Refractive Surgery Part Two
“What to expect with the different procedures”
Jordan Jangula, O.D.
Taking all of this into consideration then brings us to the two most common types of refractive surgery–LASIK and PRK. In LASIK, a flap of the cornea is created and lifted up; corneal tissue is then removed with a laser. The corneal flap is then replaced over the area of ablated (removed) tissue. Although the flap has been replaced at this point, the flap tissue is still considered affected by the surgery, and is therefore not as structurally stable as it was prior to surgery.
In PRK, only the surface layer, or epithelial layer, of the cornea is removed, rather than a flap being lifted up, and the cornea tissue is removed from a more anterior location. This allows less tissue to be affected in comparison to LASIK. For this reason, patients with thin corneas, and/or patients with corneal structures slightly deviated from the norm, receive PRK rather than LASIK. Since there is not a flap to replace over the ablated area of tissue, patients who have PRK are more uncomfortable and have blurrier vision during the healing process than patients who have LASIK. A contact lens is placed over the cornea in patients who have PRK, and is worn until the surface layer of the cornea regenerates, which takes an average of three to five days. Once the contact lens is able to be removed, the eye is generally feeling much better; vision, however, will still not be fully improved and may take a couple weeks to gain full clarity. For this reason, LASIK is preferred to PRK if it has been deemed safe to perform. There are cases in which PRK may be preferred over LASIK, including those that involve patients who are subject to impact, such as military members, MMA athletes, wrestlers etc.
Once a patient is determined to be a good candidate for either LASIK or PRK, she can then proceed with surgery if she desires. On the day of surgery, it is very normal to be nervous, and for this reason, patients are given something to calm their nerves such as Xanax or Valium. The patient will meet with the surgeon before being brought into the surgery suite. LASIK and PRK are very similar in how they are performed with the exception that there is no flap creation in PRK. For the patient, the perceived difference is very small. In both procedures no pain is felt by the patient.
During the flap creation in LASIK, a suction ring is placed on the eye; this causes the pressure inside the eye to increase to a point that results in the vision going dim to dark. This dimming of vision can last up to a minute. Once the flap is created, the surgeon lifts it up and then aligns the laser that will ablate the tissue to correct the prescription. During the ablation, the patient will hear a sound similar to clicking and may smell the gas from the laser. Once the correction is complete, the flap is placed back into position and the other eye is treated. When the surgery is complete, the patient is allowed to relax for a few minutes, and is then re-examined to make sure the flap is still in place. Usually, the flap seals down naturally and very quickly.
In PRK, as previously stated, there is no flap creation; therefore, the patient does not experience a dimming of vision. The rest of the procedure is perceived to be similar to the description stated above for LASIK, with the additional exception that instead of the flap being replaced, a contact lens is placed on the eye.
Once the final checks are done, the patient can go home and sleep. Some surgeons desire that their LASIK patients do not sleep after the procedure. This decision will be made by the surgeon. Immediately after the surgery, vision will be blurry for both LASIK and PRK patients, and once the numbing drops from the surgery wear off, their eyes will be irritated. For LASIK patients, the irritation and blurry vision generally start to make drastic improvements around six hours after the surgery. Vision and comfort may not be perfect when the patient goes to bed that night, but it will be greatly improved. For PRK patients, the vision and comfort will not start to improve significantly until about the third day. Therefore, measures such as lubricating eye drops, eye drops for pain, and oral pain medications may be used in addition to the routine eye drops.
The routine eye drop regimen consists of an antibiotic to prevent an infection, and a steroid to reduce and eliminate the swelling caused by the surgery. The exact antibiotic and steroid prescribed, as well as the dosage and duration, may differ among surgeons. A copious amount of artificial tears should be used to assist in improving patient comfort, as well as to combat the dryness that results from the surgery. If dryness is significant, other measures such as Restasis and punctal plugs may be used.
There is then a series of follow up appointments the patient will be required to fulfill. These office visits may be done at the patient’s primary optometrist’s office or at the surgeon’s office. A general follow-up schedule is one day, one week, one month and three months after the surgery for LASIK. There may be additional office visits with PRK as the healing process takes longer. Once these are completed, the patient is then expected to have routine eye exams to monitor the health of the entire eye, as well as to check for any potential complications from the surgery.
The process of refractive surgery is very involved and progresses over several months. Once completed however, due to the high success rate, patients are almost always more satisfied with the result than they anticipated. The liberation that comes from not having to wear glasses and contacts can only be fully appreciated by a patient who was, but is no longer, dependant on corrective lenses.