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https://www.readbyqxmd.com/read/29787490/clinical-performance-of-a-new-bitangential-mini-scleral-lens
#1
Henny M Otten, Bart J J J van der Linden, Esther-Simone Visser
SIGNIFICANCE: New bitangential mini-scleral lens designs provide a highly precise fit, follow the scleral shape, are comfortable to wear, and can correct residual astigmatism. This new scleral lens design complements the arsenal of medical contact lenses available to eye care practitioners. PURPOSE: The aim of this study was to evaluate the subjective and objective performance of a new mini-scleral lens design with a bitangential periphery. METHODS: In this observational study, data were collected for up to 15 months (median, 84 days; interquartile range, 76 days) from the left eyes of 133 patients fitted with this newly designed lens...
May 21, 2018: Optometry and Vision Science: Official Publication of the American Academy of Optometry
https://www.readbyqxmd.com/read/29787322/short-term-deposition-of-pm-2-5-particles-on-contact-lens-surfaces-effect-on-oxygen-permeability-and-refractive-index
#2
Zhizhang Dong, Xiaoyan Ding, Yong Li, Yifeng Gan, Yanhui Wang, Libin Xu, Yahong Wang, Zhou Ying, Juan Li
PURPOSES: To identify the deposition of fine (≤2.5 μm diameter) particulate matter (PM) particles (PM2.5 ), on contact lens surfaces and investigate the effects of such deposition on the oxygen permeability (OP) and refractive index (RI) of contact lenses. METHODS: A total of 36 contact lenses, including rigid gas permeable (RGP) and soft (SCL) lenses, was investigated. RGP (n=12) and SCL (n=12) (experimental group) lenses were incubated in a PM2.5 solution for 24 h, after which PM2...
May 22, 2018: Current Eye Research
https://www.readbyqxmd.com/read/29785085/-wet-transepithelial-phototherapeutic-keratectomy-in-the-management-of-persistent-epithelial-defects-in-the-graft
#3
Sergei V Churashov, Elena V Kudryashova, Alexei N Kulikov, Ernest V Boiko, Valerii F Chernysh, Dmitrii S Maltsev
Purpose: This study aimed to evaluate the efficacy of "wet" transepithelial phototherapeutic keratectomy (TE-PTK) for treating persistent epithelial defects (PEDs) in the corneal graft following penetrating keratoplasty (PKP). Methods: This study describes a noncomparative, prospective interventional case series. Patients with post-PKP graft epithelial defects lasting >3 months despite previous treatments with extensive wear soft contact lenses, amniotic membrane transplantation, and tarsorrhaphy were treated with wet TE-PTK...
2018: Clinical Ophthalmology
https://www.readbyqxmd.com/read/29784163/significant-disparities-in-eyeglass-insurance-coverage-in-canada
#4
Gordon Ngo, Graham Trope, Yvonne Buys, Ya-Ping Jin
OBJECTIVE: To describe patterns of access to eyeglass insurance by Canadians. DESIGN: A population-based, cross-sectional survey. PARTICIPANTS: A total of 134 072 respondents to the Canadian Community Health Survey 2003 who were aged ≥12 years. METHODS: We compared self-reported insurance coverage for eyeglasses or contact lenses provided by private, government, or employer-paid plans. RESULTS: Overall, 55...
June 2018: Canadian Journal of Ophthalmology. Journal Canadien D'ophtalmologie
https://www.readbyqxmd.com/read/29782944/a-comprehensive-review-on-contact-lens-for-ophthalmic-drug-delivery
#5
REVIEW
Jiawen Xu, Yingyan Xue, Gaoyong Hu, Tianyu Lin, Jingxin Gou, Tian Yin, Haibing He, Yu Zhang, Xing Tang
With the prevalence of electronic devices and an aging population, the number of people affected with eye disease is increasing year by year. In spite of a large number of eye drops on the market, most of them do not perform sufficiently, due to rapid clearance mechanisms and ocular barriers. To enhance drug delivery to the eye, a number of novel formulations for ocular diseases have been investigated over recent decades, aiming to increase drug retention and permeation while also allowing for sustained drug release over prolonged periods...
