Laser-assisted subepithelial keratectomy and photorefractive keratectomy versus conventional treatment of myopic anisometropic amblyopia in children

PURPOSE: To evaluate the visual and refractive results of photorefractive keratectomy (PRK) and laser-assisted subepithelial keratectomy (LASEK) for high myopic anisometropia with amblyopia and contact lens (CL) intolerance in children. Setting: Department of Ophthalmology, Masaryk University Hospital, Brno, Czech Republic. METHODS: This prospective comparative study comprised 27 children with high myopic anisometropia and amblyopia. The mean age of the children was 5.4 years (range 4 to 7 years). Multizonal PRK (13 eyes) or LASEK (14 eyes) was performed in the more myopic eye under general anesthesia using the Nidek EC-5000 excimer laser. After surgery, the dominant eye was patched. The postoperative visual and refractive outcomes were analyzed; all children had a 2-year follow-up. The 27 children (Group A) were compared with a control group of 30 children (mean age 5.1 years) (Group B) in whom myopic anisometropia and amblyopia were treated conventionally by CLs and patching the dominant eye. The visual acuity and binocular vision outcomes in both groups were analyzed and compared. RESULTS: In Group A, the mean spherical equivalent refraction was -8.25 diopters (D) +/- 2.37 (SD) (range -6.00 to -11.25 D) preoperatively and -1.61 +/- 0.73 D (range +0.50 to -2.25 D) postoperatively. The mean best corrected visual acuity (BCVA) was 0.23 +/- 0.21 preoperatively and 0.78 +/- 0.19 at 2 years. In Group B, the mean BCVA was 0.16 +/- 0.19 at the start of CL correction and amblyopia therapy and improved to 0.42 +/- 0.15 after 2 years. The mean BCVA at the final examination was significantly better in Group A (P<.05). Binocular vision improvement expressed by the proportion of patients who gained fusion and stereopsis was better overall in Group A (78%) than in Group B (33%) (P<.05). There were no complications postoperatively. CONCLUSIONS: Photorefractive keratectomy and LASEK were effective and safe methods for correcting high myopic anisometropia and improving amblyopia in children aged 4 to 7 years who were CL intolerant. Visual acuity and binocular vision outcomes were better in children who received permanent surgical correction of anisometropia than in those who were treated conventionally by CLs.     

Laser-assisted subepithelial keratectomy retreatment after laser in situ keratomileusis

PURPOSE: To evaluate the efficacy and safety of laser-assisted subepithelial keratectomy (LASEK) retreatment after laser in situ keratomileusis (LASIK). SETTING: Mater Private Hospital, Dublin, Ireland. METHODS: In this retrospective study, 22 eyes of 20 patients had LASEK retreatment for residual refractive errors after LASIK. All patients who had the procedure between January 2004 and May 2007 were included in the study. The main outcome measures at the final follow-up visit were efficacy, predictability, safety, and stability. RESULTS: The mean spherical equivalent (SE) was -4.50 diopters (D)+/-2.88 (SD) (range -10.00 to +3.87 D) before LASIK and -1.23+/-0.95 D (range -2.50 to +2.00 D) after LASIK. The mean time between the initial LASIK procedure and LASEK enhancement was 56.2+/-24.3 months (range 6 to 84 months). The mean follow-up after retreatment was 6.68+/-6.47 months (range 3 to 24 months). At the final follow-up visit, 19 eyes (86.4%) had an uncorrected visual acuity of 20/30 or better and 17 eyes (77.3%) were within +/-1.00 D of the target refraction. No patient lost more than 1 line of best corrected visual acuity or developed corneal haze greater than grade 1. CONCLUSION: Results indicate that LASEK retreatment after LASIK is a safe and effective alternative when LASIK retreatment is deemed unsafe because there is not sufficient residual corneal stromal bed or when retreatment is required many years after LASIK and relifting the original flap is expected to be problematic.     

Laser-assisted subepithelial keratectomy for the correction of myopia

PURPOSE: To evaluate the results of laser-assisted subepithelial keratectomy (LASEK) for spherical and spherocylindrical myopia. SETTING: Indiana Eye Institute, South Bend, Indiana, USA. METHODS: In a retrospective noncomparative single-surgeon interventional case series, outcomes in 222 consecutive eyes with myopia ranging from -1.25 to -11.25 diopters (D) and astigmatism up to +2.25 D treated with LASEK using a VISX Star S2 excimer laser were analyzed 4 days, 2 weeks, and 3, 6, and 12 months after surgery. RESULTS: The uncorrected visual acuity (UCVA) was 20/40 or better in 84% of eyes at 4 days and in 98% at 2 weeks. At 12 months, in 84 eyes, the UCVA was 20/15 in 16 eyes (19.0%), 20/20 in 53 (63.1%), and 20/25 in 15 (17.9%). There was no loss of best spectacle-corrected visual acuity (BSCVA), and no eye required retreatment. CONCLUSION: Laser-assisted subepithelial keratectomy for myopia provided excellent refractive and visual results with no loss of BSCVA and no serious complications. Subjective results and other measures of visual function need further evaluation.     

