Posts Tagged ‘gas permeable lenses’
A study published in the July 2009 issue of the journal Eye & Contact Lens: Science and Clinical Practice highlights the frequency of risks faced by contact lens users. The study, which analyzed a cross-section of contact lens users in a university practice setting (UCLA), showed that as many as half of all contact lens users experienced a contact lens-related complication. Some of these complications were vision-threatening, although most were benign. Complications were seen by users of all types of contact lenses, although users of rigid gas permeable lenses had a statistically significant reduction of risk compared to users of soft contact lenses.
The most common complications seen were papillae and giant papillary conjunctivitis. These can typically be treated and do not generally threaten vision. They typically cause infection, mucoid discharge, irritation, and blurred vision. Papillae and giant papillary conjunctivitis can lead to lens intolerance, forcing a return to glasses for best lens corrected vision.
Comparing Risks of LASIK and Contact Lenses
Although about half of contact lens users experience complications, contact lenses still compare favorably with LASIK and other forms of refractive surgery in terms of preserving your vision. Studies show that less than 1% of people receiving LASIK surgery experience a loss in best corrected vision. However, the likelihood of a loss of vision related to contact lens use is still significantly less.
At one time, contact lens use was associated with a potential for vision loss as high as 0.9%, but improvement in contact lens technology and wearing habits has reduced that risk significantly. Post-market studies required of all 30-day contact lenses approved by the FDA show that the approximate annual risk of vision-threatening microbial keratitis associated with contact lens use is 4 per 10,000 wearers, or 0.04%. If we assume a 14-year life for refractive surgeries, that amounts to a cumulative risk of about 0.6%. However, rates of infection are increased 4 times for people who wear contacts overnight, and up to 15 times for people who wear their contacts for more than two weeks.
LASIK complication rates resulting in vision loss used to be as high as 5%, but recently they have been reduced to about 1%, which is close to the rates for contact lenses. For most people, the comparable safety rate of LASIK seems better when compared to the vigilance necessary to keep contacts clean with daily, weekly, or biweekly removal and cleaning.
Safety Trends
However, in the near future, LASIK may be safer than contact lenses. LASIK has improved significantly in safety since its introduction. Advanced technology and experienced surgeons are largely responsible for the decrease in complications. As surgeons continue to gain experience and technology continues to advance, we can expect rates to continue dropping. Contact lenses, on the other hand, may be more risky in the future.
Microbial keratitis used to be caused by a relatively small number of microorganisms that were controllable with specific formulae of antibiotics. However, in recent years there have been more outbreaks associated with Acanthamoeba and fungal species. Some of this has been associated with specific contact lens solutions. Other times, it has been associated with the reduction of water quality standards by the EPA under the Bush administration. In the latter outbreak in Chicago during June to November of 2005, 40 people contracted Acanthamoeba keratitis, nearly seven times the historical rate of this type of infection.
In the future we may see more of what are described as “atypical” cases of microbial keratitis that may increase the risk of wearing contact lenses.
If you would like to learn more about the relative safety of LASIK and contact lenses, please visit the website of 20/20 Institute, with offices in Denver, Indianapolis, and Portland.
Article Source:http://www.articlesbase.com/vision-articles/will-lasik-be-safer-than-contacts-in-the-near-future-1369437.html
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Before laser eye surgery, an interview is carried out to determine your personal suitability for eye surgery and to determine which type of operation may suit you and give an idea of the likely results. The next stage is to carry out a thorough eye test to determine a current up to date eye prescription and to take precise measurements of the eye structures.
It is normally recommended that a friend for this examination accompanies you as part of procedure involves using eye drops which dilate your pupil and blur your vision for upto 18 hours. Also it is advised to carry a pair of sunglasses on this day,as bright lights and dilated pupils can cause discomfort. If you normally wear contact lenses these can affect the corneal curvature and consequently it is necessary if you wear soft lenses to discontinue wear for at least one week prior to,and on the day of consultation, and with hard and gas permeable lenses to discontinue wear at least four weeks prior to and on the consultation day. Normally you need to complete a general health questionaire.You are then normally given a complete eye examination. Based on the result of these examinations your eye surgeon will advise you about the most suitable procedure for you,discuss the risks and also the alternatives. You also have the opportunity to ask any further questions you may have.
