Posts Tagged ‘tissue’
Many patients have asked a relatively simple question, “why was LASIK invented at all”? A decade ago very few people even knew the word LASIK, and while the word had become a part of our lexicon, the real reason that doctors choose to do LASIK escapes many peoples understanding. We were one of the first handful of doctors in the United States, and the first to realize the potential benefits of LASIK for vision correction almost fifteen years ago. Since that time there are now over 10,000 LASIK doctors in the USA alone and a multiple of this number worldwide. The reasons for the success of LASIK are numerous but in a sentence it provides rapid, accurate, and relatively painless restoration of vision to a wide range of refractive errors. Patients are able to see like they were wearing contact lenses without all of the bother, cost, inconvenience, and risks of contacts. In general they have better visual function than provided with glasses in the same way that contact lenses are better than glasses for so many reasons.
This simple question is profound, because it touches on an invention that has changed the way in which the world views vision correction and has helped millions of people worldwide to see better without the aid of glasses or contact lenses.
For perhaps millions of years, much of human kind has suffered with vision problems. There are the serious eye diseases such as cataracts, glaucoma and a myriad of other problems. Beyond this is the simple fact that many people are unable to see clearly at distance, near, or both. This is from the imperfections of the eyeball as a camera and this was greatly helped over that last few hundred years by glasses and more recently in the last 50 years by contact lenses. Although with the advent of lasers, there was a hope that such technology could improve vision, limitations in the nature of the eye had limited laser application to vision correction until the advent of LASIK .
LASIK is a hybrid procedure, that is it involves two steps which together are able to improve vision very rapidly and predictably for patients with ametropias. The first step is to create a potential space for the laser to correct the vision and the second is to do the correction itself. In the early days of LASIK about 15-20 years ago , this potential space was made with a device called a microkeratome. This is a miniature shaver which can peel a thin layer of outer tissue from the cornea which remains attached at the edge or “hinge”. Another laser, the excimer laser then focuses on the freshly cut surface, and removes tissue in a programmed manner to reshape the eye. Finally, the flap is replaced which assumes the contour of the newly shaped cornea beneath it. It is the transfer of the shape combined with covering the treated area with living tissue that makes LASIK so remarkable. Healing occurs at the edge or seam of the flap and the eye barely knows that anything has occurred beneath. The vision is rapidly restored with no significant healing response, which is key to the success of LASIK.
Newer lasers, called femtosecond lasers, are able to make the flap layer more precisely without a cutting blade but fundamentally perform the same function. This all laser approach is a safer and slightly more effective way of restoring vision by LASIK. The current state of the art in LASIK is to use advanced femtosecond lasers such as our Visumax to make a flap, and a wavefront optimized excimer laser like our Zeiss or our Allegretto laser(s) to reshape the cornea. With this type of treatment we have a very low complication rate, and excellent vision results in most cases.
We become complacent very quickly with new technologies but it is a truly amazing and revolutionary accomplishment that in a procedure that lasts only a few minutes , a persons vision can be corrected from a lifetime of limitations.
Dr. Dishler is the first doctor to perform LASIK in Colorado, the first doctor to offer blade free LASIK in Colorado, and is a consultant, lecturer, and inventor. He is involved with several FDA studies and answers questions related to laser vision correction online.
Article Source:http://www.articlesbase.com/vision-articles/why-do-doctors-perform-lasik-as-the-most-common-vision-correction-procedure-1488131.html
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Preparation
For 2 days prior to your surgery appointment, you will be asked to stop using any eye makeup and face creams. You are more likely to pick up an infection if there are any cosmetic products on your eyelashes. Your doctor will also tell you to wash your eye area (including eyelashes and eyebrows) with shampoo right before your procedure.
You will also have to go without perfume or cologne, because the fumes can actually affect the laser. Plan on having someone drive you and pick you up after your time at the hospital as your vision will be too blurry for safe driving. Same goes for your first post-op visit. Even if you plan on public transit, you should have someone accompany you for safety.
For the surgery itself, it really only consists of 2 major steps and the entire process will be over in just a few minutes.
Step 1 – Creating Corneal Flaps
Your eye is completely numbed with a topical anesthetic, and you may also be given a sedative to help you relax for the surgery.
