Effect of amniotic membrane after laser-assisted subepithelial keratectomy on epithelial healing: clinical and refractive outcomes

PURPOSE: To evaluate the effect of an amniotic membrane (AM) on reepithelialization time, corneal haze, and postoperative visual and refractive outcomes after laser-assisted subepithelial keratectomy (LASEK) for myopia and myopic astigmatism. SETTING: Department of Ophthalmology, Yonsei University College of Medicine, and Balgeunsesang Ophthalmology Clinic, Seoul, Korea. METHODS: One hundred fifty-two eyes of 84 patients with myopia or myopic astigmatism were prospectively evaluated for 6 months after LASEK. An AM was placed as a strip on the inferior limbus in 94 eyes of 54 patients after LASEK; 58 eyes of 30 patients served as the control group. Postoperative epithelial healing time, uncorrected visual acuity (UCVA), best corrected visual acuity, remaining refractive error, and corneal haze were examined. RESULTS: The reepithelialization time was shorter in the AM group (2.40 days +/- 0.94 [SD]) than in the control group (3.90 +/- 0.97 days) (P<.001). At 6 months, 86 eyes (91.5%) in the AM group had a UCVA of 20/25 or better and 90 eyes (95.7%) had a UCVA of 20/40 or better; 48 eyes (82.8%) and 53 eyes (91.4%) in the control group had a UCVA of 20/25 or better and 20/40 or better, respectively. The mean spherical equivalent in the AM group was -0.48 +/- 0.54 diopter (D) and in the control group, -0.94 +/- 0.60 D (P<.001). The corneal haze was significantly less in the AM group than in the control group (P<.001). CONCLUSION: Amniotic membrane use after LASEK induced rapid epithelial healing with more favorable visual and refractive outcomes and lower corneal haze scores than conventional LASEK.     

Epi-LASIK versus epi-LASEK

PURPOSE: To compare the possible advantages and disadvantages of adding an alcohol solution (20%) to the epi-LASIK procedure. This study focuses on flap making, haze, and pain with and without alcohol. METHODS: A prospective study was performed on 45 patients to compare epi-LASIK with epi-LASIK plus alcohol (ie, epi-LASEK). Alcohol (20%) was applied for 20 seconds before making the flap in the epi-LASEK treatment group. In each patient, one eye underwent epi-LASIK and the fellow eye had epi-LASEK. In the epi-LASIK treatment group, mean myopic (n = 40) spherical equivalent refraction was -5.60 +/- 3.30 diopters (D) and mean hyperopic (n = 5) spherical equivalent refraction was +2.90 +/- 1.80 D. Myopic mean astigmatism was 1.40 +/- 1.20 D, and hyperopic mean astigmatism was 0.60 +/- 0.60 D. In the epi-LASEK treatment group, myopic (n = 40) mean spherical equivalent refraction was -5.90 +/- 3.50 D and hyperopic (n = 5) mean spherical equivalent refraction was +3.00 +/- 1.90 D. Mean myopic astigmatism was 1.60 +/- 1.30, and mean hyperopic astigmatism was 0.60 +/- 0.90 D. No significant differences were noted between groups (P > .05). Refraction and topography were performed preoperatively and on postoperative days 6 (contact lenses just removed), 15, 30, 60, 120, and 360. RESULTS: The epi-LASEK treatment group had less postoperative astigmatism and irregularities than the epi-LASIK group. Alcohol addition in the epi-LASEK treatment group contributed to better flap and hinge creation. Pain and haze did not increase in the epi-LASEK treatment group (P > .05). CONCLUSIONS: Flap viability does not seem to be important postoperatively in reducing pain and speeding recovery time. Alcohol facilitates flap making and improves hinge quality, and does not increase postoperative pain or haze. Adding alcohol to the epi-LASIK procedure can be advantageous in obtaining an intact hinge and a perfect flap.     