May 18, 2018: Journal of Controlled Release: Official Journal of the Controlled Release Society
https://www.readbyqxmd.com/read/29780931/case-of-progressive-hyperopia-due-to-flattening-of-cornea
#6
Hiromasa Hirai, Shinji Maruoka, Tadanobu Yoshikawa, Nahoko Ogata
Purpose: To report a case that had a progressive decrease in the visual acuity caused by a progressive increase in the hyperopia due to a flattening of the cornea. Observations: A 50-year-old woman complained of decreased vision in both eyes. Her decimal best-corrected visual acuity was 1.2 in the right and 0.5 in the left eyes, and the refractive error (spherical equivalent) was +3.75 diopters (D) for the right eye and +6.5 D for the left eye. Slit-lamp examinations showed clear corneas but Descemet's folds and fine pigmentations and opacities were present beneath the corneal epithelium in both eyes...
June 2018: American Journal of Ophthalmology Case Reports
https://www.readbyqxmd.com/read/29774672/glucose-sensitive-silicone-hydrogel-contact-lens-toward-tear-glucose-monitoring
#7
Ramachandram Badugu, Edward Albert Reece, Joseph R Lakowicz
Accurate and reliable monitoring of blood glucose is needed for the treatment of diabetes, which has many challenges, including lack of patient compliance. Measuring tear glucose is an alternative to traditional finger-stick tests used to track blood sugar levels, but glucose sensing using tears has yet to be achieved. We report a methodology for possible tear glucose monitoring using glucose-sensitive silicone hydrogel (SiHG) contact lenses, the primary type of lenses available in today's market. Initially, we assessed the interpenetrating polymer network, with nearly pure silicone and water regions, existing in the SiHGs using a polarity-sensitive probe Prodan...
May 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29765195/use-of-a-novel-extended-blink-test-to-evaluate-the-performance-of-two-polyvinylpyrrolidone-containing-silicone-hydrogel-contact-lenses
#8
Jeffery Schafer, William Reindel, Robert Steffen, Gary Mosehauer, Joseph Chinn
Background: Sustained digital display viewing reduces eye blink frequency and tear film stability. To retain water and preserve a smooth optical surface, contact lens manufacturers have integrated the humectant polyvinylpyrrolidone (PVP) into silicone hydrogel contact lenses. In this study, extended blink time (EBT) was used to assess visual stability over a prolonged blink interval of two PVP-containing silicone hydrogel lenses, samfilcon A (SAM) and senofilcon A (SEN). Materials and methods: This randomized, bilateral, masked, crossover study assessed lens performance in ten subjects after 16 hours of wear...
2018: Clinical Ophthalmology
https://www.readbyqxmd.com/read/29760483/structure-and-crystallography-of-foliated-and-chalk-shell-microstructures-of-the-oyster-magallana-the-same-materials-grown-under-different-conditions
#9
Antonio G Checa, Elizabeth M Harper, Alicia González-Segura
Oyster shells are mainly composed of layers of foliated microstructure and lenses of chalk, a highly porous, apparently poorly organized and mechanically weak material. We performed a structural and crystallographic study of both materials, paying attention to the transitions between them. The morphology and crystallography of the laths comprising both microstructures are similar. The main differences were, in general, crystallographic orientation and texture. Whereas the foliated microstructure has a moderate sheet texture, with a defined 001 maximum, the chalk has a much weaker sheet texture, with a defined 011 maximum...
May 14, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29750502/wearable-contact-lens-biosensors-for-continuous-glucose-monitoring-using-smartphones
#10
Mohamed Elsherif, Muhammad Umair Hassan, Ali K Yetisen, Haider Butt
Low-cost, robust, and reusable continuous glucose monitoring systems that can provide quantitative measurements at point-of-care settings is an unmet medical need. Optical glucose sensors require complex and time-consuming fabrication process and their readouts are not practical for quantitative analyses. Here, a wearable contact lens optical sensor was created for the continuous quantification of glucose at physiological conditions, simplifying the fabrication process and facilitating smartphone readouts. A photonic microstructure having a periodicity of 1...
