Do you need to wear glasses or contact lenses to help you see objects in the distance clearly? If so, you are nearsighted, or myopic, and this information is provided to help you decide whether or not you want to have your near sightedness corrected or partly corrected with KeraVision™ Intacs.
What is nearsightedness?
In the nearsighted eye, light rays focus in front of the retina because the curvature of the cornea is greater than that of a normal eye, or the eyeball is longer than an average eye. People with nearsightedness see nearby objects clearly, but distant objects appear blurry. During a regular eye examination, your doctor uses lenses to measure your nearsightedness in units called “diopter”.
Nearsightedness can be corrected by glasses, contact lenses and various types of refractive surgery.
KeraVision™ Intacs Intra Corneal Ring Segments (ICRS) is a way to achieve vision correction by reshaping your cornea (the clear front surface of the eye), thereby correcting its refraction (optical power).
Intacs for myopia are tiny and virtually invisible arcs that are meant to remain permanently within your cornea. However, they can be removed or replaced.
Your doctor places Intacs in your cornea during a short outpatient surgical procedure that does not involve a laser. You may notice an improvement in your uncorrected vision (without glasses) already the next day.
The procedure for placing Intacs does not involve the cutting of flaps or removal of tissue from the cornea’s central optical zone – that part of the cornea that is most important for your vision. Your doctor can help you decide what is best for you.
How the eye functions
In order to understand how Intacs will help to correct your nearsightedness, it is important to understand how the eye functions.
The cornea of the eye is composed of transparent tissue and is comparable in size to a contact lens. The cornea functions as a window through which light rays travel to the retina in the back of the eye. The retina sends this “picture” of the viewed object to the brain where the object is then “seen”. In the normal eye with perfect vision, the light rays enter the eye and are focused precisely on the retina. In this situation, a clear image is sent to the brain.
The cornea provides about 75 percent of the eye’s focusing or refractive power. The natural lens inside the eye provides the remaining focusing power. The shape, or curvature, of the cornea determines how well you see and how “in focus” an image is when it reaches the retina. Nearly all of the light that reaches the retina must pass through the central area of the cornea or the “optical zone”. Because the optical zone is so crucial or clear vision, Kera Vision Intacs were designed to be placed at the outer edge of the cornea, away from the optical zone.
What are KeraVision Intacs?
KeraVision Intacs are two small, transparent crescents or arcs. They are made of the same material (PMMA) which has been safely used for over 50 years as intraocular lens material to treat patients with cataracts (clouding of the eye’s natural lens).
KeraVision™ Intacs are designed to remain permanently in the eye, yet they can also be removed or replaced. The KeraVision procedure is typically performed in an outpatient setting using drops to numb your eye. It takes approximately 15 minutes to place KeraVision Intacs in your eye. The total procedure for one eye, including preparation tine, is usually completed in less than one hour.
Intacs are surgically placed through a tiny cut that is made to create space for Insert in the corneal tissue. Once in place, the two arcs flatten the cornea so that light rays can properly focus on the retina. Since KeraVision Intacs are inserted peripherally in the cornea, the center of the cornea remains untouched.
What are the benefits of KeraVision™ Intacs?
Intacts reduce or eliminate –1.00 to –3.00 diopters of nearsightedness. If you have this range of nearsightedness with 1.00diopter or less of astigmatism (uneven shape of the cornea that reduces any distant vision), you may benefit from Intacs.
Intacs correct nearsightedness while preserving the central part of the cornea which is most important for your vision.
Intacs can be surgically removed or replaced.
What are the risks of KeraVision™ Intacs?
You should NOT have KeraVsion Intacs placed if:
– You have autoimmune or immunodeficiency diseases (for example: lupus, rheumatoid arthritis, AIDS)
– You are pregnant or nursing
– You have known conditions of the eye that may increase the likelihood of future problems, – you are taking prescription medications that may affect corneal healing or your vision. You should discuss all medications you take with your eye doctor.
Warnings – Discuss with your doctor if you
*have insulin-dependent diabetes or other medical conditions that affect wound healing; or * you have had a Herpes infection in your eyes
If your nearsightedness is –2.75 to –3.00 diopters, your results may not be as good as those of patients who are less nearsighted. Patients in this range of nearsightedness may be more likely to have Intacs removed due to dissatisfaction with their results.
*If your nearsightedness is –1.00 diopter, you are more likely to be overcorrected resulting in blurred near vision without glasses.
*the long-term effect of Intacs on the cornea has not been established.
*If your pupils are large under low light conditions, you are more likely to experience some visual symptoms such as glare and sensitivity to light.
*Under poor visibility conditions, such as dim light or fog, you may have some reduction in the sharpness of your vision.
*If your Intacs are removed, the results of future surgical procedures to correct your vision are not known.
Are you a good candidate for KeraVision Intacs?
If you are considering KeraVision Intacs, you must
- be at least 21 years of age
- have healthy eyes that are free from disease or corneal abnormality (for example Scarring or infection)
- have nearsightedness between –1.00 – -3.00 diopters with no more than 1.00 diopter of astigmatism;
- have documented evidence that the change in your refraction is 0.50 diopter or less for at least 12 months prior to your preoperative exam.
- be informed of the risks and benefits as compared to other available treatments for nearsightedness.
Preparation for Intacs:
- Do not wear contacts lenses 2-3 weeks prior to the procedure being done, as this could affect the outcome of the procedure
2 to 3 days prior to the procedure
- If you wear eye make up, you should stop 2-3 days before the procedure to reduce the risk of infection after your procedure.
- Arrange for someone to drive you home after the procedure and to bring you back the next day for a follow up consultation
- Begin using the antibiotics and other drops as prescribed by the doctor
The day of the procedure
- Have a light breakfast in the morning
- Continue previous medications as per normal prescription
- Bring dark sunglasses with you
- Arrive 15 minutes before the procedure is due to take place, so all the paperwork and payment can be taken care of, so you are free to leave the clinic after the procedure is done.
Intacs Post operative instructions
PLEASE AVOID TOUCHING YOUR EYES AFTER THE PROCEDURE
After the procedure has taken place, go home and rest or sleep on your back to avoid pressure on your eyes. Try to avoid sleeping on your side.
What should I expect after the surgery?
- Your eyes will water and burn excessively and your nose my run. This is normal.
- Your eyes may be hard to keep open. It may be more comfortable for you to keep your eyes closed and rest.
- Your eyelids may be swollen.
- Your eyes may feel gritty or as if foreign bodies are present. This is normal and may last for several hours. Relax with your eyes closed.
- Your vision may fluctuate from blurry to foggy during the initial healing process.
- Near vision may be blurred in the first days after surgery.
- DO NOT RUB your eyes – YOU COULD RUIN YOUR SURGERY in only a few seconds.
Precautions to adhere to after the procedure
- You may shower one day after surgery, and wash CAREFULLY WITHOUT RUBBING.
- Wear your sunglasses for comfort and protection. Sunlight will not affect your results!
- Do not swim or use make-up for seven days.
- Do not take part in contact sports for a month.
- Use the eye drops given to you exactly as instructed during your waiting hours.
- If pain or redness increases call the clinic.
Your doctor will need to examine your eyes on the first day and then again at one week, one month, 3 months and one year after the LASIK surgery to monitor your progress and change treatment if necessary.