Excimer laser retreatment of residual myopia following photoastigmatic refractive keratectomy for compound myopic astigmatism

PURPOSE: To prospectively evaluate the safety, efficacy, and visual performance of excimer laser enhancement following photoastigmatic refractive keratectomy (PARK) with the Summit Apex Plus. SETTING: Stanford University School of Medicine Eye Laser Clinic, Stanford, California, USA. METHODS: As part of a Food and Drug Administration clinical trial, 93 eyes of 56 patients with a mean spherical equivalent (SE) of -4.98 diopters (D) +/- 1.80 (SD) (range -1.75 to -8.50 D) had PARK for compound myopic astigmatism using the Summit Apex Plus excimer laser and a poly(methyl methacrylate) erodible mask. Seventeen eyes with a mean SE of -2.08 +/- 0.76 D required excimer laser refractive keratectomy for residual spherical myopia or compound myopic astigmatism. Patients were prospectively followed 1, 3, 6, 9, and 12+ months after the enhancement procedure. Primary outcome variables included uncorrected visual acuity (UCVA), refraction, vector analysis, best spectacle-corrected visual acuity (BSCVA) under standard ambient conditions (photopic, scotopic, and glare), corneal clarity, and contrast sensitivity function curve under photopic and scotopic conditions. RESULTS: At the last postoperative visit, the mean sphere had been corrected 82% to a residual of -0.29 +/- 1.23 D and mean SE had been corrected 65% to a residual of -0.74 +/- 1.27 D. Eighty-two percent of eyes were within +/-1.0 D of attempted correction. Eighty-eight percent had a UCVA of 20/40 or better. Vector analysis demonstrated a difference vector of within +/-1.0 D in 75% of eyes that had PARK retreatment. There was no significant loss in the contrast sensitivity curve. Late regression associated with corneal haze and loss of BSCVA occurred in 2 eyes (11.7%). CONCLUSIONS: Retreatment following PARK for compound myopic astigmatism results in effective reduction in residual spherical myopia and compound myopic astigmatism. An improvement in UCVA without loss of contrast sensitivity can be expected in most eyes. However, regression, corneal haze, and loss of BSCVA may occur. Further studies are indicated to predict risk factors for these complications.     

Analysis of the efficacy, predictability, and safety of LASEK for myopia and myopic astigmatism using the Technolas 217 excimer laser

PURPOSE: To evaluate the efficacy, predictability, and safety of laser-assisted subepithelial keratectomy (LASEK) for the treatment of myopia and myopic astigmatism. SETTING: Stanford University Eye Laser Center, Stanford, California, USA. METHODS: This retrospective analysis comprised 102 eyes that had LASEK for myopia using the Bausch & Lomb Technolas 217 excimer laser. Primary outcome variables including uncorrected visual acuity (UCVA), best spectacle- corrected visual acuity (BSCVA), manifest refraction, and complications were evaluated at 3, 6, and 12 months. Vector analysis was performed on eyes that received astigmatic correction. RESULTS: The mean spherical equivalent was -7.03 diopters (D) +/- 2.61 (SD) preoperatively, +0.19 +/- 0.64 D at 3 months, +0.23 +/- 0.82 D at 6 months, and +0.03 +/- 0.63 D at 12 months (P<.001). At 3, 6, and 12 months, the UCVA was 20/20 or better in 66%, 67%, and 83% of eyes, respectively, and 20/40 or better in 98%, 99%, and 100%; 74%, 70%, and 83%, respectively, were within +/-0.5 D of emmetropia, and 89%, 86%, and 97%, respectively, were within +/-1.0 D. No eye lost more than 2 lines of BSCVA. At 3, 6, and 12 months, 10.0%, 8.7%, and 0% of eyes, respectively, had trace corneal haze. Vector analysis found a success rate of approximately 78% to 80% in achieving the astigmatic surgical correction at the 3 postoperative visits. CONCLUSIONS: Laser-assisted subepithelial keratectomy was an effective, predictable, and safe procedure for the treatment of myopia and myopic astigmatism. Further studies are needed to determine the role of LASEK in the refractive surgery spectrum.     

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.     

