Laser epithelial keratomileusis for the treatment of low to moderate myopia: preliminary results

PURPOSE: To analyze the refractive outcome and the postoperative pain and corneal haze following laser epithelial keratomileusis (LASEK) for the treatment of low to moderate myopia. METHODS: A monocentric prospective noncomparative study was started in June 2000, after informed consent was obtained from patients with a spherical equivalent of less than -5 diopters (D). This study actually was part of another prospective comparative study where the contralateral eye underwent photorefractive keratectomy. An epithelial debridement was performed using diluted ethanol, the epithelial flap was lifted, photoablation was performed, the flap was put back in place, and secured by a bandage contact lens. The refractive outcome was assessed, and postoperative pain and haze were graded using an analogical visual scale from 0 to 10 and a scale of 0 to 4, respectively. RESULTS: We included 17 eyes of 16 patients. LASEK was performed successfully in 15 eyes (88.2%). One of these eyes could not be assessed for the refractive outcome and postoperative haze because the epithelial flap was torn during contact lens removal. The mean postoperative pain level during the night following the procedure was 5.7+/-2.0. The mean preoperative spherical equivalent (SE) was -2.5+/-1.0 D, and after a 2-month follow-up, the mean postoperative SE was +0.26+/-0.6 D. Twelve eyes (85.7%) and 10 eyes (71.4%) were within +/-1.0 D and +/-0.5 D from the attempted correction, respectively. The corneal haze grade was less than 1 in 12 eyes (85.7%) and equal to 1 in two eyes (14.3%). No complications and no loss of postoperative best-corrected visual acuity were noted. CONCLUSIONS: LASEK appears to be a reliable and reproducible technique for the treatment of myopia-associated SE of less than -5 D. Postoperative pain is moderate and flap-related complications of LASIK are avoided.     

Laser epithelial keratomileusis for myopia

PURPOSE: To describe a new technique for excimer laser corneal surgery: laser epithelial keratomileusis (LASEK). METHODS: We report 76 eyes with spherical equivalent refractive myopia ranging from -8.00 to -22.00 D (mean -11.00 +/- 3.00 D). Using ethanol applied over an 8.5-mm-diameter area for 20 seconds, the epithelium was detached and photorefractive keratectomy (PRK) was performed. The epithelium was reapplied to the ocular surface and covered with a therapeutic soft contact lens. Treatments were carried out with the Nidek EC-5000 excimer laser. RESULTS: At a mean of 803 days after LASEK, mean spherical equivalent refraction was -1.80 +/- 2.40 D (range -9.27 to +2.00 D). Stability was reached in approximately 60 days. Fifty-nine percent of the epithelial flaps were easy to detach intact during surgery and 62.7% of patients reported no postoperative pain. Eighty-four percent of eyes had the therapeutic bandage lens removed by the fourth postoperative day. Twelve percent of eyes had incomplete epithelial flap removal. Epithelium can fall off the cornea during the healing phase. No significant subepithelial haze was seen in 95% of eyes. CONCLUSION: With LASEK, it may be possible to treat a larger diameter ablation zone in thinner corneas without the problems of a LASIK stromal flap and with less postoperative pain than PRK, with minimal subepithelial haze.     

Laser subepithelial keratomileusis for low to moderate myopia: 6-month follow-up

PURPOSE: To examine the effectiveness, safety, and stability of laser subepithelial keratomileusis (LASEK), a modified photorefractive keratectomy for low to moderate myopia. METHODS: This study evaluated the results of LASEK in 48 myopic patients (84 eyes) with a consecutive 6-month follow-up period. Preoperative myopia ranged from 3.25 to 7.00 diopters (D). Uncorrected and corrected visual acuity, manifest refraction, epithelial healing time, postoperative pain, subepithelial corneal haze, and complications were examined. RESULTS: Uncorrected visual acuity of 20/30 or better was achieved in 78.6% of eyes at 1 week and in 96.4% at 6 months after surgery. A mean refraction of within +/-0.50 D was measured in 42 eyes (50.0%) and +/-1.0 D in 79 eyes (94.0%) at 6 months. The epithelial healing time was 3.68 +/- 0.69 days (range, 3-6 days) and postoperative pain scores were 1.49 +/- 0.65. The subepithelial corneal haze scores were 0.56 +/- 0.34 and 0.16 +/- 0.25 at 1 and 6 months, respectively. As for complications, alcohol leakage during surgery occurred in 3 eyes, incomplete epithelial detachment in 3 eyes, contact lens intolerance in 5 eyes and steroid-induced elevated intraocular pressure (>21 mm Hg) in 1 eye. CONCLUSIONS: LASEK is an effective and safe procedure for low to moderate myopia. It can be considered an alternate type of refractive surgery for correction of low to moderate myopia.     

