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@#AIM:To analyse of refractive regression after laser <i>in situ</i> keratomileusis(LASIK)in moderate and high myopic eyes.<p>METHODS:A retrospective study. Thirty patients(60 eyes)with refractive regression after LASIK in our hospital from January 2016 to January 2018 were selected for statistical analysis. According to preoperative refraction, they were divided into three groups: moderate myopia group(<-6.00D), high myopia group(-6.00 to -10.00D)and super high myopia group(>-10.00D). The visual acuity, diopter, corneal curvature, CCT, intraocular pressure, ocular axis and residual corneal matrix thickness were analyzed before and after surgery.<p>RESULTS:The refractive regression rate was 8.6%(60/700 eyes). At 6mo after operation, the refractive regression of the patients were as follows: moderate myopia group, 1.31±0.15D, high myopia group, 1.76±0.23D, ultra-high myopia group: 2.53±0.35D(<i>P</i><0.05). At 6mo after operation, the diopter(-0.82±0.21, -1.03±0.27, -1.57±0.52D)of the three groups was different from that of the preoperative(-4.87±0.97, -7.46±1.03, -10.32±2.01D)and 1mo(+0.49±0.22, +0.73±0.17, +0.95±0.15D)after operation(all <i>P</i><0.05). At 6mo after operation, the CCT of the three groups(499.80±33.78, 458.89±36.93, 451.93±24.52μm)decreased(<i>P</i><0.05)compared with that before operation(523.80±23.00, 527.24±25.47, 525.80±22.36μm), and increased(487.92±38.13, 440.65±33.92, 429.35±20.14μm). There was no difference in ocular axis(25.25±0.30, 26.52±0.62, 28.63±0.21mm)between the three groups at 6mo after operation and before operation(25.13±0.54, 26.13±0.54, 28.03±1.04mm)(<i>P</i>>0.05), but there was difference between the two groups(<i>P</i><0.05). The thickness of residual corneal stroma in moderate myopia group, high myopia group and ultra-high myopia group were 332.27±21.87, 292.71±22.71 and 273.38±20.99μm, respectively(<i>P</i><0.05). There was no difference in corneal curvature and intraocular pressure between the three groups at 6mo after operation(<i>P</i>>0.05).<p>CONCLUSION: The occurrence of refractive regression after LASIK is related to preoperative refraction. High myopia and ultra-high myopia may have refractive regression due to progressive growth of eye axis, while moderate myopia may have refractive regression due to increased corneal thickness and corneal curvature changes caused by post-operative matrix repair.
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AIM:To investigate the clinical effect of excimer laser in situ keratomileusis ( LASIK ) for high myopia and its effects on central corneal thickness ( CCT ) , corneal endothelial cell density, and contrast sensitivity.?METHODS: Totally 120 cases (240 eyes) in Ophthalmic Center in our hospital with high myopia were retrospectively analyzed from November 2014 to July 2016. According to the operation method, those cases were divided into LASIK group (60 cases 120 eyes), laser assisted sub-epithelial keratectomy ( LASEK ) group ( 60 cases 120 eyes ) , and treatment effect between the two groups was compared.?RESULTS: After surgery, at 1, 3, 6 and 12mo, visual acuity, refraction spherical equivalent value between the two groups were not significantly different at each time point ( P>0. 05 ); spherical equivalent refractive power were significantly improved compared with preoperative values in the two groups (P<0. 05); at 1a after surgery, the CCT, corneal endothelial cell density of the LASIK group were greater than those of the LASEK group, the difference was statistically significant (P<0. 05). Before surgery, contrast sensitivity with 3c/d, 6c/d, 12c/d, 18c/d spatial frequency was not statistically significant between the two groups ( P > 0. 05 ); at 1a after the operation, contrast sensitivity of LASIK group with 6c/d, 12c/d spatial frequency was significantly lower than that of the LASEK group, the difference was statistically significant (P<0. 05).?CONCLUSION: The clinical effect of LASIK on high myopia is certain, and it has little effect on CCT and corneal endothelial cell density, but it has obvious influence on the contrast sensitivity.