May 11, 2018: ACS Nano
https://www.readbyqxmd.com/read/29739665/clinical-comparison-of-optimum-and-large-diameter-soft-contact-lenses
#11
James Wolffsohn, Lee Hall, Graeme Young
PURPOSE: To compare the clinical performance of large diameter lenses with optimally fit lenses in the same material and monocurve back surface design. METHOD: In a four-visit, randomised, bilateral, crossover, study, 25 myopic subjects wore optimum diameter lenses (control) and large diameter lenses (test) in random succession for 1 week each. Both study lenses were made of methafilcon A and of an identical design. Trial fittings with Frequency 55 (Coopervision) lenses modified with a design algorithm were used to determine the appropriate custom-made study lenses...
May 5, 2018: Contact Lens & Anterior Eye: the Journal of the British Contact Lens Association
https://www.readbyqxmd.com/read/29730260/inner-layer-embedded-contact-lenses-for-ph-triggered-controlled-ocular-drug-delivery
#12
Qiang Zhu, Chang Liu, Zheng Sun, Xiaofei Zhang, Ning Liang, Shirui Mao
Contact lenses (CLs) are ideally suited for controlled ocular drug delivery, but are limited by short release duration, poor storage stability and low drug loading. In this study, we present a novel inner layer-embedded contact lens capable of pH-triggered extended ocular drug delivery with good storage stability. Blend film of ethyl cellulose and Eudragit S100 was used as the inner layer, while pHEMA hydrogel was used as outer layer to fabricate inner layer-embedded contact lens. Using diclofenac sodium(DS) as a drug model, influence of polymer ratio in the blend film, EC viscosity, drug/polymer ratio, inner layer thickness and outlayer thickness of pHEMA hydrogel on drug release behavior was studied and optimized for daily use...
May 3, 2018: European Journal of Pharmaceutics and Biopharmaceutics
https://www.readbyqxmd.com/read/29726489/normative-best-corrected-values-of-the-visual-image-quality-metric-vsx-as-a-function-of-age-and-pupil-size
#13
Gareth D Hastings, Jason D Marsack, Larry N Thibos, Raymond A Applegate
The visual image quality metric the visual Strehl ratio (VSX) combines a comprehensive description of the optics of an eye (wavefront error) with an estimate of the photopic neural processing of the visual system, and has been shown to be predictive of subjective best focus and well correlated with change in visual performance. Best-corrected visual image quality was determined for 146 eyes, and the quantitative relation of VSX, age, and pupil size is presented, including 95% confidence interval norms for age groups between 20 and 80 years and pupil diameters from 3 to 7 mm...
May 1, 2018: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/29724209/microbial-keratitis-induced-endophthalmitis-incidence-symptoms-therapy-visual-prognosis-and-outcomes
#14
Daniel Zapp, Daria Loos, Nikolaus Feucht, Ramin Khoramnia, Tamer Tandogan, Lukas Reznicek, Christian Mayer
BACKGROUND: To evaluate symptoms, therapies and outcomes in rare microbial keratitis-induced endophthalmitis. METHODS: Retrospective study with 11 patients treated between 2009 and 2014. Clinical findings, corneal diseases, history of steroids and trauma, use of contact lenses, number and type of surgical interventions, determination of causative organisms and visual acuity (VA) were evaluated. RESULTS: The incidence of transformation from microbial keratitis to an endophthalmitis was 0...
May 3, 2018: BMC Ophthalmology
https://www.readbyqxmd.com/read/29720354/surface-versus-bulk-activity-of-lysozyme-deposited-on-hydrogel-contact-lens-materials-in-vitro
#15
Negar Babaei Omali, Lakshman N Subbaraman, Miriam Heynen, Alan Ng, Chantal Coles-Brennan, Zohra Fadli, Lyndon Jones
PURPOSE: To determine and compare the levels of surface versus bulk active lysozyme deposited on several commercially available hydrogel contact lens materials. METHODS: Hydrogel contact lens materials [polymacon, omafilcon A, nelfilcon A, nesofilcon A, ocufilcon and etafilcon A with polyvinylpyrrolidone (PVP)] were incubated in an artificial tear solution for 16 h. Total activity was determined using a standard turbidity assay. The surface activity of the deposited lysozyme was determined using a modified turbidity assay...
