Comparison of visual outcomes after femtosecond laser-assisted LASIK versus flap-off epipolis LASIK for myopia.

BACKGROUND: This study clinically evaluated the visual outcomes after refractive surgery for myopia using femtosecond laser-assisted in situ keratomileusis (femto-LASIK) and flap-off epipolis LASIK (epi-LASIK). METHODS: In this retrospective case series study, 40 eyes of 27 patients were divided into two groups depending on the technique used for refractive surgery. Femto-LASIK and flap-off epi-LASIK flaps were created using femtosecond laser and Epi-K™ epikeratome, respectively. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity, manifest refraction, corneal asphericity, and corneal higher-order aberrations (HOAs) were assessed pre- and postoperatively. RESULTS: The improvement in logarithm of the minimum angle of resolution (logMAR) UDVA after refractive surgery was statistically significant for both groups (P < 0.001 for all groups); it was significant better in UDVA in femto-LASIK than flap-off epi-LASIK, 0.03 ± 0.06 logMAR (femto-LASIK) and 0.54 ± 0.31 logMAR (flap-off epi-LASIK), at 1 day postoperatively; 0.02 ± 0.05 logMAR (femto-LASIK) and 0.14 ± 0.13 logMAR (flap-off epi-LASIK), at 1 week postoperatively (P < 0.001 and P = 0.019). With regard to the corneal HOAs, the increment in spherical aberration (Z4,0) was greater in flap-off epi-LASIK than femto-LASIK: 0.626 ± 0.232 µm and 0.479 ± 0.139 µm in the front cornea; 0.556 ± 0.227 µm and 0.430 ± 0.137 µm in the total cornea (P = 0.016 and P = 0.017). However, the back corneal HOA changes did not have a significant effect on the total corneal HOA changes. CONCLUSION: Femto-LASIK yielded better early visual outcomes than did flap-off epi-LASIK, but there was no significant difference between the outcomes of the two procedures, 1 week postoperatively.

Myopia progression over a 4-year period after laser-assisted refractive surgery in patients in their 20s and 30s.

PURPOSE: To investigate the increase in refractive error (RE) and axial length (AL) in myopia patients in their 20s and 30s after laser-assisted in situ keratomileusis (LASIK) or epipolis-LASIK (epi-LASIK). STUDY DESIGN: Retrospective cohort study. METHODS: This retrospective study involved 280 eyes of 140 myopia patients who underwent LASIK or epi-LASIK at the Baptist Eye Institute, Kyoto, Japan and who were followed for more than 5 years postoperatively. The patients were divided into 2 groups according to age: group A (age range, 20-29 years) and group B (age range, 30-39 years). In all patients, the RE and AL were measured at 1, 2, 3, 4, and 5 years postoperatively, and the 2 groups were compared in terms of each surgical method. RESULTS: The patients' mean age at surgery was 30.6 ± 4.9 years. No significant difference was found between the 2 groups in terms of the preoperative mean spherical equivalent (SE) or AL. In the LASIK group, the mean changes in SE during the 4 years of study in groups A and B were + 0.054 ± 0.256 D and + 0.052 ± 0.327 D, respectively (P = .93, NS), and the postoperative increases in AL were 0.059 ± 0.134 mm and 0.027 ± 0.133 mm, respectively (P = .08, NS). In the epi-LASIK group, the mean change in SE during the 4 years of study in groups A and B were -0.438 ± 0.207 D and -0.259 ± 0.454 D, respectively (P = .41, NS), and the postoperative increases in AL were 0.124 ± 0.141 mm and 0.094 ± 0.166 mm, respectively (P = .46, NS). CONCLUSION: Our findings showed no significant difference in myopia progression in patients in their 20s and 30s during a 4-year period after either LASIK or epi-LASIK.