Early clinical results of laser epithelial keratomileusis

PURPOSE: To evaluate the efficacy of laser epithelial keratomileusis (LASEK). SUBJECTS AND METHOD: LASEK was performed on 82 eyes of 42 patients whose spherical refraction ranged from -0.75 to -12.00 D (mean, -6.09 D) and cylindrical refraction ranged from 0 to -5.00 D (mean, -0.95 D). LASEK is a method of making a epithelial flap using 20% ethanol and repositioning the flap after excimer laser ablation. The clinical results of postoperative refraction and complications were examined. RESULTS: At 1 week and 1 month after the operation, 69 eyes(84.1%) and 79 eyes(96.3%) achieved an uncorrected visual acuity of 20/20 or better. At 1 week and 1, 3 months after the operation, the mean spherical refraction was +0.09 +/- 0.49(mean +/- standard deviation) D, +0.29 +/- 0.47 D, +0.13 +/- 0.46 D. At 1 month 65 eyes (79.3%) were within +/- 0.5 D and 78 eyes(95.1%) were within +/- 1.0 D. 51 eyes (62.2%) had the complication of corneal haze. CONCLUSION: LASEK achieved good uncorrected visual acuity, but there were some complications such as postoperative pain, the delayed recovery of visual acuity, and corneal haze, so that a long and careful follow-up seems necessary.     

激光角膜上皮瓣下磨镶术和激光原位角膜磨镶术治疗中高度近视的对比研究

目的比较激光角膜瓣下磨镶术(LASEK)和激光原位角膜磨镶术(LASIK)治疗中高度近视的临床效果. 方法中高度近视患者198例(394只眼).其中LASEK手术治疗93例(184只眼), LASIK手术治疗105例(210只眼). 结果术后1天,LASIK 组28 %裸眼视力达到1.0,LASEK组无1例裸眼视力达到1.0.术后1周、1、3、6月裸眼视力大于或等于1.0者,两组比较差异无显著性 (P=0.36,P=0.58,P=0.44,P=0.64).角膜地形图分析平均角膜中央屈光力与周边屈光力的差异,LASEK组(0.69)明显小于LASIK组(2.62).结论 LASEK手术矫正中高度近视均有良好的治疗效果,是一种安全、有效、预测性好的屈光手术.     

LASEK和Epi-LASIK术中去除上皮瓣治疗中低度近视疗效对比

目的比较准分子激光上皮瓣下角膜磨镶术(LASEK)和机械法准分子激光上皮瓣下角膜磨镶术(Epi-LASIK)术中去除上皮瓣治疗中低度近视的临床效果。方法将78例患者(-1.50～-6.00D)152眼随机分为A组和B组:A组行去上皮瓣的LASEK,B组行去上皮瓣Epi-LASIK。观察术后眼球疼痛刺激症状、角膜上皮愈合情况,比较2组术后1个月、3个月、6个月裸眼视力及术后6个月haze情况。结果 A、B两组术后3d眼球疼痛刺激症状0、1、2、3级例数比较,差异均无统计学意义(χ2=3.69、0.00、0.00,均为P>0.05)。A组角膜上皮平均愈合时间为(3.81±0.07)d,B组平均为(4.15±0.12)d,2组比较差异有统计学意义(t=2.42,P<0.05)。术后1个月、3个月、6个月2组裸眼视力和术后6个月haze比较差异也均无统计学意义(均为P>0.05)。结论 LASEK去除上皮瓣矫正中低度近视与Epi-LASIK去除上皮瓣矫正中低度近视相比,角膜上皮愈合更快,而术后视力恢复和haze的形成无明显差异,更具有临床应用价值。     

