Lasik, or laser-assisted in situ keratomileusis, is the most common type of refractive surgery, and vision-threatening complications are rare, according to the All About Vision website. In this procedure, the eye surgeon creates a flap of cornea, which is then folded back while a laser is used to reshape the corneal tissue below. Afterward, the flap is replaced on the cornea. The creation of the flap is a very important part of the Lasik procedure. Any problems with the flap can cause both short and long-term complications---some of which may require further surgery.
Wrinkled Flap
If the corneal flap is not replaced precisely on the cornea or the flap shifts slightly after surgery, wrinkles or striae may form in the flap. According to the See With Lasik website, if these are located in the center of the visual axis, the vision may be blurred. The surgeon can remove these wrinkles if treated early; however, sometimes the wrinkles cause long-term decrease in final visual acuity.
Thin Corneal Flap
With the new technology that can be used to create the flap in Lasik surgery, the risk of a too-thin corneal flap is very small, according to The Levinson Eye Clinic website. Performing the surgery with a thin flap can cause irregular healing, which can lead to permanently blurred vision. If an eye surgeon notices the creation of a thin corneal flap, the surgeon may replace the flap and postpone the procedure for at least three months.
Epithelial Ingrowth
Sometimes after the procedure, cells from the outer layer of the cornea get trapped under the corneal flap. These cells can grow and distort the vision of the patient. These cells can be removed by lifting the flap and clearing the cells away, according to the Robbins Laser Site website. In severe cases, the epithelial cells can damage the corneal flap.
Diffuse Lamellar Keratitis
In the complication diffuse lamellar keratitis, inflammation develops under the corneal flap, as noted on the See With Lasik website. This inflammation causes haze under the flap and can interfere with vision. For mild cases, the use of corticosteroid eye drops can solve the problem. In other cases, the flap may need to be lifted and irrigated to remove the inflammatory material.
Corneal Ectasia
Another rare complication of Lasik surgery is corneal ectasia in which the structure of the cornea is damaged by the creation of the flap or by the removal of too much tissue. This could lead to a bulging of the cornea at a later date, which can cause a significant deterioration of the vision. According to the Geneva Eye Care website, repeat surgery cannot be performed on these patients and the patient may need hard contact lenses or other procedures to correct the vision. Occasionally these patients might need a corneal transplant.
Corneal Perforation
Corneal perforation, which is a creation of a hole in the cornea, is a very serious and rare complication of Lasik surgery. The improved techniques and devices that are used for Lasik surgery reduce the incidence of this problem. Incorrect use of the technology is often at fault when perforations do occur, according to Frederick S. Brightbill and colleagues in the 2009 textbook "Corneal Surgery: Theory, Technique and Tissue." If corneal perforation occurs, the surgeon needs to suture the perforation in the eye shut; further surgery will likely be needed.
References
- Robbins Laser Site: New York Lasik Surgery
- See With Lasik: Lasik Risks and Complications
- Geneva Eye Care: Lasik Risks and Complications
- Corneal Surgery; Theory, Technique and Tissue; F.S. Brightbill, P.J. McDonnell, C.N.J. McGhee; 2009
- The Levinson Eye Clinic: Possible Lasik Complications
