Eye Matters
December 18, 2009

Laser Surgery

Laser refractive surgery procedures are now a viable alternative to glasses and contact lenses. Patients often request these procedures, especially when glasses and contact lenses do not help anymore.

So what is a laser light?

Laser light is made up of coherent light. Normal light radiates and scatters in all directions. With coherent light, however, all of the light rays travel in the same direction.{{more}} This light is very safe and only becomes effective in treatment when it is highly concentrated with the use of special lenses and mirrors.

With refractive surgery, the shape of the eye is changed with laser light to improve vision. PRK, LASIK, LASEK, are some of the procedures used. An excimer laser removes tissue to change the shape of the cornea.

What is PRK?

PRK stands for photo refractive keratectomy. In this procedure, the superficial layer of the cornea is removed to allow the excimer laser to reshape exposed corneal tissue. The patient is usually able to return to work within a few days. As the eye heals vision improves continually. PRK has now been mostly replaced by LASIK and LASEK especially because it is a more painful procedure.

What is LASIK?

Lasik stands for laser in-situ keratomileusis. This is the most common refractive procedure performed these days. In Lasik, a special blade called the microkeratome is used to make a flap of corneal tissue. This flap exposes the cornea and is hinged to one side.

The exposed tissue is then treated with excimer laser. The flap is then placed back into its original position and the procedure is finished. Most patients report an immediate improvement after Lasik. Some complain of initial blurriness, but most are able to return to their normal daily activities practically by the next day.

The advantage of the Lasik flap over the PRK procedure is that the flap helps to speed up visual recovery, reduces the risk of infection and also reduces discomfort. One disadvantage is that it cannot be used for higher refractive errors.

What is LASEK?

Lasek is a modification of the PRK and LASIK procedures. In this technique, a special solution is used to separate the thin epithelial layer from deeper corneal structures. In this way, a small flap is formed.

This flap is extremely thin and is hinged to the cornea. The exposed cornea is then treated with excimer laser. After this, the epithelial layer is smoothed back into its position and a special temporary contact lens is placed on the eye for protection.

Vision correction with Lasek is similar to that of Lasik, except for the use of contact lenses. This procedure is great for patients with high refractive errors because more tissue can be removed. The advantages here are reduced pain, shortened recovery period and low risk of infection.

Next week we dig a little deeper.

Have a great weekend.

Dr Kenneth Onu is a resident Consultant Ophthalmologist at the Beachmont Eye Institute/Eyes R Us Send questions to: Beachmont@gmail.com

Tel: 784 456-1210