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1. Risks and Side Effects
2. Pupil Size and Correction Zone

Risks and Side Effects of LASIK

Pain:

Mild headache may occur or lid tenderness from the instrument that holds the eyelid open. (Also see Prolonged Surface Healing.

Light Sensitivity:

Very common for the first 24 hours, so we will provide you with cool wrap-around sunglasses. These should be worn anytime you may be at risk of being struck in the eye during the first month after your procedure.

Tearing:

Commonly occurs within the first 2 to 4 hours and is sometimes heavy.

Blurred Vision:

Nearly everyone is functional for his or her daily activities. Mild blurring may occur for several weeks for some people. This is most common for larger corrections and is also related to your age and dryness.

Under/Over-Correction:

It is not possible to predict with absolute certainty how the eye will heal and respond to treatment. Any under-correction is usually mild and does not interfere with a patient's daily activities. If an under-correction is significant and there is enough underlying cornea (bed), you have the option of additional treatment also called an "enhancement" or refinement. Rarely, we get a small over-correction. In this case, the eyes are treated with medicinal drops, which can slightly reverse the correction to bring it back. Again at about 4 months we can correct this with laser or the CK treatment as necessary.

Glare and halos:

Sometimes occurs immediately following surgery, but does dissipate as the cornea heals internally. This is reduced or elimate by larger treatments and may actually improve night disturbance in some patients. Recent evidence implies that in many eyes the night problems are caused by a drop off in the power of the treatment as it move out toward its limit. This is magnified in smaller treatments. When eyes are seen on the orbscan after treatment with many lasers the effective area noted could be fewer than 5 mm. This is likely to be the cause of night problems and visual fluctuation. (See Pupil Size & Correction Zone)

Infection:

Every precaution is taken to avoid infection. It is critical that post-operative instructions and medications are followed and taken as directed. Although most corneal infections can be successfully treated, potential consequences include corneal scarring, perforation, and spread of the infection inside the eye. We currently use a drop that may be better able to kill a few very rare bacteria and by starting 3 days in advance you are building up a level in your cornea to protect you.

Corneal Scarring:

Significant corneal scarring is rare after LASIK surgery, but more common with PRK. Proper use of your post-operative medications is an important component in preventing this possibility.

Epithelial In-growth:

LASIK involves the creation of an interface between two layers of corneal tissue. Epithelial cells (the corneal skin) can grow into this interface. This growth is usually mild and not noticed by the patient, nor does it have an affect on vision. In rare cases, these cells may continue to grow, creating thinning of the flap and astigmatism. The epithelium is a loose sheet under the flap and is removed with excellent prognosis in nearly all cases. We use a fiber optic light pipe to identify areas of growth and fully remove them. Normally only the edge of the flap is lifted and the vision remains the same even immediately following the treatment!

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Pupil Size & Correction (Ablation) Zone

Pupil size:

This is a very important consideration in LASIK surgery. How much the pupils will dilate at night determines what size the zone of correction has to be on the cornea. If the pupil will naturally dilate beyond the zone of correction, the presence of halos and significant glare can occur.

The common way to measure dilatation is with a cobalt blue light in a dimly light room. This type of measurement is not always accurate, and may be up to 1 to 1.5mm under the actual maximum dilatation. For this reason, we here at the Future Vision Laser Center use an infrared pupil measurement in the dark using a handy cam. We will video your measurement after you have dark adapted (this is called scotoptic pupil dilation). This device assures that the "maximum dilatation" measurement is accurate. You do not get night disturbance in your vision when you are in the dark as there is no light and when there is light your pupil will react and shrink in size. However it is the only standard that we can use and if we can treat this larger size it is our opinion that we have reduced your risk of night vision problems. The other risk factor for this problem is the depth of the front part of your eye known as the anterior chamber and we will have this measurement from our Orbscan II device. View Measurement

Correction Zone:

The effective treatment zone size is important to give the best quality vision after a LASIK treatment. We are learning that many lasers under correct as they move out to the edge of the treatment. Even though the laser may claim to treat large the observed area of treatment can be very small. This is not true of the Planoscan software and the Zyoptics software of the Bausch and Lomb laser. By having a larger effective zone of correction and blending the two curves together with full power to the optical edge of your pupil, the possibility of halos and glare are greatly diminished and in some people the night vision may actually improve. In patients that currently have night vision disturbance we can likely eliminate or reduce the effect by providing a re-treatment that may only treat out at the rims of the treatment to expand and fully treat, where they were under treated on the primary treatment! This can be thought of as a refinement as it really is just a completion of the original treatment, which gives a huge pick up in night brightness and edge clarity called contrast sensitivity. This is really exciting knowledge that will take our already excellent results to the next level.

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