LASIK Complications & How to Avoid Them

Lasik Surgery: Introduction

Lasik Complications

1. Undercorrection – This problem usually occurs when the laser has not removed an adequate amount of tissue. It is often noted that regardless of how meticulously a correction is calculated and a laser is calibrated, several factors can still affect the outcome of the procedure. Experts say that these factors include but are not limited to aftershave, perfume or any other scented products; density and composition of tissue; room temperature and humidity; and regression.

2. Overcorrection – This problem occurs when the laser has removed too much corneal tissue. Usually, this occurs in the immediate postoperative period as an outcome of a normal swelling which occurs after any surgical procedure. Studies have also revealed that overcorrection occur due to the factors as outlined for undercorrection. But, certain enhancements or re-treatments are usually an option.

3. Too Small An Optical Zone – This is a LASIK laser complication which commonly occurs when the optical zone is smaller than the nighttime or dilated pupil. People who are commonly victims of this problem are those with very large pupils or very large corrections.

4. Decentered Ablation – Is commonly caused by one or more of the significant patient eye movement during the laser treatment and incorrect centering of the laser beam. In some cases, this problem is said to cause optical aberrations and astigmatism, glare, starbursts or contrast sensitivity problems.


Flap and Operative Complications

1. Dry Eye Syndrome – This case is actually not exclusive to patients who have had refractive surgery. However, reports indicated that it has developed into the most common complication after laser vision correction. It particularly affects what now appears to be the majority of all LASIK patients.

2. Free Cap – This complication occurs during the creation of the flap, but this is rarer than the one mentioned above. This is more common in patients with a flatter curve on the surface of their eye. As often said, if this problem occurs, the laser treatment may or may not proceed depending on the situation. At the start of all procedures, alignment marks are placed on the surface to realign the flap at the end of a normal procedure. But, these are also invaluable in the unlikely event of a free cap.

3. Wrinkles in the Flap – Wrinkles commonly appear when a patient rubs or squeezes his eye too tightly in the first few hours following the procedure. In refractive surgery, it is a common practice to have your eye examined with a slit lamp, prior to discharge from the clinic. This is often considered to make sure that your flap has not moved from where your surgeon had place it.


4. Incomplete, Irregular, Decentered Flap or Button Hole of Flap – According to some experts, this LASIK complication occurs at the time of flap creation. The most common cause of this is a loss of suction, or discrepancy in the fit of the eye surface to the suction plate.

5. Epithelial Abrasion – This is but another LASIK complication that usually occurs at the time of flap creation. This is said to be more common than the two complications listed above. The common victims of this are the older patients, ages 45 and above.

6. Displaced Flap – An unusual occurrence which appears from rubbing or trauma to the eye within the first 24 to 48 hours after the LASIK surgery. This is however decreased as with time and is normally very minimal after three months.

7. Infection – This is an extremely rare occurrence, but if this occurs, it could be devastating.

8. Inflammation Under the Flap – This is said to occur when the tissue under the flap reacts to minutes traces of microorganism toxins. It has been noted that all microorganisms and most of their byproducts are destroyed with heat sterilization. Unfortunately, some of these toxins are not destroyed by heat and even in very minute amounts can cause an adverse reaction. This is what triggers the inflammation to occur.

9. Debris Under the Flap – This complication is fairly common for the reason that the tear film normally has particles of oil and other material like make up and lint from clothing. What contribute to the occurrence of this are primarily the loose cells which result from the flap creation, which can cause the most problems because they may continue to grow under the flap.

So you’ve learned about the complications that may occur with the LASIK eye surgery. The question now is how to avoid such problems?



Knowing the Factors that Affect the LASIK Outcome

Although millions of people can benefit from LASIK, it is important to note in the first place that the procedure is not for everyone. Doctors typically divide potential LASIK patients into a number of categories. There are the ideal or good LASIK candidates, the less-than-ideal candidates, and the non-candidates.

The ideal LASIK candidate has the best chance of a complication-free outcome. The less-than-ideal on the other hand is at increased risk for LASIK complications, thus need to discuss them thoroughly with the surgeon before taking the operation. And, the non-candidate is not absolutely eligible for LASIK due to a preexisting condition.

Given this fact, the most important thing to consider then before proceeding for LASIK is to get screened out beforehand if you are an ideal candidate for the eye correction procedure or not.