A tool called a speculum is used to hold your eyelid open after being treated with antiseptic. The small flaps are then cut into your cornea with another instrument called a microkeratome. There are two kinds of microkeratomes. It may have an actual blade, or it can use a laser (usually called bladeless lasik or intralase). The laser version can make thinner flaps, making it a much better option for patients who can’t have traditional lasik surgery because they have cornea that is thinner than usual
Step 2 – Laser Ablation
After the flaps have been cut and folded back, the deeper corneal tissue, known as the “corneal bed” will be exposed. It’s here that the excimer laser will be applied, to ablate the corneal bed surface to change its shape. A computer program is used to help guide the laser, which will apply repeated pulses of ultraviolet (UV) light to the eye. Cells will be instantly vaporized without any damage to neighboring tissue.
This cell destruction will change the shape and curve of your underlying cornea. The flaps are then folded back into place and left to heal without stitches. When it heals, the refractive errors in your eye that required you to wear prescription lenses should be fixed now that the curve of the cornea has been adjusted.
Sam Shad is the editor of Online-Eye-Info.com, the comprehensive guide for maintaining healthy eyes and sight. Read more about post lasik operation care at his site.
Article Source:http://www.articlesbase.com/vision-articles/what-to-expect-with-a-lasik-procedure-1457605.html
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If you fancy seeing the future more clearly then vision correction could be just what you need. Whether you are short sighted, long sighted or even have astigmatism, there are specific procedures available which can help you to see things clearly once again.
Eye correction is a commonly performed procedure. There are millions of eye tests carried out every year in the United Kingdom and around 75% of British adults wear glasses or contact lenses to correct vision.
Anyone seeking a more permanent solution to vision problems could investigate the possibilities offered by laser eye surgery. There are various methods of vision correction available so it is up to you to choose the one that suits your lifestyle and situation best.
LASIK eye surgery is a highly effective procedure that is suitable for most prescriptions. Performed by ophthalmologists using a laser, LASIK surgery uses a cool beam of light to gently reshape the front surface of your eye.
For short-sighted individuals the front surface of your eye is flattened with the laser. In cases of long-sightedness the central cornea is made steeper when the laser removes tissue in this area.
Astigmatism is corrected by reshaping the steepest part of the cornea and making it more spherical.
The first step in the laser eye correction process is to speak to your optometrist about the treatment that is right for your specific vision problem. A specialist refractive optometrist will be able to determine your suitability for LASIK eye treatment based on your personal prescription and what you want to get out of the procedure.
To ensure the best possible results some opticians treat most people over eighteen years old who have had a stable prescription for twelve months.
The entire LASIK procedure can be completed in about ten minutes and both eyes can be treated by LASIK simultaneously.
The procedure is performed on an outpatient basis. You will usually sit in a reclining chair and anaesthetic drops or a wash will be applied to your eyes in order to reduce discomfort and numb the area.
Next, a flap will be cut on the surface of the cornea and then folded back so that the ophthalmologist can reach the corneal tissue beneath it.
Your cornea is then reshaped dependent on your condition with computer-controlled pulses of cool laser light. When the right amount of tissue has been removed the flap that was removed at the beginning is now replaced in its original position where it will then heal naturally.
Immediately after the LASIK surgery your eyes may feel itchy and watery. You will most likely be prescribed certain medications or eye drops to help with the healing and you will probably be required to wear eye patches while you sleep at night.
Most people are able to drive and return to work within forty eight hours of having LASIK eye surgery, unless the work environment is particularly dusty or hazardous to eyes in any way.
Adam Singleton writes for a digital marketing agency. This article has been commissioned by a client of said agency. This article is not designed to promote, but should be considered professional content.
Article Source:http://www.articlesbase.com/vision-articles/learn-more-about-lasik-eye-surgery-1315382.html
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Just as the name reflects, age-related macular degeneration (AMD) has been a severe eye disease among people over 65. The estimated number of AMD affected Americans is 3 million by 2020. As a part of the retina, macula is responsible for sharp and central vision, so that AMD may lead to vision loss.
There are generally two types: dry AMD and wet AMD, the former of which accounts for about 85-90 percent. Obvious symptoms of dry AMD include yellowish spots from deposits or debris from deteriorating tissue around the macula. Both macular tissue aging and thinning and pigment depositing can lead to dry AMD. Studies show that vitamin A, C and E may help prevent or slow progression of dry AMD. Dry AMD patients are also advised to wear sunglasses when outdoors. People with wet AMD have more severe problems: new blood vessels grow beneath the retina and leak blood and fluid, which damage light-sensitive retinal cells. Wet AMD is caused by the body’s misguided attempt to supply more nutrients and oxygen to the retina, which instead causes scarring and potential vision loss. Occult wet AMD has light blood leakage and less vision loss danger, while classic wet AMD has clear scarring and more vision loss danger.
