• What is "monovision?"
Introduction
Refractive surgery is the specialty of ophthalmology that deals with improvement and correction of optical defects of the eye. These optical defects cause people to have difficulity seeing without glasses, contact lenses, or other optical devices. The major types of optical defects are:
• Myopia or nearsightedness
• Astigmatism
• Hyperopia or farsightedness
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Vision
What is myopia or nearsightedness?
People with myopia can usually read without glasses, but they cannot see far away without glasses or contact lenses. Myopia is a hereditary condition in which the eye is either longer than it should be, or the cornea has too much curvature.
What is astigmatism?
People with astigmatism see ghost images or double images without their glasses on. In this condition, the cornea is not spherical, but is shaped more like a football or teaspoon. Light entering the eye is distorted by this lack of sphericity, causing blurry images and ghost images. Astigmatism is often combined with myopia or hyperopia.
What is hyperopia or farsightedness?
People with farsightedness can usually see pretty well until they are in their 30's or 40's. Then they begin to lose their ability to read, and after a few more years, they lose their ability to read and to see far away. This is different from presbyopia or age related loss of reading vision.
What is presbyopia?
People with presbyopia, or age-related loss of reading vision, need reading glasses to see up close. There is no surgical treatment for this condition.
What is refraction?
Refraction refers to the process that people undergo when they visit their optometrist or ophthalmologist. The doctor determines what lenses are needed to correct vision, and this process is called refraction.
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The Eye Doctor
An ophthalmologist is a medical doctor (M.D.) who has attended four years of college, four years of medical school, one year of internship in medicine, and 3 - 4 years of specialty training in treating diseases and surgery of the eye.
What is an optometrist?
An optometrist (O.D.) is a professional who attends four years of college, and 4 years of post graduate training in treating refractive errors and diseases of the eye. Optometrists are involved in the pre- and post-operative care of patients who have eye surgery. Optometrists are licensed to treat eye diseases. An optometrist is not a medical doctor or surgeon, but works closely with Dr. Denman to insure the highest level of patient care.
What is an ophthalmic technician?
An ophthalmic technician is a highly trained paramedical professional who is familiar with eye disease, refraction, contact lens fitting, and post-operative and pre-operative evaluation.
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The Procedure
What is an excimer laser?
An excimer laser is the type of laser that is used to modify or shape the front surface of the eye in order to make people see better without glasses or contact lenses. There are other types of lasers used in ophthalmology, such as the Argon laser which is used to treat diabetic retinopathy, and the Yag laser, which is used to treat membranes within the eye. The excimer laser is specifically designed to sculpt or reshape the cornea to allow light to focus more clearly without the aid of glasses or contact lenses.
What kind of laser does Doctor Denman use?
There are many different brands of excimer laser which are currently being used worldwide in refractive surgery. Dr. Denman uses the Alcon Ladarvision Exicimer Laser.
What is RK?
RK stands for Radial Keratotomy. In this technique, which does not use laser energy, delicate microscopic incisions are made with a micro-fine diamond blade. These incisions are placed in the cornea in a radial fashion, like the spokes of a wheel. By placing these incisions in the proper location, low to moderate degrees of nearsightedness can be treated.
What is AK?
AK stands for Astigmatic Keratotomy. In this technique, which does not use laser energy, small arc shaped incisions are made in the cornea to treat astigmatism. These incisions change the cornea from a spoon shape to a spherical shape, thereby allowing light to focus better. These types of incisions are combined with Radial Keratotomy incisions and sometimes are used after laser procedures to fine tune the results.
What is PRK?
PRK stands for Photorefractive Keratectomy. This was the first type of laser treatment to be approved by the FDA in the United States, and has been done world wide for about 8 to 10 years. In this technique, the energy from the excimer laser is applied directly to the surface of the cornea.
What is LASIK?
Lasik stands for Laser Assisted Stromal In-situ Keratomileusis. This technique is similar to PRK, in that the laser is used to change the shape of the cornea, but in this case the laser energy is applied to the inner layers of the cornea rather than to the outer layers. This is Dr. Denman's preferred technique.
What is a Micro-keratome?
