There are three primary types of refractive errors: myopia, hyperopia and astigmatism. Persons with myopia, or nearsightedness, have more difficulty seeing distant objects as clearly as near objects. Persons with hyperopia, or farsightedness, have more difficulty seeing near objects as clearly as distant objects. Astigmatism is a distortion of the image on the retina caused by irregularities in the cornea or lens of the eye. Combinations of myopia and astigmatism or hyperopia and astigmatism are common.
LASIK is the most commonly recommended by ophthalmologists today. This surgery procedure has shown a very high degree of success, an extremely low complication rate, less discomfort for patients and quick recovery of vision.
LASIK (Laser Assisted In Situ Keratomileusis) is a procedure in which a trained ophthalmologist uses a precise and controlled removal of corneal tissue by a special laser, reshaping the cornea and improving the focusing power of the eye.
In this procedure, an instrument called the microkeratome creates flap. Firstly, this machine creates suction against the eye, which holds the machine in the correct position and firms the eye for a precise cut. Then the surgeon engages the machine, allowing it to cut a smooth flap in the cornea. Then, the laser is used to reshape the cornea. Once the laser treatment is completed, the flap is repositioned on the surface of the eye. This flap naturally adheres to the eye, without stitches. The healing rate is much quicker with LASIK and the patient rarely feels discomfort.
The only anesthetic required for LASIK surgery is anesthetic eye drops.
PRK (Photorefractive Keratectomy) is performed on top of the corneal surface of the eye. After surgery, a bandage contact lens is placed on the eye until the tissue covering the eye heals. This time is estimated from three to four days. The only anesthetic required for PRK surgery is anesthetic eye drops.
The same type of laser is used for LASIK and PRK. Often the exact same laser is used for the two types of surgery. The major difference between the two surgeries is the way that the stroma, the middle layer of the cornea, is exposed before it is vaporized with the laser. In PRK, the top layer of the cornea, called the epithelium, is scraped away to expose the stromal layer underneath. In LASIK, a flap is cut in the stromal layer and the flap is folded back.
PRK has been performed in the U.S. since 1987 and LASIK has been performed since about 1990. Clinical trials led to FDA approval of PRK in 1995 and to FDA approval of LASIK in 1999.
Even though Myopia cannot be cured, refractive procedure can reduce the severity of myopia. This treatment is not suitable for children and young teenagers in whom myopia is in progress and has not stabilized yet.
The goal of LASIK is to make patients less dependent on their glasses or contact lenses. After the treatment, more than 85% of treated patients don’t used glasses or contacts or used them less than 10% of the time.
LASIK patients typically enjoy very rapid recovery of visual acuity, often seeing well the day of or the day following the procedure. Most patients, who are treated for nearsightedness, will have stable results after LASIK. After one to three months results will usually be permanent for most patients. However, some patients with initially good results may experience a change which is called regression, up to six months after surgery and possibly longer. Patients, who are treated for farsightedness, may have a longer visual stabilization period.
No. PRK cannot absolutely guarantee a certain result from the surgery, but it can improve the probability of achieving 20/20 vision. 95% of our patients with low through moderate ranges of myopia and/or astigmatism achieve normal or near normal natural vision from just one surgery. For those who do not achieve this quality of vision from one surgery, enhancement surgery can usually give the rest of the desired correction.
LASIK and PRK procedures are not associated with any pain or discomfort during the procedure, as the eye is topically anesthetized with drops. Occasionally some patients experience slight discomfort a few hours after the procedure. Post-operative discomfort may include slight stinging, excessive tearing and a foreign body sensation. LASIK are generally very comfortable following the procedure, usually without even the slightest discomfort. Most patients hear a clicking sound as the laser does its work. They PRK patients, however, are more likely to experience mild discomfort during the first 24 to 72 hours following the procedure while the surface of the cornea heals.
PRK patients take longer to recover good vision, perhaps days to weeks before seeing as well as patients undergoing LASIK. However, in patients with very minimal refractive error (e.g. –2.00 diopters) recover much more quickly than those with high refractive error (e.g., -8.00 diopters). As such, some ophthalmologists still prefer to recommend PRK to patients with low myopia or minimal short sightedness. Best vision typically occurs within 6 weeks to 6 months.
There is no procedure as yet that has accurately and predictably corrected presbyopia, which is the loss of near focusing capability that we all experience as we age. Most people in their 40’s and older begin to require near correction, such as bifocals or reading glasses.
Even though, there is a possibility to consider called monovision. Monovision is the correction of the dominant eye for distance and the opposite eye for near. A good method to evaluate monovision pre-operatively is to wear contacts for monovision. Be sure to discuss this option in detail with your doctor if you believe you might be a candidate because many patients will not tolerate this type of vision.
Patients can expect their results to remain stable for probably for the rest of their lives once their eyes have stabilized after the procedure. The cornea is a very stable tissue. Medical experience shows that once the cornea has been modified, it tends to stay modified permanently. There are rare cases of regression, which may be corrected with further surgery, but the vast majority of corrected eyes continue to stay in focus.
It is not possible for patients to blink during a procedure. A special instrument is used to hold the eyelids open gently. Keeping the eye open is painless because eye drops have already numbed the eye. The reflex that gives patients the desire to blink is lost.