Study of bandage contact lens on cornea epithelial healing after Epi-LASIK / 局解手术学杂志

Objective To observe the effect of bandage contact lens on cornea epithelial healing after Epi-LASIK,and to evaluate the efficacy and safety.Methods Prospective case-control study.The 92 cases(181 eyes) performing Epi-LASIK were devided into observation group and control group.The 46 cases(91 eyes) of the control group were covered with routine nursing and the other 46 cases (90 eyes) of the observation group were served with bandage contact lens after Epi-LASIK.The symptoms and signs,time of corneal epithelial recovery,visual acuity and pain of postoperation of the two groups were examined within one week.Results After Epi-LASIK treatment,there was no significant difference in visual acuity between the two groups(P ＞ 0.05).At the 1 st,3rd,and 7th day after Epi-LASIK treatment,the ache grading results of the observation group were (2.53 ± 0.62),(1.39 ± 0.71),(0.07-± 0.25);and the ache grading results of control group were (3.22 ± 0.79),(1.74 ± 0.49),(0.26 ± 0.49).Pain scores of observation group were significantly lighter than that of the control group (P ＜ 0.05).After Epi-LASIK treatment,the average time of corneal wound healing in the observation group and control group were (2.80 ±0.86) days and (4.07 ±0.68) days respectively.The average time of postoperative corneal wound healing in the observation group was shorter than control group(P ＜ 0.05).Conclusion The application of bandage contact lens on cornea epithelial healing after Epi-LASIK treatment can reduce the pain of patients and promote the recovery of cornea in myopia patients.

Clinical features of subepithelial layer irregularities of cornea.

PURPOSE: To illustrate surgical outcomes of subepithelial irregularities that were identified incidentally during laser refractive surgery. MATERIALS AND METHODS: The study group consisted of 406 patients who underwent 787 surface ablation refractive surgeries. Ophthalmologic evaluations were performed before each procedure and at 1, 3 and 6 months post-operatively. Subepithelial irregularities were evaluated by analyzing still photographs captured from video recordings. Sizes and locations were determined by a calibrated scale located at the major axis of the tracking system's reticle. RESULTS: Subepithelial irregularities were identified in 27 eyes during 787 surface ablation refractive surgeries. Most of the subepithelial irregularities did not show any abnormalities in the wavefront aberrometer. However, one case with diameter greater than 1.00 mm and one case of clustered multiple subepithelial irregularities with moderate size were corresponded significant coma (Z31) and increased higher order aberration (HOA) in the HOA gradient map. CONCLUSIONS: Corneal subepithelial irregularities may be related to problems that include significantly increased localized HOA and remaining permanent subepithelial opacity. Subepithelial irregularity should be considered even if the surface of the cornea is intact and there are no specific findings measured by corneal topography.

Excimer laser surface ablation: a review of recent literature.

The aim was to review the recently published literature on excimer laser surface ablation procedures, including photorefractive keratectomy (PRK), laser sub-epithelial keratomileusis (LASEK), microkeratome-assisted PRK (epi-LASIK) and trans-epithelial (laser-assisted) PRK, to help elucidate where and how surface ablation may best fit into current refractive surgical practice. The emphasis was on publications within the last three years and included systemic reviews, meta-analyses and randomised controlled trials. Where such evidence did not exist, selective large series cohort studies, case-controlled studies and case series with follow-up preferably greater than six months were examined and included. Refractive and visual outcomes are excellent and comparable to those after LASIK even in complex cases after previous corneal surgery. Indeed, surface ablation combined with corneal collagen cross-linking may be used in selected eyes with biomechanical instability, where LASIK is contraindicated. In addition, there is evidence to suggest that there may be less induction of higher order aberrations with surface techniques. Long-term stability and safety appear to be extremely satisfactory. The literature supports the use of modern excimer laser surface treatments, with outcomes comparable to those after LASIK and evidence of less induction of higher-order aberrations. Follow-up studies at 10 to 20 years indicate excellent stability and safety.

Laser-assisted subepithelial keratectomy versus epipolis laser in situ keratomileusis for myopia: a meta-analysis of clinical outcomes.

