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.

Epilasik versus Lasek con queratectomía refractiva optimizada y ablación customizada por topografía / Epilasik versus Lasek with optimized refractive keratectomy and topography-customized ablation

OBJETIVO: Valorar la efectividad de la cirugía con excímer láser, utilizando como técnicas quirúrgicas para remover el epitelio corneal, láser epitelial queratomileusis in situ (Epilasik) o queratectomía epitelial asistida con láser (Lasek), a partir de un estudio topoaberrométrico en pacientes con astigmatismo miópico compuesto. MÉTODOS: Se realizó un estudio prospectivo en la consulta de Segmento Anterior del Centro Internacional de Retinosis Pigmentaria Camilo Cienfuegos. Se estudiaron 80 ojos de 40 pacientes, con astigmatismo miópico compuesto entre -1 y -6 dioptrías, con un seguimiento de 6 meses como mínimo. Se evaluó la agudeza visual sin corrección, queratometría, refracción dinámica, refracción cicloplójica, topografía corneal, paquimetría, tonometría, biomicroscopia, estudio de la lágrima y fondoscopia. En todos los casos se aplicó el software de análisis de frente de onda corneal. Se realizó Lasek en los ojos derechos y Epilasik en los izquierdos, con queratectomía refractiva optimizada en ambos procederes. RESULTADOS: En los casos en que se realizó Lasek, la agudeza visual sin corrección varió de 0,12 a 0,93, el promedio de esfera preoperatoria se modificó de -2,77 a -0,08 dioptrías en el posoperatorio, y el cilindro de -1,79 a -0,37 dioptrías, la aberración esférica a 6 mm solo cambió de 0,22 a 0,24 um y el coma de 0,19 a 0,20 um. En los casos en que se realizó Epilasik la agudeza visual sin corrección varió de 0,07 a 0,93, el promedio de esfera preoperatoria se modificó de -3,79 a -0,01 dioptrías en el posoperatorio y el cilindro de -1,25 a -0,35 dioptrías, la aberración esférica a 6 mm cambió de 0,26 a 0,39 um y el coma de 0,19 a 0,22 um. En cuanto a la microscopia confocal se observó que la recuperación fue más rápida en los casos operados mediante la técnica Epilasik. CONCLUSIONES: En ambas técnicas la mejoría de la agudeza visual fue estadísticamente significativa, disminuyeron la esfera y el cilindro promedio de forma muy similar...

OBJECTIVE: To assess the effectiveness of Excimer laser surgery, using either epithelial laser in situ keratomileusis (Epilasik) or laser-assisted epithelial keratectomy as surgical techniques, on the basis of a topoaberrometric study of patients with compound myopic astigmatism. METHODS: A prospective study was conducted in the Anterior Segment Service of Camilo Cienfuegos International Center of Pigmentary Retinitis. Eighty eyes from 40 patients with compound myopic astigmatism (-1 to -6 dioptres) were studied, with a minimal follow-up of 6 months. Visual acuity without correction, keratometry, dynamic refraction, cycloplexic refraction, corneal topography, pachymetry, tonometry, biomicroscopy, study of the tear and funduscopy were all evaluated. The corneal waterfront analysis software was used for all the cases. Lasek was the chosen technique for right eyes whereas Epilasik was used for left eyes, using optimized refractive keratectomy in both procedures. RESULTS: In those cases treated with Lasek technique, visual acuity without correction changed from 0,12 to 0,93; preoperative sphere average changed -2,77 to -0,08 dioptres at the postoperative phase, the cylinder went from -79 to -0,37 dioptres, spheral aberration at 6mm slightly changed from 0,22 to 0,24 um and the coma varied from 0,19 to 0,20 um. In the cases subjected to Epilasik, visual acuity without correction varied from 0,07 to 0,93; the preoperative sphere average modified from -3,79 to 0,01 dioptres in the postoperative period, the cylinder went from -1,25 to -0,35 dioptres, spheral aberration at 6mm changed from 0,26 to 0,39 um, and the coma varied from 0,19 to 0,22 um. As to confocal microscopy, it was observed that recovery was faster in cases operated on with Epilasik technique. CONCLUSIONS: The improvement in visual acuity was statistically significant in both techniques and the decrease in the average sphere and cylinder was very similar; however, the variation in the spheral aberrat...

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.

Measurements of Dynamic Contour Tonometry After Penetrating Keratoplasty and EpiLASIK

PURPOSE:To analyze the clinical results of Goldmann applanation tonometry (GAT) and Pascal dynamic contour tonometry (PDCT) and the influences of central corneal thickness and keratometric power in eyes that underwent EpiLASIK or penetrating keratoplasty. METHODS: Measurements of intraocular pressure by GAT and PDCT as well as keratometric power and central corneal thickness were measured in 45 eyes that underwent penetrating keratopasty and 63 eyes that underwent EpiLASIK. These parameters were also measured in healthy eyes with no specific disorders to create a control group. RESULTS: In the keratoplasty group, the PDCT results were significantly higher than the GAT results by 1.22+/-2.84 mmHg (p=0.006), but neither method showed a significant correlation with CCT or keratometric power. In the EpiLASIK group, PDCT was higher as 3.45+/-2.35 mmHg than GAT, and the corrected results of GAT were not different from the results of PDCT. In the control group, GAT was affected by central corneal thickness and keratometric power, but PDCT showed no significant relationship with these two factors. CONCLUSIONS: After EpiLASIK or penetrating keratoplasty, both of which change CCT and keratometric power, IOP cannot be accurately measured by GAT. In these patients, PDCT may play an important clinical role since it is less affected by corneal properties.

