Normal Eye(Emmetropia)
The eye is like a camera. In a camera, light passes through a lens system back onto the film. The cornea and lens are at the front of the eye (anterior chamber) and are similar to a camera's lens system. The retina is located at the back of the eye (posterior chamber) and is similar to the camera's film. In the normal eye, light rays of an image pass through the cornea and the lens and are focused directly on the retina to produce a clear image.
What is a Refractive Error?
Normally, rays of light entering the eye are brought to a precise focus on the retina – the light sensitive layer lining the back of the eye. When such a focus is not achieved, a refractive error results and vision is not clear. These imperfections in the focusing power of the eye are called refractive errors. The common refractive errors are:
Myopia, or Nearsightedness;
Hyperopia, or Farsightedness;
Astigmatism
Myopia (Near sightedness)
A myopic eye is longer than normal or has a cornea that is too steep, so that the light rays focus in front of the retina. Close objects look clear,but distant objects appear blurred
.
Hyperopia (Farsightedness):
Hyperopia is term used to describe the condition of farsighted. The causes of hyperopia are typically genetic and involve an eye that is too short or a cornea i.e. too flat, so that images focus at a point behind the Retina. People with hyperopia can usually see distant objects well, but have trouble focusing on nearby objects.
Astigmatism (Distorted vision):
ASTIGMATISM (cylindrical error) occurs when incoming light rays unable to reach a common focus within the eye. Astigmatism distorts or blurs vision for both near and far objects. The cornea is the clear front window of the eye. A normal cornea is round and smooth, like a basketball. When you have astigmatism, the cornea curves more in one direction than in the other, like a football. It is possible to have astigmatism in combination with myopia or hyperopia.
Treatment for Refractive errors:
There are several alternatives to correct your vision. Eyeglasses or contact lenses are the most common methods of correcting refractive errors. They work by refocusing light rays on the retina, compensating for the shape of your eye. Refractive surgery is also an option to correct or improve your vision. These surgical procedures are used to adjust your eye's focusing ability by reshaping the cornea, or front surface of your eye.
Are you an ideal candidate for corneal refractive surgery?
Be at least 18 years of age, with a stable refraction for the past 1-year.
Have healthy eyes that are free from any eye diseases or corneal abnormalities (E.g. Scar, Infection, etc)
EXCIMER LASER:
The use of the EXCIMER LASER in corneal refractive surgery has greatly increased the safety of the procedure as the refractive correction is achieved by the removal of a little as 10 to 20% of the total corneal thickness.
The excimer laser is a “cool” laser, and does not generate heat in the cornea. The laser energy destroys intermolecular bonds in the corneal tissue resulting in tissue removal by a process termed “photoablative decomposition”. The exquisite precision with which tissue can be removed and the absence of thermal damage render this laser particularly suitable for surgery on the delicate cornea.
Removal of corneal tissue alters the corneal contour. By specifically removing tissue from different portions of the cornea, the surgeon is able to correct the different refractive errors .
LASIK Surgery
LASIK (or Laser-Assisted In-Situ Keratomileusis) is the most modern surgical procedure for correcting vision problems like myopia, hyperopia, and astigmatism. This is an advanced laser vision correction technique in which the curvature of the cornea is reshaped using a laser that is capable of removing tissues with precision up to a micron level.
There are three steps in Lasik surgery.
STEP 1- With the help of keratome corneal flap is made.
STEP 2- With the help of excimer laser corneal reshaping is done.
STEP 3 - Corneal flap is put back.
The main purpose of surgery is to offer sufficient good vision to patients so that they are not dependent upon glasses most of the time. Some of the possible side effects of LASIK are undercorrection, overcorrection, glare, halos, and reduced contrast sensitivity. Wavefront Assisted Customised LASIK (C-LASIK) Wavefront assisted customized LASIK is an exciting new laser vision correction method where not only are refractive errors corrected but a spot laser also removes tiny aberrations in the eye, reducing night vision problems and improving the quality of vision. This technique can help to improve the outcome of LASIK. This cutting edge technology has been borrowed from astronomers, wherein an instrument called the aberrometer (Zywave) measures minute imperfections in the eye, so that they can be corrected during LASIK surgery. The procedure minimizes the likelihood of new aberrations occurring, which could reduce the quality of vision and make people prone to night vision problems like haloes, glare and ghost images.
With older lasers, only the spherical and cylindrical power could be corrected. Since an aberrometer can measure many different types of aberrations, in addition to the sphere and cylinder, surgeons can use it to correct many more aberrations. . This can be especially important at night, when the aberrations are particularly severe because the pupil is larger.
