Archive for July, 2007

The medical profession, like any profession, has a language of its own. When talking or reading about LASIK eye surgery, even medical professionals may encounter terms with which thye are unfamiliar. Here are some terms that you will find over and over in the articles on these websites.

PROBLEMS

Dry Eye Syndrome: tear ducts cannot produce enough tears to keep the eye moist. This can cause blurring of vision, irritation and pain.

Ghost Image: a faint additional image of the item at which you are looking. It is caused by irregular healing of the surface of the cornea. This effect is distracting. You wouldn’t watch a TV station with this problem!.

Glare: additional luster around lights.

Halos: fuzzy rings around lighted objects

Haze: clouding in the cornea that makes it seem you are looking through smoke.

Keratoplasty: Cornea transplant. Keratoplasty can be lamellar or penetrating. (see below)

Lamellar keratoplasty: transplant of layers of the cornea.

Overcorrection: amount of achieved correction is more than planned.

Penetrating keratoplasty: replacement of the entire cornea.

Regression: backwards shift in eyesight from the initial results of LASIK surgery.

Undercorrection: amount of achieved correction is less than planned.

LASER AND SURGICAL TERMS

Ablation: vaporization of tissue with the excimer laser.

Corneal flap: layer of the outer surface of the eye that is cut and folded back during LASIK surgery for access to the stroma.

Enhancement: A secondary LASIK surgical procedure performed to correct errors from the first surgery.

Excimer laser: the ultraviolet laser used in LASIK surgery to remove tissue from the stroma

FDA: Food and Drug Administration. This United States government agency is responsible for the evaluation and approval of medical devices.

femtosecond laser: the laser sometimes used in LASIK surgery to cut the flap of cornea.

Laser: Light Amplification by Stimulated Emission of Radiation. Powerful light that is used in LASIK to cut tissue.

LASIK: Laser Assisted In Situ Keratomileusis. This surgical procedure cuts a flap in the cornea with a microkeratome blade or a femtosecond laser and use an excimer laser to reshape the inner part of the cornea (stroma) to improve vision.

Microkeratome: sharp blade affixed to a vacuum ring. In LASIK, it is placed over the eye with vacuum pressure to cut a layer of the cornea for surgical access.

Monovision: correcting one eye for near vision and the other eye for
distance vision. This is sometimes done with contact lenses and sometimes with LASIK.

Off label use: use of an approved drug or instrument in a way that has not been specifically sanctioned, yet is still permissible.

Photorefractive keratotomy (PRK): removal of the surface layer of the cornea by gentle scraping and using of an excimer laser to reshape the inner layer of the cornea (stroma.)

Radial keratotomy (RK): surgical procedure correcting nearsightedness by flattening the cornea with incisions. This older procedure is less invasive than LASIK.

This is just the beginning of all the terms you encounter when researching LASIK eye surgery. Keep a notebook handy when doing your research. Write down terms you don’t understand, then have them explained to you. Be fully aware of what a surgery involves before you submit yourself to it.

When trying to understand LASIK eye surgery, it helps to know its history. This is an outline of the development of refractive surgeries, including Radial Keratotomy, PRK, and LASIK. By knowing this, you will be informed and better able to ask questions of your surgeon.

Refractive surgery is done on the eye to diminish dependence on corrective lenses. These surgeries can correct refractive errors, such as
nearsightedness, farsightedness and astigmatism. LASIK was preceded by several other procedures. The concept of changing the shape of the cornea to improve vision was conceived in the mid-1800s when an experiment using a spring-mounted mallet attempted to flatten the cornea through the closed eye.

Incisional surgery (keratotomy) was tried in The Netherlands in 1898. In the 1940s and 1950s there were clinical trials in Japan. These surgeons placed incisions in the cornea, causing it to flatten, thereby correcting nearsightedness. They concluded that the amount of vision correction achieved was directly related to the number and size of the incisions. A USSR surgeon experimented in Radial Keratotomy (RK) in the 1960’s, and made RK safer by placing incisions on the anterior surface of the eye, instead of the posterior. Predictable results were achieved by using steel surgical blades and a standard formula of correction.

The National Eye Institute study in the US in the late 1970s demonstrated RK’s effectiveness, but a high percentage of patients with fluctuating vision was noted. This caused decreased popularity of RK, but development of diamond micrometer cutting blades and microscopic guidance caused a surge in RK surgeries in the early 1990s.

