosis, epiphora, blurred vision, discomfort, photophobia, discharge, ocular redness and swelling. All suspected infectious corneal ulcers were scraped for microbial culture and two slides were prepared. Data were analyzed using SPSS software, version 18.0. Results: A total of 14 patients (17 eyes were recruited into the study (100% female. The patients’ age ranged from 16-37 years old (mean age 21.58±7.23 years. The most prevalent observed clinical signs were pain and redness. Three samples reported as sterile. The most common isolated causative organism was pseudomonas aeroginosa (78.6%, Staphylococcus aureus 14.3%, and enterobacter 7.1%, respectively. Treatment outcome was excellent in 23.5%, good in 47.1%, and poor in 29.4% of cases. Conclusion: Improper lens wear and care as well as the lack of awareness about the importance of aftercare visits have been identified as potential risk factors for the corneal ulcer among contact lens wearers. Training and increasing the awareness of adequate lens care and disinfection practices, consulting with an ophthalmologist, and frequent replacement of contact lens storage cases would greatly help reducing the risk of microbial keratitis.

  13. Age and other risk factors for corneal infiltrative and inflammatory events in young soft contact lens wearers from the Contact Lens Assessment in Youth (CLAY) study.

    Science.gov (United States)

    Chalmers, Robin L; Wagner, Heidi; Mitchell, G Lynn; Lam, Dawn Y; Kinoshita, Beth T; Jansen, Meredith E; Richdale, Kathryn; Sorbara, Luigina; McMahon, Timothy T

    2011-08-24

    To describe age and other risk factors for corneal infiltrative and inflammatory events (CIEs) in young, soft contact lens (SCL) wearers and to model the age-related risk. A multicenter, retrospective chart review of 3549 SCL wearers (8-33 years at first observed visit, +8.00 to -12.00D, oversampling lens care products, and SCL wearing history. Event diagnoses were adjudicated to consensus by reviewers masked to wearer identity, age, and SCL parameters. Significant univariate risk factors for CIEs were subsequently tested in multivariate generalized estimating equations. Charts from 14,305 visits observing 4,663 SCL years yielded 187 CIEs in 168 wearers. Age was a significant nonlinear risk factor, peaking between 15 and 25 years (P lens wear, use of multipurpose care products, silicone hydrogels, and extended wear were all significantly associated with CIEs with SCL wear. Use of SCLs in young patients aged 8 to 15 years was associated with a lower risk of infiltrative events compared with teens and young adults. In terms of safety outcomes, SCLs appear to be an acceptable method of delivering optics designed to manage myopia progression in children and young teens in the future.

  14. Acanthamoeba Keratitis among Rigid Gas Permeable Contact Lens Wearers, United States, 2005–2011

    Science.gov (United States)

    Cope, Jennifer R.; Collier, Sarah A.; Schein, Oliver D.; Brown, Allison C.; Verani, Jennifer R.; Gallen, Rachel; Beach, Michael J.; Yoder, Jonathan S.

    2016-01-01

    Objective To describe the clinical presentation and outcomes of Acanthamoeba keratitis (AK) in rigid gas permeable (RGP) contact lens wearers and identify modifiable risk factors. Design A case-control investigation. Participants Case-patients were RGP contact lens-wearing U.S. residents with a diagnosis of AK during 2005–2011. Controls were RGP contact lens wearers with no history of AK and at least 12 years of age. Methods Case-patients were identified during two multi-state AK outbreak investigations. Controls from the first investigation in 2007 were identified using a reverse address directory. In the second investigation, controls were recruited from participating ophthalmology and optometry practices. Case-patients and controls were interviewed by phone using a standardized questionnaire. Odds ratios (ORs) and Fisher’s exact P-values were calculated to assess risk factors associated with infection. Main Outcome Measures AK, a rare eye disease primarily affecting contact lens wearers, is caused by free-living amebae, Acanthamoeba spp. Results We identified 37 case-patients in the two investigations, 10 (27%) from the 2007 investigation and 27 (73%) from 2011. There were 17 healthy controls, 9 (53%) from 2007 and 8 (47%) from 2011. Among case-patients, 9 (24%) wore RGP lenses for orthokeratology or therapeutic indication; no controls wore RGP lenses for these indications. Significant risk factors for AK were wearing lenses for orthokeratology (OR undefined, P=0.02), sleeping while wearing lenses (OR 8.00, P=0.04), storing lenses in tap water (OR 16.00, P=0.001), and topping off contact lens solution in the case (OR 4.80, P=0.01). After stratifying by use of RGP lenses for orthokeratology, storing lenses in tap water and topping off remained significant exposures. Conclusions Nearly a quarter of case-patients were orthokeratology wearers. Using tap water to store RGP lenses and topping off solution in the lens case were modifiable risk behaviors identified

  15. Acanthamoeba Keratitis among Rigid Gas Permeable Contact Lens Wearers in the United States, 2005 through 2011.

    Science.gov (United States)