You can then decide whether or not to proceed to a surgical appointment.The advantages resulting from laser eye surgery are ability to see immediately on waking up, no more fumbling for your glasses in the dark, not having to wear glasses or contact lenses saving time and lots of money on opticians visits as well as trouble in maintenance and upkeep, improved self confidence in appearence (hopefully!), easier participation in sports leading to an overall improvement in feeling of personal well being. Most of the patients, who undergo laser eye surgery claim that they are satisfied with procedure and it has improved the quality of their life significantly and often state that they regret not having it sooner.
Lasik eye surgery is a laser surgery procedure for vision correction.The technique involves using a laser which is controlled by a computer to reshape the front surface of the eye(cornea). As with all surgery a pre-op consultation is required to ascertain the best eye surgery for the individual.In normal vision light enters the eye and is bent by the cornea and focussed to produce a sharp image on the back of the eye the retina. When a person has a refractive/visual error like short or long sight the light is bent such that a blurred image is produced.
Lasik eye surgery can be used to correct short sight, long sight and stigmatism (correct spelling astigmatism).Older patients who have presbyopia/age related near vision problems cannot have their vision improved with this procedure. The cornea has an alcohol solution applied to help lift the epithelial flap which is then cut(a fine layer about 50 microns thick ) with a Trephine blade (ALSO CAN BE CUT WITH A LASER BUT AGAIN IT IS A SIMILAR PROCEDURE ) , but not completely removed and remains hinged on one side allowing it to be replaced inthe same position. The surgeon raises the flap, and an excimer laser shapes the the cornea to the dimensions determined at the pre op consultation.The eye surgeon replaces the epithelial corneal flap, within minutes, natural forces hold it in situ, and the eye surgery is finished.The surgery as with LASIK takes approximately 15 mins each eye. However recovery normally takes a bit longer approximately one week and there is usually some discomfort for the next 48 hours.
This is just a general outline of the what happens after laser eye surgery procedures following refractive surgery (as there are wide variations depending on individual needs and surgery techniques).Patients are normally provided with antibiotic eye medication and lubricating eye drops to be used in the days immediately after surgery. It is common and good procedure for the eye surgeon who performed your operation to exam your eyes the day immediately after any eye surgery. Further appointments are then generally advised at the desired intervals. In the first few days and hours after surgery it is important to refrain from touching or rubbing the eyes and to try and rest as much as possible and to use any medication prescribed.Protective eye shields are normally provided to prevent rubbing of eye during the night whilst sleeping.Within 3-4 days most normal day to day activities like housework,driving and shopping can be resumed. After 2-3 weeks Most sporting activities can be resumed ,however hard contact activities such as boxing,football martial arts are best left for 3 months or more to ensure the best chance of full recovery.Following the post operation laser eye surgery aftercare program advised by your eye surgeon is very important in the overall.
Dr. Ajay Khanna who heads the Refractive Surgery & Vitreo Retinal Services at Dr. Om Parkash Eye Institute India has been performing Laser correction for specs since 1997.Dr. Ajay Khanna has been the earlier ones in the country to start with Thin Flap Lasik to treat patients with high myopia & thin corneas. This eye hospital was the first in the country to use for laser correction of specs, the state-of-the-art, Customized Lasik using NAVEX Quest -NIDEK CX III with Pentacam and OPD Scan.
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Also called RGPs, rigid gas permeable or oxygen permeable lenses, gas permeable (GP) contact lenses are less-known than soft lenses. RGPs are different from “hard” contact lenses, which have disappeared today, although they were popular before the invention of soft lenses in 1971. PMMA hard lenses are uncomfortable and prohibit oxygen from passing through the lenses.
Invented in the late 1970s, GP lenses contain silicone, which is more flexible than PMMA and allows more oxygen to pass through, creating more comfort and better vision. They also have many other advantages, such as more durable and deposit resistant, easier to clean, and less expensive. However, GP lenses demand a longer adapting period than soft lenses.
GP lens is the right solution for people unsatisfied with soft lenses, such as vision fussy individuals, people with astigmatism, presbyopia or keratoconus, or individuals after a refractive surgery. GP lenses offer the best answer for bifocal lenses for people with presbyopia. Ortho-k lenses also use GPs.
GP lenses are not flawless. They require a regular wearing for most comfort and a longer time to adjust, which never happen to soft lenses. GPs may still cause blurry eyes when they are removed, even if the situation will soon disappear. GP lenses also need more careful cleaning and storing since they last at least one year.