BACKGROUND: To identify possible differences between laser-assisted subepithelial keratectomy and epipolis laser in situ keratomileusis for myopia. DESIGN: Meta-analysis. PARTICIPANTS: Patients from previously reported comparative studies treated by laser-assisted subepithelial keratectomy versus epipolis laser in situ keratomileusis. METHODS: A systematic literature retrieval was conducted in the MEDLINE, EMBASE and Cochrane Library, up to January 2013. The included studies were subject to a meta-analysis using a RevMan 5.1 version software. MAIN OUTCOME MEASURES: The differences in efficacy, predictability, safety, epithelial healing time, pain perception and corneal haze formation. RESULTS: A total of six studies involving 517 eyes were included. There were no statistically significant differences in the final proportion of eyes with uncorrected visual acuity of 6/6 or better (P = 0.43), mean postoperative uncorrected visual acuity (P = 0.53), final proportion of eyes with refraction within ± 0.50 D (P = 0.62) and ± 1.00 D (P = 0.16) of target, final proportion of eyes losing two or more lines of best spectacle-corrected visual acuity (P = 1.00), healing time of corneal epithelium (P = 0.58), final proportion of eyes with corneal haze grade 0.5 or higher (P = 0.26), and corneal haze levels (P = 0.36). CONCLUSIONS: There were no significant differences in efficacy, predictability, safety, epithelial healing time and corneal haze formation between laser-assisted subepithelial keratectomy and epipolis laser in situ keratomileusis, but the result was limited. Future more data are required to detect the potential differences between the two procedures.

Long term results of Epi-LASIK and LASEK for myopia.

PURPOSE: To evaluate the long term clinical and confocal results of mechanical (Epi-LASIK) versus alcohol-assisted laser epithelial keratomileusis (LASEK) for correction of myopia. SETTING: Gazi University Medical School, Department of Ophthalmology, Ankara, Turkey. DESIGN: Retrospective study. METHODS: Twenty-two eyes treated with LASEK and twenty eyes treated with Epi-LASIK were evaluated with a mean follow-up duration of 45 months. Mechanical separation of the epithelium was performed with Lasitome epithelial separator, and alcohol-assisted separation with 25s application of 18% alcohol. Laser ablation was performed with the ESIRIS laser. All patients were examined daily until epithelial closure; at 1, 3, 6, and 12 months; and every year subsequently. Main outcome measures were uncorrected visual acuity (UCVA), manifest refraction, haze, and gray scale value in confocal microscopy, efficacy and safety indexes. RESULTS: Preoperative myopic spherical equivalent refraction was -4.65 ± 1.74 D in the LASEK and -3.87 ± 1.30 D in the Epi-LASIK-treated eyes (p=0.36). Of both LASEK and Epi-LASIK-treated eyes, 95% achieved 20/25 or better final UCVA. The grade of haze and mean gray scale value in confocal microscopy were similar in LASEK and Epi-LASIK-treated eyes at all postoperative periods. The efficacy index was 0.94 in LASEK group and 0.96 in Epi-LASIK group (p=0.44). The safety index was 1.01 in LASEK group and 1.02 in Epi-LASIK group (p=0.42). CONCLUSIONS: Both LASEK and Epi-LASIK offer safe and effective correction of myopia in the long term.

Management of post-photorefractive keratectomy pain.

Photorefractive keratectomy (PRK) is a refractive procedure gaining popularity that eliminates the risk of ectasia and flap complications that can occur after laser in situ keratomileusis. Post-operative discomfort is a major drawback after PRK and thus the management of pain and discomfort following PRK is of great importance. We summarize corneal pain pathways and summarize current approaches to pain management after PRK.

Comparison of clinical results between flap-on and flap-off techniques of epithelial-laser in situ keratomileusis in correction of low to moderate myopia in eyes with thin corneas.