Laser-assisted subepithelial keratectomy enhancement of residual myopia after primary myopic LASEK: six-month results in 10 eyes

PURPOSE: To determine whether residual myopia after primary laser-assisted subepithelial keratectomy (LASEK) can be corrected by repeated LASEK and whether this procedure is safe and effective. SETTING: University Eye Clinic, University of Regensburg, Regensburg, Germany. METHODS: Laser-assisted subepithelial keratectomy was performed in 10 eyes that had had primary LASEK for myopia. The initial mean spherical equivalent (SE) was -6.2 diopters (D) (range -2.5 to -8.0 D), and the residual mean SE was -1.6 D (range -1.0 to -3.0 D). The retreatment ratio was 7.6%. The exposure time of the corneal epithelium to alcohol (20% ethanol) was 30 seconds plus an additional 10 to 15 seconds in cases of strong epithelial adherence. Laser ablation was performed with a Keracor 117 excimer laser (Chiron Technolas). The follow-up after the second LASEK treatment was 6 months. RESULTS: The epithelial flap for repeated LASEK was successfully created in all 10 eyes. The postoperative course in the eyes was uneventful. Six months after LASEK enhancement, the SE refraction was within +/-0.5 D in all eyes. No eye lost more than 1 line of best corrected visual acuity, and the uncorrected visual acuity was 20/20 or better in 8 eyes. Significant haze was not observed after repeated LASEK (mean 0.35 before and 6 months after LASEK enhancement). CONCLUSIONS: Laser-assisted subepithelial keratectomy enhancement appears to be safe and effective for the correction of residual myopia after primary LASEK. Repeated epithelial flap preparation is possible without technical modifications.     

Early clinical results of laser epithelial keratomileusis

PurposeTo evaluate the efficacy of laser epithelial keratomileusis (LASEK).Subjects and methodLASEK was performed on 82 eyes of 42 patients whose spherical refraction ranged from −0.75 to −12.00 D (mean, −6.09 D) and cylindrical refraction ranged from 0 to −5.00 D (mean, −0.95 D). LASEK is a method of making an epithelial flap using 20% ethanol and repositioning the flap after excimer laser ablation. The clinical results of postoperative refraction and complications were examined.ResultsAt 1 week and 1 month after the operation, 69 eyes (84.1%) and 79 eyes (96.3%) achieved an uncorrected visual acuity of 20/20 or better. At 1 week and 1 and 3 months after the operation, the mean spherical refraction was +0.09±0.49 (mean±standard deviation) D, +0.29±0.47 D, +0.13±0.46 D, At 1 month 65 eyes (79.3%) were within ±0.5 D and 78 eyes (95.1%) were within ±1.0 D; 51 eyes (62.2%) had the complication of corneal haze.ConclusionLASEK achieved good uncorrected visual acuity, but there were some complications such as postoperative pain, the delayed recovery of visual acuity, and corneal haze, so that a long and careful follow-up seems necessary.     

机械法准分子激光角膜上皮瓣下磨镶术矫治高度近视

目的　研究机械法准分子激光角膜上皮瓣下磨镶术 (Epi LASIK)矫治高度近视的手术特点和临床疗效。方法　采用自动旋转型Epi LASIK角膜上皮刀制作上皮瓣,以ZeissMel 80准分子激光仪进行激光切削,术后配戴绷带式角膜接触镜 3 ~5d,术后随访时间 3 ~6个月,研究术后症状、角膜上皮瓣愈合特点、视觉质量及Haze形成情况。结果　共有 30例 (52只眼 )高度近视患者接受Epi LASIK手术,其中病理性近视 36只眼,单纯性高度近视 16只眼。平均等效球镜为 ( -12 82±4 38)D。49只眼制作完好的上皮瓣,直径为 8~9mm,上皮瓣蒂均位于上方。1只眼上皮瓣包含部分基质组织, 2只眼上皮瓣游离。术后 1d检查,上皮瓣基本透明 36只眼,轻度水肿 15只眼, 1只眼角膜上皮瓣中度水肿。取角膜接触镜时, 50只眼角膜上皮愈合完好。4只眼术后有中度刺激症状,其余患者有轻度刺激症状,持续 2d。术后 3个月, 44只眼 ( 84 61% )术后屈光度数在预期值的±1 00D内,未见最佳矫正视力下降, 10只眼( 19 23% )最佳矫正视力提高 1行或 2行。术后 3个月, 8只眼(15 38% )角膜Haze0 5级, 2只眼 (3 84% )Haze1级,其余患者角膜透明。随访 6个月的 28只眼,角膜Haze0 5级 3只眼,其余患者角膜透明。术后 1个月对比敏感度下降,术后 3个月逐渐恢复,术后高阶像差较术     