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Excimer laser in situ keratomileusis (LASIK) is a typical surgical technique which precisely cutting cornea to rectify refractive error with excimer laser.Since the safety,stability,predictable postoperative vision affirmed,it has been accepted by multiple myopia patients in recent years.AC/A is a significant composition of visual function.Nowadays,numerous scholars have pay close attention to its transformation after LASIK,and this paper reviewed the variation trend of AC/A,the influencing factors and its possible mechanisms.
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@#Objective To compare the therapeutic effect of epithelial flap removed laser subepithelial keratomileusis (LASEK) and femtosecond laser assisted LASIK (FS-LASIK) in the treatment of moderate and low myopia. Methods A total of 103 patients (103 eyes) of low and moderate myopia were selected, 51 patients (51 eyes) were treated with LASEK and 52 patients (52 eyes) were treated with FS-LASIK. Data of uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), residual equivalent spherical degree (SE), total high-order aberrations (HOAs), spherical aberration, coma and trefoil were examined before operation and 1month and 3 months after operation, and compared between two groups of patients. Results There were no significant differences in UCVA and BCVA 1 month and 3 months postoperatively between the two groups. SE shifted to myopia direction in LASEK group compared with that of FS-LASIK group 1 month postoperatively (P＜0.05), but reached a similar level 3 months after surgery. The HOAs and spherical aberration were significantly increased 1 month and 3 months postoperatively compared with those before operation in LASEK and FSLASIK groups (P＜0.05). Coma was significantly increased 1 month postoperatively in FS- LASIK group and returned to the preoperative level 3 months postoperatively, while it remained at baseline 1 month and 3 months postoperatively in the LASEK group. The HOAs and coma were significantly higher 1 month postoperatively in FS-LASIK group compared to those of LASEK group (P＜0.05), while they reached a similar level 3 months postoperatively. Conclusion The therapeutic effect of epithelial flap removed LASEK can reach a level equal to FS-LASIK at the early stage after surgery. It is a good selectable choice for patients with low to moderate myopia.
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AIM:To investigate the curative effect of 1 g/L bromfenac sodium eye drops on high myopia astigmatism in patients after sub-Bowman keratomileusis.· METHODS:Totally 48 cases (96 eys) of High myopic astigmatism (-6.00D＜ equivalent sphere＜-11.00D) from our hospital were selected and randomly divided into 2 groups,24 cases(48 eyes) each.The control group was treated with fluorometholone eye drops,the experimental group was treated with 1g/L bromfenac sodium eye drops,and 2 groups were treated for 2wk.Uncorrected visual acuity,intraocular pressure and corneal topography (K1,K2,the degree of astigmatism) were recorded,at the same time visual symptoms and signs score,corneal haze and DLK were compared at preoperative and postoperative 1d,1wk,1 and 3mo.RESULTS:At different time points,uncorrected visual acuity,intraocular pressure,K1 value,K2 value,the degree of astigmatism of the two groups were statistically significant (P ＜ 0.05).Compared with preoperative,distance visual acuity increased at postoperative 1d,1wk,1 and 3mo;at postoperative 1 and 3mo intraocular pressure decreased(P＜0.05).Compared with the control group,the patients in the experimental group had better uncorrected visual acuity at postoperative 3mo and lower intraocular pressure at postoperative 1 and 3mo(P＜0.05).Compared with preoperative,K1,K2 value of two groups decreased at postoperative 1 and 3mo,the degree of astigmatism increased(P＜0.05).There was no significant difference in K1,K2 and astigmatism between the two groups at postoperative 1 and 3mo (P＞ 0.05).The symptoms and signs of the two groups were similar,and there was no haze phenomenon after operation.The DLK evaluation of the experimental group was better than that of the control group (P＜0.05).CONCLUSION:The 1 g/L bromfenac sodium eye drops and fluorometholone eye drops have similar efficacy in the treatment of SBK after operation,but it can effectively reduce the risk of DLK and intraocular pressure,avoid the adverse reactions caused by glucocorticoid,and is an effective treatment plan.
