Short sight or “Myopia” is ability to see near objects clearly and disability to see far objects clearly. During adolescence, the power of glasses changes along with the change of height and voice. The change stabilizes at about 20 years of age. This power usually remains with out much of change up to the age of forty. It is not possible to treat myopia with medicines or special food.
Radial Keratotomy is a simple surgical procedure, which can treat powers up to – 5.00 Diopters (points). It is not as sophisticated as Laser treatment but is very much cheaper and gives good results for myopia up to – 5.00 dioptors.
However, the advent of laser has reduced the popularity of radial keratomy. Excimer Laser treatment is the latest method of treating short sight. Both the eyes are treated at the same sitting to avoid gross difference of power between the two eyes. Very rarely one eye is treated at a time. A week’s rest is advisable after LASIK laser treatment and a month after PRK.
There are two types of treatment available:
1. PRK or surface treatment: In PRK, the laser is applied directly on the surface of the cornea after removing the epithelium (skin of the cornea).
The laser reshapes the cornea into a lens of required power. The skin of the cornea grows back in about 4 to 7 days after treatment. Till the skin of the cornea grows back, the patient will have irritation of the eyes and will find it difficult to open the eyes. The visual recovery will start only after the skin grows back. Patient will have to apply medicines for 3 to 6 months after PRK. PRK has an upper limit of minus 9.00 Diopters (points) for treatment. PRK is cheaper than Lasik treatment.
2. LASIK (laser treatment under the partial thickness corneal flap): In this treatment, a computer-controlled kerotome (Blade) cuts the cornea to raise a 60 to 80-micron (1 micron = 1/1000 mm.) corneal flap. Laser is applied under the flap.
The corneal flap is replaced after the procedure. Here the skin of the cornea is not removed and so the patient’s discomfort is minimal. The visual recovery is rapid and the patient is able to regain near normal vision on the very next day. Medicines have to be applied for a month following LASIK Laser treatment.
The major draw back of Laser treatment is that it is not possible to guarantee a 100% cure for every body. Some people may have – 0.5 or -1.0 Diopter residual power. But for a person who was wearing – 10.0 or -15.0 Diopter glasses prior to laser treatment, these small residual powers are not significant. Being a surgical procedure, LASIK also has it own risks like all other surgical procedures.