Laser-assisted subepithelial keratectomy for myopia: two-year follow-up

PURPOSE: To assess and compare the clinical results (efficacy, safety, stability, and postoperative pain or discomfort) of laser-assisted subepithelial keratectomy (LASEK) and conventional photorefractive keratectomy (PRK) for the correction of low to moderate myopia. SETTING: Department of Ophthalmology, Masaryk University Hospital, Brno, Czech Republic. METHODS: A prospective comparative study was performed in 184 eyes of 92 patients who had surface excimer ablation for the correction of myopia. The preoperative mean spherical equivalent (MSE) was -4.65 diopters (D) +/- 3.14 (SD) (range -1.75 to -7.50 D). In each patient, LASEK was performed in 1 eye and PRK in the fellow eye by the same surgeon. The first eye treated and the surgical method used in the first eye were randomized. Both procedures were performed with the Nidek EC-5000 excimer laser using the same parameters and nomogram. The postoperative pain level, visual recovery, complications (haze), uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and refractive outcome were evaluated and compared. All eyes completed a 24-month follow-up. RESULTS: The postoperative MSE was -0.18 +/- 0.53 D in the PRK eyes and -0.33 +/- 0.46 D in the LASEK eyes. At 1 week, the mean UCVA was 0.64 +/- 0.21 and 0.87 +/- 0.23, respectively. No LASEK eye lost a line of BSCVA. There were no statistically significant differences between PRK and LASEK eyes in the safety and efficacy indices at 2 years. The mean pain level was significantly lower on days 1 to 3 in the LASEK eyes (P <.05). The mean corneal haze level was lower in the LASEK eyes (0.21) than in the PRK eyes (0.43) (P <.05). Seventy-nine patients preferred LASEK to PRK. CONCLUSIONS: Laser-assisted subepithelial keratectomy provided significantly quicker visual recovery, eliminated post-PRK pain, and reduced the haze level in eyes with low to moderate myopia compared with conventional PRK. It provided good visual and refractive outcomes. There were no serious complications.     

Laser subepithelial keratomileusis for myopia of -6 to -10 diopters with astigmatism with the MEL60 laser

PURPOSE: To evaluate the efficacy, predictability, and safety of laser subepithelial keratomileusis (LASEK) for treatment of high myopia with astigmatism. METHODS: LASEK was performed in 61 eyes of 36 consecutive patients with myopic spherical equivalent refraction of -6.00 to -10.00 D using the Aesculap-Meditec MEL60 excimer laser. Data were collected prospectively with a follow-up of 6 to 17 months. Main outcome measures recorded were UCVA, BSCVA, residual refractive error, corneal haze, and complications. RESULTS: Ninety-six percent of eyes achieved 20/40 or better UCVA at 1 month. At 12 months, 64% of eyes achieved 20/20 and 92% achieved 20/40 or better UCVA. Two eyes lost 2 lines of BSCVA at 6 or 12 months. Accuracy of correction was +/- 0.50 D from emmetropia in 82% of eyes, and +/- 1.00 D in 90% at 12 months. No eye showed more than grade 1 haze. Grade 1 haze was observed in three eyes at 12 months. One patient had mild postoperative keratitis, which was successfully treated. CONCLUSIONS: LASEK with the Aesculap-Meditec MEL60 excimer laser appeared to be safe, effective, and highly predictable in treating high myopia.     