    Cope, Jennifer R; Collier, Sarah A; Schein, Oliver D; Brown, Allison C; Verani, Jennifer R; Gallen, Rachel; Beach, Michael J; Yoder, Jonathan S

    2016-07-01

    To describe the clinical presentation and outcomes of Acanthamoeba keratitis (AK) in rigid gas permeable (RGP) contact lens wearers and to identify modifiable risk factors. Case-control investigation. Patients were RGP contact lens-wearing United States residents with a diagnosis of AK from 2005 through 2011. Controls were RGP contact lens wearers with no history of AK who were at least 12 years of age. Patients were identified during 2 multistate AK outbreak investigations. Controls from the first investigation in 2007 were identified using a reverse address directory. In the second investigation, controls were recruited from participating ophthalmology and optometry practices. Patients and controls were interviewed by phone using a standardized questionnaire. Odds ratios (ORs) and Fisher exact P values were calculated to assess risk factors associated with infection. Acanthamoeba keratitis, a rare eye disease primarily affecting contact lens wearers, is caused by free-living amebae, Acanthamoeba species. We identified 37 patients in the 2 investigations, 10 (27%) from the 2007 investigation and 27 (73%) from 2011. There were 17 healthy controls, 9 (53%) from 2007 and 8 (47%) from 2011. Among patients, 9 (24%) wore RGP lenses for orthokeratology or therapeutic indication; no controls wore RGP lenses for these indications. Significant risk factors for AK were wearing lenses for orthokeratology (OR, undefined; P = 0.02), sleeping while wearing lenses (OR, 8.00; P = 0.04), storing lenses in tap water (OR, 16.00; P = 0.001), and topping off contact lens solution in the case (OR, 4.80; P = 0.01). After stratifying by use of RGP lenses for orthokeratology, storing lenses in tap water and topping off remained significant exposures. Nearly one quarter of patients were orthokeratology wearers. Using tap water to store RGP lenses and topping off solution in the lens case were modifiable risk behaviors identified in RGP wearers who wore lenses for both orthokeratology

  16. Photocatalytic destruction of hexane eliminates emissions in contact lens manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Kittrell, J.R.; Quinlan, C.W. [KSE, Inc., Amherst, MA (United States); Shepanzyk, J.W. [Schering-Plough Corp., Union, NJ (United States)

    1996-12-31

    Successful application of an emerging photocatalytic technology is described, to control industrial volatile organic compound (VOC) emissions of mixed hexanes in process exhaust air. The manufacture of disposable contact lenses includes batch solvent degreasing, using an aliphatic hydrocarbon solvent. VOC air emissions result from this degreasing operation. The batch degreasing process presents a demanding emissions control challenge, due to intermittent operations, high concentrations of aliphatic hydrocarbon, and highly variable flow rates and VOC concentrations. In plant operations discussed in this paper, VOC destruction efficiencies in excess of 99% were achieved, well beyond that required for regulatory compliance. The destruction of the aliphatic hydrocarbons was effected without formation of products of incomplete combustion (PIC`s). The system was effective and reliable, even with the heat release which resulted from the oxidation of elevated concentrations of aliphatic hydrocarbons. System features were incorporated which provide excellent system reliability. Rapid system response was demonstrated, ensuring effective performance in intermittent operations. Photocatalytic oxidation was shown to be cost-effective by analysis of capital investment requirements and operating expense, and was found to have economics superior to an alternative system based on carbon adsorption. 6 refs., 2 figs., 5 tabs.

  17. The conjunctival sensitivity in soft contact lens wearers.

    Science.gov (United States)

    Igarashi, Tsutomu; Ono, Masafumi; Fujimoto, Chiaki; Suzuki, Hisaharu; Takahashi, Hiroshi

    2015-08-01

    We determined the influence of soft contact lenses (SCLs) on conjunctival sensitivity. A total of 26 volunteers (11 males, 15 females; mean age 28.3 ± 4.6 years; range 22-39 years) without dry eye were enrolled in the study. Subjects with a low corneal touch threshold, atopic keratoconjunctivitis, or vernal keratoconjunctivitis were excluded. In 26 participants, 12 were disposable SCL wearers. Touch thresholds were determined using a Cochet-Bonnet esthesiometer with a 0-60 mm nylon monofilament in 5 mm increments. The length (mm) was converted to tension (g/mm(2)). Mean touch sense thresholds in the SCL wearers (n = 12) and non-wearers (n = 14) were 10.7 ± 2.57 and 24.6 ± 7.3 g/mm(2) in the whole conjunctiva, and 9.07 ± 3.02 and 19.2 ± 7.8 g/mm(2) in the upper palpebral conjunctiva, respectively. Significant differences were observed in all locations (p < 0.01). The enhanced conjunctival sensitivity associated with SCL use may contribute to the dry eye-like symptoms in SCL users who do not have dry eye.

