Dry eye is the most common complication of LASIK. Corneal nerves that are responsible for tear production are severed when the flap is cut. Medical studies have shown that these nerves never return to normal densities and patterns. Symptoms of dry eye include pain, burning, foreign body sensation, scratchiness, soreness and eyelid sticking to the eyeball. The FDA website warns that LASIK-induced dry eye may be permanent. Approximately 20% of patients in FDA clinical trials experienced “worse” or “significantly worse” dry eyes at six months after LASIK.(1)
LASIK patients have more difficulty seeing detail in dim light (loss of contrast sensitivity) and experience an increase in visual distortion at night (multiple images, halos, and starbursts). A published review of data for FDA-approved lasers found that six months after LASIK, 17.5 percent of patients report halos, 19.7 percent report glare (starbursts), 19.3 percent report night-driving problems and 21 percent complain of eye dryness.(1) The FDA website warns that patients with large pupils may suffer from debilitating visual symptoms at night.
The flap never heals. Researchers found that the tensile strength of the LASIK flap is only 2.4% of normal cornea.(2) LASIK flaps can be surgically lifted or accidentally dislodged for the remainder of a patient’s life. The FDA website warns that patients who participate in contact sports are not good candidates for LASIK.
LASIK permanently weakens the cornea. Collagen bands of the cornea provide its form and strength. LASIK severs these collagen bands and thins the cornea.(3) The thinner, weaker post-LASIK cornea is more susceptible to forward bulging due to normal intraocular pressure, which may progress to a condition known as keratectasia and corneal failure, requiring corneal transplant.
In a 2003 survey of American Society of Cataract and Refractive Surgery (ASCRS) members,(7) 91% of surgeons who responded did not offer patients the choice of having one eye done at a time. Performing LASIK on both eyes in the same day places patients at risk of vision loss in both eyes, and denies patients informed consent for the second eye. The FDA website warns that having LASIK on both eyes at the same time is riskier than having two separate surgeries.
The medical literature contains numerous reports of late-onset LASIK complications such as loss of the cornea due to biomechanical instability, inflammation resulting in corneal haze, flap dislocation, epithelial ingrowth, and retinal detachment.(8) The LASIK flap creates a permanent portal in the cornea for microorganisms to penetrate, exposing patients to lifelong increased risk of sight-threatening corneal infection.(9) Complications may emerge weeks, months, or years after seemingly successful LASIK.
Since LASIK does not eliminate the need for reading glasses after the age of 40 and studies show that visual outcomes of LASIK decline over time,(10) LASIK patients will likely end up back in glasses – sometimes sooner rather than later.
There is no clearinghouse for reporting of LASIK complications. Moreover, there is no consensus among LASIK surgeons on the definition of a complication. The FDA allowed laser manufacturers to hide complications reported by LASIK patients in clinical trials by classifying dry eyes and night vision impairment as “symptoms” instead of complications.(1)
LASIK is irreversible, and treatment options for complications are extremely limited. Hard contact lenses may provide visual improvement if the patient can obtain a good fit and tolerate lenses. The post-LASIK contact lens fitting process can be time consuming, costly and ultimately unsuccessful. Many patients eventually give up on hard contacts and struggle to function with impaired vision. In extreme cases, a corneal transplant is the last resort and does not always result in improved vision.
Some leading surgeons have already abandoned LASIK for surface treatments, such as PRK, which do not involve cutting a corneal flap. It is important to remember that LASIK is elective surgery. There is no sound medical reason to risk vision loss from unnecessary surgery. Glasses and contact lenses are the safest alternatives.