Yes. Complications are rare, but can include infection, damaged flaps, inadequate healing, unstable vision and progressive over-correction. In rare cases refractive surgery may result in loss of vision or infection. There also are possible side effects, including fluctuating vision, occasional halos around lights at night, temporary pain and sensitivity to light and glare, some post surgical pain and other effects lasting up to six months such as hazy vision. Side effects typically diminish as the eye heals. It is strongly recommended to discuss with your ophthalmologist all potential side effects and complications to fully understand the relative risks of refractive surgery.
Although the goal of refractive surgery is to provide best vision without glasses, up to 15-20% of patients will still need glasses or contacts after the procedure. Some of these patients will elect to have an enhancement procedure to improve their uncorrected visual acuity. Majority of studies have shown that the chance that someone would need an enhancement is proportional to the original amount of refractive error and the risks of an enhancement are similar to those of the original procedure.
Phaco Emulsification is the most sophisticated method of removing a cataract. The clouded cataractous lens is extracted by fragmenting it into tiny pieces with ultrasound energy and aspirated out with a suction device and removed through a small self sealing wound. The lens is injected into the eye through a small opening and then it opens up within the eye. Short duration of surgery, early rehabilitation, minimum post-operative restrictions, and earlier restoration of vision are the main advantages of this method.
Cataract surgery is a procedure that takes approximately 10 to 15 minutes. It uses local anesthesia in the form of eye drops. Patients are awake during the surgery and after surgery, restrictions are minimal. This procedure is elective. Some of the more common reasons an individual chooses cataract surgery are:
Decreased vision: Problems reading fine print or difficulty seeing the street signs.
Foggy vision
Halos around lights
Glare
Decreased ability to perform daily tasks: problems seeing to play cards, bowl or play golf, reading medication instructions and failure to pass a driver’s visual examination are common.
You also need to know what you can reasonably expect for visual improvement following the procedure before your make this decision. Also, you need to be informed about the health of your eyes, the risks and complications of surgery, and the alternatives as well as the potential benefits for you. Although millions of people have undergone safe and successful cataract surgery, complications, though rare, can and do occur. The most serious complication of eye surgery is blindness, due to infection, retinal detachment or technical problems with the surgery and your eye. You must be fully informed about the surgery and its attendant risks before making an informed decision to proceed.
In most cases, cataract surgery is performed on an outpatient basis and does not require an overnight stay in the hospital. You may see clearly on the very first day after surgery. Most patients agree that vision returns quickly, although the exact timing varies from patient to patient. For some patients, experiencing blurred vision for about a week is normal. The Most of times, patients can resume the daily routines within 24 hours.
The cornea is the tissue on the very front of the eye covering the iris and pupil. This surgical procedure involves the removal of the damage tissue and replacement with a healthy human cornea. It works with the lens to provide focusing power to the eye.
The surgery is painless due to the administration of a local anesthetic at the beginning. However, some patients may be given general anesthesia, depending on their medical condition. Some pain medicine could be given after surgery to control any residual pain present during the recovery period.
After the procedure it is important to use the eye drops as prescribed, to not rub or press on the eye, to use over-the-counter pain medication, reduce exercise until healed or according to your doctor advisement, use the eye shields and patches as direct by your doctor, and not to drive until given approval.
You will need someone to drive you home. If the procedure is performed under local anesthesia, you can go home after a short stay at the center. The use of general anesthesia will delay your leaving by about two additional hours; to be sure the effects are wearing off.
When you leave the hospital you will wear a patch and a shield. This will be removed the next day at your follow up visit at the doctor's office. After that you will be wearing dark glasses during the day and a protective shield at night only. Your vision will be blurry for approximately 3 - 6 months.
At 3 months you will start having your sutures removed and they should all be removed by the end of 6 months a little longer if you are older. At the end of 6 months you will be fitted with glasses or contact lenses. During the whole 6-month period you will take anti -rejection drops and antibiotic drops approximately 4 times a day.
For the first 6 weeks heavy exercise and lifting of heavy objects will be prohibited but otherwise you can live a normal life. Most people return to work 3-7 days after their surgery depending on the type of work they do.
An extremely important part of the recovery period is constant vigilance as to signs of rejection. Rejection occurs in 5-30% of all transplants and there is an increased risk if this operation is a second transplant after rejection of an initial one. If the rejection is noticed early, medication can be administered that will halt the reaction and save the transplant.
Rejection occurs because the body's immune system recognizes the donor tissue as foreign and mounts a response against it. This damages the tissue such that it can no longer maintain the fluid balance, causing it to swell and lose clarity. Although the tissue will not fall out of the eye upon rejection, another transplant may be necessary to replace the tissue if too much damage occurs.
There are four signs of rejection that can be remembered by the mnemonic RSVP: redness, sensitivity to light, decreased vision, or pain. Any of these four symptoms, experienced after the initial healing period, should be reported to your ophthalmologist immediately.
In Pterygium Surgery, the abnormal tissue is removed from the cornea and sclera (white part of the eye). In traditional "bare sclera" pterygium removal, the underlying white of the eye (sclera) is left exposed. Eyedrops are used to anesthetize the surface of the eye, after which a small device is inserted to hold the eyelids apart A little anesthetic is injected into the fleshy part of the pterygium, elevating it from the surface of the eyeball, after which the pterygium is peeled away. If pterygia are present in both eyes, the second eye is operated at least one week after the first.
In many cases, pterygium redness and discomfort can be controlled with lubricant eye drops (artificial tears). When symptoms of redness, irritation, or blurred vision are resistant to this treatment, or when vision is affected by progressive growth of a pterygium, surgery is considered.