PURPOSE: To prospectively compare flap-on and flap-off techniques of epithelial-laser in situ keratomileusis (epi-LASIK) for the correction of low to moderate myopia in patients with thin corneas. METHODS: In this randomized, interventional study, the cohort was comprised of 88 eyes (44 patients) with myopia which underwent epi-LASIK. The epithelium was separated as a 9 mm flap with 2-4 mm nasal hinge with epikeratome (Lasatom, Gebauer Medizintechnik GmbH, Neuhausen, Germany) and the ablation was performed with the MEL 80 excimer laser (Carl Zeiss, Meditec, Jena, Germany). Thirty-eight eyes underwent flap-on Epi-LASIK where the flap was repositioned after ablation (flap-on group) and 50 eyes underwent flap-off Epi-LASIK where the epithelial flap was discarded (flap-off group). Pre- and post-operative uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), and spherical equivalent (SE) were collected for each group. Post-operative pain, time to epithelialization, and corneal haze were also collected postoperatively. Variables were compared with the paired t-test, chi-squared test and one-way analysis of variance. Statistically significance was indicated by p < 0.05. RESULTS: The mean preoperative SE was -3.89 ± 1.9 diopters (D) for the flap-on group and -3.92 ± 2.17 D for the flap-off group (p = 0.96). The mean follow-up was 12 months. The mean pain score was comparable on all postoperative days except the 2nd postoperative day where the flap-on had significantly lower mean pain scores (p = 00). Time for epithelial healing was 4.39 ± 0.49 days in flap-on group and 4.64 ± 0.69 days in flap-off group (p = 0.07). There was no significant difference in the postoperative UCVA between groups (p = 0.77). Corneal haze at the end of postoperative follow-up was not different between groups (p = 0.217). CONCLUSION: There is no significant difference in the clinical outcomes between flap-on and flap-off techniques of Epi-LASIK for the correction of low to moderate myopia.

Comparison of TGF-ß1 in tears and corneal haze following Epi-LASIK with and without mitomycin C.

AIM: To compare transforming growth factor-ß1 (TGF-ß1) levels in tears and the degree of corneal haze formation following epithelial laser in situ keratomileusis (Epi-LASIK) with and without the use of mitomycin C (MMC) and to investigate the effect of MMC on corneal wound healing. METHODS: Thirty-two patients (64 eyes) with high myopia underwent Epi-LASIK surgery, and MMC was randomly used in one eye in each patient. The epithelialization process was observed, and the TGF-ß1 level in tears was measured at 1 day, 3, and 7 days postoperatively for comparison with baseline. Corneal haze was graded at 1 month, 3, and 6 months after surgery. RESULTS: Mean preoperative spherical equivalent refraction was -8.24±2.18D (range -6.00 to -10.50D) in the MMC group and -7.82±1.55D (range -6.00 to -9.75D) in the non-MMC group. There was no significant difference between the two groups (P=0.38). Mean epithelialization time was (5.02±0.68) days in the MMC group and (4.86±0.57) days in the non-MMC group (P=0.31). Tear fluid TGF-ß1 levels were similar before surgery (P=0.34), but were significantly higher in the non-MMC group at 1 day, 3, and 7 days postoperatively (P=0.004, 0.008, and 0.012, respectively). Corneal haze scores 1 month after surgery were significantly higher in the non-MMC group (P=0.03), and similar at 3 and 6 months after surgery (P=0.28 and 0.62, respectively). CONCLUSION: MMC did not delay epithelialization. In early postoperative period, lower TGF-ß1 levels in tears and a lower grade of corneal haze were observed in the MMC group. Our findings suggest that the ability of MMC to inhibit Epi-LASIK-induced haze might be mediated through TGF-ß1 suppression.

Evaluation of analgesic efficacy of bromfenac sodium ophthalmic solution 0.09% versus ketorolac tromethamine ophthalmic solution 0.5% following LASEK or Epi-LASIK.

