Lasik Surgery

Introduction

LASIK stands for Laser in situ keratomileusis. This operation is performed in people with near sightedness, far sightedness or astigmatism and involves reshaping the thin transparent layer in front of the eyes known as cornea to restore normal vision. It is opted by many who do not wish to wear glasses or contact lens. This procedure is advised for people with very severe nearsightedness. The advantages of this operation include its painlessness, ease, almost 80% correction of vision, allowance for repeat correction and immediate improvement in vision from the day of the surgery.

Surgery Procedure

The condition of the cornea needs to be judged before this procedure is undertaken. This includes measurement of corneal thickness, corneal mapping, refraction, eye pressure and the extent of pupil dilation. If the patient wears rigid gas permeable contact lenses they will be advised to stop using them for at least 3 weeks before surgery. If they wear soft contact lenses then they need to stop for at least 3 days before surgery.

The underlying corneal layer is then reshaped using laser beams.

Usually this operation is performed under local anesthesia wherein the site of operation is numbed. This operation takes around 10 to 15 minutes to be completed. Patient may be given oral drugs to allay anxiety and pain.

Once in the operation theatre patient will be draped in sterile surgical drapes and the eye will be placed before the microscope. With use of an instrument called the speculum the eyelids will be held open during the surgery. During the surgery to prevent drying of the cornea a solution called the BSS or Balanced Salt Solution is continuously used to irrigate the eye surface. An instrument called the microkeratome is used to peel off the top flap of the cornea. The underlying corneal layer is then reshaped using laser beams. Once the shaping is complete so that the light beams can be directly focused over the retina, the top flap is replaced and the surgery is completed. Once the flap remains undisturbed and in position for several minutes the speculum and the surgical drapes are gently removed. Patient will then be allowed to blink slowly. A repeat examination can ensure the proper positioning of the flap. Antibiotic eye drops are then applied.

A see through bubble shield is applied over the eye to prevent inadvertent rubbing. Vision is usually hazy or blurry over the first day but rapidly improves. Patient will be examined within 24 hours of the operation.

Recuperation and post operative complications

After discharge patient will need to apply eye drops containing antibiotics and solution to moisten the eyes for several days. They will be seen by the ophthalmologist in one or two weeks and at regular intervals till six months after surgery. The visual acuity and correction of astigmatism can be assessed during these visits.

Disadvantages of this procedure include over or under correction of vision and corneal damage. The procedure may also lead to temporary dryness of eyes, glare, blurriness and difficulty in vision in sunlight or at night.

Alternatives to LASIK include non surgical correction of vision with glasses or contact lenses. Surgical alternatives to LASIK include removal and replacement of the actual lens of the eye with an intraocular lens implant or placement of intracorneal rings.