Cause of Corneal Haze
Corneal haze
tends to be caused by an agressive wound response after Lasik, Bladeless
Lasik, PRK, LASEK, or Epi-Lasik. In response to the "wound" of laser vision correction surgery ablation, the cornea can become clouded with white cells.
Corneal haze is very,
very rare after Lasik or Bladeless Lasik because the flap of corneal
stromal tissue "fools" the eye into not realizing that it has had surgery.
It acts like a natural bandage. The wound response after Lasik is significantly muted and different than the wound
response to PRK, LASEK, or Epi-Lasik.
Corneal haze is more likely after PRK, LASEK, and Epi-Lasik
because the laser energy is applied directly to the surface of the cornea. Without the Lasik flap, the cornea fully responds to the wound of laser vision correction surgery.
It is rare, however, for a normal healthy cornea to respond with corneal haze after PRK, LASEK, or Epi-Lasik if the correction is less than 6.00 diopters. The cornea tends to tolorate well the ablation necessary for moderate and low refractive error.
Corneal haze caused by excimer laser ablaion is relatively benign, even if it causes temporary vision disturbance. However, haze can also be caused by more serious
problems that require an immediate response. A patient that experiences the symptoms of corneal haze should report the problem to a eye doctor immediately.
Symptoms
Corneal haze is commonly visable upon examination by a doctor. The patient's vision may become blurred, defocused, or obscured. This ofter presents as halos around light sources or glare in bright light. Minor
haze may cause no vision problems for the patient.
Treatment
Corneal haze caused by a wound response will resolve as healing completes. In more severe cases a doctor may prescribe eye drops or other medication to encourage healing and hasten the cycle.
In nearly every case of corneal haze, even when severe, the haze eventually resolves with healing. The issue is the amount of time that will be necessary and what steps should be taken to hasten the process. With common refractive surgery induced haze, the haze resolves within days, but may take three to six months. The vision symptoms of halos and glare commonly resolve faster than the actual haze.
Prevention
Because haze tends to ocurr in PRK, LASEK, and Epi-Laisk when more than about 6.00 diopters of refraction correction is attempted, these procedures should be avoided for patients who require large amounts of correction. Patients with healthy corneas and less than 6.00 diopters of error likely will not experence haze. Haze tends no not occur in Lasik patients at any amount of correction. Selecting Lasik instead of PRK, LASEK, or Epi-Lasik may be appropriate if the correction is high.
Haze also may be more likely to occur in an unhealthy eye or a patient with other healing related disorders like keloid or autoimmune disease. A patient with these types of problems may not be an appropirate candidate for refractive surgery.
It has been found that having a patient take 500mg of vitamin C (yes, plain old vitamin C) twice a day for a week before PRK, LASEK, or Epi-Lasik and at least two weeks after surgery significantly reduces the incidence of corneal haze. Vitamin C appears to be helpful, but more study is needed to determine just how much help is provided with oral vitamin C supplements. It is really not known if vitamin C is enough to prevent haze for someone who needs 8.00 diopters of correction, but is not enough for someone who needs 10.00. The limits need to be determined.
The use of the topical eye drop Mitomycin C during surgery dramatically reduces the probability of haze, and can be used to treat haze when it occurs, but this is rather strong medicine. Mitomycin C is appropriate when required, but probably needs to be avoided if possible. Also, Mitomycin C changes how much tissue the laser ablates with each pulse, so the doctor needs to manually change the treatment plan. This requires additional expertise.
Looking For Best Lasik Surgeon?
If you are ready to choose a doctor to be evaluated for conventional
or custom wavefront Lasik, Bladeless Lasik, PRK, or any refractive surgery procedure, we recommend you consider a doctor who has been evaluated and certified by the USAEyes nonprofit organization.
Locate a USAEyes Evaluated & Certified Lasik Doctor.
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