Refractive Options Available
Laser Assisted In-Situ Keratomileusis
In Laser Assisted In-Situ Keratomileusis (LASIK), the physician uses a special instrument called a microkeratome. Drops are placed in the eyes to numb the cornea. The microkeratome makes a flap in the cornea about 130-160 microns thick and about 9 mm in diameter. The precisely cut, thin corneal flap remains attached to the cornea by a hinge.
The flap is then gently folded back exposing the underlying cornea. The excimer laser is then used to achieve the desired correction. The flap is gently put back to the original position without the need of stitches. The cornea has amazing bonding power to allow the flap to stay in place.
Laser Epithelial Keratomileusis
Laser Epithelial Keratomileusis (LASeK) is a newer procedure that combines features of both PRK and LASIK. Like LASIK, a flap of tissue is created that allows exposure to the inner aspect of the cornea.
Rather than using a microkeratome device to create the flap, LASeK requires a dilute alcohol solution that weakens the outer layer of the cornea - called the epithelium - enough so that a flap can be created with a blunt instrument. The treatment then continues the same as a LASIK procedure, with the epithelial flap being carefully repositioned once the laser is completed.
In Photorefractive Keratectomy (PRK), the excimer laser reshapes the cornea by removing particular cells of the outer layer. In 1995, the FDA approved PRK to correct up to 7 diopters of myopia. It may be used to correct hyperopia as well. Because the laser beam is so precise, only the surface of the cornea is affected. A contact lens is then put into the treated eye, acting like a bandage while the cornea is healing for the first 24-48 hours.
With PRK, eyes are treated one at a time, about one week apart. Patients might have mild discomfort for about 24-48 hours. The ophthalmologist will prescribe some medicine to alleviate the discomfort. Patients will see a gradual change in their vision day to day. More post-op visits are involved with PRK so the doctor can watch the cells of the cornea heal. The patient will have the same visual results from PRK as with LASIK.
Refractive Lensectomy and Phakic Intraocular Lens Implantation
Some patients are not suitable candidates for laser vision correction, because either they are too nearsighted or farsighted, or some of the other measurements are not compatible with laser surgery. These patients might be suitable for intraocular lens implantation, with a refractive lensectomy, in which the crystalline lens is replaced with an artificial lens, in the same way as cataract surgery is done, or a synthetic lens can be placed in the eye on top of the patient’s natural lens.
INTACS (Intracorneal ring segments) for keratoconus is a procedure for patients with advanced keratoconus who are not able to achieve adequate vision with contact lenses and glasses, but are not ready for a corneal transplant procedure.
Keratoconus is a condition in which the cornea becomes progressively more conical in shape resulting in high degrees of irregular astigmatism. The INTACS procedure can help make the cornea more regular in shape so that patients can successfully resume their contact lens wear or glasses.
Conductive Keratoplasty (CK) is for patients who would like to improve their near vision or reading vision. CK uses applied radio-frequency energy around the periphery of the cornea, heating and shrinking corneal tissue. This increases the central corneal curvature improving near vision.