LASIK & Refractive Surgery cont.
Photorefractive Keratectomy (PRK)
Photorefractive keratectomy, or PRK, is a laser vision correction procedure that reshapes the cornea to correct mild to moderate conditions of:
- Nearsightedness, or myopia
- Farsightedness, or hyperopia
PRK uses an excimer laser to remove a small amount of the anterior portion, or front, of the cornea to correct refractive errors. Unlike the LASIK procedure, where a flap is created to access the cornea, PRK removes the epithelial, or outer layer, of the cornea so that it can be reshaped with an excimer laser to remove tissue from the surface. This process flattens the cornea and achieves the corneal steepening needed for vision correction.
Advantages of the Photorefractive Keratectomy Procedure
The PRK procedure provides the surgeon with greater control over the location and amount of tissue being removed, which allows patients to enjoy much more accurate results. The PRK method involves gently sculpting the cornea rather than cutting, allowing the surgeon to treat greater degrees of nearsightedness, as well as farsightedness and astigmatism.
Up to 95 percent of patients with a correction of up to -6.00 diopters achieved a vision of 20/40 or better after PRK, with up to 70 percent achieving 20/20.
Some of the advantages of the PRK procedure include:
- Less depth of laser treatment
- Patients with thin corneas are eligible for PRK
- No corneal flap complications
Results of the Photorefractive Keratectomy Procedure
The results of PRK are considered comparable to those of LASIK, although some patients may experience vision of only 20/40, and others may still need glasses or contact lenses after their procedure. PRK does not correct presbyopia, a natural change in the eyes that affects everyone over the age of 40, so patients that need reading glasses will continue to need them after surgery. It is important for patients to maintain realistic expectations in order to be satisfied with the results of PRK.
Refractive Lens Exchange
Refractive lens exchange (RLE), also known as clear lens extraction, or CLE, is a surgical procedure for vision correction that replaces the natural lens of the eye with an intraocular lens, or IOL. Using the same surgical techniques as cataract surgery, the clear lens of the eye is removed and replaced with an IOL to change the focusing power of the eye.
An alternative to laser vision correction, the RLE procedure avoids the need for a corneal modification that is used during the LASIK procedure, and instead uses the same procedures performed in cataract surgery.
Patients who choose to undergo refractive lens exchange have several options when it comes to the type of IOL that will be implanted into the eye. The RLE procedure uses the same IOLs used in cataract surgery and is able to treat all types of visual disorders, including farsightedness, nearsightedness, presbyopia and astigmatism. Patients are provided with a choice of the most advanced premium IOLs which will allow them to see clearly at all distances.
Candidates for Refractive Lens Exchange
Refractive lens exchange is ideal for patients who:
- Want to reduce or eliminate their dependence on glasses or contact lenses
- Are between the ages of 45 and 75 years of age
- Have high myopia, or nearsightedness, high hyperopia, or farsightedness, presbyopia or astigmatism, with or without cataracts
- Have early symptoms of cataracts
- Are poor candidates for LASIK or PRK
- Have no health issues that affect the eyes
Patients with astigmatism can undergo additional correction during their procedure through relaxing incisions in the outer margins of the cornea, known as Limbal Relaxing Incisions. These incisions create a symmetrical cornea and help reduce or even eliminate astigmatism in the eye. There are also IOLs that correct astigmatism to allow these patients to see clearly.
The Refractive Lens Exchange Procedure
The refractive lens exchange procedure is performed on an outpatient basis using the same techniques as those for cataract surgery.
A topical or local anesthesia is applied to the eyes to minimize discomfort during the procedure. Through a tiny incision of 3mm or less, the natural lens of the eye is removed and replaced with an IOL that is inserted through the same opening. Once inserted, the lens is unfolded and moved into its permanent position in the eye. There are no stitches needed as the incision will be able to seal on its own. The refractive lens exchange procedure takes just 20 minutes to perform and offers patients significant and immediate results.