New York-Patients undergoing surface ablation procedures performed using the Epi-K (Moria) for epithelial flap creation had better uncorrected visual acuity (UCVA) and comfort early on when the flap was replaced (epi-LASIK) than when it was removed (advanced surface treatment). However, surface ablation with flap removal may be associated with a benefit of better UCVA at 1 month, according to the results of a prospective clinical trial.
Daniela Jardim, MD, clinical fellow in vision correction surgery, New York Eye and Ear Infirmary, New York, reported the findings.
"The early benefits of epi-LASIK may occur because the replaced flap acts as a bandage contact lens, while the better vision outcomes at 1 month in eyes where the flap was removed may be due to the presence of a more normal epithelial surface," Dr. Jardim said.
All patients enrolled in the study were informed about its study design and purpose and had one eye randomly assigned to surgery with epithelial flap replacement and the other with the flap removed. The LADARVision excimer laser (Alcon Laboratories) was used for all ablations.
Preoperative and postoperative care were the same for all eyes, and the latter included placement of a bandage contact lens, which was removed after 4 to 6 days.
Both the patients and postoperative examiner were masked as to which eye received which surgery.
Follow-up visits were conducted daily until bandage contact lens removal. Outcomes assessed included distance UCVA and patient ratings of pain comparing one eye with the other.
During the first 2 days after surgery, UCVA was comparable in both eyes in 21% of patients, but was better in the epi-LASIK-treated eye in 57%. Pain was rated as the same in both eyes during the first 2 days after surgery by 29% of patients, and 64% of patients considered the epi-LASIK-treated eye to be less painful. By day 3, pain was minimal in all eyes, and during the rest of the early postoperative follow-up, there were no significant differences between treatment groups with regard to UCVA or pain.
At 1 month, half of the patients had better UCVA in the epi-LASIK-treated eye and UCVA was comparable in both eyes in 29% of patients.
Dr. Jardim explained that the purpose of conducting the study was to gather data for addressing contemporary goals of refractive surgery.
"Patients are no longer satisfied with good visual acuity. Now they are demanding fast visual recovery, minimal postoperative pain, and long-term stability," she said.
"Sub-epithelial ablation after epithelial cleavage with a mechanical separator was developed in 2003 as a method that could provide the benefits of LASEK while avoiding the use of alcohol to provide a more vital epithelial layer, which would result in a procedure with less pain and faster recovery," Dr. Jardim continued.
She noted that the design of the Epi-K is based on the One Use Plus disposable microkeratome.
Its features include one-handed operation, excellent visibility, dual motors for independent oscillation and translation, and a simple, adjustable stop mechanism. In addition, its metal suction ring has a small horizontal diameter, which enhances patient comfort, and with its disposable head, the Epi-K minimizes risk of separator damage during insertion.
"This is a more important issue for an epikeratome than for a microkeratome that uses a sharp blade. Precision machining of the metal blade used in the Epi-K produces a uniformly and reproducibly blunt edge," Dr. Jardim said.