A micro-keratome is a special cutting device that is used to create a flap of tissue consisting of the outer 20% of the cornea. This flap is retracted, and the laser energy is applied to the inner layers of the cornea in the Lasik technique. The micro-keratome is used in Lasik and is also used in ALK procedures. Micro-keratomes have been used for many years.
INTRALASE link: http://www.intralase.com
Is refractive surgery of any kind as accurate as glasses?
In general, the prescription of glasses is more accurate than any type of refractive surgery. However, the vast majority of patients do not require glasses after refractive surgery.
What are the differences between PRK and LASIK?
They both are used to improve nearsightedness and astigmatism by changing the shape of the cornea, the clear front window of the eye, to allow better vision without glasses or contacts. They both use the same laser, but they differ in technique and post operative recovery.
In PRK, the outer layer of the cornea is reshaped with the laser, but in LASIK, a thin flap of the cornea is lifted; then the underlying cornea is treated with the laser, and then the flap is laid back in place.
During the post operative recovery period, we usually see these differences between PRK and LASIK: A bandage contact lens is worn for 3-4 days after PRK, but there is usually no contact with LASIK. The vision usually recovers more slowly after PRK. LASIK eyes usually recover more quickly. Patients who have PRK usually need to use drops for several weeks. LASIK patients use drops for about 1 week. If retreatment is needed to improve the result, PRK patients need to wait at least 6 months. Lasik patients may be retreated at 2 months. The end results of PRK and LASIK are about the same. The great majority of patients have 20/40 or better unaided vision.
Studies of patient satisfaction after refractive surgery reveal that the great majority of patients are satisfied with their results. Most patients are able to go without glasses or contacts, most of the time. They feel it is great to be able to see better without optical devices. But because patients differ in their response to surgery, no guarantees can be made as to the perfection of surgical results.
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Benefits and Risks
What are the complications of RK or AK?
Like any surgical procedure RK and AK can be associated with side effects or complications. Serious complications or sight threatening complications such as infection or perforation of the eye, are fortunately rare. However, minor side effects such as seeing halos around lights at night, seeing a star burst effect when looking at lights, and having fluctuations in vision throughout the day are somewhat more common, though they tend to disappear in most people after a few weeks. A full description of the complications of RK and AK is available through our office.
What are the complications of PRK and LASIK?
Sight threatening complications are fortunately rare with refractive surgery, and PRK is no exception. However, PRK tends to be a process that heals slowly, allowing visual recovery to be more slow than with Lasik procedures.
On the other hand, LASIK procedures are more technically complex and can have complications related to this. A full list of side effects of these procedures is available from Dr. Denman's office.
A through discussion of complications can be found a http://www.fda.gov/cdrh/lasik/
What kind of vision can I expect after refractive surgery?
No guarantees can be made as to the results of any kind of surgical procedure whether it is done on your big toe or your eye. However, I think it is safe to say that the vast majority of patients have at least 20/40 vision without glasses after surgery, and many of them have 20/30 to 20/20 vision after surgery. No specific predictions in any individuals case can be made but in general, patients with lower degrees of correction are somewhat more predictable than patients with higher degrees of correction. Patients with higher degrees of correction may require more than one procedure, but through a variety of techniques, the goal of much improved vision without glasses can be achieved in almost all cases. Dr. Denman will inform you if he feels there are any unusual circumstances which could prevent you from obtaining a good result.
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What is right for you?
How do you decide whether you should have RK, PRK or LASIK?
You may send in your glasses prescription and your age and sex, and we will be able to tell you which procedures would be most appropriate for you. If you are seriously considering surgery, you will come in for a complete eye evaluation, at which time Dr. Denman will determine which procedure would be most likely to succeed in your case.
Why do people have refractive surgery?
The reasons are endless, but most people feel a strong need to be less dependent on optical devices for vision. This may be because of occupational reasons, such as police officers and fire fighters. It may be desirable to participate actively in sports in which glasses and contact lenses can sometimes be a hindrance. It may be for cosmetic reasons, because patients feel that they do not look their best in glasses and cannot wear contact lenses. Other reasons include intolerance to contact lenses such as in patients who have dry eyes. Many patients have expressed the feeling that they are almost immobilized if they should lose their glasses or contact lenses and have difficulty functioning in any capacity. Most people want to see better and not be so dependant on optical devices.