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To analyze dryeye disease after the femtosecond laser and mechanical microkeratome for laser in situ keratomileusis ( LASlK ) by Oculus dry eye analyzer examination.METHODS: The people who had femtosecond LASlK ( FS-LASlK ) and mechanical microkeratome LASlK in Weifang Eye Hospital from January 2014 to April 2014 were observed. Sixty patients ( 120 eyes ) who had corneal refractive surgery were collected. The average age of patients was 27. 46 ± 6. 65 years old. The LASlK group had 28 patients ( 56 eyes ) and the FS-LASlK group had 32 patients ( 64 eyes ) . The tears river altitude, first tear break up time ( BUT) , and average BUT at preoperative, 1wk and 1mo after operation were observed by Oculus dry eye analyzer.RESULTS:By Oculus dry eye analyzer examination, the preoperative tears river altitude of patients was 0. 25 ± 0. 10mm. First BUT was 6. 70 ± 3. 86s. Average BUT time was 10. 14 ± 4. 51s. At 1wk after operation, the tears river altitude of patients was 0. 19±0. 04mm. The first BUT time was 4.87±1.71s. The average BUT time was 7.77±2.30s. There was significant difference between preoperative and 1wk after operation (P<0. 05). At 1mo after operation in two groups, the tears river altitude of patients was 0. 19 ± 0. 18mm . The average BUT 8. 72 ± 2. 54s. The BUT was 5. 02 ± 2. 30s. There was significant difference between preoperative and 1mo after operation (P<0. 05). The two groups had significant difference in average tears river altitude and average BUT between 1mo and 1wk after operation. There was no significant difference in the first BUT between 1mo and 1wk after operation. There was no significant difference between LASlK and FS - LASlK groups at any time of the test (P<0. 05).CONCLUSlON: LASlK and FS - LASlK patients have different degree of dry eye symptom after operation. Dry eye symptoms mainly display in the decrease of tear production and the stability of tear film. lt will be better after giving artificial tears. Oculus dry eye analyzer is a non-invasive examination equipment. lt can reflect the amount of tears and the stability of tear film. lt is usefull in rapid diagnosis of dry eye and judgment of the degree of dry eye symptom after LASlK operation.
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Background Femtosecond laser in situ keratomileusis (LASIK) inevitably injury keratocytes and corneal nerve fibers.The research report about postoperative morphological changes of corneal nerve regeneration and keratocytes in femtosecond LASIK is still rare.Objective The aim of this study was to observe the kinetic changes of keratocytes and corneal nerve in corneal flap after femtosecond LASIK.Method Femtosecond laser manufacture corneal flap of LASIK surgery was performed on 60 eyes of 30 patients with refractive error using both femtosecond laser system and excimer laser treatment system.The repair of corneal wound was examined by slit lamp microscope,and the morphology of keratocytes and corneal nerve were observed with confocal microscope 1 week,1month,3 months after surgery,respectively.Results No haze or flap folds were found under the slit lamp microscope from 1 week through 3 months after operation.One week after surgery,the corneal stromal cells at the interface of the corneal flap appeared to be a mild activation status in 42 eyes (70％),but the activated cells gradually reduced with lapse of time.Three months after surgery,mild activation state still was found in 7 eyes (12％).One week after surgery,independent,short (＜50 μm),curved subbasal nerve fibers were exhibited in 7 eyes (12％),and curved filamentous nerve fibers were discovered in 48 eyes (80％) one month after surgery.The nerve fiber length of subbasal nerve was ＞200 μm in 27 eyes (45％) and classes beaded structure appeared 3 months after operation but were still different with preoperative subbasal nerve fibers.One week after the operation,filaments or discontinuous nerve fibers could been seen in 46 eyes (77％) at theinterface,and long nerve fibers or filamentous nerves were visible around the terminal or periphery of nerve fibers in 49 eyes (82％) one month after surgery,and long nerve fibers or filaments of nerve fibers were visible in 57 eyes (95％) 3 months after the surgery.Conclusions Femtosecond LASIK cause wound reaction at cellular level.Corneal nerve fibers recover with the extension of time,but there are still some morphological differences 3 months after surgery from preoperation.