  18. Anterior stromal puncture for treatment of contact lens-intolerant keratoconus patients.

    Science.gov (United States)

    Kang, Su Yeon; Park, Young Kee; Song, Jong-Suk; Kim, Hyo Myung

    2011-01-01

    To report the results and effectiveness of anterior stromal puncture for contact lens-intolerant keratoconus patients with subepithelial fibrotic nodules. Nine eyes of nine keratoconus patients who were rigid gas-permeable contact lenses (RGP)-intolerant due to subepithelial nodular scars were included in this study. The nine patients were enrolled in the study between March 2008 and December 2008. After confirming nodular elevation from slit-lamp biomicroscopy, the area where the epithelium of nodular scars had sloughed was punctured by anterior stromal puncture using a 26-gauge needle attached to a 1-ml syringe under slit-lamp biomicroscopy. The RGPs of all patients were refitted around 4 weeks after the puncture. Five of the nine patients were male, and the average patient age was 29.6 years (SD ± 5.22 years). Mean follow-up time was 13.7 months (SD ± 4.8 months), and the epithelial defect healed in 1.4 days on average. After the puncture, four of nine patients presented with a recurrent erosion of the nodule during follow-up and needed a second puncture. All the patients showed good contact lens tolerance and satisfactory contact lens fit. No complications such as corneal perforation or keratitis developed. Anterior stromal puncture using a 26-gauge needle can be a successful and effective method to induce corneal epithelium and Bowman's layer reattachment. It can be used as an outpatient procedure to improve RGP tolerance in patients with keratoconus with elevated subepithelial nodules.

  19. KNOWLEDGE, ATTITUDE AND PRACTICE OF CONTACT LENS USERS AMONG MEDICAL COLLEGE STUDENTS IN BANGALORE

    Directory of Open Access Journals (Sweden)

    Sujatha

    2015-09-01

    Full Text Available INTRODUCTION: The use of contact lens (CL for the correction of refractive errors, cosmetic use and their usage as a therapeutic modality for corneal pathologies has increased many fold over the years. The present study was conducted with the aim to find the knowledge , attitude and pattern of CL use amongst medical college students and to highlight the complications and the correct method to be followed. MATERIALS AND METHODS: This study included 520college students out of which 114 students who have worn contact lens for any period were included for the study. RESULTS: Results showed that 94.7% of the CL users use the daily wear soft contact lens’ most quoted reasons of usage were comfort and convenience (59.6% with cosmetic benefit (29.8% as the next most common reply. Common complaints were that of general discomfort (foreign body sensation, dry eyes and watering eyes. With the advent of e commerce 26.3% of students are buying lenses are online. CONCLUSION: Educated use of CLs amongst its users is advised in view of the symptoms and associated complications that may occur. Electronic media is playing a commendable role in the sales and educating the buyers about do’s and don’t’s of contact lens use

  20. Preparation, characterization and antimicrobial study of a hydrogel (soft contact lens) material impregnated with silver nanoparticles.

    Science.gov (United States)

    Fazly Bazzaz, Bibi Sedigheh; Khameneh, Bahman; Jalili-Behabadi, Mohammad-mehdi; Malaekeh-Nikouei, Bizhan; Mohajeri, Seyed Ahmad

    2014-06-01

    Contact lenses that incorporate antimicrobial properties may reduce the risk for microbial-associated adverse events for lens wearers. The aim of this study was to assess the antimicrobial effects of silver nanoparticles (NP) when impregnated in a hydrogel material. Hydrogel disks, used as a proxy for soft contact lenses, were prepared with silver NPs to add an antimicrobial effect to the polymer. Six groups of disks were created, each with a different concentration of silver NPs. The antimicrobial effect of the hydrogels against Pseudomonas aeruginosa (ATCC15442) and Staphylococcus aureus (ATCC6538) was evaluated at 6, 24, 48 and 72 h. Silver NP concentrations ranged from 20.71 to 98.06 μg/disk. All groups demonstrated excellent antibacterial effects against P. aeruginosa at each time point. After 6h all disks didn't exhibit desirable antibacterial activity against S. aureus; whereas except those with 20.71 μg silver NPs showed antibacterial activity at 24h and only the disks with 57.13 and 98.06 μg silver NPs showed antimicrobial activity at 48 and 72 h. The development of contact lenses made of a silver NP-impregnated hydrogel material may bring antimicrobial effects sufficient to decrease the risk of microbial-related adverse events for lens wearers. Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  1. Intraocular pressure and ocular pulse amplitude using dynamic contour tonometry and contact lens tonometry