BACKGROUND: To evaluate the analgesic efficacy of bromfenac sodium ophthalmic solution 0.09% compared with ketorolac tromethamine ophthalmic solution 0.5% in laser epithelial keratomileusis (LASEK) or epithelial keratomileusis (epi-LASEK), sometimes referred to as epi-LASIK. METHODS: Eighty eyes (from 40 patients, 18 men and 22 women) undergoing bilateral simultaneous LASEK or epi-LASEK were randomized to receive ketorolac in one eye and bromfenac in the other. Mean age was 33.13 ± 9.34 years. One drop of bromfenac or ketorolac was instilled in each eye 15 minutes and one minute prior to surgery, and two and four hours following surgery. Patients were instructed to instill the medications on-label each day through postoperative day 4. The subjects completed pain and visual blurriness assessments from day of surgery to postoperative day 4. Uncorrected visual acuity was tested on postoperative days 1 and 6. RESULTS: For each of the five days, pain scores for bromfenac-treated eyes were significantly less than that for ketorolac-treated eyes (P < 0.01). Of the 40 patients, 32 (80%) said bromfenac provided better postoperative analgesia than ketorolac. There was no statistically significant difference in visual blurriness scores between the two groups (P > 0.1). Uncorrected visual acuity did not vary significantly between the treatment groups (P > 0.1). No serious adverse events were noted. CONCLUSION: Bromfenac is subjectively superior to ketorolac in reducing postoperative pain following LASEK or epi-LASEK. The subjects tolerated the drugs well with no serious adverse outcomes and no difference in uncorrected visual acuity.

Meta-analysis of clinical effectiveness of on-flap and off-flap epi-LASIK for myopia / 中华实验眼科杂志

Background Recently,whether the epithelial flaps should be removed or preserved during the Epi-LASIK and its affection on clinical results are concerned.Objecfive This system analysis was to evaluate and compare the clinical effectiveness between on-flap Epi-LASIK and off-flap epi-LASIK for myopia. Methods A systematic literature retfieval was conducted in the MEDLINE,EMBase,Coehrane Library,CBM disc,CNKI from 2003 through 2009.The possible differences in reepithelization time,pain sensation,and haze after surgery were compared between on-flap and off-flap Epi-LASIK for myopia.The statistical analysis was performed using a RevMan 4.2 software.The data was extracted,and the methodological quality was evaluated by two reviewers independently with weighted mean difierence(WMD)for the effectiveness analysis and odds ratio(OR)for counting variable.The quality of included literature was scored according to the Jadad Scale. Results A total of 8 studies involving 251 patients(502 eyes)were included in the meta-analysis.Of these eight studies.five studies were randomized clinical trials and the other three studies were retrospective cohort studies.Compared with on-flap Epi-LASIK group,off-flap Epi-LASIK group had a better postoperative outcome in the mean reepithelization time(WMD=1.32,95％CI-1.82to-0.82,P<0.01)and pain scores at 3,5 day(WMD=-O.99,95％CI-1.71 to-0.28,P(0.01)(WMD=-0.94.95％CI-1.35 to-0.54,P<0.01)after surgery.No significant difierenees were found in the eye numbers of haze at 1 month(OR=0.62,95％C1 0.34 to 1.12,P=0.11),3 months(OR=0.70,95％C1 0.31 to 1.55,P=0.38)and 6 months(OR=1.14,95％C1 0.58 to 2.26,P=0.71)between these two types of operation.The pain scores at the first day after surgery was not significantly different between these two groups(WMD=-0.17,95％CI -0.55 to 0.20,P=0.37). Conclusion The effectiveness of off-flap Epi-LASIK is superior to on-flap Epi-LASIK for myopia.Some high-quality randomlizd and control studies are needed for the further clinical evaluation.

Early postoperative pain and visual outcomes following epipolis-laser in situ keratomileusis and photorefractive keratectomy.