Currently, new versions of lenses that combine the visual clarity from GPs and comfort from soft lenses are available, which remove the most significant obstacle for GPs. These special lenses are used for presbyopia, keratoconus and LASIK recovery.
this article is come from:<a target=”_blank” href=”http://vision.firmoo.com/contact-lenses/gas-permeable-lenses.html”>http://vision.firmoo.com/contact-lenses/gas-permeable-lenses.html</a>
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Before laser eye surgery, an inteview is carried out to determine your personal suitability for eye surgery and to determine which type of operation may suit you and give an idea of the likely results.The next stage is to carry out a thorough eye test to determine a current up to date eye prescription and to take precise measurements of the eye structures. It is normally recommended that you are accompanied by a friend for this examination as part of procedure involves using eye drops which dilate your pupil and blur your vision for upto 18 hours. Also it is advised to carry a pair of sunglasses on this day,as bright lights and dilated pupils can cause discomfort. If you normally wear contact lenses these can affect the corneal curvature and consequently it is necessary if you wear soft lenses to discontinue wear for at least one week prior to,and on the day of consultation,and with hard and gas permeable lenses to discontinue wear at least four weeks prior to and on the consultation day.Normally you need to complete a general health questionaire.You are then normally given a complete eye examination. Based on the result of these examinations your eye surgeon will advise you about the most suitable procedure for you,discuss the risks and also the alternatives.You also have the opportunity to ask any further questions you may have. Visit http://www.accuratesight.com for more information and answers to your queries. You can then decide whether or not to proceed to a surgical appointment.The advantages resulting from laser eye surgery are ability to see immediately on waking up, no more fumbling for your glasses in the dark, not having to wear glasses or contact lenses saving time and lots of money on opticians visits as well as trouble in maintenance and upkeep, improved self confidence in appearence (hopefully!), easier participation in sports leading to an overall improvement in feeling of personal well being. Most of the patients, who undergo laser eye surgery claim that they are satisfied with procedure and it has improved the quality of their life significantly and often state that they regret not having it sooner. Lasik eye surgery is a laser surgery procedure for vision correction.The technique involves using a laser which is controlled by a computer to reshape the front surface of the eye(cornea). As with all surgery a pre-op consultation is required to ascertain the best eye surgery for the individual.In normal vision light enters the eye and is bent by the cornea and focussed to produce a sharp image on the back of the eye the retina. When a person has a refractive/visual error like short or long sight the light is bent such that a blurred image is produced. Lasik eye surgery can be used to correct short sight, long sight and stigmatism (correct spelling astigmatism).Older patients who have presbyopia/age related near vision problems cannot have their vision improved with this procedure. The cornea has an alcohol solution applied to help lift the epithelial flap which is then cut(a fine layer about 50 microns thick ) with a Trephine blade (ALSO CAN BE CUT WITH A LASER BUT AGAIN IT IS A SIMILAR PROCEDURE ) , but not completely removed and remains hinged on one side allowing it to be replaced inthe same position. The surgeon raises the flap, and an excimer laser shapes the the cornea to the dimensions determined at the pre op consultation.The eye surgeon replaces the epithelial corneal flap, within minutes, natural forces hold it in situ, and the eye surgery is finished.The surgery as with LASIK takes approximately 15 mins each eye. However recovery normally takes a bit longer approximately one week and there is usually some discomfort for the next 48 hours. This is just a general outline of the what happens after laser eye surgery procedures following refractive surgery (as there are wide variations depending on individual needs and surgery techniques).Patients are normally provided with antibiotic eye medication and lubricating eye drops to be used in the days immediately after surgery. It is common and good procedure for the eye surgeon who performed your operation to exam your eyes the day immediately after any eye surgery. Further appointments are then generally advised at the desired intervals. In the first few days and hours after surgery it is important to refrain from touching or rubbing the eyes and to try and rest as much as possible and to use any medication prescribed.Protective eye shields are normally provided to prevent rubbing of eye during the night whilst sleeping.Within 3-4 days most normal day to day activities like housework,driving and shopping can be resumed. After 2-3 weeks Most sporting activities can be resumed ,however hard contact activities such as boxing,football martial arts are best left for 3 months or more to ensure the best chance of full recovery.Following the post operation laser eye surgery aftercare program advised by your eye surgeon is very important in the overall. Dr. Ajay Khanna who heads the Refractive Surgery & Vitreo Retinal Services at Dr. Om Parkash Eye Institute India has been performing Laser correction for specs since 1997.Dr. Ajay Khanna has been the earlier ones in the country to start with Thin Flap Lasik to treat patients with high myopia & thin corneas. This eye hospital was the first in the country to use for laser correction of specs, the state-of-the-art, Customized Lasik using NAVEX Quest -NIDEK CX III with Pentacam and OPD Scan. Dr. Om Parkash Eye Institute 117-A, The Mall, Amritsar-143001 (Punjab) INDIA Tel : +91-183-2221128, 2221132, 6531128, 6541132 Mob: +91-98158-15888 Fax: 0091-183-2220910
Before laser eye surgery, an inteview is carried out to determine your personal suitability for eye surgery and to determine which type of operation may suit you and give an idea of the likely results.The next stage is to carry out a thorough eye test to determine a current up to date eye prescription and to take precise measurements of the eye structures.
