762 resultados para rigid lens
Resumo:
Along with other facets of commericialization, the contact lens market has become globalized during the past 30 years. The major international companies have worldwide distribution networks and supply lenses of the same product names and replacement frequencies to all nations, with a few minor adjustments for marketing and regulatory reasons. Small and medium-sized companies, often producing more specialized lenses, are also active in markets across the world.
Resumo:
For the past 12 years, the International Contact Lens Prescribing Survey Consortium has sent surveys to a selection of Canadian optometrists in order to collect information on the contact lenses they fit and basic demographic data of the patients. Canada is one of about 40 countries that contributes to the global study and while annual reviews of the study data are presented, information published for any one market is limited due to the size of the dataset.1 This manuscript presents a more detailed analysis on the Canadian market for 2011.
Resumo:
The 13th annual survey of Australian contact lens prescribing was conducted between January and April 2012. The same format as in previous years was employed. About 3,000 members of Optometrists Association Australia were sent an e-mail message with a link to a downloadable questionnaire, and a request that this be accessed, printed and completed to provide details of the first 10 patients fitted with contact lenses after receipt of the questionnaire.
Resumo:
Purpose The aim of this study is to assess the refractive and visual outcomes following cataract surgery and implantation of the AcrySof IQ Toric SN6AT2 intraolcular lens (IOL) (Alcon Laboratories, Inc) in patients with low corneal astigmatism. Materials and Methods A retrospective, consecutive, single surgeon series of ninety-eight eyes of 88 patients following cataract surgery and implantation of the AcrySof IQ Toric SN6AT2 IOL in eyes with low preoperative corneal astigmatism. Postoperative measurements were obtained at one month post surgery. Main outcome measures were monocular distance visual acuity and residual refractive astigmatism. Results The mean preoperative corneal astigmatic power vector (APV) was 0.38 ± 0.09 D. Following surgery and implantation of the toric IOL, mean postoperative refractive APV was 0.13 ± 0.10 D. Mean postoperative distance uncorrected visual acuity (UCVA) was 0.08 ± 0.09 logMAR. Postoperative spherical equivalent refraction (SER) resulted in a mean of - 0.23 ± 0.22 D, with 96% of eyes falling within 0.50 D of the target SER. Conclusions The AcrySof IQ Toric SN6AT2 IOL is a safe and effective option for eyes undergoing cataract surgery with low amounts of preoperative corneal astigmatism.
Resumo:
"Contact Lens Complications has become established as the definitive guide to the ocular response to contact lens wear. In this highly anticipated third edition, award-winning contact lens author, clinician and researcher, Professor Nathan Efron, presents a thoroughly revised and expanded, clinician-friendly account of how to identify, understand and manage contact lens complications in modern-day practice. Professor Efron is renowned for his ability to distil often complex principles of ocular physiology and pathology into an easy-to-read, highly structured format. The subject matter is systematically laid out, with various complications arranged logically by tissue structure - which is the way practitioners naturally approach clinical problems. Beautifully presented and lavishly illustrated with full-colour schematic diagrams and clinical pictures, this book can serve as both a practical chair-side manual and authoritative reference."--publisher website
Resumo:
Rigid lenses, which were originally made from glass (between 1888 and 1940) and later from polymethyl methacrylate or silicone acrylate materials, are uncomfortable to wear and are now seldom fitted to new patients. Contact lenses became a popular mode of ophthalmic refractive error correction following the discovery of the first hydrogel material – hydroxyethyl methacrylate – by Czech chemist Otto Wichterle in 1960. To satisfy the requirements for ocular biocompatibility, contact lenses must be transparent and optically stable (for clear vision), have a low elastic modulus (for good comfort), have a hydrophilic surface (for good wettability), and be permeable to certain metabolites, especially oxygen, to allow for normal corneal metabolism and respiration during lens wear. A major breakthrough in respect of the last of these requirements was the development of silicone hydrogel soft lenses in 1999 and techniques for making the surface hydrophilic. The vast majority of contact lenses distributed worldwide are mass-produced using cast molding, although spin casting is also used. These advanced mass-production techniques have facilitated the frequent disposal of contact lenses, leading to improvements in ocular health and fewer complications. More than one-third of all soft contact lenses sold today are designed to be discarded daily (i.e., ‘daily disposable’ lenses).
Resumo:
Health promotion progresses a social justice and empowerment agenda and thus emphasises working with people to increase their control over their health. Certainly, Australia has experienced much success in this endeavour and is internationally recognised as a leader. However, health promotion has failed Indigenous Australians; a fact that is echoed in the health outcomes that ironically provide us with the “moral imperative” to act. Further investigation has also revealed health promotion’s foundation in colonial imaginings. Thus, this paper calls for the culture of health promotion to be examined as a risk factor for poor Indigenous health. To complement this call, this paper presents findings of an ethnographic study of Indigenous health promotion practice, undertaken from a postcolonial and critical whiteness framework. These findings provide a narrative of strength and innovative approaches, highlighting the value of Indigenous knowledge. These findings also contradict the biomedical tendency to construct culture as illness-producing. More broadly, this study’s findings entail important lessons for health promotion to consider, if it is to move beyond the rhetoric, to truly increase people’s control over their health.