Below are some criteria that could negatively affect your visual outcome or even disqualify you for LASIK completely. Note them carefully for there is a possibility that your surgeon will run some objective examinations for most of these criteria. If you think that you might fit into one of the categories below, just let your surgeon know. And, if he skips a test, don’t hesitate to ask why. You can even ask your surgeon to have the test done.

Poor Vision

When it comes to how much vision correction LASIK can provide, some limits are set for every candidate. There are some patients who have poor eyesight that they are beyond the help of refractive surgery. As noted, the FDA limits on approved procedures do not include those with more than -14.00 diopters of myopia, more than 6.00 diopters of astigmatism or over +6.00 diopters of hyperopia.

Anterior Eye Health

Typically, the eye specialists divide the eye into two portions: anterior (front) and posterior (back). In terms of the anterior portion, the doctors commonly employ a biomicroscope known as a slit-lamp to examine the anterior portions for abnormalities that could affect you LASIK outcome. For this specific test, you will need to place your in the chin rest over the examining chair and the doctor will simply shine a light onto your eyes and examine the anterior portions through the microscope.

Posterior Eye Health

By examining the posterior portion of your eye, the doctor is able to distinguish certain eye diseases, such as ocular hypertension, glaucoma, and diabetic retinopathy. This examination is known as fundus exam and the doctor performs this by shining a light into your eye and looking through your pupil.

Wobbly Prescription

One should note that as we mature, our eyes change shape and size. This is the reason why a young person’s eyeglasses or contact lens prescription is constantly changing. Most of these prescriptions become constant by the age of 18, but many do not and continue to change throughout our 20s. Well, the LASIK surgeons commonly prefer to operate on patients who are over 18 and whose prescriptions have not changed significantly in two years. This is considered because operating on eyes that are still in the process of growing creates the risk that the vision corrected will be negated as the eyes continue to change. So, before you can qualify for LASIK, the doctor will compare the results of your eye exam with your history to see if your prescription is stable.

Large Pupils

In the first place, the area treated by the LASIK laser is only a small, circular part of the cornea. If you have larger than average pupils, their circumference might exceed that of the treatment area, causing a different kind of visual problem, especially at night when your pupils are at their largest. Note that large pupils can result to some visual problems such as starburst, ghosting, and halos.

Dry Eyes

Dry Eye is but a very common condition. This primarily affects people age 40 above, especially women. Studies have shown that this complication is may occur when your eyes fail to produce enough tears to keep the cornea moist, or when the tears dissipate too quickly. So, before taking the procedure, it is important to know if your eyes are chronically dry as this condition can affect post-LASIK healing, including the quality of vision you achieve.

If you think that you might have chronically dry eyes, ask your surgeon to administer the Schirmer test. This will actually the amount of moisture on your eyes with the use of a thin piece of paper placed in your eye.

Irregular Cornea

Another factor that could affect your LASIK outcome is the irregularity of your cornea. Often said is that, if the cornea is too irregular in shape, it can’t be operated on. Your doctor will examine your cornea with a corneal topographer to make sure that you qualify. The topographer works with its camera taking picture of your eye, and a computer generates a map of your cornea.

Thin Cornea

Some people have corneas that are too thin, so there’s not enough tissue to create a good flap. In this case, LASIK could worsen rather then improve the quality of your vision. So before taking the procedure, you doctor must measure the thickness of your cornea with a device called a corneal pachometer. If in the end you are not considered an ideal candidate for LASIK because of a thin cornea, other vision correction methods may be available to you though.

Overall Health

There are several systemic diseases that could also keep you from being an ideal candidate for LASIK. These hindrances could include autoimmune disorders and conditions that require a medication that slows healing. These are said increase your risk of complications.

Also, if you arte pregnant or nursing, you are not an ideal candidate for the reason that the related hormonal changes can temporarily affect the shape of your eyes. So, before considering the procedure, your surgeon will obtain information about your overall health from a number of sources, including the records from your primary-care doctor and the fundus exam.


In summary, what you can do to avoid some of those above mentioned LASIK problems is to determine whether you are an ideal candidate or a less than ideal candidate for LASIK. Knowing that will give you an idea of the result you can expect from LASIK. But, to further help your surgeon determine your risk of complications, send your medical records to him or her and make sure to get the necessary tests and measurements done. Take a routine eye exam, slit-lamp exam, fundus exam, corneal thickness, corneal topography, corneal pupillometry, and schirmer test if possible.