Keratomileusis surgery was developed in the 1970s. Research into the use of the excimer laser began in 1973. Its first ophthalmological use was in 1981 and the race was on for LASIK. Automated Lamellar Keratectomy (ALK) was created in 1982, using an automated device called a microkeratome. The first PRK in the US was performed in 1987 on a blind eye and in 1988 the first United States PRK was done on a person with nearsightedness. LASIK, as it is known today, was originally described in 1989 when a Greek physician used the excimer laser to treat the stroma beneath a flap.

The US Food and Drug Administration approved the use of the Summit laser for PRK correction of nearsightedness in 1995 and the VISX laser in 1996, after a series of clinical studies. The excimer laser was approved for PRK in 1995 for correcting nearsightedness. LASIK became more predictable and the word spread about the lack of pain and the rapid visual improvements. Demand grew. In 1997, the FDA listed the procedure as ‘off label’ and any licensed physician was permitted to perform LASIK. The FDA approved LASIK as a medical procedure in 1999. Some estimates say that LASIK accounts for 98% of all refractive surgeries worldwide.

Vision problems have plagued humanity since our beginning. We developed corrective lenses long before we attempted to surgically correct vision. It was a long road to the development of LASIK eye surgery. Even though LASIK is generally successful, new developments in surgery may vastly improve even this procedure in the near future.

Before you have LASIK eye surgery, you should ask questions of your surgeons, and be comfortable with the answers. Below are 20 questions you should ask, along with the answers you should expect. If your surgeon does not take the time to answer these questions to your satisfaction, change surgeons.

1… How long have you been doing LASIK surgery? (at least three years)

2… How many successful LASIK procedures have you done? (at least 500)

3… How many have you done in the past year? (at least 250)

4… How many with this particular laser equipment? (at least 100)

5… Do my occupation, leisure activities, and hobbies have any bearing on my candidacy for LASIK eye surgery? (Absolutely)

6… How many patients do you turn away as being unsuitable for this procedure? (Answer should never be “none”.)

7… How many of your patients achieve Snellen UCVA scores of 20/40 or better after this surgery? (90% is normal)

8… How many of your patients achieve Snellen UCVA scores of 20/20 or better after this surgery? (50% is normal)

9… Six months after LASIK surgery, how many of your patients still have unresolved complications? (should be less than 3%)

10… Have you ever been denied malpractice insurance coverage? (Should be “never”.)

11… Have you ever had your hospital privileges revoked? (Should be “no.”)

12… Has the FDA specifically approved the equipment you will use for this procedure? (If no, should justify the off-label use to your satisfaction.)

13… Will you measure the thickness of my cornea, perform a contrast sensitivity test, a glare sensitivity test and corneal topography before and after LASIK surgery? (Should be “yes,” but if “no”, then surgeons should arrange for you to be tested elsewhere at your own expense.)

14… Will you perform tear volume (Schirmer) and tear breakup (TBUT) tests before recommending LASIK eye surgery? (Should be “yes.” These reveal whether you have unusually dry eyes, and should not have LASIK eye surgery.)

15… What certifications do you hold? (should have American Board of Ophthalmology, American Board of Eye Surgery, and/or the Council for Refractive Surgery Quality Assurance.)

16… Is there any reason why I would not have excellent LASIK eye surgery results? (If you or the surgeons have doubts about achieving what you consider to be a successful result, don’t have the surgery.)

17… What is the worst LASIK eye surgery outcome experienced by your patients? What was done to rectify the situation? (Should be fully honest. If no bad outcomes, change surgeons. NO one is perfect.)

18… If I need an enhancement surgery, what is the charge for the additional procedure? (Should be no charge for enhancement within a year after surgery.)

19… If other surgeons will be handling my pre- and/or postoperative care, may I see you at any time without their authorization? (Should be yes.)

20… What should I expect the first few weeks after surgery? How long is the healing period? (Answer should include explanations of side effects that may occur.)

If your surgeons can answer the above questions to your satisfaction, then you should be able to go into LASIK eye surgery with confidence. If they appear uncomfortable about these questions, or seems too hurried to explain, find other doctors. Your vision is too important to risk.