Photorefractive keratectomy for post-penetrating keratoplasty myopia and astigmatism

PURPOSE: To determine the safety, effectiveness, and predictability of photorefractive keratectomy (PRK) for the correction of myopia and astigmatism after penetrating keratoplasty. SETTING: Gazi University, Medical School, Department of Ophthalmology, Ankara, Turkey. METHODS: Photorefractive keratectomy was performed in 16 eyes of 16 patients with postkeratoplasty myopia and astigmatism who were unable to wear glasses due to anisometropia and were contact lens intolerant. They were examined for uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and corneal transplant integrity before and after surgery. RESULTS: The mean follow-up after PRK was 26.0 months +/- 15.7 (SD) (range 12 to 63 months). The mean preoperative spherical equivalent refraction of -4.47 +/- 1.39 diopters (D) was -3.39 +/- 1.84 D (P >.05) at the last postoperative visit and the mean preoperative cylinder of -5.62 +/- 2.88 D was -3.23 +/- 1.70 D (P <.05); refractive regression correlated with the amount of ablation performed. The BSCVA decreased in 3 eyes (18.8%), and the UCVA decreased in 2 (12.5%). Six eyes (37.5%) had grade 2 to 3 haze, which resolved spontaneously in 4 eyes within a relatively long time but caused a decrease in BSCVA in 2 (12.5%). Two of the eyes (12.5%) had a rejection episode after PRK and were successfully treated with topical steroids. CONCLUSIONS: Photorefractive keratectomy to correct postkeratoplasty myopia and astigmatism appears to be less effective and less predictable than PRK for naturally occurring myopia and astigmatism. Corneal haze and refractive regression are more prevalent, and patient satisfaction is not good.     

Laser in situ keratomileusis for the correction of myopia and myopic astigmatism

PURPOSE: To evaluate the efficacy, safety, predictability, and surgically induced astigmatism (SIA) of laser in situ keratomileusis (LASIK) for the correction of myopia and myopic astigmatism. SETTING: Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan. METHODS: This retrospective study comprised 69 eyes that had LASIK to correct myopia and 74 eyes that had LASIK to correct myopic astigmatism. The excimer laser keratectomy was performed using a Summit Apex Plus machine. Refraction, visual acuity, and computerized corneal videokeratography data from the preoperative and postoperative examinations were collected. The astigmatic change was calculated by the Alpins vector analysis method. RESULTS: The preoperative spherical equivalent at the glasses plane in the myopia and myopic astigmatism groups was -8.08 diopters (D) and -9.73 D, respectively. At 6 months, the spherical equivalent and residual corneal astigmatism were -0.25 D and 0.85 D, respectively, in the myopia group and -0.71 D and 0.82 D, respectively, in the myopic astigmatism group. In the myopia group, 88% of eyes were within +/-1.0 D of the intended myopia correction and in the myopic astigmatism group, 85% were within +/-1.0 D of the targeted spherical equivalent and 90% were within +/-1.0 D of the intended astigmatism correction. The uncorrected visual acuity was 20/40 or better in 94.1% of eyes in the myopia group and 92.5% of eyes in the myopic astigmatism group. The SIA magnitude was 0.66 D with the axis randomly distributed in the myopia group. The mean astigmatism correction index was 0.97, the mean magnitude of error was 0.13 D +/- 0.62 (SD), and the mean angle of error was -3.70 +/- 13.73 degrees in the myopic astigmatism group. CONCLUSION: Laser in situ keratomileusis had similar predictability, safety, and efficacy in the treatment of myopia and myopic astigmatism. The astigmatism correction was effective, but the results suggest that subjective astigmatism of less than 1.0 D need not be treated with the Summit Apex Plus laser.     

Laser in situ keratomileusis for myopia and compound myopic astigmatism using the Technolas 217 scanning-spot laser