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    Grus Franz-H

    2004-03-01

    Full Text Available Abstract Background The new Ocular Dynamic Contour Tonometer (DCT, investigational device supplied by SMT (Swiss Microtechnology AG, Switzerland allows simultaneous recording of intraocular pressure (IOP and ocular pulse amplitude (OPA. It was the aim of this study to compare the IOP results of this new device with Goldmann tonometry. Furthermore, IOP and OPA measured with the new slitlamp-mounted DCT were compared to the IOP and OPA measured with the hand-held SmartLens®, a gonioscopic contact lens tonometer (ODC Ophthalmic Development Company AG, Switzerland. Methods Nineteen healthy subjects were included in this study. IOP was determined by three consecutive measurements with each of the DCT, SmartLens®, and Goldmann tonometer. Furthermore, OPA was measured three times consecutively by DCT and SmartLens®. Results No difference (P = 0.09 was found between the IOP values by means of DCT (mean: 16.6 mm Hg, median: 15.33 mm Hg, SD: +/- 4.04 mm Hg and Goldmann tonometry (mean: 16.17 mm Hg, median: 15.33 mm Hg, SD: +/- 4.03 mm Hg. The IOP values of SmartLens® (mean: 20.25 mm Hg, median: 19.00 mm Hg, SD: +/- 4.96 mm Hg were significantly higher (P = 0.0008 both from Goldmann tonometry and DCT. The OPA values of the DCT (mean: 3.08 mm Hg, SD: +/- 0.92 mm Hg were significantly lower (P = 0.0003 than those obtained by SmartLens® (mean: 3.92 mm Hg, SD: +/- 0.83 mm Hg. Conclusions DCT was equivalent to Goldmann applanation tonometry in measurement of IOP in a small group of normal subjects. In contrast, SmartLens® (contact lens tonometry gave IOP readings that were significantly higher compared with Goldmann applanation tonometer readings. Both devices, DCT and SmartLens® provide the measurement of OPA which could be helpful e.g. for the management of glaucoma.

  2. Coinfection with Acanthamoeba and Pseudomonas in contact lens-associated keratitis.

    Science.gov (United States)

    Sharma, Reetika; Jhanji, Vishal; Satpathy, Gita; Sharma, Namrata; Khokhar, Sudarshan; Agarwal, Tushar

    2013-02-01

    To report coinfection with Acanthamoeba and Pseudomonas aeruginosa in a case with contact lens-associated keratitis. A 20-year-old woman presented to the emergency department of our hospital with a 4-day history of progressively increasing pain, redness, photophobia, mucopurulent discharge, and diminution of vision in her right eye. She was being treated for contact lens-related Pseudomonas keratitis in another hospital before presentation. Gram stain of corneal scrapings revealed gram-negative bacilli. Both Gram stain and 10% KOH wet mount showed the presence of Acanthamoeba cysts. Microbiological cultures obtained from contact lenses and contact lens storage case showed the presence of Pseudomonas aeruginosa and Acanthamoeba. Topical therapy was started in the form of hourly gentamycin 1.3%, cefazolin 5%, chlorhexidine 0.02%, propamidine 0.1%, polymyxin B 30,000 IU eye drops, and neosporin (neomycin, bacitracin, polymyxin) eye ointment four times a day. Symptomatic improvement was observed within 48 hours, along with a decrease in the density of infiltrates and a reduction in the anterior chamber reaction. Repeat corneal scrapings on day 10 showed Acanthamoeba but no bacilli. Progressive resolution of the infiltrate was noted during the next few days. Epithelialization was complete by day 24, following which the amoebicidal therapy was tapered during the next 4 weeks. Complete resolution of keratitis was achieved after 7 weeks of treatment. Both P. aeruginosa and Acanthamoeba are potentially devastating causes of microbial keratitis. Our case highlights the importance of considering the possibility of a concurrent infection in cases with contact lens-related keratitis.

  3. Spinning pipe gas lens aberrations along the axis and in the boundary layer

    Directory of Open Access Journals (Sweden)

    Cosmas Mafusire

    2013-11-01

    Full Text Available When the walls of an open-ended horizontal steel pipe are heated before the pipe is rotated along its axis, the exchange of the expelled heated air with the incoming cooler air, sucked in along the axis, results in a medium capable of focusing a laser beam propagating along the pipes axis a spinning pipe gas lens. However, the interaction of the heated and cooler air generates local density fluctuations which generate aberrations on the laser beam wavefront. We present results for the characterisation of these aberrations using a Shack- Hartmann wavefront sensor. The measurements show that along the axis, rotating the pipe decreasesy-tilt as a result of the removal of distortions caused by gravity, although there is an increase in higher-order aberrations. However, in the boundary layer, the dominant aberration isx-astigmatism which increases with rotation speed. The results are confirmed by the measurement of the beam quality factor which increases as a result of the increase in the size of the higher-order aberrations. The spinning pipe gas lens is a device which can be used to focus laser beams using air only, but, in the process, the air introduces distortions which reduce the quality of the beam.