Can contacts be worn after refractive surgery?
Dr. Denman has had uniform success in almost all cases of patients who have for one reason or another needed to wear contacts after RK, PRK or LASIK surgery. It would be very unusal to need contact lenses, but if this were necessary for complete correction of vision under certain circumstances, in most cases a contact lens fitting is fairly easily done.
What kinds of medical problems preclude surgery?
Rheumatoid Arthritis, Sjogrens Syndrome, Systemic Lupus Erythematosus (SLE), Auto Immune Disease, Herpes Simplex Virus infection of the eyes, Herpes Zoster Virus infection of the eyes, glaucoma, retinal detachment surgery, cataract surgery or other eye surgery.
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Practical Matters
How much does refractive surgery cost?
See the section on the web page for cost.
Is financing available?
See the section on the Web page regarding financing.
How do you pick an eye surgeon?
That is an interesting question that has no easy answer. Like a lot of things if life, you have to do some research on anyone that provides an important service to you. One of the best ways to help you decide whether to pick a certain doctor is to ask other people who have had a similar treatment whether they felt their doctor did a good job for them and how they were treated by the staff. In other words, how did they come out, and how did they like their experience. Did they feel pressured? Did the doctor and staff have enough time for them? Then you must make an appointment to discuss your options with the doctor, and you must then make a judgement as to whether you feel comfortable with the doctor. Sometimes your intuition will help you to make your decision.
If you can't get a recommendation from a friend, then check the following:
The American Board of Ophthalmology should certify your eye surgeon.
He (or she) should ideally be on the active staff of a major metropolitan medical center.
He should be qualified in both incisional surgery (such as radial keratotomy) as well as laser procedures such as PRK and LASIK.
It would also be wise to select a doctor that has been performing eye surgery for a number of years.
There are a number of ophthalmologists in the Portland metropolitan area who perform refractive eye surgery. You need to select someone who is a caring physician, who has your best interest at heart. If you feel that you can freely communicate with your doctor and the staff and if you feel that they can answer all of your questions, you're probably in a good place.
What is the worst thing that could possibly happen with refractive surgery?
The worst thing that could happen with any type of eye surgery would be loss of vision secondary to infection or surgical complication. This type of event is extremely rare but has been reported.
What is elective surgery?
Elective surgery is surgery that you want to have but you do not necessarily need to have it. For example, you vision can be corrected with glasses. You do not need to have refractive surgery, but you may want to have it done to see better without glasses.
When can I return to work after refractive surgery?
The "down time" after refractive surgery is fortunately quite short. Most patients who have surgery are functional within 24 hours and resuming most normal activity. Most patients are back to work in 1-2 days. Dr. Denman occasionally will see a patient who requires longer for recovery and needs more time off work. Since each patient is individually analyzed, Dr. Denman or his staff can specifically answer these concerns.
Can I talk to someone who has had the surgery?
Dr. Denman's staff can refer you to patients who have had refractive surgery who are about the same age as you are, and who have similar refractions.
What is monovision?
When patients reach 40 or 50 years old, they begin to need glasses for reading. This process is not related to their ability to see in the distance. For example, people who have had perfect vision all their lives will require reading glasses when they get to a certain age. Similarly, patients who have had refractive surgery, if they are corrected for distance, when they reach the age of maturity, they will begin to need reading glasses. There is only one way to avoid reading glasses. This to have one eye that is a little bit nearsighted so that it can read close, and leave the other eye corrected for distance. This works in 90% of the cases at least. Dr. Denman always recommends under-correcting the first eye if you are in your 40's to leave you a little bit nearsighted so that you can read. The second eye is corrected for distance. In this way, you will be able to adapt to the difference between your eyes and will be able to carry on almost all activities including reading, driving and other activities without the aid of glasses. It will take you about 2 months to get used to this difference between your eyes, but it isn't difficult to get used to it. If you cannot get used to it, Dr. Denman can re-treat the under-corrected eye, but then you would need to wear reading glasses.
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