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.

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

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.

Clinical Outcomes of Wavefront-Guided Epi-LASIK: 6-Months Follow-up

PURPOSE: We evaluate the clinical outcomes after wavefront-guided (WFG) Epi-LASIK in mild and moderate myopia . METHODS: The uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), manifest refraction, total high order aberrations, contrast sensitivity for day and night vision, and pain score in 114 eyes of 61 patients who had undergone WFG Epi-LASIK were measured preoperatively and at 1 day, 1 week, 1 month, 2 months, and 6 months postoperatively. RESULTS: At 1 day, 1 week, 1 month, 2 months and 6 months postoperatively, UCVA & BCVA had improved significantly. At 1 month postoperatively, the spherical equivalent was -0.93+/-0.74 and showed a stable pattern at 6 months postoperatively. There was no statistically significant difference in total high-order aberration between preoperatively measurements and measurements taken at 6 months postoperative (p=0.745). At a frequency of 19 cpd, night contrast sensitivity showed significant statistical difference (p=0.010) but no difference at low and medium frequencies between preoperative measurements and postoperative six months measurements. Pain subsided at 2 weeks postoperative. All patients maintained clear cornea and suffered no complications. CONCLUSIONS: At 6 months postoperatively, patients who underwent Wavefront-guided Epi-LASIK showed successful results for the correction of moderate myopia and excellent contrast sensitivity at night time. Wavefront-guided Epi-LASIK may solve the visual quality problem after refractive surgery and, therefore, may be clinically useful.

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.

Corneal Epithelial Separation and Corneal Wound Healing Effect between Alcohol and Mechanical Device for Epithelial Flap

PURPOSE: Laser epithelial keratomileusis (LASEK) is a refractive surgery technique in which the cornea is covered with the epithelial flap after keratectomy. However, there have been reports of tissue damage by the alcohol utilized in this procedure while preparing the epithelial flap, which has led to novel methods. One of these is the mechanical designing of the epithelial flap named epipolis laser assisted in situ keratomileusis (Epi-LASIK). This study evaluates the histologic features and wound healing process of the corneal flap using Epi-Tome, which is the epithelial cutter of the newly introduced Epi-Lasik. METHODS: Twenty-four eyes of 12 dogs were devided into two groups. In one group (n=12), 20% alcohol was used and, in the other group (n=12), Epi-Tome (Gebauer, Germany) was used to make a corneal flap. The size change of a fluorescein-stained epithelial defect was followed postoperatively at 6, 12, 24, and 36 hours. RESULTS: The maximum decrease in defect size were observed at 0 to 6 hours in the Epi-Tome group, and from 6 to 12 hours in the alcohol group; the value were 10.01+/-5.32 mm2 and 9.23+/-4.75 mm2 respectively. Histologic review revealed that there was less tissue damage and smoother cut edge in the Epi-Tome group compared to the alcohol group, and the adhesion between stroma and epithelium was faster in the Epi-Tome group. CONCLUSIONS: Mechanically detached corneal flaps had favorable chances of survival such that re-epithelialization occurred early in the postoperative phase. A few epithelial fragments at a corneal section plane prevent corneal opacification and minimize inflammatory reaction, thus reducing postoperative pain.

An analysis of visual quality after Epi-LASIK / 医学研究生学报

Objective: Epi-LASIK appeared to be effective and safe in the treatment of high myopia,but some patients complain about visual symptoms postoperation.The purpose of this study was to evaluate the high order aberrations(HOAs) of the vision-decreased eyes treated by Epi-LASIK,and to analyze the causes of postoperative glare,scieropia and monocular diplopia.Methods: We evaluated 76 eyes of 49 patients treated by Epi-LASIK with a questionnaire three months after surgery,and from them selected 34 eyes of 27 patients who scored less than 80 points and complained of postoperative visual symptoms,including glare(25 eyes in 20 patients),scieropia(7 eyes in 5 patients)and monocular diplopia(2 eyes in 2 patients).Another 42 symptom-free eyes of 22 patients treated by Epi-LASIK were included in the control group.The root mean square(RMS) of total HOAs,coma and SA were determined with the iTrace Visual Function Analyzer from the central 6.0 mm zone,and the modulation transfer function(MTF) was simulated with the iTrace 3.1 software.Results: Significant differences were found in the RMS of total HOAs,coma and SA between the eyes with visual symptoms and those without,and the values of ablation zone decentration were significantly higher in the former than in the latter(P