  4. Indirect evaluation of corneal apoptosis in contact lens wearers by estimation of nitric oxide and antioxidant enzymes in tears

    Directory of Open Access Journals (Sweden)

    R P Bhatia

    2010-01-01

    Full Text Available Background : Contact lens induced trauma to the corneal epithelium results in increased release of inflammatory mediators. The keratocyte apoptosis is directly related to epithelial injury and has been correlated with increased production of nitric oxide. Potent antioxidant enzymes protect cells from oxidative damage by inactivating reactive oxygen species and thus inhibiting apoptosis. This study aims at determination of total nitric oxide and antioxidant enzymes in tears which will be an indirect criteria for assessing apoptosis. Materials and Methods : Nitric oxide and antioxidant enzymes were estimated in tears of 25 soft contact lens wearers and compared with 25 age and sex matched controls. Results : Statistically significant increase of nitric oxide (P< 0.001, superoxide dismutase (P< 0.001 and glutathione peroxidase (P< 0.001 levels was seen in tears of contact lens wearers as compared to controls. There was also statistically significant increase in the levels of antioxidant enzymes, superoxide dismutase (P< 0.05 and glutathione peroxidase (P< 0.01, with increase in the total duration of contact lens wear in years. Conclusions : Increase in the level of nitric oxide and antioxidant enzymes in tears of contact lens wearers suggested that contact lens wear suppresses the process of apoptosis. However, it was also postulated that the increased levels of nitric oxide balances the anti-apoptotic activities of increased levels of antioxidant enzymes by its pro-apoptotic activity leading to protective outcomes in contact lens wearers.

  5. A survey of contact lens-related complications in a tertiary hospital in China.

    Science.gov (United States)

    Li, Weiwei; Sun, Xuguang; Wang, Zhiqun; Zhang, Yang

    2017-10-12

    To describe the type of complications related to contact lens (CL) wear in a tertiary hospital in XX, China. A retrospective study of 141 patients who complained discomfort after wearing contact lens on an outpatient basis of XX Hospital were conducted from the January 2012 to December 2015. The data included patients' demographics, lens type, history, slit-lamp examination, reports of corneal scrapings, culture, and examination of in vivo confocal microscopy. Binary logistic regression was used to analyse the possible factors which were associated with more severe corneal complications and superficial punctuate keratitis (SPK). About 86.52% were female and 13.48% were male, the age varied between 12 and 56 years old. Of the 141 patients, 82.27% were soft CL wearers, 2.84% were rigid gas permeable lens (RGP) wearers, and 14.89% patients used overnight orthokeratology. The most common complication was dry eye (36.88%), followed by SPK (36.17%) during these cases. Blepharitis and meibomian gland dysfunction (MGD) were noted in 31.91% of cases. Microbial keratitis was seen in 15 patients including 7 cases of Acanthamoeba keratitis. Age was a significant factor to be a case of corneal infection or inflammation [Exp (B)was 0.918, p=0.030], MGD and blepharitis was found to be significantly associated with being a case of SPK [Exp(B)was2.276, p=0.047]. The commonest complication was dry eye in this study, followed by SPK. Lid margin and meibomain gland should be paid attention to before contact lens prescription. Younger CL wearers need follow-up examinations. Copyright © 2017. Published by Elsevier Ltd.

  6. Rotationally asymmetric multifocal IOL implantation in acquired nystagmus with spectacle and contact lens intolerance.

    Science.gov (United States)

    Amigó, Alfredo; Bonaque, Sergio

    2013-07-01

    To describe a case of refractive lens exchange with multifocal intraocular lens implantation in a 52-year-old woman with emmetropic presbyopia who had near glasses and contact lens intolerance after acquired nystagmus. Preoperative corrected distance visual acuity was 20/25 in the right eye, 20/20 in the left eye, and 20/20 binocularly. Corrected near visual acuity was 20/30 in the right eye and 20/20 in the left eye, reaching 20/20 binocularly but showing unsatisfactory binocular vision with asthenopia and intolerance to prolonged reading. The surgical plan entailed bilateral implantation of multifocal intraocular lens. Three months postoperatively, uncorrected distance visual acuity was 20/20 in the right eye and 20/20 in the left eye, reaching 20/20 binocularly. Monocular and binocular uncorrected near visual acuity of 20/20 was achieved without symptoms of asthenopia in prolonged reading. There were no changes in nystagmus characteristics after surgery. Multifocal intraocular lens implantation to manage a case of clinically significant acquired nystagmus may be a safe alternative, especially if others options have failed. Copyright 2013, SLACK Incorporated.

  7. A Wirelessly Powered Smart Contact Lens with Reconfigurable Wide Range and Tunable Sensitivity Sensor Readout Circuitry.

    Science.gov (United States)

    Chiou, Jin-Chern; Hsu, Shun-Hsi; Huang, Yu-Chieh; Yeh, Guan-Ting; Liou, Wei-Ting; Kuei, Cheng-Kai

    2017-01-07

    This study presented a wireless smart contact lens system that was composed of a reconfigurable capacitive sensor interface circuitry and wirelessly powered radio-frequency identification (RFID) addressable system for sensor control and data communication. In order to improve compliance and reduce user discomfort, a capacitive sensor was embedded on a soft contact lens of 200 μm thickness using commercially available bio-compatible lens material and a standard manufacturing process. The results indicated that the reconfigurable sensor interface achieved sensitivity and baseline tuning up to 120 pF while consuming only 110 μW power. The range and sensitivity tuning of the readout circuitry ensured a reliable operation with respect to sensor fabrication variations and independent calibration of the sensor baseline for individuals. The on-chip voltage scaling allowed the further extension of the detection range and prevented the implementation of large on-chip elements. The on-lens system enabled the detection of capacitive variation caused by pressure changes in the range of 2.25 to 30 mmHg and hydration level variation from a distance of 1 cm using incident power from an RFID reader at 26.5 dBm.