替代PRK和LASIK的激光角膜上皮磨削術(LASEK)

Objective To introduce and compare the one year' s result of LASEK (Laser Epithelial Keratomileusis) as an alternative to concurrent PRK and LASIK procedures for myopia. Methods This retrospective clinical study comprised operative and postoperative notes of consecutive 16 myopic patients (27 eyes, M:F=9:18) who had receied LASEK procedures with at least one year or more follow-up (12～18 months). And we comparved the LASEK with other surgeries such as PRK and LASEK in view-point of surgical advantages, visual improvement, and post-operative. complications such as corneal haziness, etc. Results We divided two groups of myopic patients according to the degrees of myopia (group 1 (N=14 eyes)-2.5D.～-6.00D.) and group 2 (N=13 eyes); -6.25D. ～-10.25D.). Through the LASEK procedure, surgical tension was surely less than that of LASIK which has always a possible complications concerned directly with a microkeratome. One week after LASEK, post-operative. Refractive powers and uncorrected visual improvement showed up to near normal ranges in all 27 eye cases. But In post-operative, corneal haziness, only trace-degree (0.5) was noted in one eye case of high myopic group. As other complications, we observed a failed case of epithelial flap making with a case of T-lens related central epithelial defect and a case of tight lens syndrome. Conclusion LASEK is to be the most safe and effective excimer laser refractive surgery as an alternative procedure of PRK and LASIK. LASEK has also an advantageous choice in high myopic cases having thin cornea, or narrow interpalpebral fissure or deep sunken eyeball etc.     

LASEK (laser subepithelial keratomileusis)

Laser subepithelial keratomileusis (LASEK) is a relatively new refractive surgical technique that purportedly combines the advantages of laser in-situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). Like LASIK, on the one hand, it employs a "flap" and consequently has the advantages of faster visual recovery, less postoperative pain, reduced stromal haze, and faster epithelial healing than PRK. Like PRK, on the other hand, because the procedure is performed on the anterior cornea, there are virtually no flap- or interface-related complications per se. It may thus be safer for patients who are at an inherently higher risk of developing flap complications, such as those with small palpebral fissures, deep-set eyes, corneal basement membrane dystrophy, and extremely steep or flat corneas. Furthermore, it conserves precious stroma in eyes with thin corneas or high myopia, which otherwise may not qualify for LASIK. It may also be more apropos for patients whose jobs or recreational activities put them at a higher risk of corneal trauma. In a very timely fashion, for reasons discussed below, LASEK may also prove to be superior to LASIK in customized ablations.     

Traumatic epithelial flap detachment after laser subepithelial keratomileusis

PURPOSE: To report a case of corneal epithelial flap detachment 20 days after laser subepithelial keratomileusis (LASEK). METHODS: A 30-year-old man underwent LASEK for correction of myopia. On postoperative day 8, he was comfortable and the corneal epithelium healed completely with uncorrected visual acuity (UCVA) of 20/20. On postoperative day 20, the corneal epithelial flap on the right eye detached and was lost during pressure patching after puncture of the hordeolum. RESULTS: The corneal defect was treated with a bandage contact lens, levofloxacin, and hyaluronic acid eye drops. Ten days after detachment, UCVA had improved to 20/20 and the epithelium had closed completely. CONCLUSIONS: Mild trauma can cause epithelial flap detachment during the early postoperative period of LASEK.     

Laser subepithelial keratomileusis for the correction of high myopia with the Schwind ESIRIS scanning spot laser

