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AIM: To investigate the probably mechanism of amniotic extraction inhibiting haze formation after epipolis laser in situ keratomileusis (Epi-LASIK) in rabbit cornea.METHODS: Thirty rabbit corneas were performed with Epi-LASIK.All eyes were randomly divided into three groups: eyes treated with amniotic extraction (AE group),eyes treated with 1g/L dexamethasone (hormone group) and eyes treated with solvent (solvent control group).Haze grade evaluation was performed under the slit lamp after Epi-LASIK for 1,4 and 8wk.The repair of corneal epithelium was observed by using HE staining,and the expression of NF-kB protein P65 was detected by immunohistochemistry.The expression levels of inflammatory cytokines (TNF-α,TGF-β1 and IL-1) and anti-inflammatory cytokines (IL-4,IL-10 and IL-13) were determined by ELISA.RESULTS: HE staining showed that the basal cells of corneal epithelium were more uniform and arranged regularly in AE groups after Epi-LASIK for 1wk as compared with the hormone group and the solvent control group.After 4wk,there were a few of new collagen fibers in the superficial stroma of AE group,forming a small amount of scar.After 8wk,the corneal stroma of AE group showed a small amount of new collagen fibers,arranged regularly,and rarely formed scar.At the early stage (1 and 4wk),AE treatment has an obviously effect on inhibiting the secretion of inflammatory factors (TNF-α,TGF-β1 and IL-1) and anti-inflammatory factors (IL-4,IL-10 and IL-13),and the difference was statistically significant (P<0.01).Moreover,the activation of the NF-kB signaling pathway was significantly inhibited by treatment with AE in the early postoperative period (1 and 4wk).CONCLUSION: Amniotic extraction may reduce the inflammatory response in corneal epithelial cells by inhibiting the NF-kB signaling pathway,thereby inhibiting the formation of collagen and scar and the occurrence of haze.
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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.
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AlM: To comprehensively evaluate of visual quality after epipolis laser in situ keratomileusis ( EPl-LASlK) in mild to moderate myopia.METHODS: Sixty cases ( 120 eyes ) undergone EPl-LASlK with equivalent diopter ( SE ) were divided into two groups:mild myopia group (60 eyes) and moderate myopia group ( 60 eyes ) . Objective visual acuity, aberration, contrast sensitivity and glare sensitivity were measured before and 1wk; 1, 6mo after operation, and made comparative analysis. RESULTS: Postoperative uncorrected visual acuity ( UCVA ) of two groups were better than that of preoperative(P<0. 05). Postoperative 6mo, there were significant differences on total high RMS between two groups ( P < 0. 05 ). Before operation and 6mo after operation, higher - order aberrations had statistically significant difference between two groups (P<0. 05). After 1wk and 1mo, there were statistical significances at the five frequencies between two groups (P<0. 05). After 6mo, the mild myopia group returned to preoperative levels, however, moderate myopia group in the high frequency region ( 18. 0c/d ) had significant difference with before surgery (P<0. 05). 1wk after surgery, there were statistically significant differences on the 3. 0, 6. 0, 12.0, 18. 0c/d frequency in both groups (all P<0. 05), 1mo after surgery, there were significant difference at 12.0, 18.0c/d frequencies (all P<0.05), after 6mo, both groups returned to preoperative levels, showed no significant difference.CONCLUSlON:Visual quality is poorer in mild myopia patients than that in moderate myopia at early stage after EPl-LASlK. Better visual quality is observed at mid-late stage.
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By reshaping the cornea without the creation of a stromal flap, excimer laser corneal surface ablation eliminates flap-related complications and avoids the risk of ectasia that may occur after laser assisted in situ keratomileusis ( LASIK ) . Post-operative pain is one of the most significant disadvantages of surface ablation and thus the management of pain and discomfort following surface ablation is of great importance. We summarize mechanism of corneal pain and current approaches to pain management after surface ablation.