April 30, 2018: Contact Lens & Anterior Eye: the Journal of the British Contact Lens Association
https://www.readbyqxmd.com/read/29717120/flexible-and-ultra-lightweight-polymer-membrane-lasers
#16
Markus Karl, James M E Glackin, Marcel Schubert, Nils M Kronenberg, Graham A Turnbull, Ifor D W Samuel, Malte C Gather
Organic semiconductors enable the fabrication of a range of lightweight and mechanically flexible optoelectronic devices. Most organic semiconductor lasers, however, have remained rigid until now, predominantly due to the need for a support substrate. Here, we use a simple fabrication process to make membrane-based, substrate-less and extremely thin (<500 nm) organic distributed feedback lasers that offer ultralow-weight (m/A<0.5 gm-2 ) and excellent mechanical flexibility. We show operation of the lasers as free-standing membranes and transfer them onto other substrates, e...
May 1, 2018: Nature Communications
https://www.readbyqxmd.com/read/29714326/compensating-additional-optical-power-in-the-central-zone-of-a-multifocal-contact-lens-forminimization-of-the-shrinkage-error-of-the-shell-mold-in-the-injection-molding-process
#17
Lien T Vu, Chao-Chang A Chen, Chia-Cheng Lee, Chia-Wei Yu
This study aims to develop a compensating method to minimize the shrinkage error of the shell mold (SM) in the injection molding (IM) process to obtain uniform optical power in the central optical zone of soft axial symmetric multifocal contact lenses (CL). The Z-shrinkage error along the Z axis or axial axis of the anterior SM corresponding to the anterior surface of a dry contact lens in the IM process can be minimized by optimizing IM process parameters and then by compensating for additional (Add) powers in the central zone of the original lens design...
April 20, 2018: Applied Optics
https://www.readbyqxmd.com/read/29708242/co-delivery-of-timolol-and-hyaluronic-acid-from-semi-circular-ring-implanted-contact-lenses-for-the-treatment-of-glaucoma-in-vitro-and-in-vivo-evaluation
#18
Ankita R Desai, Furqan A Maulvi, Mihir M Pandya, Ketan M Ranch, Bhavin A Vyas, Shailesh A Shah, Dinesh O Shah
Glaucoma is a chronic disease, which is currently treated using frequent high dose applications of an eye drop solution; this method is tedious, and most of patients are non-compliant to it. Contact lenses are emerging as a convenient option to sustain the release of ophthalmic drugs. However, the incorporation of a drug/formulation changes the optical and physical properties of contact lenses. Contact lens users have also reported pink eye syndrome; this makes contact lenses unsuitable to be accepted as a medical device...
April 30, 2018: Biomaterials Science
https://www.readbyqxmd.com/read/29705891/keratomycosis-due-to-tintelnotia-destructans-refractory-to-common-therapy-treated-successfully-with-systemic-and-local-terbinafine-in-combination-with-polyhexamethylene-biguanide
#19
Wolfgang J Behrens-Baumann, Wolfram Hofmüller, Ina Tammer, Kathrin Tintelnot
PURPOSE: To report on a wearer of rigid gas-permeable contact lenses with a keratomycosis due to Tintelnotia-a new genus of Phaeosphaeriaceae-treated with terbinafine and polyhexamethylene biguanide. METHODS: Chart review of a patient with fungal keratitis treated additionally with systemic and topical terbinafine 0.25% after symptoms increased under conventional antimycotic therapy with voriconazole. Antifungal susceptibility had been tested in vitro. RESULTS: After starting an additional treatment with systemic and topical terbinafine, the severe corneal infection was sufficiently resolved...
April 28, 2018: International Ophthalmology
https://www.readbyqxmd.com/read/29704130/recurrent-corneal-erosion-caused-by-retained-sutures-in-blepharoplasty
#20
I-Hsin Ma, Bo-I Kuo, Yu-Chih Hou
PURPOSE: To present recurrent corneal erosion (RCE) caused by late suture exposure after blepharoplasty. METHODS: Four patients who have unilateral RCE were found to have previous blepharoplasty. The RCE was associated with late suture exposure. The clinical courses, characteristics, methods to identify the suture exposure and treatment were presented. RESULTS: The clinical presentations including local erosion of upper bulbar conjunctiva, corneal abrasion lines, local corneal epithelial defects with rough border, and subepithelial opacity were noticed in all four patients...
April 27, 2018: International Ophthalmology
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