PURPOSE: To evaluate the safety, efficacy, predictability, and visual results of laser in situ keratomileusis (LASIK) using the Bausch & Lomb Technolas(R) 217 scanning-spot laser for the treatment of myopia and compound myopic astigmatism. SETTING: Stanford Eye Laser Center, Stanford, California, USA. METHODS: In a prospective study, 110 eyes of 58 patients with a mean spherical equivalent (SE) of -4.87 diopters (D) +/- 2.5 (SD) (range -1.0 to -11.4 D) had LASIK for myopia and compound myopic astigmatism using the Technolas 217 scanning-spot laser. The primary outcome variables included preoperative and postoperative best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA), achieved versus attempted correction, vector analysis of astigmatism, and complications. RESULTS: One hundred ten eyes were available for analysis at 3 months. The mean SE refraction was reduced 95% (mean -0.23 +/- 0.4 D), and astigmatism was reduced 70% (mean 0.28 +/- 0.3 D). One day postoperatively, 100% of eyes had a UCVA of 20/40 or better, 96% had 20/25 or better, 77% had 20/20 or better, and 39% had 20/15 or better. At the 3-month examination, 100% of eyes had a UCVA of 20/40 or better, 95% had 20/25 or better, 83% had 20/20 or better, and 48% had 20/15 or better. Ninety percent of eyes were within +/-0.5 D of emmetropia. No eye lost 2 or more lines of BSCVA. CONCLUSIONS: The Technolas 217 scanning-spot laser produced excellent postoperative UCVA and BSCVA. It was predictable, safe, and effective for the treatment of myopia and compound myopic astigmatism. Long-term follow-up is needed to assess the stability of the procedure.     

Predictability and outcomes of photoastigmatic keratectomy using the Nidek EC-5000 excimer laser

PURPOSE: To evaluate the effect of astigmatic correction on the accuracy of the myopic and astigmatic correction in patients having photorefractive astigmatic keratectomy (PARK) and in those having photorefractive keratectomy (PRK). SETTING: Specialist excimer laser refractive clinic. METHODS: This prospective consecutive case series comprised 6097 eyes with a preoperative mean spherical equivalent (MSE) of -4.63 diopters (D) +/- 1.95 (SD) (range -0.75 to -13.00 D) and a mean cylinder of -1.13 +/- 0.73 D (range -0.50 to -6.00 D) having PARK with a Nidek EC-5000 excimer laser. Visual and refractive outcomes were assessed 12 months postoperatively and compared with those in 3004 eyes that had spherical PRK. RESULTS: At 12 months, the MSE was -0.02 +/- 0.79 D and the mean cylinder was -0.49 +/- 0.47 D in the PARK group; the MSE was -0.07 +/- 0.66 D in the PRK group. An MSE within +/-0.05 D of emmetropia was achieved by 69.8% and within +/-1.00 D, by 87.9%. The uncorrected visual acuity (UCVA) was 20/20 or better in 42.6% and 20/40 or better in 91.2%. Statistical significance (P <.001, analysis of variance) was achieved for MSE, sphere, cylinder, haze, and visual acuity (best corrected [BCVA] and UCVA) based on the preoperative cylinder. The loss of BCVA varied from 1.1% to 5.8% depending on the degree of astigmatism treated. Accuracy varied with the attempted myopic correction and the attempted astigmatic correction. CONCLUSIONS: Excimer laser PARK was an effective treatment for compound myopic astigmatism, but predictability decreased and complications increased as the attempted astigmatic correction increased.     

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.     

Excimer laser photorefractive keratectomy for high myopia and myopic astigmatism.

BACKGROUND AND OBJECTIVE: To determine the efficacy, safety, and predictability of excimer laser photorefractive keratectomy of high myopia and myopic astigmatism. PATIENTS AND METHODS: 76 eyes of 52 patients with myopia from -8.00 to -23.50 diopters (D) with or without astigmatism up to -5.50D were treated with the VISX 20/20 excimer laser (VISK, Santa Clara, CA) and a multi-zone ablation technique. Visual acuity, manifest refraction, corneal haze, and topography were evaluated at 1 week and 1, 3, 6, 12, and 18 months postoperatively. RESULTS: Postoperative refractions were generally stable after 12 months. At the last follow-up all patients were within - 1.96 D of the intended correction. Eighteen months postoperatively, 68% of patients undergoing photorefractive keratectomy (PRK), and 65% of patients undergoing photo astigmatic refractive keratectomy (PARK), were within 1 D of planned refraction. Furthermore, 87% of patients after PRK and 80% of patients after PARK had a visual acuity of 20/40 or better. CONCLUSIONS: High myopia with or without astigmatism was successfully treated in most of the patients using PRK. The stability of the postoperative refraction during the first 18 months seems to be good. The incidence of adverse effects was low but improvements in the future should further reduce complications, thus increasing the safety of refractive procedures.     