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Background Wearing of soft contact lens,as one of the important methods to correct ametropia,has been widely applied at present.The clinically deleterious effects of soft contact lens have been reported,but researches about influence of apoptosis of corneal epithelial cells are scant.Objective This study was to detect and compare the ratio of apoptosis of corneal epithelial cells between the patients with contact lens wearing and without contact lens wearing,and explore the influence of soft contact lens wearing for long term on growth of corneal epithelial cells after injury.Methods A retrospective nest case-controlled study was designed.Forty eyes of 20 myopic patients with wearing of soft contact lens for ≥5 years and 40 eyes of 20 myopic patients without wearing of soft contact lens were included in Affiliated Hospital of Guiyang Medical College.All the patients received the off-flap epipolis laser in situ keratomileusis (Epi-LASIK) from 2010 October to 2011 June.The corneal flaps were collected during the surgery.The apoptosis of corneal epithelial cells was detected by flow cytometry(FCM),and the difference of apoptotic proportion between the two groups was compared using independent sample t test.Results The FCM scatter plot showed that compared to the without contact lens wearing group,the early stage of apoptotic cells with high staining annexin V and low staining proaium iodide (PI) were much more,and survival cells with low staining annexin V and PI were less,and necrotic and late stage of apoptotic cells with high staining of annexin V/PI were more in the with contact lens wearing group.The early stage of apoptosis proportion of corneal epithelial cells was (11.23 ± 5.31)％ in the with contact lens wearing group,and that in the without contact lens wearing group was (7.31± 5.43)％,showing a significant difference between them (t=2.754,P=0.008).Conclusions A long term wearing of contact lens induce more apoptosis of corneal epithelial cells,which can result in a disorder of structure and function of ocular surface during the wound healing stage.
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Background Tight junctions are thought to play a significant role in the maintenance of the corneal epithelial defense for the eye,and the restoration of the tight junctions is critical during epithelial wound healing after refractive surgery.However,there are few reports about this study. Objective The aim of this study was to investigate and compare the expression of occludin in corneal epithelium following flap-free epipolis laser insitu keratomileusis (Epi-LASIK) and laser-assisted subepithelial keratectomy ( LASEK ). Methods Forty-eight clean New Zealand white rabbits were randomized into 2 groups,and 24 rabbits for each group.Flap-free Epi-LASIK and LASEK were performed in the right eyes of the rabbits in two groups,and other 2 age matched normal rabbits were as normal controls.The animals were sacrificed and the corneal samples were obtained at 1,2,3,5 days after surgery.Immunofluorescence staining was used to detect the expression of occludin in the corneal epithelium,and RT-PCR was used to identify the level of occludin mRNA in the central cornea. Results Occludin protein was expressed innormal corneal epithelium and showed the green fluorescence with the regular arrangement.The fluorescence intensity was lower in 1 -2 days in LASEK group with the irregular arrangement;while the fluorescence signal in corneal epithelium was stronger in flap-free Epi-LASIK group.3-5 days after surgery,the fluorescence intensities were bothenhanced in two groups.RT-PCR showed that the relative expression of occludin mRNA in corneal epithelium was 0.11 ±0.02,0.25 ± 0.03,0.43 ± 0.04 in LASEK group 1,2,3 days after surgery,respectively,and was lower than those of flap-free Epi-LASIK group ( 0.20± 0.04,0.44 ± 0.04,0.76 ± 0.04 ),showing significant differences between these two groups ( t =6.476,12.898,17.315,P＜ 0.05 ).No significant difference was seen in the expression of occludin mRNA in 5 days after surgery between two groups( t=-0.733,P＞0.05).The relative values of occludin mRNA expression in corneal epithelium were gradually increased with time prolongation,presenting a significant difference among various time points ( Ftime =768.903,P =0.000). Conclusions The reformation of occludin in flap-free Epi-LASIK group is faster than that in LASEK group.Therefore,flap-free Epi-LASIK is prominant in reducing the stimulated symptoms and complication after the surgery.