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-assisted subepithelial keratectomy for anisometropic amblyopia in children: outcomes at 1 year

PURPOSE: To assess the refractive, visual acuity, and binocular results of laser-assisted subepithelial keratectomy (LASEK) for anisomyopia, anisohyperopia, and anisoastigmatia in children with various levels of amblyopia secondary to the anisometropic causes. SETTING: Nonhospital surgical facility with follow-up in a hospital clinic setting. METHODS: This retrospective review was of 53 children with anisometropia who had LASEK to correct the refractive difference between eyes. All LASEK procedures were performed using general anesthesia. Patients were divided into 3 groups according to their anisometropia as follows: myopic difference greater than 3.00 diopters (D), astigmatic difference greater than 1.50 D, and hyperopic difference greater than 3.50 D. The children were followed for at least 1 year, and their refractive status, visual acuity, and binocular vision were assessed and recorded at 2 and 6 months as well as 1 year. RESULTS: The mean age at treatment was 8.4 years (range 10 months to 16 years). The mean preoperative anisometropic difference was 6.98 D in the entire group, 9.48 D in the anisomyopic group, 3.13 D in the anisoastigmatic group, and 5.50 D in the anisohyperopic group. One year after LASEK, the mean anisometropic difference decreased to 1.81 D, 2.43 D, 0.74 D, and 2.33 D, respectively, and 54% of all eyes were within +/-1.00 D of the fellow eye, 68% were within +/-2.00 D, and 80% were within +/-3.00 D. Preoperative visual acuity and binocular vision could be measured in 33 children. Postoperatively, 63.6% of children had an improvement in best corrected visual acuity (BCVA) and the remainder had no noted change. No patient had a reduction in BCVA or a loss in fusional ability after LASEK. Of the 33 children, 39.4% had positive stereopsis preoperatively and 87.9% had positive stereopsis 1 year after LASEK. CONCLUSION: Laser-assisted subepithelial keratectomy is an effective surgical alternative to improve visual acuity in anisometropic children unable to tolerate conventional methods of treatment or in whom these methods fail.     

Laser-assisted subepithelial keratectomy for low to high myopia and astigmatism

PURPOSE: To evaluate the safety and efficacy of laser-assisted subepithelial keratectomy (LASEK) for the treatment of low to high myopia and astigmatism. SETTING: Solo private practice, Mountain View, California, USA. METHODS: Laser-assisted subepithelial keratectomy was performed in 146 eyes of 83 consecutive patients with myopia or myopic astigmatism using a VISX Star S2 excimer laser (72 eyes) or a Nidek EC-5000 excimer laser (74 eyes). The mean preoperative myopic spherical equivalent was -5.32 diopters (D) (range -1.25 to -14.38 D). Data were collected prospectively with a follow-up of 1 to 12 months. Outcome measurements included uncorrected visual acuity (UCVA), manifest refraction, best spectacle-corrected visual acuity (BSCVA), corneal haze, and complications. RESULTS: After 6 and 12 months, no eye lost 2 or more lines of BSCVA. After 6 months, the UCVA was 20/20 in 57% of eyes and 20/40 or better in 96%. After 12 months, it was 20/20 in 56% of eyes and 20/40 or better in 96%. No eye developed corneal haze that affected visual acuity. There were no serious or vision-threatening complications. CONCLUSIONS: Laser-assisted subepithelial keratectomy was safe and effective in treating a wide range of myopia and astigmatism. The potential advantages of LASEK over laser in situ keratomileusis (LASIK) include the elimination of stromal flap complications and greater choice in patient selection. The disadvantages include varying degrees of pain for 2 days and blurry vision for several days postoperatively.     

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.     

