Millennium Laser Eye Centers also offers PRK/LASEK to patients that are better candidates for this type of technology.
In this process, the surgeon first removes the surface cells of the cornea, and then an excimer laser is used to sculpt the underlying tissue. The surface cells regenerate over the course of 48-72 hours under a contact lens bandage. To use an analogy, the cornea is a 400-page book with a fifty-page thick cover on either side, the cover is discarded and the first few pages of the book are removed. The next 4-7 days following the procedure, the cover then grows back.
For some patients who have thinner corneas LASIK is not an option. As mentioned previously, the sculpting of the cornea in LASIK takes place following the creation of a corneal flap. If the cornea is not thick enough to make this flap, remove the requisite amount of tissue and still leave enough tissue behind to maintain the structural integrity of the cornea, the patient must seek alternative means of vision correction like LASEK or PRK.
The patient will not feel discomfort during this procedure. Following the procedure, expect a gritty sensation with some mild to moderate irritation in the first few days, which will improve with time. Not all patients experience significant discomfort since topical analgesics (Advil-like drops) and a contact lens bandage are used as the surface layer fills in to cover the exposed corneal nerve endings. Numbing drops are provided during the first 24 hours in the event of severe irritation. All discomfort should be completely resolved within 2-3 days, except in the rarest of cases.
LASEK, pronounced lay-SEK, is a variant of the original excimer laser vision correction procedure called photo-refractive keratectomy (PRK); the procedure first approved for simple myopia by the FDA in 1995. It differs from LASIK in that no flap is created and that the sculpting of the corneal tissue which results in visual improvement is delivered in its more superficial layers. Visual recovery is similar to PRK and is not as rapid as that which occurs with LASIK, taking 3-7 days in comparison with the typical 24 hour recovery with LASIK.
Because of the rich innervation of the cornea, marked discomfort occurs whenever the cornea has a break in its surface layer. However, since the protective surface layer of the cornea, called the epithelium, grows back when disrupted, it must be removed to deliver the corrective laser treatment. It then takes anywhere between two and four days for this re-growth of the epithelium to occur.
LASEK differs from PRK only in its handling of the epithelium. In PRK, the epithelium can be removed by multiple methods, one including a rotary brush. In LASEK, an attempt is made to preserve the epithelium. To perform LASEK a metallic ring with a semi-sharp edge for 300¡ is used to cookie cut a “hinged flap” of epithelium while simultaneously creating a well for a dilute alcohol preparation that softens the epithelium’s attachment to the underlying tissue. An instrument is then used to peel back the epithelium, the laser treatment is delivered, and the epithelium in replaced. A bandage contact is inserted to protect the loose tissue and it heals back in place and smooths out over a period of days to weeks.