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We report the outcome of conventional epipolis laser in situ keratomileusis (Epi-LASIK, flap-on) and lamellar epithelial debridement (LED; Epi-LASIK, flap-off) in myopic patients with dermatologic keloids. Three patients, who were all noted to be susceptible to keloid scarring, received conventional Epi-LASIK in their right eyes and LED in their left eyes. The patients were followed-up for 6 to 21 months after their surgeries, and the outcomes were then evaluated. In case 1, the preoperative spherical equivalent (SE) was -6.5 diopters (D) in the right eye (OD) and -6.25 D in the left eye (OS). At 21 months postoperatively, the uncorrected visual acuity (UCVA) was 20 / 12.5 in both eyes. In case 2, the preoperative SE was -5.25 (OD) / -6.00 (OS). After six months, the postoperative UCVA was 20 / 12.5 in both eyes. In case 3, the preoperative SE was -4.5 (OD) / -2.0 (OS). The UCVA at the six-month follow-up was 20 / 12.5 in both eyes. No adverse events, including corneal haze, occurred in any of the patients. All three of our patients reported excellent visual outcomes following both conventional Epi-LASIK and LED, despite their histories of keloid formation. The present cases suggest that both Epi-LASIK and LED may be safe and effective techniques for myopic patients with dermatologic keloids.
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Adulto , Feminino , Humanos , Desbridamento , Óculos , Seguimentos , Queloide/complicações , Ceratomileuse Assistida por Excimer Laser In Situ/métodos , Miopia/complicações , Período Pós-Operatório , Dermatopatias/complicações , Resultado do Tratamento , Acuidade VisualRESUMO
Background Epipolis laser in situ keratomihusis(Epi-LASIK) is an potential surgery for myopia because it synthesize advantages of LASEK and LASIK. But its clinical effectiveness and safeness is remarkable.Objective This study was to evaluate the clinical curative effects and safeness of Epi-LASIK for myopia in different diopter of population. Methods Retrospective study was designed for 208 eyes of 104 patients who underwent EpiLASIK for the correction of myopia. The patients were divided into two groups according to preoperative diopter:lower myopia group( ≤ -6.00 D, 111 eyes) and high myopia group ( ＞-6.00 D,97 eyes). The time of epithelial healing, postoperative syndrome, postoperative visual acuity, refraction, intraocular pressure (IOP) , the safe index, the efficacy index and haze were evaluated at 1,3,6,12 months postoperatively. The written informed consent was obtained from each individual before surgery. Results After operation, 20 eyes ( 18.02% ) of lower myopia group and 29 eyes (29.90%) of high myopia group had obvious pain, presenting statistically significant difference between two groups (X2 = 4. 060, P＜0.05 ). The mean time of epithelial healing was (5.49±0. 83 )days in lower myopia group and (5.85± 0.68 )days in high myopia group with a delayed epithelial healing time in high myopia group( u= 3. 377 ,P＜0.05 ).One year after the treatment,the uncorrected visual acuity( UCVA ) ≥ 1. 0 was 90. 99% ( 101 eyes) in lower myopia group and 75.26% ( 73 eyes) in high myopia group, and 9.91% ( 11 eyes) and 15.46% ( 16 eyes) of the eyes improved byl line or more in best spectacle corrected visual acuity(BCVA) ;whereas 3.60% (4 eyes)and 6. 18% (6 eyes)lost a line or more. 91.89% ( 102 eyes) and 85.57% (83 eyes) in both groups gained within 1.00 D of the attempted correction. The safety index and efficacy index were 1.04 and 0. 98 in lower myopia group,and 1. 01 and 0. 96 in high myopia group without statistically significant difference( P＞0. 05 ). haze occurred in 6 eyes in lower myopia group and 9 eyes in high myopia group and the difference in haze grading was not statistically significant between two groups ( P＞0. 05 ). The high intraocular pressure appeared in 10 eyes and 9 eyes in low myopia group and high myopia group respectively during the fellow up duration and back to normal after topical use of timolol. Conclusion Epi-LASIK is an effective and safe method for correction of different diopters of myopia because of its mild symptom and lower incidence of haze.