If you have AMD, your central vision has shadowy areas. During a retinal exam, the doctor may detect early signs of AMD and then an Amsler grid can be used to measure your central vision. For a further affirmation, your retinal blood vessels surrounding the macula will be examined. Many researches have showed that macular degeneration is mostly caused by aging and eye tissue deterioration. Other confirmed or potential risk factors for AMD include drug side effects, smoking, family ADM history, high blood pressure, lighter eye color, obesity, over-exposure to UV lights, fat diet and so on.
AMD-affected people in their 90 develop vision loss at a possibility that is 15 times of that for people in their 60s. And overweight patients have a risk of advanced ADM that is double of that for people with normal body weight. Gene variants are also related to AMD, which is known as family disease. Smoking is reported to bring higher rates of vision loss on ADM patients. AMD occurs more frequently in whites, so that people with lighter eye color are suspected to suffer AMD at a higher incidence. Toxic drugs such as Aralen and phenothiazine may cause side effects that lead to AMD.
Currently, no outright cure is available for AMD. For dry AMD, FDA has never approved any treatment, although nutritional intervention may slow its progression. Those nutrients include zinc, lutein, zeaxanthin and vitamin A, C, and E. For wet AMD, FDA has approved drugs including Lucentis, Macugen and Visudyne to stop or slow abnormal blood vessel growth.
Since complete recovery from vision loss caused by ADM is impossible, regular Amsler grid tests are useful to detect underlying AMD risk. For people with vision loss, many low vision devices such as magnifying glasses are available.
this article is come from: http://vision.firmoo.com/eye-diseases/causes-and-treatments-for-macular-degeneration.html
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What to expect before, during, and after surgery will vary from doctor to doctor and patient to patient. The US FDA provides a compilation of patient information developed by manufacturers and healthcare professionals, but cannot replace the dialogue you should have with your Beverly Hills Lasik surgeon. Read this information carefully and with the checklist, discuss your expectations with your doctor.
The surgery itself should take less than 30 minutes. You will lie on your back in a reclining chair in an exam room containing the laser system. The laser system includes a large machine with a microscope attached to it and a computer screen.
A numbing drop will be placed in your eye by a skilled Lasik surgeon Los Angeles laser eye surgery experts tell us, the area around your eye will be cleaned, and an instrument called a lid speculum will be used to hold your eyelids open.
Your doctor may use a mechanical microkeratome (a blade device) to cut a flap in the cornea. If a mechanical microkeratome is used, a ring will be placed on your eye and very high pressures will be applied to create suction to the cornea. Your vision will dim while the suction ring is on and you may feel the pressure and experience some discomfort during this part of the procedure. The microkeratome, a cutting instrument, is attached to the suction ring. Your doctor will use the blade of the microkeratome to cut a flap in your cornea. Microkeratome blades are meant to be used only once and then thrown out. The microkeratome and the suction ring are then removed.
According to a top Lasik doctor Los Angeles laser eye specialists may use a laser keratome (a laser device), instead of a mechanical microkeratome, to cut a flap on the cornea. If a laser keratome is used, the cornea is flattened with a clear plastic plate. Your vision will dim and you may feel the pressure and experience some discomfort during this part of the procedure. Laser energy is focused inside the cornea tissue, creating thousands of small bubbles of gas and water that expand and connect to separate the tissue underneath the cornea surface, creating a flap. The plate is then removed.
You will be able to see, but you will experience fluctuating degrees of blurred vision during the rest of the procedure. The doctor will then lift the flap and fold it back on its hinge, and dry the exposed tissue. The laser will be positioned over your eye and you will be asked to stare at a light. This is not the laser used to remove tissue from the cornea. This light is to help you keep your eye fixed on one spot once the laser comes on.
When your eye is in the correct position, your doctor will start the laser. At this point in the surgery, you may become aware of new sounds and smells. The pulse of the laser makes a ticking sound. As the laser removes corneal tissue, some people have reported a smell similar to burning hair. A computer controls the amount of laser energy delivered to your eye. Before the start of surgery, your Beverly Hills Lasik eye doctor will have programmed the computer to vaporize a particular amount of tissue based on the measurements taken at your initial evaluation. After the pulses of laser energy vaporize the corneal tissue, the flap is put back into position.
A shield should be placed over your eye at the end of the procedure as protection, since no stitches are used to hold the flap in place. It is important for you to wear this shield to prevent you from rubbing your eye and putting pressure on your eye while you sleep, and to protect your eye from accidentally being hit or poked until the flap has healed.
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/what-to-expect-during-lasik-eye-surgery-1113003.html
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