  8. Design, characterization and visual performance of a new multizone contact lens

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    Rodriguez-Vallejo, Manuel; Monsoriu, Juan A; Furlan, Walter D

    2016-01-01

    Objectives: To analyze the whole process involved in the production of a new bifocal Multizone Contact Lens (MCL) for presbyopia. Methods: The optical quality of a new MCL was evaluated by ray tracing software in a model eye with pupil different diameters with the lens centered and decentered. A stock of low addition (+1.5 D) MCL for presbyopia was ordered for manufacturing. Power profiles were measured with a contact lens power mapper, processed with a custom software and compared with the theoretical design. Nine lenses from the stock were fitted to presbyopic subjects and the visual performance was evaluated with new APPs for iPad Retina. Results: Numerical simulations showed that the trough the focus curve provided by MCL has an extended depth of focus. The optical quality was not dependent on pupil size and only decreased for lens decentered with a pupil diameter of 4.5 mm. The manufactured MCL showed a smoothed power profile with a less-defined zones. The bias between experimental and theoretical zone s...

  9. Non-invasive objective and contemporary methods for measuring ocular surface inflammation in soft contact lens wearers - A review.

    Science.gov (United States)

    Chao, Cecilia; Richdale, Kathryn; Jalbert, Isabelle; Doung, Kim; Gokhale, Moneisha

    2017-10-01

    Contact lens wear is one of the primary risk factors for the development of ocular surface inflammatory events. The purpose of this review is to examine and summarize existing knowledge on the mechanisms of contact lens related ocular surface inflammation and the evidence for the effectiveness of current objective methods to measure ocular surface inflammation. Contact lens wear is postulated to trigger an inflammatory response on the ocular surface due to mechanical, chemical, hypoxic stress, or by the introduction of microbes and their toxins. Apart from the traditional signs of inflammation, such as swelling, oedema, redness and heat, on the ocular surface, other methods to measure ocular surface inflammation in sub-clinical levels include tear inflammatory mediator concentrations, conjunctival cell morphology, and corneal epithelial dendritic cell density and morphology. Tear inflammatory mediator concentrations are up- or down-regulated during contact lens wear, with or without the presence of associated inflammatory events. There is higher conjunctival cell metaplasia observed with contact lens wear, but changes in goblet cell density are inconclusive. Dendritic cell density is seen to increase soon after initiating soft contact lens wear. The long term effects of contact lens wear on dendritic cell migration in the cornea and conjunctiva, including the lid wiper area, require further investigation. Currently patient factors, such as age, smoking, systemic diseases and genetic profile are being studied. A better understanding of these mechanisms may facilitate the development of new management options and strategies to minimize ocular surface inflammation related to contact lens wear. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  10. Nonadhesive, silica nanoparticles-based brush-coated contact lens casesCompromising between ease of cleaning and microbial transmission to contact lenses

    NARCIS (Netherlands)

    Qu, Wenwen; Hooymans, Johanna M. M.; Qiu, Jun; de-Bont, Nik; Gelling, Onko-Jan; van der Mei, Henny C.; Busscher, Henk J.

    Surface properties of lens cases are determinant for their cleanability and for microbial transmission from lens cases to contact lenses (CLs). PEG-polymer-brush-coatings are known to decrease microbial adhesion more than other surface-coatings. Here, we applied a robust, silica nanoparticles-based

  11. A two-week clinical evaluation of the safety of Systane® Ultra in contact lens-wearing patients

    Directory of Open Access Journals (Sweden)

    David Kading

    2010-01-01

    Full Text Available David KadingSpecialty Eyecare Group, Kirkland, WA, USAObjective: To evaluate the safety of Systane® Ultra Lubricant Eye Drops (test solution in contact lens wearers. A currently marketed contact lens rewetting drop was the control solution.Participants: This investigator- and patient-masked, single-site, randomized, and prospective study involved 45 successful contact lens wearers.Methods: Eligible subjects’ baseline biomicroscopy findings, visual acuity, and corneal staining score were recorded. Subjects received either the test or control solution with masked labeling. Subjects were instructed to instill their assigned solution in both eyes: 15 minutes prior to lens insertion, at least one drop during lens wear and another drop immediately following lens removal. After 14 days, biomicroscopy results, visual acuity, and corneal staining score were recorded.Results: No adverse events were documented for either the test or the control solution. For subjects using Systane® Ultra, no statistically significant change was detected in visual acuity (= 0.7667 or corneal staining score (P = 1.000. For subjects using the control solution, the change in visual acuity (P = 0.0011, mean difference = 1.70 ± 3.22 standard deviation was not clinically relevant and there was no significant change in corneal staining score (P = 0.5413.Conclusions: This clinical study provided evidence of safety and compatibility of Systane® Ultra Lubricant Eye Drops in contact lens wearers.Keywords: lubricant eye drop, contact lens, safety, dry eye

