Laser Vision Correction- Lasik & PRK
Laser vision correction procedures can improve the eye's natural focus by changing the shape of the cornea. Both of the most frequently used techniques, PRK and LASIK use the excimer laser to remove micro-thin layers of tissue from the cornea.
In PRK, the topmost "skin" layer of the cornea is mechanically removed using surgical instruments. The laser is then focused on the newly exposed outer layers of the cornea, reshaping its curvature to correct the refractive error.
In LASIK, a cutting device called a microkeratome is used to cut a thin flap on the surface of the cornea. This thin flap is folded back, and the laser is used to remove thin layers of tissue from the exposed mid-corneal layers. The application of the laser energy is the same as in PRK or surface ablation. Following the sculpting or reshaping of the cornea, the flap is returned into position, and it adheres to the cornea without stitches.
The cornea, which is the transparent covering on the eye's front wall, is designed to both transmit and focus light rays as they enter the eye. If the cornea is not shaped properly or is somehow clouded, whether because of injury, infection or disease, visual acuity is compromised, and a transplant may be recommended.
There are several different corneal transplant procedures available to help restore vision in patients with corneal problems. The traditional corneal transplant procedure, penetrating keratoplasty, involves replacing the entire damaged cornea with a healthy one from a human donor. Technological advances have allowed for the development of specialized procedures in corneal transplantation. They include endothelial keratoplasty and deep anterior lamellar keratoplasty, which replace only the damaged part of the cornea while leaving the healthy parts intact.
A topical anesthesia is administered to the patient before the procedure begins. The surgeon prepares the donor cornea and makes a mark on the surface of the patient's cornea to determine the size needed for the transplant, outlining the area needed for replacement.
After removing the damaged membrane from the eye, the donor cornea is folded into a shape and placed onto the eye. A single stitch closes the incision.
Sometimes the new cornea unfolds on its own; other times, the surgeon may need to unfold it. When the replacement cornea is unfolded, a second stitch is then made to close the wound and anchor the new cornea in place. An air bubble is injected underneath the cornea, to ensure that it is centered on the eye, and the pupil is dilated with eye drops.
Advanced Transplantation- Boston KPro
The keratoprosthesis is made of clear plastic with excellent tissue tolerance and optical properties. It consists of two parts which when fully assembled has the shape of a collar button. The device is made of a new type of plastic that allows nutrients to enter the eye more quickly than previous designs. The device is inserted into a corneal graft, which is then sutured into the patient’s cloudy cornea.