PURPOSE: To compare early postoperative pain and visual outcomes after epipolis-laser in situ keratomileusis (epi-LASIK) and photorefractive keratectomy (PRK) in the treatment of myopia. METHODS: A retrospective chart review was designed and included 49 eyes in 30 patients who underwent epi-LASIK and 54 eyes in 29 patients who underwent PRK. During the early postoperative period (days 1 to 5), pain, uncorrected visual acuity (UCVA), and time to epithelial healing were recorded. Visual outcomes were followed for up to six months. RESULTS: Mean preoperative spherical equivalent refraction for the epi-LASIK group was -3.99+/-1.39 diopters (D) and that of the PRK group was -3.54+/-1.27 D. The pain scores on the fourth postoperative day were significantly higher in the epi-LASIK group than in the PRK group (p=0.017). Duration of pain in the epi-LASIK group was longer than in the PRK group (p=0.010). Mean healing time was significantly longer in the epi-LASIK group than in the PRK group (p<0.000). In addition, UCVA in the epi-LASIK group at postoperative days 1 and 3 were significantly lower than those in the PRK group (p=0.021 and p<0.000, respectively). Uncorrected visual acuity at one week and one month after epi-LASIK were lower than those after PRK (p=0.023 and p=0.004, respectively). CONCLUSIONS: In the epi-LASIK patients, pain relief, corneal healing, and visual recovery seemed to be slower during the early postoperative period compared to those of the PRK patients. With longer duration of follow-up, however, there were no significant differences in visual outcome between the two groups.

Comparison of Short Term Clinical Results Between Epi-LASIK and Femtosecond LASIK

PURPOSE: To compare short-term clinical results of femtosecond LASIK with those of epi-LASIK. METHODS: Twenty subjects (40 eyes) underwent femtosecond LASIK and 20 subjects (40 eyes) underwent epi-LASIK for myopia with astigmatism. The results of each surgery were compared with regard to visual acuity, spherical equivalent, safety, efficacy, stability, predictability and high order aberration. RESULTS: Postoperative uncorrected visual acuities were 0.51 +/- 0.11, 0.95 +/- 0.08, and 0.97 +/- 0.08 for epi-LASIK and 0.76 +/- 0.19, 0.97 +/- 0.07, and 0.98 +/- 0.06 for femtosecond LASIK at one week, one month, and two months after surgery, respectively. Femtosecond LASIK showed faster improvement in visual acuity. Postoperative spherical equivalents were -0.83 +/- 0.24, -0.31 +/- 0.19, and -0.27 +/- 0.09 for epi-LASIK and -0.47 +/- 0.21, -0.28 +/- 0.15, and -0.25 +/- 0.12 for femtosecond LASIK. Safety, efficacy, stability, and predictability showed no differences between the two groups. High order aberrations were increased significantly; however, no significant difference between the two groups was found. CONCLUSIONS: Both epi-LASIK and femtosecond LASIK are effective for surgical correction of myopia with fast visual rehabilitation. In addition, epi-LASIK and femtosecond LASIK showed good safeties, efficacies, predictabilities, and stabilities.

Early Postoperative Pain and Visual Outcomes Following Epipolis-Laser In Situ Keratomileusis and Photorefractive Keratectomy

PURPOSE: To compare early postoperative pain and visual outcomes after epipolis-laser in situ keratomileusis (epi-LASIK) and photorefractive keratectomy (PRK) in the treatment of myopia. METHODS: A retrospective chart review was designed and included 49 eyes in 30 patients who underwent epi-LASIK and 54 eyes in 29 patients who underwent PRK. During the early postoperative period (days 1 to 5), pain, uncorrected visual acuity (UCVA), and time to epithelial healing were recorded. Visual outcomes were followed for up to six months. RESULTS: Mean preoperative spherical equivalent refraction for the epi-LASIK group was -3.99+/-1.39 diopters (D) and that of the PRK group was -3.54+/-1.27 D. The pain scores on the fourth postoperative day were significantly higher in the epi-LASIK group than in the PRK group (p=0.017). Duration of pain in the epi-LASIK group was longer than in the PRK group (p=0.010). Mean healing time was significantly longer in the epi-LASIK group than in the PRK group (p<0.000). In addition, UCVA in the epi-LASIK group at postoperative days 1 and 3 were significantly lower than those in the PRK group (p=0.021 and p<0.000, respectively). Uncorrected visual acuity at one week and one month after epi-LASIK were lower than those after PRK (p=0.023 and p=0.004, respectively). CONCLUSIONS: In the epi-LASIK patients, pain relief, corneal healing, and visual recovery seemed to be slower during the early postoperative period compared to those of the PRK patients. With longer duration of follow-up, however, there were no significant differences in visual outcome between the two groups.

