LASIK and Eye Surgery Blog - Clearview Eye and Laser Medical Center

Laser use for eye surgery, and most other types of surgery, has become widespread in recent years, and for many good reasons. First, what is a laser?

It's a man-made light, made for a specific purpose. Each laser has a set wavelength, which is another way of saying that each laser is a specific color. They can have a visible color, or they can be outside our visible range, which makes them either infrared or ultraviolet.

Light is a form of energy, and a laser provides its energy is a very useful way: the laser light travels in lockstep, directional and parallel. This makes for a very precise, focused beam of light which can be used surgically. It is different from flashlights or headlights, for instance, which are scattered light.

Of course some lasers are not suitable for surgeries, being too hot and powerful. The lasers used for vision correction are called Excimer lasers (a made-up name based on the way these lasers are created). They are relatively cool, ultraviolet lasers.

Little or no bleeding

Lasers are used in medicine and dentistry in place of blades. Use of a blade will cut and cause bleeding, creating the risks of too much bleeding, blood clots, and infection, and leaving a scar afterwards. Use of a laser avoids all this. The laser is set to penetrate at a certain depth, and in directing its focused energy it breaks the connections between certain cells, but not between others.

Those cells are now disconnected, and will vaporize in the laser's warmth. As the laser does this, it also seals the tissue where it worked. So blood vessels are closed and do not bleed.

Speed, accuracy and less anesthetic

Lasers pulse or beam very quickly. They work fast and with microscopic accuracy, far faster and more accurate than any hand-held blade could ever be. Because they do not cut, and cause no collateral damage, less anesthetic needs to be used, and sometimes none at all.

Lasers have revolutionized medicine and dentistry. We are fortunate to live in an era where surgery is vastly safer, less painful, and faster than it has ever been before. Our laser vision center in San Diego, California offers precise, safe, and fast LASIK vision correction which was not at all possible a few decades ago.

Have you ever noticed little shapes floating around in front of your vision? They might look like strings or like specks of different sizes and shapes. If you look at a blank wall or a blue sky, you can see them more clearly.

They appear to be in front of your eyes, but actually they're inside the eye. Our eyes are full of fluid:

• The aqueous fluid is in the anterior chamber, in front of the lens
• The vitreous fluid is in the posterior chamber, between the lens and the retina

The floaters are little clumps of cells in the vitreous fluid and they cast shadows on the retina, which is what we see. They tend to form in middle-aged eyes, as the vitreous fluid starts to thicken a little. One cause of the floaters is the vitreous gel pulling away from the retina, a condition known as a posterior vitreous detachment. This happens more often in people who:

• Are nearsighted
• Have had some inflammation in the eye
• Have had a cataract surgery

Many floaters are harmless and will fade away. But if you suddenly start to see floaters, give us a call or send an email, especially if you are over about 45 years of age. The floaters themselves are not necessarily harmful, but the vitreous gel pulling away from the retina can sometimes tear the retina, causing a little bleeding, and this may look to you like new floaters. A torn retina is certainly a serious problem, as it could lead to retinal detachment and blindness if not treated.

In our San Diego, California Medical Laser Center, we offer cataract surgery to restore vision after cataracts have developed. It's a matter of removing the cataract-clouded natural lens, and replacing it with an artificial lens.

At first that might seem like a rather drastic step to take. But the alternative is drastic too: eventual blindness. There is no way of stopping or reversing cataract formation and removing the lens is the only way to remove the cataract.

Actually, it's a simple surgery and here's how it works.

Through a very small incision at the side of the eye, and using ultrasound (silent, fast, and gentle), Dr. Feldman breaks up the clouded lens. It is then easy to remove by gentle suction. The membrane which surrounds the lens is left in place.

The artificial lens (intraocular lens, abbreviated as IOL) is then inserted through the same incision and placed within the same membrane which enclosed the natural lens. There are four IOLs we offer, and they all give you clear vision at multiple distances. They each use a different technology to do that. One of them, Crystalens, is attached to the same little eye muscles which controlled the natural lens. Now they control the IOL.

Subjectively, you will not feel any difference having an IOL in your eye instead of its natural lens. There will be small differences in your vision that you will quickly become used to, and your vision will be very much clearer than it was with the cataract lens still in place. That increased clarity is noticeable at once and increases during the first week. You can resume your normal activities that same day or the next day.

You can read more about all this on our Cataracts page and Cataract Surgery Questions page. You might also want to take a look at the many enthusiastic Testimonials to Dr. Feldman’s skill.

CustomVue™ LASIK Laser Treatment is the trade name for vision correction done by the Wavefront-guided LASIK system manufactured by VISX. This is the system we use to do our LASIK procedures. We use it for the diagnosis of your eyes’ exact contours, and to guide the laser during your treatment.

For the diagnosis phase, it has the WaveScan WaveFront System and for treatment, it has the STAR S4 Excimer Laser System. It's physically a complete system for LASIK, with all the components we need to give you the world's best vision correction.

• Laser – to precisely do your vision correction and give you 20/20 vision, or close to it;
• Computer – to store the information gathered about your eyes and display it on the monitor as graphs and 3-D colored maps;
• Patient bed – for your comfort during the procedure, and for ease of access to your eyes for Dr. Feldman;
• Microscope – so that Dr. Feldman can see your eyes at five different magnifications;
• Iris Registration – technology which tracks eye movements during treatment so as to keep the laser exactly focused on the pre-determined treatment area;
• ActiveTrak – an eye tracking technology which monitors your eyes in three dimensions so that no dilation is required
• ActiveTrak Automatic Centering – which locates and sets the treatment center to the center of your eye’s pupil.
• Variable Spot Scanning – technology which uses beam sizes from 0.65 mm to 6.5 mm, scanning the treatment area and using the beams which will best conserve your eye tissue.