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Background Excimer laser corneal refractive surgery is widely used because it reduces the dependency of refractive error eye to glasses.However,the adverse effects of anti-inflammatory drugs is a problem after operation.Lotemax eyedrops is a kind of steroidal anti-inflammatory drug,with a good effect on the operative eye.But its influence on intraocular pressure(IOP) after long-term topical administration is less studied.Objective This study was to investigate the influence of lotemax eyedrops on IOP after long-term topical administration in myopic eyes received excimer laser corneal refractive surgery.Methods An one-month retrospective case serial study was adopted.The case history data of 1552 eyes from 1552 Patients who received excimer laser corneal refractive surgery were collected in Tangshan Eye Hospital from 2011 January to 2012 January,including 321 eyes with laser in situ keratomileusis(LASIK),608 eyes with sub-Bowman keratomileusis (SBK) and 623 eyes with femtosecond laser for flap excimer laser in situ keratomileusis(FS-LASIK).Lotemax eyedrops was topically administered after operation 4 times per day initial and then decreased 1 time weekly for 1 month.IOP was measured in before,1 week,2 weeks,3 weeks,4 weeks after operation with non-contact tonometer.The increasing range of IOP was divided into ＜5 mmHg,5-15 mmHg and ＞ 15 mmHg after operation.Optical head parameters were measured by Heidelberg retina tomography when IOP increasing after operation.Results Within 1 month,elevated IOP was found in 47 of 1552 eyes after administration of lotemax eyedrops,including 3.12％ (10/321) in the LASIK group,3.29％ (20/608) in the SBK group and 2.73％ (17/623) in the FS-LASIK group,without significant difference among them(x2 =1.95,P＞0.05).The IOP elevated 1 week after operation and remained normal after that till drug withdrawal in all eyes.There were no significant differences in the disk area (1.65 ±0.44) mm2 vs.(1.66 ±0.44) mm2,disk volume (0.40 ±0.09)mm3 vs.(0.39±0.08) mm3 and mean nerve fiber layer thickness (0.28 ± 0.08) mm vs.(0.29 ± 0.07) mm in IOP elevation duration compared with 1 month after IOP recovery(t =0.34,0.81,0.48,P＞0.05).Conclusions Topical administration of 0.5％ lotemax eyedrops after excimer laser corneal refractive surgery leads to reversible high IOP.It is very important to monitor the IOP during use of the drug.
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Background Whether negative suction during excimer laser in situ keratomileusis(LASIK) affect the structure and function of retina or not is in controversy,but it seems that temporary hypertention induced by negative suction is a key factor of impairment of retina in LASIK.ObjectiveThis study attempts to study the influence of transient high intraocular pressure (IOP) during LASIK on the contents of retinal amino acid.MethodsThe both eyes of 45 New Zealand white rabbits were suctioned for different periods (20s,45s,3min) with negative pressure generator during the LASIK to make the instantaneous high IOP models,and LASIK without negative suction was performed in the both eyes of 15 rabbits in the control group.The changes of the contents of retinal amino acids were evaluated with High Performance Liquid Chromatography(HPLC) at 0,7,10,14 and 28 days postoperatively and compared with those of control group.ResultsThere were no statistically significant differences in the contents of retinal amino acids among different time points after operation in negative suction for 20s group and 45s group,respectively(P＞0.05).At negative suction for 3minuts,the content of glutamic acid in retina was significantly increased in comparison with control group in 7,10,14 and 28 days (P＜0.05),and no statistically significant difference was seen in the contents of glutamic acid at postoperative instant group compared with control group(P＞0.05).A statistically significant difference in the contents of glutamine,tryptophan,phenylalanine was revealed among postoperative 10 days,14 days and 28 days groups comparison with control group (P＜0.05).ConclusionThe acute IOP elevation caused by negative suction during LASIK results in the reversible increase of retinal amino acids.The duration of negative suction time influent the reconstruction of retinal structure.