Postoperative Pain and Epithelial Wound Healing in Epi-LASIK With and Without an Epithelial Sheet Preservation

PURPOSE: To investigate the influence of preservation of an epithelial sheet in Epi-LASIK on postoperative pain and epithelial wound healing time. METHODS: This prospective study included 34 eyes of 17 patients with myopia who received Epi-LASIK. An epithelial flap was created using the epikeratome (Centurion SES, Norwood Abbey EyeCare, Australia). After the stroma was ablated using the MEL 80 (Carl Zeiss Meditec. Germany) excimer laser, the epithelial sheet was replaced on the stromal bed in one randomly selected eye of each patient, and removed in the contralateral eye. The pain scores at postoperative day 0, 1, 2, 5 and the numbers of days for the complete epithelial wound healing were compared between the sheet-preserved and the sheet-removed eyes. At 1 month postoperative, uncorrected visual acuity (UCVA), refractive error and corneal haze were also compared. RESULTS: Pain scores on the day of operation were lower in sheet-preserved group and statistically significant (p=0.01). On postoperative day 1, 2, and 5, pain scores did not reach statistical significance (p=0.24, 0.08, 0.56, respectively). The mean epithelial healing time was 4.88+/-0.93 days for the flap-preserved eyes and 4.29+/-0.77 days for the flap-removed eyes, which showed statistical significance (p=0.01). No significant difference was noted between the 2 groups for mean UCVA, corneal haze and refractive error at 1 month postoperative. CONCLUSIONS: A preserved epithelial sheet reduced early postoperative pain but did not accelerate epithelial wound-healing rate.

Comparison of Short Term Clinical Results Between LASEK and Epi-LASIK

PURPOSE: To compare short-term clinical results of LASEK and epi-LASIK. METHODS: Fifteen subjects (30 eyes) underwent uncomplicated LASEK on one eye and uncomplicated epi-LASIK on the other eye by a single surgeon, and uncorrected visual acuity, refractive change, postoperative pain, and postoperative satisfaction were compared at postoperative week one, at one month, and at three months. RESULTS: Postoperative uncorrected visual acuities were 0.68+/-0.20, 0.96+/-0.22, and 1.05+/-0.17 for LASEK and 0.75+/-0.21, 0.92+/-0.14, and 1.01+/-0.21 for epi-LASIK at one week, one month, and three months, respectively. Epi-LASIK showed faster improvement in visual acuity at one week, while LASEK showed faster improvement afterward. However, no statistical significance was found. Spherical equivalet of LASEK was -0.66+/-1.28D and that of epi-LASIK was -0.61+/-0.92D at postoperative week one, implying faster refractive recovery for epi-LASIK, but after one month, LASEK was faster in refractive recovery and all these changes were not statistically significant. Durations of postoperative pain were 3.13+/-1.25 days for LASEK and 3.02+/-1.32 days for epi-LASIK. Pain scores (0~10 point scale), however, were also lower for LASEK by 0.33 point, 0.57 point, and 0.45 point for postoperative day 1, 2, and 3, respectively. No statistical significance was noted in either pain duration or pain score. When asked for overall satisfaction, six subjects preferred LASIK, four subjects preferred epi-LASIK, and five subjects showed no preference. CONCLUSIONS: Both LASEK and epi-LASIK are effective for surgical correction of myopia, and no significant difference in visual recovery, refractive change or degree of postoperative pain was noted in this study.

