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| Laser Epithelial Keratomileusis, Lasek When I presided a panel at ASCRS in 1999, Massimo Camellin presented the technique for the first time. We gave him the ribbon for the best paper for this original contribution. Lasek is a surgical technique that combines the features of Lasik and PRK. It involves creating a hinged flap, ablating the exposed stroma and repositioning the flap back onto the ablated surface. It offers the advantages of avoiding the flap complications associated with Lasik and decreasing the epithelial healing time and postoperative discomfort after PRK. The new epithelium, which regenerated within 7 days. Postoperative pain appears limited, if any. 1. Indications Patients with a low degree of myopia (< -4 D) who are at particularly lower risk for sub epithelial haze are candidates for Lasek. The main indications for Lasek are thin corneas and professions that predispose the patient to flap trauma (combat sports). Good candidates for Lasek are also patients with previous filtering surgery, patients who are afraid of Lasik, and patients with deep-set eyes. 2. Technique Lasek technique evolved from PRK with alcohol-assisted epithelial removal. Lasek is based on the detachment of the epithelium from the underlying basal membrane via the use of an alcohol solution that softens the epithelium and allows it to be " rolled" back into the flap, which can be repositioned over the cornea following excimer ablation. Epithelial trephination is designed to leave a hinge of about 80° to 100° at the 12 o'clock position. A rotation of about 10° is made to form the incision. Two to three drops of 20% alcohol solution is placed onto the cornea within the marker and left in place for 30 seconds. The area is then dried and thoroughly washed with water and the pre-cut margin lifted with a modified Desmarres spatula. The epithelial flap is gently detached, gathered, and folded up at the 12 o'clock position. Following a traditional PRK treatment, with light smoothing at its conclusion, the epithelial flap is then repositioned with a small spatula. Following the treatment, a soft contact bandage lens is applied for 4 days to keep the flap in place and allow for re-reepithelialization. Lasek appears to offer the advantages of PRK while avoiding its drawbacks. The postoperative regimen mandates bandage contact lens wear for at least the first few days and also include topical treatment with an antibiotic, a corticosteroids, and a nonsteroidal anti-inflammatory drug. Considering the postoperative care requirements of Lasek and its slightly longer operative time compared with PRK, anticipated patient cooperation becomes a key consideration. Although Lasek results in pain in some patients, its use in low myopes has the advantage of minimal scarring and medical complications even if an epithelial defect occurs as in PRK. The main limitation of Lasek is the unpredictable epithelial healing and postoperative pain. Further studies are needed to improve the viability and adherence of the epithelial flap. 3. Advantage Drawback. The mean advantage of Lasek compared to Lasik is the avoidance of flap complications due to the microkeratome. The advantages of Lasek compared with PRK are reduced pain, less infection risk and a somewhat shortened visual recovery time. The drawback is the fact that it is more time causing, that more follow-up visits are necessary and that retreatments are difficult. Lasek after PRK is also difficult. (3) Ref. 1. Laser Epithelial Keratomileusis ( RT Ang, DT Azar. American Academy of Ophthalmology Dallas 2001). 2. Dan Durrie.ASCRS San Diego 2001;Papere presentation 3. Wilson S. Lasek:the next great procedure? Review of Refractive Surgery. November 2001. |
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