Corrective Laser Eye Surgery

To gain a better understanding of corrective laser eye surgery, it is important to know a bit more than you might already know, about the eye.

Most corrective surgery is done on he cornea.  The cornea is that part of the eye that focuses light coming into the eye onto the retina so that we may see. It works on the same principle as the lens of a camera, which serves to focus the light on film to create an image. This focusing and bending of light is technically referred to as “refraction.”  

When there are imperfections in the shapes of the eye and the cornea, the image projected onto the back of the eye (the retina) will be blurred, be out of focus, or will suffer from other distortions. Imperfections to the focusing power of the eye are referred to as "refractive errors." These refractive errors are subdivided into 3 main classes:  

1. Myopia (nearsighted)
   
2. Hyperopia (farsighted) 
   
3. Astigmatism (distortion of vision)
   

A person with Myopia will have difficulty seeing far away objects clearly. Reversely, a person with hyperopia will have more trouble seeing objects that are near, clearly. Astigmatism is simply a distortion of what is seen due to irregularities in the cornea, and can sometimes be found in conjunction with myopia or hyperopia.

Contact lenses and glasses are designed to correct or compensate for imperfections in the eye. But today there are Surgical procedures designed to improve the focusing power of the eye. Such procedures are called “refractive surgery” or “corrective laser eye surgery.” Laser surgery consists of  precise and controlled removal of corneal tissue with the use of a surgical laser.  Through this procedure, the cornea is reshaped, in order to correct its focusing power.

The majority of  patients are very satisfied  with the results of corrective laser surgery However, as with any surgical procedure, there are some risks involved. It is therefore important to have a good understanding of the limitations and  possible complications of corrective laser surgery.

Before deciding to undergo corrective surgical procedure, you should appraise yourself of the risks and benefits involved so that you can make an informed decision based on your own personal values.  Avoid being influenced by others who have undergone similar procedures, as their situations might not have been the same as yours.  

Possible side effects of corrective laser eye surgery

• Loss of vision: A few patients lose lines of vision on the vision chart as a result of treatment.  These might not be correctable  afterwards, even with the use of , contact lenses, glasses, or surgery. 
  
• Other debilitating visual symptoms: In some cases, patients have developed glare, halos, and/or double vision.  These can seriously hinder nighttime vision. Even with good vision under good lighting conditions.  A few patients see less well in situations of low contrast, i.e. at night, in fog, or in misty weather conditions. 
  
• Corrective laser eye surgery is not a guarantee of 20/20 vision.  Not all patients achieve 20/20 vision as a result of the corrective surgery. You might still need to use glasses or contact lenses. If you were in need of corrective reading glasses before surgery, this might still be the case after surgery.
  
• Dry eye syndrome as a result of corrective laser surgery.  Another possible side effect as a result of surgery, is a reduction in the ability to produce tears to keep the eye moist.  A condition called “Dry Eye.”  Not only does this cause discomfort, but it can reduce your visual quality with intermittent blurring and other symptoms. This condition could be permanent. 
  
• Results are less predictable in patients with large refractive errors. It is important to discuss your expectations with your doctor.  Also realize that you still might require glasses or contacts after the surgical procedure. 
  
• Results for farsighted patients, can diminish with age. For a farsighted patient, the level of improved vision experienced as a result of surgery can decrease with age. It is therefore advisable to take this up with your doctor in order to inform yourself fully of expected results.
  
• Long-term data is not available. As corrective laser eye surgery is a relatively new procedure and technology, long-term effects are not available. The first laser corrective surgery using LASIK was approved for use in 1998. It follows then, that the long-term safety and effectiveness of LASIK surgery is still not fully known, even in medical circles.