There are two other companies which manufacture similar vision correction systems, but we chose the VISX CustomVue system as being the most powerful, flexible, and precise system for your vision correction. With only one pair of eyes each, we all need to be careful who we trust for treating them, and LASIK surgeons need to be careful to use only the best and most reliable technology.

On November our blog was about the cornea's curvature and how that relates to being nearsighted, farsighted or astigmatic. This blog is about the cornea's structure.

It has layers. In some ways it's similar to skin. Really, the cornea is the eye’s skin, in that it protects the eye's interior. Skin has layers too. In both cornea and skin, the top layer, the epithelium, is continually replacing itself. Cells die and are discarded from the surface. Below the surface layer in both eyes and skin are other layers containing and protecting many other structures.

LASIK treatments are not done right on the epithelium because the corneal surface is changeable and would eventually sabotage or undo the LASIK correction. Instead, the LASIK laser works on the next layer down, the stroma. This is why a flap must be created and folded back to give access; or (as in PRK) some surface cells must be removed.

The corneal stroma is a stable layer. When the laser changes its curvature, it will remain that way, and your vision will be permanently improved. It’s also the thickest layer. It consists of tiny parallel collagen fibers. Being parallel, they give clarity to the cornea and light can pass through unimpeded.

Below the stroma is a membrane and then the endothelium, which is only one cell thick. It removes water from the cornea to keep it clear. Translucence and correct curvature are the two central features of the cornea, and if these are impaired, vision suffers.

Many people know that myopia is nearsightedness, but what is nearsightedness exactly? Yes, it's the ability to see well up close but not at distances. What causes that?

The shape of the cornea (clear front part of the eye) causes it. We are all born with eyes of a certain shape. If the shape is within certain parameters, we have what is called 20/20 vision. Then we don't need glasses to see well at all distances.

A myopic eye has a steeper cornea than normal. Like all clear, curved structures, the cornea bends (refracts) light rays as they pass through it into the eye. The eye's lens, another clear, curved structure, does the same thing. To see clearly at all distances, the cornea and lens together have to somehow bend all incoming light at the right angle to make it focus on the retina, the eye’s "camera film". When the cornea bends the light too much to start with, the lens must adjust for that if we are to see clearly at all distances.

The lens adjusts by its ability to accommodate. Tiny muscles attached to the lens pull on it or relax and let it go. This makes it more sharply curved, or flatter. This happens automatically as we look from our book, for instance, to a tree across the road.

When light is traveling to the eye from your book, it needs to be bent at a steeper angle than light traveling from the tree. So the lens can correct the cornea's over-refraction and allow you to read your book, because less correction is required. But it can’t correct the over-refraction of light coming from the tree. The tree looks blurry because its light is being focused in front of the retina.

This is why reshaping the cornea corrects nearsightedness. The too-steep cornea is made slightly flatter, so that it doesn't over-refract. In our Clearview Eye and Laser Medical Center here in San Diego, California, we offer three specific ways to reshape the cornea and eliminate your myopia: LASIK, PRK, and IntraLase.

Over recent years, technology for vision correction has developed and refined and expanded, so that now there is a wide selection of procedures to choose from. It all began with what is now known as traditional LASIK, and gradually it became evident that LASIK was not for everyone.

How could more people be safely offered this astounding vision correction? Expanding the candidate pool became desirable, and new ideas and techniques multiplied. At Clearview Eye and Laser Medical Center here in San Diego, California, we offer three major types of eye surgery:

• LASIK
• PRK
• IntraLase

If you are nearsighted, farsighted, or astigmatic, you can probably qualify for one of these three types of eye surgery.

The term LASIK by now usually means Custom Wavefront LASIK, unless it is amended as “Traditional LASIK”. We offer CustomVue, the wavefront system manufactured by VISX. It is a highly sophisticated system for eye correction. It both diagnoses the eye's exact shape, and guides the excimer laser in treatment.

PRK, the next type of eye surgery we offer, sidesteps one of the stages in the LASIK procedure. It creates no flap on the cornea. In LASIK, that little flap is folded back to allow laser treatment, and then replaced afterwards. PRK is a better choice for people with thinner or steeper corneas. Instead of a flap, PRK removes a tiny amount of surface tissue, which regrows after treatment. This gives you a slightly longer recovery period, but vision correction which is just as amazing.

IntraLase includes the flap-creating step, but instead of using the special LASIK blade to create it, it uses a second laser. That laser can create a thinner flap, so IntraLase is another choice for people with thinner or steeper corneas. The flap being so thin, it is covered with a bandage contact lens during recovery.

Eye physicians will probably have further technology choices in the coming years, and be able to offer ever more precise, fast, and effective eye surgery.

• LASIK
• PRK
• IntraLase
• Presbyopia
• Implantable Contact Lenses
• Intacs
• Cataracts
• BOTOX®

Previous Posts

• Is corneal tissue removed during LASIK?
• Bladeless or All-Laser LASIK
• When can I travel by plane after having laser visi...
• When can makeup be worn after LASIK?
• Recovering from your Laser Vision Correction proce...
• What happens on the day of my laser vision correct...
• How long should I keep my contacts out before havi...
• Should I stop wearing contact lenses before LASIK?...
• What to Expect at your Laser Vision Correction Con...
• Great Vision starts with Healthy Eyes

Archives

• May 2007
• October 2007
• November 2007
• December 2007
• January 2008
• February 2008
• March 2008
• April 2008
• May 2008
• June 2008
• July 2008
• September 2008
• October 2008
• November 2008
• December 2008
• January 2009
• February 2009
• March 2009
• April 2009
• May 2009
• June 2009
• July 2009