Posts Tagged ‘visual acuity’
Dry eye is a common eye problem, and there are many causes of dry eyes, one of which is the postoperative side effect of Lasik surgery. In normal circumstances, Lasik surgery, some studies show that, is one of the main causes of dry eye, although sometimes certain people seem to experience no dry eye symptoms.
Reasons why Lasik surgery leads to dry eye are as follows. In the process of a Lasik procedure, there must be a corneal flap created by either a steel blade or a laser, during which the corneal tissue and corneal nerves are supposed to be broken up. What is more, the following reshaping of corneal by laser will come to further disrupt the nerve tissue. If the patient suffer from a comparatively more seriously eyesight problem, the nerve tissue is thought to be cut deeper, which does more side effect to eyes. Then due to the whole disruption, the nerve tissue, when recovering and regenerating, is normally hard to produce tears to keep eyes moistened. Thus dry eye symptoms emerge.
( What is more, for supplement only, whether the corneal surface and tear lay are created to be qualified or smooth is closely related to another eyesight problem of “ghosting” and “fuzziness”, as when light comes into eyes, it meet with the tear layer at the very first. If the corneal surface or tear layer is of irregularity and deficiency, visual acuity will be greatly affected.)
As a surgeon, considering the possible side effects of dry eyes, and ghosting or fuzziness images creation, I advise several ways to minimize those possibilities after operation: have an overall examination concerning eyes, including the evaluation of preexisting dry problems; apply the Intralase FS lasers, but not the steel razor blade microkeratome to create the corneal flap, which is believed to be more able to minimize unsmooth and unqualified corneal surface and tear layer; after the surgery, use artificial tears and gel lubricants for a series of days. Those who do not have the experience of dry eyes after lasik surgery are also suggested to. The cyclosporine 0.05% eye drops (Restasis) are recommended.
It has been researched that the above regimens are able to relieve dry eyes, as well as other eye problem after Lasik surgery. By persisting in the regimens, improvement of eyesight, but also the prevention from secondary side effects can be guaranteed. Besides, get more information of Lasik surgery in advance is also helpful to enhance the outcomes.
more info
·Dry eye causes and treatments
·Flaxseed oil for dry eye treatment
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Article Source:http://www.articlesbase.com/vision-articles/how-to-relieve-dry-eye-caused-by-lasik-surgery-1697531.html
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Thanks to continued advances in laser eye surgery, refractive surgery tools and techniques, glasses and contact lenses are fast becoming obsolete for many patients with astigmatism. Patients with undetected astigmatism often experience headaches, fatigue, eyestrain and blurred vision at all distances. Because astigmatism may not be recognized as the cause of these symptoms, this condition may go undiagnosed and continue to affect sufferers. Astigmatism can also be present in children, affecting their ability to see well in school and while playing sports.
Characterized by an irregular curvature of the cornea, astigmatism can be detected by regular eye examinations and successfully treated using procedures such as laser in-situ keratomileusis (LASIK), photorefractive keratectomy (PRK), laser epithelial keratomileusis (LASEK), laser thermokeratoplasy (LTK) and astigmatic keratotomy (AK; Table 1). An ophthalmologist can determine which type of procedure will work best for each patient.
Worldwide, >17 million people have undergone laser refractive surgery, and refractive surgery is one of the most commonly performed operations in the United States and by Beverly Hills LASIK surgeons. The newest laser-assisted procedures are approved by the U.S. Food and Drug Administration to treat up to 6 diopters (D) of astigmatism correction, which includes roughly 98% of all astigmatism patients. Advances in laser technology continue to improve treatment outcomes.
Guttman reported on a recent study by Barraquer, a private practitioner in Colombia, of 364 astigmatic myopic patients treated with a new generation “flying spot” excimer laser. Barraquer reported postoperative best-corrected visual acuity of 20/20 or better in 99% of treated eyes at 3 months. Astigmatic correction was achieved to within ±0.50 D in 92% of eyes.
Remember that for patients in or around Beverly Hills LASIK was used after the detection of astigmatism to treat it in its early and advanced stages. Because children may also have astigmatism, it is important that eye examinations be scheduled at regular intervals to detect any astigmatism early on.
Guttman C. Laser yields safe, predictable correction for astigmatism. Ophthalmology Times, Advanstar Communications, January 1, 2008;36.
Andrew I. Caster, M.D. has performed over fourteen thousand procedures to correct nearsightedness, farsightedness, and astigmatism. Dr. Caster is widely considered one of the most knowledgeable Lasik surgeons in the United States. Los Angeles Magazine selected Dr. caster as “The Best Lasik Surgeon in Los Angeles” and W Magazine listed him as one of two top Lasik surgeons in the United States. For more information please visit: http://www.castervision.com/
Article Source:http://www.articlesbase.com/vision-articles/refractive-surgery-eliminates-glasses-for-many-astigmatic-patients-1597619.html
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Eyesight is usually described in terms of visual acuity. When someone says “20/20 vision” we normally think of perfect vision. However, acuity is just one aspect of how well you actually see. Vision quality can be just as important in your day-to-day life. Higher order aberrations can diminish vision quality without affecting your score on the eye chart. Wavefront diagnosis detects these tiny imperfections in your eye prior to laser vision correction so that you can have precise correction and to avoid making them worse.
High Order Aberrations and Vision Quality
High order aberrations can cause problems with your vision including:
- Glare
- Shadows
- Poor contrast sensitivity
- Poor night vision
- Halos
- Double vision
These problems affect the quality of your vision, but do not always affect your visual acuity. Visual acuity is what is measured on the eye chart and is typically diminished by lower order aberrations – myopia (nearsightedness), hyperopia (farsightedness), and astigmatism.
While visual acuity is certainly important and can affect your eligibility for some professions and ability to hold a driver’s license, the importance of vision quality and the impact it has on your quality of life should not be overlooked.
Wavefront Technology
Wavefront technology is not new, but it has only been utilized in ophthalmology since the 1990’s. It was developed for astronomers to use in adjusting their telescopes to get the clearest image.
In ophthalmology Wavefront technology is used for diagnosis and to guide the laser during refractive surgery.
Wavefront Diagnosis and Why It is Important
During the diagnostic phase of your treatment Wavefront is used to create a 3-D map of your eyes. It detects the tiny high order aberrations that other tests cannot pick up. Light is passed into your eye, passes through the parts of your eye and reflects back out. Any differences in the pattern of the light as it passes in and when comes back out are aberrations.
High order aberrations can be made worse by LASIK surgery. Wavefront diagnosis reveals these aberrations to your ophthalmologist so he can correct them, work around them in a way that will not exacerbate any existing problems with your vision quality, or when appropriate advise against the surgery.
Wavefront diagnosis can help your eye surgeon determine whether or not LASIK or another type of laser vision correction can improve your vision. If you do not have any higher order aberrations, you may choose traditional LASIK. If you do have them, you need custom LASIK which will use the map created during your diagnosis to guide the surgery, producing very precise results.
Even if you plan to have traditional LASIK surgery, you need the Wavefront diagnosis to determine if it is safe for you.
If you have vision problems that include halos, starburst, double vision, or other problems with vision quality, please visit Eyes.com to learn more about how you can improve your eyesight.
Article Source:http://www.articlesbase.com/vision-articles/wavefront-diagnosishigher-order-aberrations-1552261.html