Lasik MD
Your Guide to LASIK Eye Surgery
Am I a Candidate for LASIK?
Warnings
While contraindications can generally be thought of as "black or white", "yes or no" issues, warnings represent more of a gray zone. With warnings, surgery is not recommended, but it can still be contemplated under certain circumstances.
Diabetes is a warning due to a number of concerns. Diabetics are notoriously slow healers and more prone to infection. With time, poorly controlled blood sugar can lead to diabetic retinopathy, which is characterized by leaky blood vessels in the retina. Even over the short-term, fluctuations in blood sugar can cause dramatic shifts in the eye's focusing power, which can make accurate preoperative measurements difficult.
Each surgeon has his or her own threshold for treating diabetic patients. At the very minimum, most insist that blood sugar levels be steady and normal, with no diabetic retinopathy present.
Herpes keratitis: The herpes family of viruses includes Herpes Types I and II, along with varicella zoster. Herpes Type I typically causes recurring cold sores above the waist, whereas Type II more often affects the genitalia. Varicella zoster, on the other hand, causes chickenpox and, if reactivated, shingles. All three herpes viruses can lead to herpes keratitis, a recurring infection of the cornea.
Herpes keratitis spans a spectrum from brief episodes of mild disease to prolonged inflammation that can last for many months and lead to permanent scarring and loss of vision. Because laser vision correction could result in reactivation, individuals with a history of herpes keratitis should not have surgery.
Dry eye: Because surgery makes the eyes even drier, preexisting dry eye disease is a relatively common reason for surgeons to recommend against laser vision correction. When severe, postoperative dryness causes scratchiness, pain and blurred, filmy vision that takes weeks or months to clear up. In fact, most surgeons agree that some of their most unhappy patients are those whose vision is still blurry because they are waiting for dryness to clear.
Although it is helpful to inform the doctor of any history of dry eye or artificial tear use, ultimately, the dryness level must be determined by formal tests, such as the tear break-up time, fluorescein, lissamine green or rose bengal staining, Schirmer's test or biochemical tear analysis. Only then can a determination be made as to the likelihood of postoperative dry eye problems.
Severe allergies increase the likelihood of postoperative inflammation and dryness and raise the concern that eye rubbing could traumatize a LASIK or IntraLASIK flap. On rare occasions, surgery may be inadvisable. However, most surgeons rarely if ever encounter allergies of this severity.