Comparison of Laser Epithelial Keratomileusis Versus Epipolis-Laser in Situ Keratomileusis for Moderate to High Myopia

PURPOSE: To compare the clinical visual results and complications of laser-assisted subepithelial keratectomy (LASEK) and epipolis laser in situ keratomileusis (Epi-LASIK). METHODS: A retrospective analysis of a case series of eyes treated with LASEK or Epi-LASIK with a follow-up of six months was performed. Twenty-two eyes were treated with LASEK, and 20 eyes were treated using Epi-LASIK. The main outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and manifest refraction at one week, one month, three months, and six months after refractive surgery, and the presence of any complications. RESULTS: There was no significant difference of UCVA and mean postoperative spherical equivalent (SE) between the eyes treated with LASEK or Epi-LASIK at one week, three months, and six months. However at one month there was significant difference of UCVA. Additionally, in a comparison between moderate and serve myopia, there was no significant difference of UCVA and mean postoperative spherical equivalent (SE) between groups treated with LASEK or Epi-LASIK at one week, one month, three months, and six months. Seven eyes treated with LASEK and two eyes treated with Epi-LASIK showed persistent epithelial erosion less than one week. Two eyes treated with LASEK exhibited newly-developed corneal opacity, which persisted-through the last visit. CONCLUSIONS: Epi-LASIK showed clinical visual results and complications comparable to LASEK and showed better epithelial healing.

Factors Associated with the Successful Separation of Corneal Epithelium in Epi-LASIK

PURPOSE: To determine the incidence and perioperative factors of flap-related complications from Epi-LASIK. METHODS: In this study, 122 eyes of 66 patients who had Epi-LASIK using Centurion SES(TM) epikeratome (Norwood Eye Care, Australia) were enrolled. Associations of pre-operative corneal curvature, white-to-white distance, central corneal thickness, refractive error, dry eye, punctate corneal erosion, pannus, and history of wearing contact lenses with flap-related complications were investigated. To decrease flap-related complications, surgeons pressed patients' eyelids with a speculum during epithelial separation, and the effect of this method was verified. RESULTS: Complete epithelial separation was achieved in 74 eyes (60.6%), incomplete separation in 29 eyes (23.8%), and free epithelial sheet in 19 eyes (15.6%). Thin corneas (P=.041), a history of wearing contact lenses (P=.008), and the duration of contact lens use (P=.003) significantly decreased the incidence of successful epithelial separation. Pressing down the eyelids with a speculum while separating the epithelial sheet increased the incidence of complete separation from 50.6% to 83.8% (P=.003). CONCLUSIONS: The risk of flap-related complications from Epi-LASIK may be higher in people who use contact lenses and in people who have thin corneas. The risk can be reduced by pressing the eyelids with a speculum during epithelial separation.

The impact of recombinant human epidermal growth factor on a number of parameters after Epi-lasik surgery / 重庆医科大学学报

Objective:To investigate the impact of recombinant human epidermal growth factor(rhEGF)on a number of parameters following Epi-lasik surgery.Methods:Two hundreds cases with myopia(396 eyes)were randomly divided into two groups:100 cases in both groups.Epi-lasik was performed on these patients.Patients receiving non-steroid,corticosteroid,antibiotic and artificial-tears eye drops following Epi-lasik were categorized into control groups.Patients receiving rhEGF eye drops 3 days before and after Epi-lasik in combination with postoperative non-steroid,corticosteroid,antibiotic and artificial-tears eye drops were categorized into rhEGF group. Breakup time of tear film(BUT)was evaluated before and after the operation.Haze development,the rate of the flap melting,healing time of melted flap,postoperative irritation,residual refractive error and visual acuity were evaluated after the operation.Results:There was no difference between control group and rhEGF group concerning the preoperative spherical equivalent,preoperative BUT,the rate of postoperative flap melting,residual refractive error 6 months after Epi-lasik.However,there was significant difference between control group and rhEGF group as regard the following parameters:postoperative BUT,control group,10.43?1.08 s,rhEGF group 12.21?1.43 s,P