  12. Rigid gas-permeable contact lens-assisted cataract surgery in patients with severe keratoconus.

    Science.gov (United States)

    Oie, Yoshinori; Kamei, Motohiro; Matsumura, Nagakazu; Fujimoto, Hisataka; Soma, Takeshi; Koh, Shizuka; Tsujikawa, Motokazu; Maeda, Naoyuki; Nishida, Kohji

    2014-03-01

    We describe rigid gas-permeable (RGP) contact lens-assisted cataract surgery in patients with severe keratoconus. During cataract surgery in cases with severe keratoconus, the intraocular images are distorted and visual perspective is lost because of irregular corneal astigmatism. Poor visibility can lead to complications, including posterior capsule rupture and corneal endothelial cell damage. To overcome these problems, an RGP contact lens was placed on the cornea in 2 cases. The image distortion decreased markedly, and the visual perspective improved. Intraocular manipulations such as irrigation/aspiration were performed safely. Improvement in transillumination led to good visualization of the anterior and posterior capsules. No intraoperative or postoperative complications developed in either case. This technique provided excellent visualization during cataract surgery in patients with severe keratoconus. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  13. On the the Contact Lens Problem: Modeling Rigid and Elastic Beams on Thin Films

    Science.gov (United States)

    Trinh, Philippe; Wilson, Stephen; Stone, Howard

    2011-11-01

    Generally, contact lenses are prescribed by the practitioner to fit each individual patient's eye, but these fitting-philosophies are based on empirical studies and a certain degree of trial-and-error. A badly fitted lens can cause a range of afflictions, which varies from mild dry-eye-discomfort, to more serious corneal diseases. Thus, at this heart of this problem, is the question of how a rigid or elastic plate interacts with the free-surface of a thin viscous film. In this talk, we present several mathematical models for the study of these plate-and-fluid problems. Asymptotic and numerical results are described, and we explain the role of elasticity, surface tension, viscosity, and pressure in determining the equilibrium solutions. Finally, we discuss the implications of our work on the contact lens problem, as well as on other coating processes which involve elastic substrates.

  14. Microlight-emitting diode with integrated Fresnel zone plate for contact lens embedded display

    Science.gov (United States)

    Mirjalili, Ramin; Parviz, Babak A.

    2012-07-01

    We report the fabrication and testing of 30-μm radii circular InGaN blue light-emitting didode (LEDs) grown on sapphire wafers, with cointegrated Fresnel zone plates (FZP) with outermost ring radii of 99.6 μm on the backside of the sapphire substrates to provide a collimated output. After being embedded on a contact lens platform such LEDs with integrated lenses can aid in producing in-focus images on the human retina. We measured an image width of 50 μm created by a FZP f/3 subsidiary focal point at 230 μm from the surface. We also demonstrate the construction and wireless operation of a contact lens with predetermined embedded text.

  15. Antenna and coil design for wireless signal detection and charging of embedded power active contact lens.

    Science.gov (United States)

    Ng, Benny; Heckler, Paul; Do, Alex; Azar, Phillip; Leon, Errol; Smilkstein, Tina

    2014-01-01

    This paper presents a screen printed 2.4 GHz antenna and induction charging coil for an active contact lens with a single large pixel user display and on-board 3.8 V 5 uAh rechargeable battery. The antenna traces are printed using silver conductive paste on a 25 um polyethylene terephthalate (PET) substrate. The incoming signal from the antenna feeds into an IC that amplifies and rectifies the signal. The coil provides wireless energy transfer to inductively charge a thin film battery [1] located on the contact lens. The printed antenna achieved a S11 of -4 dB at 2.4 GHz and a gain of -13 dB.

  16. First Report of Hartmannella keratitis in a Cosmetic Soft Contact Lens Wearer in Iran

    Directory of Open Access Journals (Sweden)

    Hoda Abedkhojasteh

    2013-09-01

    Full Text Available Background: Poor hygiene will provide good condition for corneal infections by opportunistic free-living amoebae (FLA in soft contact lens wearers. In the present study an amoebic keratitis due to Hartmannella has been recognized in a 22-year-old girl with a history of improper soft contact lens use. She had unilateral keratitis on her left eye. Her clinical signs were eye pain, redness, blurred vision and photopho­bia. The round cysts of free-living amoebae were identified in non-nutrient agar medium by light microscopy. These cysts were suspected to be Hartmannella using morphological criteria. A PCR assay has been confirmed that the round cysts were belonged to H. vermiformis.