It is normally recommended that you are accompanied by a friend for this examination as part of procedure involves using eye drops which dilate your pupil and blur your vision for upto 18 hours. Also it is advised to carry a pair of sunglasses on this day,as bright lights and dilated pupils can cause discomfort. If you normally wear contact lenses these can affect the corneal curvature and consequently it is necessary if you wear soft lenses to discontinue wear for at least one week prior to,and on the day of consultation,and with hard and gas permeable lenses to discontinue wear at least four weeks prior to and on the consultation day.Normally you need to complete a general health questionaire.You are then normally given a complete eye examination. Based on the result of these examinations your eye surgeon will advise you about the most suitable procedure for you,discuss the risks and also the alternatives.You also have the opportunity to ask any further questions you may have. Visit http://www.accuratesight.com for more information and answers to your queries.
You can then decide whether or not to proceed to a surgical appointment.The advantages resulting from laser eye surgery are ability to see immediately on waking up, no more fumbling for your glasses in the dark, not having to wear glasses or contact lenses saving time and lots of money on opticians visits as well as trouble in maintenance and upkeep, improved self confidence in appearence (hopefully!), easier participation in sports leading to an overall improvement in feeling of personal well being. Most of the patients, who undergo laser eye surgery claim that they are satisfied with procedure and it has improved the quality of their life significantly and often state that they regret not having it sooner.
Lasik eye surgery is a laser surgery procedure for vision correction.The technique involves using a laser which is controlled by a computer to reshape the front surface of the eye(cornea). As with all surgery a pre-op consultation is required to ascertain the best eye surgery for the individual.In normal vision light enters the eye and is bent by the cornea and focussed to produce a sharp image on the back of the eye the retina. When a person has a refractive/visual error like short or long sight the light is bent such that a blurred image is produced.
Lasik eye surgery can be used to correct short sight, long sight and stigmatism (correct spelling astigmatism).Older patients who have presbyopia/age related near vision problems cannot have their vision improved with this procedure. The cornea has an alcohol solution applied to help lift the epithelial flap which is then cut(a fine layer about 50 microns thick ) with a Trephine blade (ALSO CAN BE CUT WITH A LASER BUT AGAIN IT IS A SIMILAR PROCEDURE ) , but not completely removed and remains hinged on one side allowing it to be replaced inthe same position. The surgeon raises the flap, and an excimer laser shapes the the cornea to the dimensions determined at the pre op consultation.The eye surgeon replaces the epithelial corneal flap, within minutes, natural forces hold it in situ, and the eye surgery is finished.The surgery as with LASIK takes approximately 15 mins each eye. However recovery normally takes a bit longer approximately one week and there is usually some discomfort for the next 48 hours.
This is just a general outline of the what happens after laser eye surgery procedures following refractive surgery (as there are wide variations depending on individual needs and surgery techniques).Patients are normally provided with antibiotic eye medication and lubricating eye drops to be used in the days immediately after surgery. It is common and good procedure for the eye surgeon who performed your operation to exam your eyes the day immediately after any eye surgery. Further appointments are then generally advised at the desired intervals. In the first few days and hours after surgery it is important to refrain from touching or rubbing the eyes and to try and rest as much as possible and to use any medication prescribed.Protective eye shields are normally provided to prevent rubbing of eye during the night whilst sleeping.Within 3-4 days most normal day to day activities like housework,driving and shopping can be resumed. After 2-3 weeks Most sporting activities can be resumed ,however hard contact activities such as boxing,football martial arts are best left for 3 months or more to ensure the best chance of full recovery.Following the post operation laser eye surgery aftercare program advised by your eye surgeon is very important in the overall.
editor, writer, http://www.accuratesight.com
Article Source:http://www.articlesbase.com/vision-articles/lasik-eye-surgery-before-and-after-lasik-eye-operation-1163559.html