Herpes virus infections have become an increasing health concern over the last few decades. One of the major contraindications to having Lasik eye surgery is a history of herpetic infections of the eye. The herpes variant that most often causes corneal eye infections is usually the same one that causes oral cold sores. In the eye, herpes simplex viruses can cause a recurrent inflammatory reaction of the cornea which can cause long term scarring and distortion which can permanently reduce vision. It's the potential recurrent nature of this infection that tends to be the most problematic. Some individuals have only rare attacks while others have frequent, chronic, and recurrent problems that continually add more scar tissue over time. The virus will manifest itself at unpredictable times causing inflammation then scarring and afterward it will go dormant and remain quiet for extended periods of time. During these quiet times, the virus is still present in the body but remains hidden in our nerve tissue. It is kept at bay at these times by the strength of our immune systems, but any stressor which affects or suppresses the immune system can allow the virus to attack the cornea again. Currently, there is no true cure for herpes infections.
In addition to being the major site of ocular herpetic infection, the cornea is the part of the eye where Lasik surgery is performed. It's believed that surgery involving laser treatment to the corneal surface may act as a stimulus to activate the dormant herpes virus in an otherwise quiet eye. Theoretically, this stimulus could initiate chronic, recurrent herpes corneal infections and lead to potential scarring of the eye. Also, it has been shown that topical steroid eye drop use in patients with active herpes infections can lead to prolonged problems. After Lasik surgery, patients typically use steroid eye drops for several days to a week. However, steroids act by suppressing the immune system, so they are generally avoided whenever possible in the eyes of patients known to be affected by the herpes virus. Patients with ocular herpes can become "steroid dependent" and cannot be taken off of the steroid drops without significant inflammation recurring. As we noted earlier, the herpes virus usually remains dormant in the nerves of the eye and is kept quiescent by our normal immune system. So the immunosuppressive effect of a steroid can lead to an imbalance allowing the chronic reactivation of the herpes virus in that individual. The combined risk of the stress of laser treatment in conjunction with steroid use makes patients with ocular herpes very poor Lasik surgery candidates.
It should be stressed that there is no way to know if Lasik surgery will cause a herpes reactivation in the eye. Nobody has ever conducted a study of known patients that have a history of herpes eye infections to determine if Lasik does in fact significantly increase the rate of recurrent infection and inflammation. Because of the possibility of chronic inflammation and scarring, we avoid Lasik in any patient that has a history of herpetic infections of the eye so nobody has ever intentionally designed a study that might put those individuals at risk. Certainly, some patients have undergone eye surgery or other traumatic stresses to the eye without a herpes reactivation. But because of the elective nature of Lasik, generally ophthalmologists agree that the risk is not warranted for the potential benefit. Theoretically, significant scarring could lead to significantly diminished vision which is the opposite of the goal of the Lasik surgery itself.
Medications do exist which can help to control herpes eye infections when they do occur. Many of the newer medications have increased effectiveness compared to older therapies and hopefully further developments will make significant visual loss from this disorder more unlikely. However, to date, there is no complete cure so the risk for reactivation remains. I have had patients ask whether they could use those medications as a preventative and still go forward with Lasik surgery. At this point, my answer to those people is no, it is still not a good idea. We just don't know enough about the potential risk under these circumstances. Perhaps in the future, a therapy or cure which reduces that risk adequately will be found, but until that day, patients with a history of herpetic eye infections should avoid Lasik eye surgery.
Dr. John Suson MD is an ophthalmologist and a clinical instructor at the Medical College of Wisconsin. Currently, Dr. Suson is in private practice with his sister at their "Suson Eye Specialists" clinic. Dr. Suson offers a free consumer guide to laser eye surgery at http://supereyes.com/get-our-complete-consumer-guide.html.
For further information on herpetic eye infections, I recommend the American Academy of Ophthalmology's website. http://www.geteyesmart.org/eyesmart/diseases/herpes-keratitis.cfm