PURPOSE: To investigate the efficacy of laser subepithelial keratomileusis (LASEK) for the correction of high myopia with the Schwind ESIRIS scanning spot laser (Schwind eye-tech-solutions Gmbh & Co, Kleinostheim, Germany). METHODS: Fifty-one patients (76 eyes) were treated with a mean preoperative spherical equivalent refraction of -7.55 diopters (D) (range: -6.0 to -10.75 D). All eyes received a LASEK technique using 15% alcohol with a 20-second application. RESULTS: An intact epithelial flap was obtained in 73 (96%) eyes. At 1 week, uncorrected visual acuity (UCVA) was > or =20/30 in 53 (70%) eyes and > or =20/60 in all eyes. At 6 months (n=76), the mean SE was +0.08 D (range: -1.00 to +1.875 D) with 73 (96%) eyes within +/-1.0 D of the intended correction and 60 (79%) eyes within +/-0.5 D. At 12 months (n=46), the mean SE was -0.07 D (range: -1.375 to +2.0 D) with 44 (96%) eyes within +/-1.0 D of the intended correction and 37 (80%) eyes within +/-0.5 D. Myopic cylindrical corrections were attempted in 68 eyes (range: -0.25 to -4.25 D) with vector analysis demonstrating a mean 85% correction. At last follow-up, UCVA was > or =20/20 in 47 (62%) eyes, > or =20/25 in 63 (83%) eyes, and > or =20/40 in 75 (99%) eyes. Three (4%) eyes gained two lines of Snellen decimal equivalent best spectacle-corrected visual acuity compared to preoperative levels, 68 (89%) eyes showed no change or gained one line, and 5 (7%) eyes lost one line. None lost more than one line. Only 2 (3%) eyes at 6 to 12 months had more than +1 axial corneal haze and 50 (66%) showed no evidence of haze on slit-lamp examination. CONCLUSIONS: Laser subepithelial keratomileusis for myopia up to -11.00 D with the Schwind ESIRIS laser provides good refractive and visual outcomes, with acceptable visual recovery and minimal complications.     

Comparison of silicone and non-silicone hydrogel soft contact lenses used as a bandage after LASEK

PURPOSE: To evaluate two different soft contact lens materials for continuous-wear bandage contact lenses after laser epithelial keratomileusis (LASEK). METHODS: A prospective, observer-masked study was conducted of 32 eyes of 16 consecutive patients. Inclusion criteria were candidates for bilateral LASEK, myopia of < or = -6.00 diopters (D), astigmatism < -1.50 D, and bilateral best spectacle-corrected visual acuity of 20/20 or better. Patients were randomly selected for a balafilcon A (PureVision; Bausch & Lomb) bandage contact lens in one eye and a poly-2-hydroxyethylmethacrylate-co-methacrylate glycerol (EquiS 60; mark'ennovy) in the fellow eye. Corneal epithelial status, conjunctival and limbal hyperemia, lens movement, contact lens debris, and the responses to a subjective comfort questionnaire were assessed postoperatively. The parameters were evaluated preoperatively and 1 and 5 days postoperatively. Paired Student t test and chi-square tests were used when appropriate. RESULTS: Thirty-two eyes of 16 consecutive patients who underwent LASEK to correct low to moderate myopia were analyzed. The mean spherical equivalent refraction was -3.25 D. There was no difference in conjunctival or limbal hyperemia, contact lens debris, or subjective comfort between lenses at any postoperative visit. In contrast, the corneal epithelial status was statistically better in the eyes with a silicone bandage contact lens 5 days after LASEK (P = .01). CONCLUSIONS: The results suggest that the bandage contact lens material used after LASEK affects the corneal epithelial healing process.     

Comparison of laser epithelial keratomileusis and photorefractive keratectomy for low to moderate myopia

PURPOSE: To compare the effectiveness, safety, and stability of laser epithelial keratomileusis (LASEK), a modified photorefractive keratectomy (PRK) technique, with those of conventional PRK for low to moderate myopia. SETTING: Department of Ophthalmology, Yonsei University School of Medicine, Seoul, Korea. METHODS: In this prospective study, 27 patients with a manifest refraction of -3.00 to -6.50 diopters were treated and followed for 3 months. In each case, PRK was performed in 1 eye and LASEK in the other eye. The first eye treated and the surgical method used in the first eye were randomized. Postoperative pain, epithelial healing time, uncorrected visual acuity (UCVA), manifest refraction, corneal haze, and surgical preference were examined in PRK- and LASEK-treated eyes. RESULTS: During the 3 month follow-up, there were no significant between-eye differences in epithelial healing time, UCVA, or refractive error. However, LASEK-treated eyes had lower postoperative pain scores (P =.047) and corneal haze scores (1 month; P =.02) than PRK-treated eyes. Seventeen patients (63%) preferred the LASEK procedure. CONCLUSIONS: Laser epithelial keratomileusis safely and effectively treated eyes with low to moderate myopia. It reduced the incidence of significant postoperative pain and corneal haze and may prevent the flap- and interface-related problems of laser in situ keratomileusis.     