  17. Activity of a melimine derived peptide Mel4 against Stenotrophomonas, Delftia, Elizabethkingia, Burkholderia and biocompatibility as a contact lens coating

    DEFF Research Database (Denmark)

    Dutta, Debarun; Zhao, Timothy; Cheah, Kai Bing

    2017-01-01

    was active against all the bacteria tested (MIC50 ranged from 31–1000 μg ml−1) and produced an antimicrobial surface on contact lenses. Mel4-coating resulted hydrophilic surface without any significant change in contact lens parameters, and showed no signs of cytotoxicity or ocular irritation during rabbit...... wear. During human clinical trial, there were no differences between Mel4 coated and uncoated contact lenses in lens performance indicators and ocular signs such as corneal fluorescein staining. Mel4 and control uncoated lenses had no differences in ocular symptoms during lens wear. Conclusion Mel4 has...... achieved antimicrobial activity against variety of Gram negative bacteria that are often resistant to the action of cationic peptides and have been implicated in contact lens related adverse events. Mel4-coated contact lenses were safe to wear....

  18. Acanthamoeba encystment: multifactorial effects of buffers, biocides, and demulcents present in contact lens care solutions

    Directory of Open Access Journals (Sweden)

    Kovacs CJ

    2015-10-01

    Full Text Available Christopher J Kovacs, Shawn C Lynch, Marjorie J Rah, Kimberly A Millard, Timothy W Morris Bausch & Lomb Incorporated, Rochester, NY, USA Purpose: To determine whether agents which are purportedly capable of inducing encystment of Acanthamoeba can recapitulate the signal when tested in differing formulations. Methods: In accordance with the International Standard ISO 19045, Acanthamoeba castellanii ATCC 50370 trophozoites were cultured in antibiotic-free axenic medium, treated with test solutions, and encystment rates plus viability were measured via bright field and fluorescent microscopy. Test solutions included phosphate-buffered saline (PBS, borate-buffered saline, biguanide- and hydrogen peroxide (H2O2-based biocides, propylene glycol (PG and povidone (POV ophthalmic demulcents, and one-step H2O2-based contact lens disinfection systems. Results: Only PBS solutions with 0.25 ppm polyaminopropyl biguanide (PAPB and increasing concentrations of PG and POV stimulated A. castellanii encystment in a dose-dependent manner, whereas PBS solutions containing 3% H2O2 and increasing concentrations of PG and POV did not stimulate encystment. Borate-buffered saline and PBS/citrate solutions containing PG also did not stimulate encystment. In addition, no encystment was observed after 24 hours, 7 days, or 14 days of exposures of trophozoites to one-step H2O2 contact lens disinfection products or related solutions. Conclusion: The lack of any encystment observed when trophozoites were treated with existing or new one-step H2O2 contact lens care products, as well as when trophozoites were exposed to various related test solutions, confirms that Acanthamoeba encystment is a complex process which depends upon simultaneous contributions of multiple factors including buffers, biocides, and demulcents. Keywords: propylene glycol, contact lens care system, hydrogen peroxide disinfecting solution

  19. A case with Stenotrophomonas maltophilia keratitis related to contact lens use

    Directory of Open Access Journals (Sweden)

    Mehmet Sinan Dal

    2012-03-01

    Full Text Available We examined a 30 years old female patient, which had aparacentral corneal abcess due to contact lens use. Wetook samples from corneal abcess and fluid in the contactlens and sent for microbiological examination. After takensamples, gatifloxacin was started for antibiotherapy. Stenotrophomonasmaltophilia was grew in both samplesduring microbiological examination. Gatifloxacin antibiotherapywas continued and corneal abcess formation wasregressed and treated in the course of therapy. J Clin ExpInvest 2012; 3(1: 121-122

  20. Application of fibrin glue with bandage contact lens in pterygium surgery

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2014-05-01

    Full Text Available AIM: To explore the efficacy of fibrin glue with bandage contact lens for pain relief after pterygium surgery performed with limbal autograft transplantation.METHODS: A prospective clinical trial was carried out in 52 patients(72 eyesoperated for primary nasal pterygium. All patients were randomly divided into the fibrin glue with bandage contact lens group(experimental group, 28 cases, 38 eyesand suture group(control group, 24 cases, 34 eyes. Autologous limbal graft taken from the superotemporal limbus was used to cover the sclera after pterygium excision under local anesthesia with 20g/L lidocaine. In experimental group, the transplant was attached to the sclera with fibrin tissue adhesive and in control group with 10-0 Virgin silk sutures. Experimental group weared bandage contact lens after surgery while the control group did not. The degree of pain after surgery was evaluated at 1, 2, 3, 5 and 7d after surgery. Follow-up was 6mo, matching degree of graft and complication such as infection, relapse, implant healing badness and subconjunctival cyst were mainly observed and recorded.RESULTS: The pain index scores of the experimental group were significantly less than those of control group(all P=0.000. In observation period, all conjunctival autografts in both groups were successfully attached and were intact without falling off, dissolution or recurrence and there were no complications such as infection, relapse, implant healing badness and subconjunctival cyst.CONCLUSION: Fibrin glue with bandage contact lens could significantly release pain response afterpterygium excision surgery.