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Objective To explore the relationship between age and refractive predictability of excimer laser in situ keratomileusis (LASIK)for the correction of myopia.Design Retrospective case series.Participants 362 patients(703 eyes)who had performed LASIK.Methods According to the age,patients were divided into four groups(≤30y,31～34y,35～39y and≥40y).Their preoperative and postoperative refractive powers examined with automatic refactor as well as manifest optometry were analysed and followed up from 6 months to 2 years.According to pre-operative refractive power,patietns were divided into low and moderate myopia group(≤-6.00D), high myopia group(-6.25～-12.00D)and super-high myopia group(≥-12.25D).The eyes with refractive power at post-operative 2 years≥-1.00D were regressive eyes.Main Outcome Measures Refractive error before surgery,intended residual refractive power and 3,6, 12, 24 months post-operative refractive powers.Results There were no significant differences between intended residual refractive powers and refractive powers at post-operative 6 month in 3 groups(
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Objectives: To observe the clinical course of diffuse lamellar keratitis(DLK) after laser in situ keratomileusis(LASIK) and to investigate the presentation and management of DLK. Methods:Among 3500 patients underwent LASIK in our center, 18 eyes in 10 patients received DLK were examined. All eyes were examined with slitlamp biomicroscope at the course of 3 days,7 days,14 days,1 month, 2 months and 6 months after the operation. Visual actuity was measured. Results:Symptoms were controlled after 1 week treatment of topical corticosteroids and antibiotics. Resolution of DLK occurred after 1 to 2 months. Uncorrected visual acuity is 1.0 to 1.5 in 16 eyes and 0.8 to 1.0 in 2 eyes. Conclusions:DLK is a complication after LASIK, it usually occurs in 1 to 7 days postoperatively, more likely in male. Topical corticosteroids and antibiotics can get a satisfied outcome. Systemic corticosteroids and antibiotics are needed in serious cases. Early stage of DLK must be distinguished from corneal epithelial implantation and interface infection.
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Objective To evaluate the effect of modified suction ring in laser in situ keratomileusis(LASIK) for special eyeballs.Methods Those eyeballs that couldn't be sucked successfully with regular suction ring were performed with modified suction ring, and the characteristic of those eyes was analyzed.Results Fifteen eyes of 9 cases were included in this study and were sucked successfully with modified suction ring with intact corneal flap.Eight eyes of 5 cases had small corneal power especially in the peripheral section. The corneal power in the peripheral section of 7 eyes was less than 41D. Corneal diameter of 1 eye was 9.5mm and 6 eyes of 3 cases had small palpebral fissure.Conclusions The modified suction ring is safe and effective for those eyes with flat cornea, small corneal diameter and small palpebral fissure.
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Objective To evaluate the effects of the excimer laser in situ keratomileusis (LASIK) for treatment of high myopia.Methods LASIK was performed on 308 eyes of 186 patients who were followed up for one year. The patients were divided into two groups (group A and group B) according to preoperative diopters.Results One year after surgery, in group A(-6.0～-10.0D) the uncorrected visual acuities of 0.5 and 1.0 were in 95.76% and 77.58% of the eyes, the mean residual refraction was -0.32D±0.46D. In group B(-10.25～-20.0D) the uncorrected visual acuities of 0.5 and 1.0 were in 62.24% and 37.06% of the eyes, the mean residual refraction was -0.92D±1.13D.Conclusion It is an effective and safe refraction surgery to correct high myopia with LASIK.
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We studied 52 eyes of 41 patients who received excimer laser in situ keratomileusis with VisX 20/20 and were followed up for at least 6 months. Tweenty three patients were male and mean age was 30.7 years old (21-49 years old). Mean preoperative spherical equivalent was -11.69+/-4.02D and mean postoperative spherical equivalent was -0.49+/-1.32D at I month, -0.73+/-l.17D at 3 months and -1.11+/-l.21D at 6 months. Mean uncorrected visual acuity preoperatively was 0.06 and postoperatively was 0.62 at I month, 0.64 at 3 months, 0. 62 at 6 months. Mean corrected visual acuity preoperatively was 0.77 and postoperatively was 0.76 at I month, 0.78 at 3 months and 0.81 at 6 months. Seven eyes (13%) gained 2 lines or more of spectacle corrected visual acuity and I eye lost 2 lines of spectacle corrected visual acuity. There was no significant contrast sensitivity change between preoperation and postoperation. No eye had intraoperative complications. Postoperative complications included 9 eyes (17%) of interface foreign bodies, 7 eyes (13%) of cap microwrinkling and 15 eyes(29%) of night glare. No eye had postoperaive corneal opacity.