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.     

Photorefractive keratectomy for residual myopia after cataract surgery

PURPOSE: To evaluate the effectiveness, predictability, and safety of photorefractive keratectomy (PRK) for correcting residual myopia and myopic astigmatism after cataract surgery with intraocular lens implantation. SETTING: Refractive Surgery and Cornea Unit, Instituto Oftalmológico de Alicante, Alicante, Spain. METHODS: Thirty consecutive eyes (30 patients) had PRK for residual myopia after cataract surgery. Surface PRK with a VISX Twenty-Twenty excimer laser was used in all patients. Follow-up was 1 year. RESULTS: Before PRK, no eye had an uncorrected visual acuity (UCVA) of 20/40 or better. Twelve months after PRK, 16 eyes (53.33%) had a UCVA of 20/40 or better. After PRK, best corrected visual acuity (BCVA) improved 1 line or more in 14 eyes (46.66%) over the preoperative values, and 15 eyes (50.00%) had the same BCVA as before PRK. Mean pre-PRK refraction of -5.00 diopters (D) +/- 2.50 (SD) decreased significantly to -0.25 +/- 0.50 D at 12 months (P < .001). At 12 months, the spherical equivalent was within +/- 1.00 D of emmetropia in 27 eyes (90.00%). No vision-threatening complications occurred. CONCLUSION: Photorefractive keratectomy was an effective, predictable, and safe procedure for correcting residual myopia and myopic astigmatism after cataract surgery.     

Effectiveness of laser-assisted subepithelial keratectomy without mitomycin-C for the treatment of high myopia

PURPOSE: To evaluate the effectiveness and therapeutic range of laser-assisted subepithelial keratectomy (LASEK) without mitomycin-C (MMC) to treat high myopia. SETTING: Isik Eye Clinic, Ankara, Turkey. METHODS: This study comprised 31 highly myopic eyes (19 patients) that had LASEK. Before primary LASEK treatment and 1, 3, 6, 12, and 24 months after, all patients had a complete ophthalmic examination including visual acuity, refractive outcomes, and biomicroscopy. RESULTS: The mean spherical equivalent (SE) was -9.01 diopters (D) +/- 2.66 (SD) preoperatively and -1.00 +/- 1.15 D at the end of follow-up. At 24 months, the mean SE was within +/-1.00 D of the intended correction in 23 eyes (74.19%). The median uncorrected visual acuity (UCVA) increased from 20/606 preoperatively to 20/28.6 at 24 months and the median best corrected visual acuity, from 20/25 to 20/22, respectively. Total higher-order and spherical aberrations increased significantly at the end of follow-up. All 14 eyes that had ablations greater than -8.62 D developed varying degrees of haze. Significant myopic regression (>1.00 D) leading to UCVA loss occurred in all eyes with a preoperative SE of -12.00 D or greater. CONCLUSIONS: The results of LASEK without MMC were excellent in eyes with up to -8.6 D of SE. All eyes with a preoperative SE between -8.6 and -12.0 D developed haze but had acceptable refractive and visual outcomes. Haze and myopic regression limited the success of LASEK in eyes with a preoperative SE of -12.0 D and greater.     

Laser-assisted subepithelial keratectomy in children

PURPOSE: To evaluate whether laser-assisted subepithelial keratectomy (LASEK) achieves effective targeted myopic correction with less post-treatment corneal haze than observed with photorefractive keratectomy (PRK) in children who fail traditional forms of treatment for myopic anisometropic amblyopia and high myopia. SETTING: Nonhospital surgical facility with follow-up in a hospital clinic setting. METHODS: This prospective study comprised 36 eyes of 25 patients. The mean patient age at treatment was 8.27 years (range 1.0 to 17.4 years). Patients were divided into 3 groups: those with myopic anisometropic amblyopia (13 patients/13 eyes), those with bilateral high myopia (11 patients/22 eyes), and those with high myopia post-penetrating keratoplasty (1 patient/1 eye). All patients were treated with LASEK under general anesthesia using the Visx 20/20 B excimer laser and a multizone, multipass ablation technique. Although the myopia was as high as -22.00 diopters (D) spherical equivalent (SE) in some eyes, no eye was treated for more than -19.00 D SE. RESULTS: At 1 year, the mean SE decreased from -8.03 D to -1.19 D. Forty-four percent of eyes were within +/-1.0 D of the targeted correction; 78% of eyes had clear corneas with no haze. In the entire group, the mean best corrected visual acuity improved from 20/80 to 20/50. A functional-vision survey demonstrated a positive effect on the patients' ability to function in their environments after LASEK. CONCLUSIONS: Laser-assisted subepithelial keratectomy in children represents another method of providing long-term resolution of bilateral high myopia and myopic anisometropic amblyopia with minimal post-laser haze. The reduction in post-laser haze with LASEK compared to that with the standard PRK technique may represent an advantage in treating these complex patients.     

