Envision Eye Center LASIK RISKS

The risk of serious infection is reduced five-fold from approximately 1/1000 with PRK to 1/5000 with LASIK

The risk of PAIN is reduced five-fold from approximately 1/10 with PRK to 1/50 with LASIK. With LASIK, it is common to feel an eyelash sensation or the feeling one has after wearing contact lenses all day. Patients may be light sensitive, with tearing, but this is usually short-lived. The eye may be red and the lids may be swollen following the procedure but this quickly resolves.

The risk of scar tissue or corneal haze is reduced approximately five to ten-fold with LASIK compared to PRK. The risk of scar formation with PRK ranges from 1% to 5%, increasing in incidence with the degree of attempted correction. Scar tissue is composed of collagen proteins that develop in the surface of the eye with PRK and beneath the corneal flap with LASIK. It presents usually as a dirty windshield type of appearance to your vision. Haze will generally improve over several months.

The two side effects that are similar for both LASIK and PRK procedures are Night Glare and Blurriness. They are very common early in the healing process, and are observed by most patients. The risk of night glare is four-fold higher with astigmatic corrections. Both night glare and blurriness typically, but not always, improve over several months.

Night Glare is common in nearsighted individuals even before any refractive procedure is performed, but increases almost immediately in the healing process and is more common when only one eye is treated. Typically, 6 months after both eyes have been treated, only 2% of patients still experience significant night glare that interferes with their night driving. Severe night glare can impair vision in all reduced lighting conditions producing blurriness, ghosting, or halos. Patients with large pupils and severe myopia and/or significant astigmatism are at greater risk for night glare.

Almost all patients describe Blurriness immediately following surgery. Blurriness to one degree or another is common. With LASIK procedures, there is considerable improvement in vision within the first 24 to 48 hours. Approximately 95% of the visual recovery occurs within the first several days, with the last 5% of vision improving over 3 to 6 months. Patients experience a large quantitative jump in vision within days, with the qualitative fine tuning or sharpness of vision taking much longer, on the order of several weeks. Many patients experience a profound and dramatic visual improvement and become able to read half or more of the eye chart the next day, but most state it is still not clear and crisp, but rather has been described as "Vaseline Vision". Approximately, 1% to 2% of patients independent of the procedure performed will develop corneal irregularities reducing the sharpness, crispness, and clarity to their vision preventing them from reading the bottom two or more lines on an eye chart that glasses, contact lenses, or another surgery cannot restore. That is, the initial blurriness resolves in 98% to 99% of patients over 6 to 12 months, however, it may be permanent in 1% to 2% of treated patients. There is no way of predicting or predetermining who will be the 1% to 2%. A patient who loses sharpness, will have vision that is permanently worse than the vision the patient enjoyed with glasses or contact lenses prior to surgery. Each patient heals differently and this may cause differential results in seemingly similar patients. The recovery from blurriness after PRK is typically much slower than with LASIK.

Corneal Flap Complications: The entire incision time for making the flap is approximately 2-3 seconds, but during this brief interval a variety of things are important for an optimal result. Primarily, there must be adequate internal suction pressure within eye. Suction pressure and microkeratome assembly and function determine the thickness of the corneal flap tissue. There is a 1% risk that the eye will experience a corneal flap complication. The primary result of inadequate suction pressure is a corneal flap that is too thin which may result in:

Postponing the procedure for 3 months

Temporary or permanent blurred vision Other potential flap complications include a corneal flap incision that is too long-resulting in a free flap; this may increase the potential for a prolonged visual recovery, blurred vision, and epithelial ingrowth (discussed below). Corneal flap incisions that are too short necessitate postponing surgery for 3 months. Occasionally, (approximately 5%), the microkeratome may cause an abrasion on the corneal flap. This is unlikely to cause a change in the visual result, but may cause discomfort for a longer time than usual (on the order of days rather than hours) and may necessitate the use of a bandage contact lens. The overwhelming majority of LASIK complications are related to the creation of the corneal flap.

Epithelial Ingrowth: During the first 24 hours, the epithelial protective layer grows over the edge of the corneal flap. There is a 1%-2% risk that epithelial cells may grow underneath the flap. This is more common in people with protective layers that bond poorly to the eye surface. Any intraoperative breakdown of the protective layer may increase the incidence of epithelial ingrowth. Treatment involves lifting the flap and clearing out the cells. Untreated, epithelial ingrowth may distort vision and may actually damage the flap if severe and progressive. Small ingrowths do not usually present any visual problems and need only to be monitored.

Flap Striae: Within the flap is a layer of cornea called Bowman’s layer that has the consistency of cellophane paper. In a small number of cases, micro folds or striae can occur after the flap has been properly positioned. These microstriae can cause distortions in vision, blurred vision, and double vision. If they are treated early (within one-two weeks) they are usually of no consequence. They are treated by lifting the flap and repositioning it with pressure on the cornea to relieve them. This technique is most successful if done early on as microstriae can become permanent with time. By lifting the flap and repositioning it, it is often necessary to break through the healed epithelium and this increases the risk of epithelial ingrowth.

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Loss of Vision: LASIK surgery can possibly cause loss of vision or loss of the best corrected vision. This can be due to infection (internal or external) or irregular scarring or other causes and unless successfully controlled by antibiotics, steroids, or other necessary treatment, could even cause loss of the infected eye. Vision loss can be due to the cornea healing irregularly, which could add astigmatism, and make wearing glasses or contact lenses necessary or lead to loss of useful vision. Irregular cornea healing could result in a distorted corneal surface so that distorted vision or "ghosting" occurs. This may or may not be correctable by spectacles, contact lenses or further surgery.

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Visual Side Effects: Other complications and conditions that can occur with LASIK surgery include: anisometropia (difference in power between the two eyes); aniseikonia (difference in imaging size between the two eyes) double vision; hazy vision; fluctuating vision during the day and from day to day; increased or decreased sensitivity to light that usually gets better but may not; glare and halos around light which usually diminish with time, but may not.

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Over correction or under correction: It may be that LASIK surgery will not give you the results you desired. It could be that the eye is under corrected. If this occurs, it may be possible or necessary to have additional surgery to fine-tune or enhance the initial results. It will be up to Dr. Ruff to determine the appropriate time to pursue such options. It is also possible that your eye may be overcorrected to the point of being farsighted. At this point, this can also be corrected with the VISX laser. Significant over corrections are treated with glasses or contact lenses. It is also possible that your initial results may regress over time. The regression is usually not severe but may be treated with an enhancement, glasses or contact lenses.

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Other Risk: Other reported complications include: corneal ulcer formation; endothelial cell loss (loss of cell density in the inner layer of the cornea, possibly resulting in corneal swelling); ptosis (droopy eyelid); corneal swelling; contact lens intolerance; retinal detachment; hemorrhage. Complications could also arise requiring further corrective procedures including either a partial (lamellar) or full-thickness corneal transplant using donor cornea. These complications include: loss of corneal flap; damage to the corneal flap; progressive corneal thinning (estasia). Sutures may also be required which could induce astigmatism.

There are also potential complications due to anesthesia and medications that may involve other parts of the body. Some patients experience a toxic response to the anesthetic drops that could lead to epithelial (surface protective layer) sloughing. This can lead to more irritation and discomfort than normal while healing. It could also lead to slower vision recovery.

It is also possible that the microkeratome or laser could malfunction and the procedure stopped. This could possibly result in the procedure being postponed for up to three months.

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Later Discovered Complications: LASIK is a relatively recent technique. You should be aware that other complications may occur in the future that have not yet been reported. Longer term results may reveal additional risks and complications.