Laser-assisted subepithelial keratectomy for dry eye associated with soft contact lenses

PURPOSE: To evaluate the efficacy and safety of laser-assisted subepithelial keratectomy (LASEK) in myopic patients with preoperative dry eye associated with extended soft contact lens use. SETTING: Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan. METHODS: This nonrandomized prospective interventional case series study comprised 9 patients (18 eyes) with dry eye and keratoconjunctivitis associated with long-term complicated soft contact lens use. Prior to LASEK surgery and for 1 year following surgery, measurements and comparisons were made of uncorrected visual acuity, best corrected visual acuity (BCVA), manifest refraction, symptoms, tear function, ocular surface abnormality, and corneal sensitivity. RESULTS: No significant differences (P > .05) in the mean results of the Schirmer test with anesthesia and tear breakup times before and after LASEK were evident. Corneal sensitivity recovered within 1 month after LASEK. No complications occurred during or after LASEK. Subepithelial haze and superficial punctate epithelial defects occurred in 1 eye, representing a loss of 1 Snellen line of BCVA. CONCLUSION: Laser-assisted subepithelial keratomileusis in dry eyes and keratoconjunctivitis associated with complicated soft contact lens wearing was safe and efficacious.     

LASEK治疗中高度近视的临床研究

目的　观察准分子激光角膜上皮瓣下磨镶术(LASEK)治疗中高度近视的临床效果。方法　LASEK治疗4 6例 (92眼 )中高度近视 ,屈光度 - 4 .2 5～ - 17.0D ,随访 3～ 15月 ,观察症状、视力、屈光状态、角膜并发症等情况。结果　术后刺激症状与PRK类似 ,无明显haze出现。视力 :术后第 3月 ,裸眼视力≥ 0 .8者 86眼 ,≥ 1.0者 78眼 ,第 6月裸眼视力≥ 0 .8者 81眼 ,≥ 1.0者 73眼。结论　LASEK治疗中高度近视安全性更高 ,术后视觉效果更好 ,拓宽了准分子激光应用的适应证     

Laser-assisted subepithelial keratectomy versus photorefractive keratectomy for the correction of myopia. A prospective comparative study

PURPOSE: To compare the early postoperative visual rehabilitation after laser-assisted subepithelial keratectomy (LASEK) and photorefractive keratectomy (PRK) for the correction of myopia. SETTING: CODET Aris Vision Institute, Tijuana, Mexico. METHODS: This prospective study included 50 eyes of 25 patients with myopia who received LASEK in 1 eye and PRK in the contralateral eye. Excimer laser corneal ablation was done using the Nidek EC-5000 excimer laser. Patients were seen at 1 and 3 days, 1 week, and 1 month. Discomfort, subjective uncorrected visual acuity (UCVA), objective UCVA, best corrected visual acuity (BCVA), corneal clarity (haze), and time for corneal reepithelialization were analyzed. RESULTS: Seventy-two percent and 80% of the LASEK eyes had more discomfort at 1 day and 3 days, respectively. Eighty percent and 96% of the PRK eyes had better subjective UCVA at 1 day and 3 days, respectively. Corneas were fully reepithelialized at a mean of 3.3 days +/- 0.5 (SD) and 3.6 +/- 0.5 days in the PRK and LASEK groups, respectively. At 1 month, the UCVA was similar in both groups; no eye had lost lines of BCVA or developed haze. CONCLUSIONS: Both LASEK and PRK were effective and safe procedures in the surgical correction of myopia at the 1-month postoperative visit. Patients reported less discomfort and better visual acuity in their PRK eye during the early postoperative period. Patients should be informed that LASEK, whose acronym is similar to that of laser in situ keratomileusis, has a recovery speed that is similar to that of surface laser refractive procedures such as PRK.     

Long-term outcomes of photorefractive keratectomy and laser-assisted subepithelial keratectomy in children

PURPOSE: To assess the long-term refractive, visual acuity, binocular vision, and quality-of-life outcomes of photorefractive keratectomy (PRK) and laser-assisted subepithelial keratectomy (LASEK) in children. SETTING: Non-hospital surgical facility with follow-up in a hospital clinical setting. METHODS: In this retrospective review, 56 eyes of 39 patients had PRK or LASEK under general anesthesia. Patients were examined preoperatively and postoperatively at 2 and 6 months and 1 year and then annually for a minimum of 3.5 years. Recorded variables included demographics, refractive error, best corrected visual acuity (BCVA), stereopsis, corneal haze, and quality of life. RESULTS: The mean age at surgery was 6.5 years (range 1.0 to 17.4 years). At the final postoperative examination (mean 5.15 years), the mean spherical equivalent was -1.73 diopters (D) in all patients, -3.20 D in PRK patients, and -1.37 D in LASEK patients. Refraction and corneal clarity were stable over the long term in all eyes. In 28 eyes that were measurable preoperatively, visual acuity improved by a mean of 1.6 lines (range 0 to 7 lines). Seven patients (18%) had measurable stereopsis before surgery and 19 (49%), after PRK or LASEK. No patient had reduced BCVA or loss of binocular fusion postoperatively. On a quality-of-life questionnaire, no family recorded negative opinions of the procedure or negative social or functional outcomes postoperatively. CONCLUSION: Photorefractive keratectomy and LASEK were effective and stable surgical alternative treatments in children with refractive errors who were unable to tolerate or who failed conventional methods of treatment.     