Transepithelial photorefractive keratectomy mode using SCHWIND-ESIRIS excimer laser: initial clinical results

AIM: To evaluate postoperative pain, uncorrected visual acuity (UCVA), and cornea haze value after transepithelial photorefractive keratectomy (T-PRK) performed with aspherical ablation profile using SCHWIND ESIRIS excimer laser. METHODS: Retrospective case series. Fifty-nice eyes (32 patients) with myopia associated with or without astigmatism underwent phototherapeutic keratectomy (PTK) followed by photorefractive keratectomy (PRK) which performed by Optimized Refractive Keratecomy (ORK)-CAM software based on aspherical ablation profile using SCHWIND ESIRIS excimer laser. Postoperative pain scale was measured on a questionnaire through five levels. Haze was graded by five grades, and UCVA, manifest refraction spherical equivalent (MRSE) were analyzed. RESULTS: Mean pain level was (1.37±0.613) (range: 1 to 3), the mean time picking out the soft contact lens was (6.22±1.73) days, at 3 months, UCVA was 1.0 for 40 eyes (67.8%), 0.5 for all eyes (100.0%). The UCVA was significantly less than the preoperative best spectacle corrected visual acuity (BSCVA) (t=-2.84, P=0.006), haze value was (0.27±0.25), no patients had a haze grade up to 2. Mean MRSE was (0.76±0.96) diopter(D) by 3 months. CONCLUSION: The outcomes from this study show that using the SCHWIND ESIRIS aspherical ablation profile for transepithelial PRK has a good visual result. The primary advantage is related to a spherical ablation profile, automatically considers the ablation volume of the stroma and the accurate and smooth removal of the epithelium with PTK. Additional studies are needed to determine long-term outcomes.     

LASEK and photorefractive keratectomy for myopia: clinical and confocal microscopy comparison

PURPOSE: To compare postoperative visual acuity and corneal morphology after laser epithelial keratomileusis (LASEK) versus photorefractive keratectomy (PRK) in the correction of low to moderate myopia. METHODS: In a double-blind, randomized clinical trial, 50 myopic patients (mean: -4.5 +/- 1.35 diopters) were randomized to receive LASEK in one eye and PRK in the fellow eye. No mitomycin C eye drops were used in this study. Patients were observed daily for 4 days, then at 1 month and every 3 months up to 1 year. Uncorrected and best-corrected visual acuity (UCVA and BSCVA), manifest refraction, corneal epithelium healing time, postoperative pain, and corneal haze were evaluated. Corneal wound healing was quantified with corneal confocal microscopy. RESULTS: Refractive error, UCVA, and BSCVA were not statistically different between eyes treated with LASEK and PRK. Corneal epithelium healing time was 2.52 +/- 0.99 days in the eyes treated with PRK and 2.29 +/- 0.52 days in the eyes treated with LASEK (P=.22). The postoperative pain score was 2.17 +/- 0.87 in the eyes treated with PRK and 2.62 +/- 0.60 (P=.02) in the eyes treated with LASEK. Corneal confocal microscopy showed fewer stromal activated keratocytes and less extracellular matrix deposition in the eyes treated with LASEK than in the eyes treated with PRK at 1 month postoperatively (P=.003). CONCLUSIONS: LASEK is an effective and safe procedure for low to moderate myopia, but it seems more painful until full corneal reepithelization. In the early postoperative period, the corneal wound healing process is significantly less intense in eyes treated with LASEK than in eyes treated with PRK. The role of LASEK in corneal wound healing modulation remains controversial.     

