Subepithelial scarring after laser-assisted subepithelial keratectomy

Abstract

Reply: The decision of whether to perform bilateral, same-session LASEK or a sequentially staged procedure must be made for each individual patient. In recent surveys,1 most responding refractive surgeons in the United States indicated that they perform bilateral, same-session surface ablations. As Kervick appropriately points out, the risks of bilateral surface ablation include but are not limited to bilateral scarring, infection, and bilateral outliers in refractive outcome. These risks must be weighed against problems with anisometropia, depth perception, and time lost from work inherent in performing staged procedures in patients, many of whom may be contact lens intolerant. Identifiable risk factors specific for an increased risk for developing corneal haze after surface ablations include atopy, uncontrolled collagen vascular disease, postoperative exposure to ultraviolet (UV) light, and ablations greater than 100 μm or than 0.18 of the total corneal thickness. Such patients can be treated prophylactically with intraoperative mitomycin-C or postoperatively with autologous serum in addition to an intensive corticosteroid regimen, oral vitamins C and E,2 and UV-blocking sunglasses.3 In the patient whom we described, the 2 identifiable preoperative risk factors for the development of corneal haze were the ablation depth (104 μm and 108 μm) and the ratio of ablation depth to total cornea thickness (greater than 0.21). Our current LASEK surgical protocol would, therefore, use prophylactic intraoperative treatment with mictomycin-C.4 With this prophylactic regimen, we have not observed the development of diffuse, dense, disciform corneal haze with resulting loss of best spectacle-corrected visual acuity in a 1-year follow-up of more than 500 consecutive LASEK patients. However, 1 LASEK patient with −11.0 D of myopia treated with intraoperative mitomycin-C presented with the sudden onset of dense, reticular subepithelial fibrosis that manifested in only 1 eye 18 months postoperatively. The patient had had an uncorrected visual acuity of 20/20 with no corneal haze at 1 year after LASEK. Waiting 2 or 3 months to perform surgery in the contralateral eye would not have identified this or other patients who may go on to develop late-onset postoperative haze. Jay S. Pepose MD, PhD Mujtaba A. Qazi MD Azim M. Mirza MD St. Louis, Missouri, USA