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Background Compare with the lamellar laser refractive surgery,the laser slip on the surface operation is a better method in the correct of refractive error without the flap-related complications.However,whether to remain corneal epithelial flap and its influence for epithelial healing and visual restoration are still under investigation.Objective The aim of this study was to compare the short-term clinical efficacy of epipolis laser insitu keratomileusis (Epi-LASIK) and flap-free Epi-LASIK for correction of refractive error in high myopia.Methods The paired control design was adopted.Sixty eyes of consecutive 30 patients with high myopia were collected in this study.The written consent form was obtained from each patients prior to operation.Regular EpiLASIK was performed in the right eyes and the flap-free Epi-LASIK was carried out in the left eyes.Patients were followed-up for one month.The postoperative ocular irritation symptoms were scored,and the healing period of corneal epithelium and uncorrected visual acuity were examined at 1,3 and 5 days after operation.The naked visual acuity,diopter,best corrected visual acuity and the grading of haze were recorded and compared between the two groups at one month after operation.Results After surgery,the scores of corneal irritation were 3.13 ±0.43 and 3.30±0.47on the first day,showing insignificant differences between these two groups (t =- 1.54,P＞0.05 ).However,there existed statistically significant difference in the scores of corneal irritation on the third day after operation between the two groups (t =- 17.95,P＜0.01 ).The average time of corneal epithelial healing were (2.58 ±0.49 ) days in the flapfree Epi-LASIK group and ( 3.98 ±0.74) days in Epi-LASIK group with the significant difference between them (t=-11.36,P＜0.01 ).There was no statistical difference in uncorrected visual acuity in the first day (0.59±0.12 vs 0.58±0.11,t=0.39,P＞0.05),the fifth day (0.69±0.08 vs 0.67±0.09,t=0.84,P＞0.05) and 1 month (t =-1.90,P＞0.05 ).No significant difference was seen in the diopter between the two groups in 1 month after surgery (-1.03±0.45 vs -1.07 ±0.38,t =-0.31,P＞0.05 ).The eye numbers of corneal haze for 0 grade were 27 ( 90.00％ ) and over the 0.5 grade were 3 ( 10.00％ ) in flap-free Epi-LASIK group respectively,and those of corneal haze for 0 grade were 26(86.66％ ) and above the 0.5 grade were 4 (13.33％) in Epi-LASIK group respectively,showing a considerably difference between the two groups (x2 =0.0031,P＞0.05).Conclusions Both the flapfree or reserved epithelial Epi-LASIK allow the safe and effective correction of refractive error in high myopia,showing good predictability and stability in short term.Flap-free Epi-LASIK can relieve the corneal irritation symptom and accelerate the healing of corneal epithelium and recovery of visual acuity.