Transepithelial photorefractive keratectomy mode using SCHWIND-ESIRIS excimer laser: initial clinical results

AIM: To evaluate postoperative pain, uncorrected visual acuity (UCVA), and cornea haze value after transepithelial photorefractive keratectomy (T-PRK) performed with aspherical ablation profile using SCHWIND ESIRIS excimer laser. METHODS: Retrospective case series. Fifty-nice eyes (32 patients) with myopia associated with or without astigmatism underwent phototherapeutic keratectomy (PTK) followed by photorefractive keratectomy (PRK) which performed by Optimized Refractive Keratecomy (ORK)-CAM software based on aspherical ablation profile using SCHWIND ESIRIS excimer laser. Postoperative pain scale was measured on a questionnaire through five levels. Haze was graded by five grades, and UCVA, manifest refraction spherical equivalent (MRSE) were analyzed. RESULTS: Mean pain level was (1.37±0.613) (range: 1 to 3), the mean time picking out the soft contact lens was (6.22±1.73) days, at 3 months, UCVA was 1.0 for 40 eyes (67.8%), 0.5 for all eyes (100.0%). The UCVA was significantly less than the preoperative best spectacle corrected visual acuity (BSCVA) (t=-2.84, P=0.006), haze value was (0.27±0.25), no patients had a haze grade up to 2. Mean MRSE was (0.76±0.96) diopter(D) by 3 months. CONCLUSION: The outcomes from this study show that using the SCHWIND ESIRIS aspherical ablation profile for transepithelial PRK has a good visual result. The primary advantage is related to a spherical ablation profile, automatically considers the ablation volume of the stroma and the accurate and smooth removal of the epithelium with PTK. Additional studies are needed to determine long-term outcomes.     

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 in situ keratomileusis for residual myopia after photorefractive keratectomy

PURPOSE: To evaluate the efficacy and safety of laser in situ keratomileusis (LASIK) for myopic regression and undercorrection after photorefractive keratectomy (PRK). SETTING: The Eye Institute, Sydney, Australia. METHODS: Fifty eyes of 32 patients were treated by LASIK for residual myopia following primary PRK. The mean spherical equivalent refraction (SEQ) was -2.92 diopters (D) +/- 1.57 (SD) (range -0.75 to -7.88 D). The mean refractive cylinder was 0.96 +/- 0.74 D (range 0 to 3.50 D). For analysis, the eyes were divided into 2 groups: those with 0 or low corneal haze (Group 1) and those with severe corneal haze (Group 2). In Group 1, the SEQ was -1.99 +/- 0.79 D (range -0.75 to -3.75 D) and in Group 2, -3.77 +/- 1.62 D (range -0.75 to -7.90 D). The procedure was performed using the Chiron Automated Corneal Shaper and the Summit Apex Plus laser. The mean interval between PRK and LASIK was 25 months (range 9 to 59 months). The following parameters were studied before and after LASIK retreatment: SEQ, mean refractive cylinder, uncorrected visual acuity (UCVA), and best corrected visual acuity (BCVA). Complications after LASIK retreatment were evaluated. RESULTS: Six months after LASIK, the mean SEQ in all eyes was -0.65 +/- 0.86 D (range +1.50 to -3.35 D); 70.0% of eyes were within +/-1.00 D of emmetropia and the UCVA was 6/12 or better in 72.5%. The mean SEQ in Group 1 was -0.22 +/- 0.55 D (range -0.88 to -1.50 D) and in Group 2, -0.97+/- 0.92 D (range 0.12 to -3.25 D); the UCVA was 6/12 or better in 94.0% of eyes in Group 1 and in 56.0% in Group 2. No statistically significant between-group difference was found in lines of Snellen acuity lost or gained at 6 months. No eye lost more than 1 line of BCVA. CONCLUSIONS: Laser in situ keratomileusis appears to be a safe, effective, and predictable procedure for treating eyes with 0 or low haze with residual myopia after PRK. It is less predictable in eyes with severe haze.