Laser-assisted subepithelial keratectomy and photorefractive keratectomy for the correction of hyperopia. Results of a 2-year follow-up

PURPOSE: To evaluate and compare the efficacy, safety, predictability, and stability of laser-assisted subepithelial keratectomy (LASEK) and photorefractive keratectomy (PRK) for low to moderate hyperopia with a 2-year follow-up. SETTING: Department of Ophthalmology, Masaryk University Hospital, Brno, Czech Republic. METHODS: This prospective comparative single-surgeon study included 216 eyes of 108 patients with hyperopia who received PRK in 1 eye and LASEK in the contralateral eye. The mean patient age was 38.3 years (range 25 to 58 years). The mean preoperative spherical equivalent (SE) cycloplegic refraction was +3.67 diopters (D) +/- 1.15 (SD) (range +2.00 to +5.00 D), and astigmatism was less than 1.00 D. In each patient, PRK was performed in 1 eye (Group A) and LASEK was performed in the other eye (Group B) using the Nidek EC-5000 excimer laser. Postoperative uncorrected visual acuity (UCVA), best corrected visual acuity, contrast sensitivity, manifest and cycloplegic refractions, refractive stability and predictability, postoperative pain, and corneal haze were examined and statistically analyzed. A P value less than 0.05 was considered significant. RESULTS: At 1 week, the UCVA was 20/40 or better in 58% of PRK eyes and 85% of LASEK eyes (P =.037); at 2 years, it was 20/40 or better in 81% and 91%, respectively (P =.076). At 2 years, the UCVA for near was N8 or better in 73% of PRK eyes and 89% of LASEK eyes (P =.064). No patient lost 2 or more lines of Snellen visual acuity. The safety index was 1.03 in PRK eyes and 1.08 in LASEK eyes. Refractive stability was achieved at 6 months in LASEK eyes and at 12 months in PRK eyes. The mean SE cycloplegic refraction decreased from +3.58 D (PRK eyes) and +3.76 D (LASEK eyes) at baseline to +0.74 D and +0.32 D, respectively, at 2 years; in 57% and 78% of eyes, respectively, the refraction was within +/-0.50 D of the targeted refraction. Peripheral corneal haze scores at 3 to 9 months and pain scores at 1 to 3 days were significantly lower in the LASEK group than in the PRK group. CONCLUSIONS: Laser-assisted subepithelial keratectomy for hyperopia up to +5.00 D provided good visual and refractive results. It significantly reduced postoperative pain, grade of peripheral ring-shaped corneal haze, and regression of hyperopia. Hyperopic LASEK provided quicker visual recovery and achieved better efficacy, predictability, and refractive stability than hyperopic PRK.     

Refractive surgery for high bilateral myopia in children with neurobehavioral disorders: 2. Laser-assisted subepithelial keratectomy (LASEK).

INTRODUCTION: A subpopulation of children with high myopia and neurobehavioral disorders is noncompliant with spectacle wear and ill-suited to correction using contact lenses. We report the results of refractive surgery in a series of these children treated bilaterally using excimer laser technology. METHODS: Clinical course and outcome data were collated prospectively in a group of 9 children (mean age, 10.2 years; range, 3-16 years) with neurobehavioral disorders exacerbated by chronic noncompliance with spectacle wear, causing profoundly low functional vision. Myopia in the 18 eyes ranged from -3.75 to -11.5 D (mean -16.6 D) and the desired refraction was approximately +1D. Correction was achieved by bilateral laser-assisted subepithelial keratectomy (ie, LASEK) performed under brief general anesthesia. Mean follow-up was 17 months (range, 6-36 months). RESULTS: Myopia correction averaged 7.9 D. Eighty-nine percent (16/18 eyes) were corrected to within +/-1 D of goal refraction. Uncorrected acuity improved postoperatively in all 18 eyes, with commensurate gains in behavior and environmental visual interaction in 88% (15/17 children). Myopic regression averaged approximately 0.8 d/year. the only complication encountered was mild (1+) corneal haze in 35% of treated eyes. DISCUSSION/CONCLUSIONS: Bilateral excimer laser surgery is effective for improving functional vision substantially in highly myopic, neurobehaviorally impaired children who have difficulties wearing glasses. Myopic regression is common. Further study is indicated to determine the long-term safety of these and alternative refractive procedures in similar pediatric populations.     

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.