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Background Free-flap Epi-LASIK surgery show a fast epithelial healing and mild trauma responses.Its mechanism is notable. Objective The aim of this study was to compare the corneal epithelial healing response following photorefractive keratectomy(PRK)and flap-free Epi-LASIK surgery. Methods Twelve experimental rabbits were randomly assigned to high cutting group(-10.00 D)and low cutting group(-3.00 D),and 2 normal matched rabbits were used as controls.PRK was performed in lateral eyes and flap-free epipolis laser in situkeratomileusis(Epi-LASIK)surgery was curried out in the fellow eyes.The corneal wound healing response in early stage of post-operation was examined under the slim lamp,and the inflammatory cells infiltration in cornea,basic fibroblast growth factor(bFGF)and nuclear transcription factor(NF-KB)expressions in corneal stroma were detected by hematine-eosin staining and immunohistochemstry in the seventh day after operation. Results The inflammatory reaction was milder in the eyes with Epi-LASIK than ones of PRK under the slim lamp.No significant difierences were found in numbers of inflammatory cells in cornea.expressions of bFGF and NF-κB in corneal stroma between two types of surgeries in low cutting group(P＞0.05).In high cutting group,the numbers of inflammatory cells were(12.25±1.22)/400 field in PRK eyes,and those of free-flap Epi-LASIK eyes were(6.67±0.31)/400 field,showing obvious difference between them(t=-8.87,P＜0.01).Expressions of NF-κB(A value)in cornea were 6.11±1.36 and 41.82±8.7 1 in PRK eyes of low cutting group and high cutting group.and those in free-flap Epi-LASIK were 3.01±0.81 and 11.59±4.55.indicating a drastically increase in PRK eyes(P＜0.05).The expressions of bFGF(A value)in corneal stroma were 33.59±6.98 and 123.68±18.81 in PRK eyes and those in free-flap Epi-LASIK eyes were 69.20±8.85 and 123.68±1 8.81 in low cutting group and high cutting group,presenting a considerably decrease in PRK eyes (P＜0.05).The corneal epithelial healing was faster in free-flap Epi-LASIK eyes than that in PRK eyes.and deeper cutting slowed the healing procedure. Conclusion In low cutting group,healing time of corneal epithelium is close between PRK and flap-free Epi-LASIK.But in high cutting group,epithelial healing is faster and inflammatory reaction is lighter in flap-free Epi-LASIK compared with PRK.
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Objective To evaluate the efficacy of Epipolis laser in situ keratomileusis(Epi-LASIK)and laser in situ keratomileu- sis(LASIK)on high myopia patients.Design Prospective,case-controlled study.Participants 62 patients(123 eyes)with high myopia. Methods 62 patients(123 eyes)underwent Epi-LASIK or LASIK surgery for high myopia:28 patients(56 eyes)underwent Epi-LASIK and 34 patients(67 eyes)underwent LASIK.The differences in postoperative uncorrected visual acuity(UCVA),best corrected visual acuity(BCVA),refraction,and root mean square(RMS)of high-range wavefront aberration were compared one-week,one-month, three-months and six-months postoperatively.Main Outcome Measures UCVA,BCVA,refraction,and RMS of high-range wavefront aberration.Results There was no serious complication during and after the operation.The recovery of postoperative UCVA after Epi-LASIK was slower than that of LASIK.One week postoperatively,the proportion of UCVA≥0.8 of Epi-LASIK(46.4%)was less than that of LASIK(77.6%)(P=0.0003).No significant differences were found in those of Epi-LASIK(85.7%,94.6%,91.1%)and those of LASIK(92.5%,95.5%,94.0%)one-month,three-months and six-months postoperatively(P=0.590,0.822,0.530).BCVA was same after Epi-LASIK and LASIK.The proportion of mean spherical equivalents within?0.50D for Epi-LASIK(42.9%,51.8%,60.7%,64.3%)had no difference with those for LASIK(53.7%,59.7%,71.6%,73.1%)one-week,one-month,three-months and six-months postoperatively (P=0.230,0.378,0.200,0.290).The postoperative RMS increased after both surgeries,especially after LASIK.At postoperative one-month,three-months and six-months RMS of Epi-LASIK(1.51?0.77)?m,(1.32?0.76)?m,(1.18?0.71)?m were much higher than the (0.87?0.27)?m preoperative ones(P=0.016,0.019,0.026).At postoperative one-month,three-months and six-months RMS of LASIK (2.41?0.81)?m,(2.17?0.63)?m,(1.89?0.87)?m were also much higher than the preoperative(0.91?0.22)?m(P=0.011,0.008,0.006). There were significant differences between the RMS of Epi-LASIK and LASIK one-month,three-months and six-months postoperatively (P=0.039,0.035,0.033).The I grade haze was found in two eyes after Epi-LASIK.Conclusion Epi-LASIK has better visual quality re- sult than LASIK on correcting high myopia.(Ophthalmol CHN,2007,16:336-339)