Global Courant
LASIK and LASEK are similar forms of laser eye surgery used to correct nearsightedness, farsightedness, astigmatism and (under special circumstances) presbyopia. LASIK is an acronym for “Laser-Assisted In Situ Keratomileusis,” while LASEK stands for “Laser Assisted Sub-Epithelial Keratomileusis.” The reference to “sub-epithelial” in the second acronym gives a clue to the differences between these two surgeries.
epithelium
In LASEK, the epithelium, or the thinnest outer layer of the cornea, is not cut with the microkeratome cutting blade used in LASIK, but with a finer tool called a trephine. Both surgeries create a covering for the cornea, which can be put back in place at the end of the procedure. Because it uses a thinner cutting instrument, the LASEK procedure can make this covering of only the epithelium, while LASIK involves cutting into deeper layers of the cornea.
When the epithelial layer is moved out of the way, a laser changes the shape of the cornea underneath, returning the epithelium to its natural position. Sometimes the thin tissue is too weak to be put back in place. In these cases, it is removed, essentially making the procedure a PRK.
Results
Using the epithelial layer as a natural protective dressing can improve healing and reduce the incidence of postoperative haze compared to PRK. While all the tissue is present right after surgery, it takes time to attach to your eye. A smooth, central epithelium is crucial for clear vision. It normally takes three to ten days for the layer to heal and for the cornea to resurface.
Both LASEK and LASIK procedures have their pluses and minuses. After epithelial “E” surgery, recovery takes a few days longer and may involve more postoperative pain than “I” surgery, which, despite a deeper cut, is generally painless. On the other hand, LASEK is less likely to cause dry eyes than LASIK and results in fewer postoperative blurring problems, perhaps because “E” preserves more corneal tissue.
In a blur
Haze is a scar-like material in the cornea caused by the wound reaction of the cornea. The “healing haze” of a cornea usually lasts three to six months. The stronger the recipe being treated, the bigger the problem and the more unpredictable the results. Haze involves the body shedding tissue and thus results in a partial reversal of treatment. It is usually not bad enough to obstruct vision, but can cause glare while driving at night. Even with LASEK, there may be a higher incidence of corneal clouding for patients with a very high degree of nearsightedness (nearsightedness).
Good candidates
“E” surgery is a great option for patients who have previously been rejected for “I” surgery because of thin or unusually shaped corneas or large pupils. It’s also better for people with dry eye syndrome because it cuts such a thin layer that the corneal nerves that control our tear reflex remain undamaged. Laser “E” surgery is relatively new and is only performed by select surgeons for laser vision correction, so candidates should have access to a surgeon experienced in the procedure and equipment.
LASIK vs LASEK – Spelling or Important
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