Laser-assisted subepithelial keratectomy (LASEK) without alcohol versus photorefractive keratectomy (PRK)

PURPOSE: To evaluate epithelial healing and visual outcome after laser-assisted subepithelial keratectomy (LASEK) without alcohol de-epithelialization and to compare this technique to photorefractive keratectomy (PRK) in myopia. METHODS: In a series of 1953 patients undergoing bilateral myopic PRK, an epithelial flap could be obtained by manual de-epithelialization in the left eye of 56 patients without alcohol exposure. The right eye was treated by PRK and the left by LASEK (i.e., repositioning the viable flap after surface ablation). The two eyes were compared in terms of pain, uncorrected visual acuity (UCVA) in decimals, correction achieved, and haze. The epithelial healing pattern was assessed in the LASEK eyes. RESULTS: The flap remained viable, showing a peripheral junction, in 25 eyes (45%). Pain was higher in the PRK eye in 11/56 patients (20%), higher in the LASEK eye in 23/56 patients (41%), and the same in both eyes in 22/56 patients (39%). UCVA at one week was slightly better in the LASEK eyes (median 0.7 versus 0.6, p = 0.002 with Wilcoxon test), but was the same in PRK and LASEK eyes after 1 month (median 0.9 in both). Median haze at 6 months was 0.5 in the PRK eyes and 0 in the LASEK eyes (Wilcoxon p = 0.007). Median postoperative defocus equivalent at 9 months was 0.5 diopters in both the PRK and the LASEK eyes. CONCLUSIONS: Although our study might have selected patients with loose epithelium, LASEK performed by manual de-epithelialization in the absence of alcohol exposure is not less painful than PRK, even in case of flap survival. Visual recovery speed, as well as haze, is slightly better than in PRK, although the difference is clinically negligible.     

准分子激光原位角膜磨镶术和准分子激光上皮下磨镶术矫正高度近视的视觉质量对比研究

目的 从视觉质量的角度评价准分子激光原位角膜磨镶术（LASIK）和准分子激光上皮下磨镶术（LASEK）矫正高度近视的疗效。方法对34人（68眼）进行LASIK或LASEK手术的高度近视患者（其中LASEK19人38眼，LASIK组15人30眼）术前，术后1月和术后3月时评价视觉质量，包括术后裸眼视力（UCVA），最佳矫正视组（BCVA组），对比敏感度，眩光和波前像差。结果 LASEK组UCVA提高较LASIK组慢。LASEK和LASIK的术后IN2VA无差异。LASEK组术后的对比敏感度无下降；眩光在术后1月时下降，术后3月时恢复至术前水平。LASIK组术后1月时对比敏感度和眩光均明显下降，术后3月时对比敏感度恢复但眩光仍未恢复至术前水平。LASEK组和LASIK组术后1月和3月的高阶像差RMS均较术前大，但前者比后者小。LASEK组有一定的haze发生，但程度轻。结论 LASEK矫正高度近视能获得更好的视觉质量，关键在于如何更好的保留上皮瓣的活力。     

准分子激光上皮下角膜磨镶术治疗中高度近视的效果分析

目的探讨准分子激光上皮下角膜磨镶术（LASEK）治疗中高度近视的疗效。方法40例（79眼）行LASEK,屈光度-3．50D～-15．00D,平均-8．50D;随访6个月,观察早期眼部症状、视力、眼压、屈光状态、雾状角膜浑浊（haze）程度及屈光回退等情况。结果LASEK术后早期眼部刺激症状较重;术后角膜上皮愈合时间为3～7d,平均为5d;术后2周裸眼视力（UCVA）〉0．5者71眼（89．87％）,术后6个月UCVA等于或优于术前最佳矫正视力（BCVA）者74眼（93．67％）;术后6个月发生（haze）：0级76眼（96．20％）;0．5级2眼（2．53％）;2级1眼（1．27％）;无1级及2级以上haze。结论LASEK治疗中高度近视有一定的疗效,但手术后早期跟部刺激症状重,视力恢复慢,haze和屈光回退有待观察与研究。