The C LASIK procedure leads to more accurate vision correction, better night vision, greater predictability of the surgical outcome, reduced glare, enhanced contrast sensitivity, greater safety and efficacy.
FAQ on Lasik: Frequently asked question on lasik
Here are the answers to a selection of the questions that are most commonly asked. Don't forget that I am available by phone to answer any other questions you may have, so please feel free to ask. M 9824241014
WHAT IS LASIK?
LASIK Stands for LASER IN SITU KERATOMILESIUS.It is a form of laser vision correction that is capable of correcting range of glass numbers. The procedure uses a computer controlled excimer laser to correct your vision.
Does LASIK hurt?
The treatment itself is painless because we put a few anesthetic drops in your eyes to make you even more comfortable. You will feel pressure on and around the eye during treatment. With LASIK, some patients may experience a feeling of "something in the eye" for a day or so after treatment.
Do the results from laser treatment permanent?
Yes. Most of the eye growth takes place up to the age of 18 years. After this the eye number tends to stabilize and not change. Lasik should be done after the stability of the glass number has occurred for at least 1 year. The results are then permanent .
How do I know if I am a good candidate for LASIK?
A large percentage of nearsighted, farsighted, and astigmatic patients are potential candidates for LASIK. Patients who are 18 years of age or older, have healthy eyes that are free from retinal problems, corneal scars, and any eye disease are suitable. Along with being medically suitable, the best candidates are people with a lifestyle or occupation in which they are dissatisfied with their contact lenses or glasses. By having an evaluation, examination, and consultation with you, the doctor will be able to determine if you are a good candidate.
How long does LASIK take?
In our practice, LASIK is performed as an office procedure. The entire treatment takes about 5 to 7 minutes per eye or approximately 15 minutes for both eyes.
Should I opt for Standard/Conventional Lasik or Wavefront Lasik ?
Standard or Conventional Lasik is good if you are fine with the vision that you experience with your glasses and lenses. But if you wish to opt for better quality, sharper vision and a more advanced laser technology then you must consider the option of Wavefront Custom Lasik. The difference to the pricing is marginal, but the visual results after Wavefront Lasik are highly superior.
What kind of Anesthesia is used during the treatment?
Numbing eye drops are used. Sometimes an oral medication is used to help with relaxation. Don't worry - no needle or intravenous drugs are used.
Can you have both eyes treated at the same time?
Treatment can be performed on both eyes on the same day. You may elect to have one eye done at a time.
How long after laser treatment can I see?
Visual recovery after treatment is rapid. Most people achieve good vision the day after surgery and find that their eyes feel fairly normal 24 hours later. You will be able to resume your routine activities like driving, watching T.V, Reading and working on the computer within 2 days. However, your sight will improve even further, and the very best vision could take two weeks to achieve
Will I need reading glasses after the treatment?
Generally, patients under 40 years of age read well without glasses following the treatment. Patients over 40 may need magnification for reading fine print. Presbyopia is the term that refers to the natural weakening of the focusing muscles that occurs in our early to mid 40s, causing us to need the magnification that reading glasses provide...
How soon can I use eye makeup?
You may resume wearing eye makeup starting 1-2 weeks after your treatment. We strongly recommend that you purchase new eye makeup, specifically mascara, to avoid potential infection following your treatment.
How soon after the treatment can I exercise?
Non-contact sports can be resumed as soon as you feel capable. Eye protection is always recommended for racquet sports or rough sports where there is a risk of being hit in the eye.
Can I see the treatment as it is being performed?
You will be "awake" but very relaxed. You will not be able to see any of the details of the treatment. You will see a number of lights, but the images will be blurred.
Will I experience pain after the treatment?
Some patients experience a feeling of burning or scratchiness. This feeling generally lasts from one to three hours following the treatment. Most people feel fine soon after the treatment.
When can I go back to work?
Most patients are back to work full-time the day after treatment. An additional day or two is rarely required before returning to work. If you can we, recommend that you take it easy for a couple of days.
What is the Success Rate for the Lasik Procedure?
Success Rate depends on several factors, the most important being the degree of nearsightedness, farsightedness or astigmatism. Depending on the prescription, the surgeon can help determine the likelihood of reaching 20/20 Approximately 95 percent of eyes treated with LASIK reach 20/40 or better vision with one procedure, which is the requirement for driving legally without correction.
DR PIYUSH UNADKAT
M.B.D.O.M.S
OPHTHALMOLOGIST
Shraddha Hospital,
Indira circle chowk,
Rajkot-05
Contact: 0281 2585478
09824241014
drpiyushunadkat@gmail.com
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