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Objective:To investigate the status of corneal epithelial remodeling and changes in corneal aberration after femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) and FS-LASIK combined with corneal collagen cross-linking (FS-LASIK Xtra), and to analyze the relationship between corneal epithelial thickness (CET) and corneal aberration.Methods:A cohort study was conducted.A total of 172 patients (172 eyes) who underwent FS-LASIK at Yinhai Eye Hospital of Chengdu University of Traditional Chinese Medicine were enrolled from June 2021 to February 2022.The 172 eyes were divided into FS-LASIK group (94 eyes) and FS-LASIK Xtra group (78 eyes) according to the surgical procedure, with a total follow-up of 6 months.The cornea was divided into a central 2-mm ring and a ring of 2-5 mm centered on the central cornea.CET at 9 regions in the central 0-5 mm area was measured by OCT before and at 1, 3 and 6 months after surgery, and the corneal higher-order aberration (HOA) was measured by the iTrace visual function analyzer.The main outcomes were the increase in CET (ΔCET), and corneal HOA at 6 months after surgery.The relationship between central corneal ΔCET and corneal aberration was analyzed.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Yinhai Eye Hospital of Chengdu University of Traditional Chinese Medicine (No.2021yh-009). Written informed consent was obtained from each subject.Results:At 1, 3 and 6 months after surgery, the central, superior, superior nasal, nasal, inferior nasal, inferior, inferior temporal, temporal and superior temporal ΔCET were significantly smaller in FS-LASIK Xtra group than in FS-LASIK group (all at P<0.05). In FS-LASIK Xtra group, 6-month postoperative central, superior, superior nasal, inferior and inferior temporal ΔCET were significantly larger than those at 1 month after surgery, and 3- and 6-month postoperative temporal ΔCET were significantly larger than that at 1 month after surgery, and 6-month postoperative superior temporal ΔCET was significantly larger than those at 1 and 3 months after surgery (all at P<0.05). In FS-LASIK group, 3- and 6-month postoperative central, superior, inferior and inferior temporal ΔCET were significantly larger than those at 1 month after surgery, and 6-month postoperative superior nasal ΔCET was significantly larger than that at 3 months after surgery, and 6-month postoperative nasal, inferior nasal, temporal, superior temporal ΔCET were significantly larger than those at 1 and 3 months after surgery (all at P<0.05). There was no significant difference in vertical trefoil, vertical and horizontal coma changes at different time points after surgery between both groups (vertical trefoil: χ2group=4.27, P=0.118; χ2time=0.01, P>0.05.vertical coma: χ2group=5.74, P=0.057; χ2time=0.08, P=0.957.horizontal coma: χ2group=3.97, P=0.137; χ2time=0.51, P=0.773). The tilted trefoil changes at 1, 3 and 6 months after surgery of FS-LASIK Xtra group were significantly larger than those of FS-LASIK group (all at P<0.05). The 6-month spherical aberration change in FS-LASIK Xtra group was significantly higher than that at 1 month after surgery, and the 6-month spherical aberration change in FS-LASIK group was significantly higher than that at 1 and 3 months after surgery (all at P<0.05). The 6-month total HOA change in FS-LASIK group was significantly lower than that at 1 and 3 months after surgery (all at P<0.05). In FS-LASIK group, central corneal ΔCET was weakly positively correlated with spherical aberration at 1 and 6 months after surgery ( rs=0.257, P=0.008; rs=0.244, P=0.012), and was weakly positively correlated with total HOA ( rs=0.253, P=0.009; rs=0.279, P=0.004). Conclusions:The postoperative ΔCET after FS-LASIK Xtra is smaller than that after FS-LASIK, but the homogeneity of ΔCET in each region is similar between the two groups.The changes in corneal HOA after surgery are similar in both groups, and there is a certain association between the overall epithelial distribution and corneal aberration.
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Objective:To investigate the effect of peripheral plus ring size and its potential associations with pupil diameter (PD) on axial length (AL) elongation in myopic patients after wearing orthokeratology lenses.Methods:A case-control study was conducted.One hundred eyes from 100 myopic patients who underwent orthokeratolokgy lenses fitting were enrolled at Beijing Ming Vision and Ophthalmology from January to June 2020.AL and central corneal thickness (CCT) measurements were obtained using Lenstar LS900 ocular biometry, and steep keratometry (Ks), flat keratometry (Kf) were assessed using the TMS-4 corneal topographer.The patients were divided into larger peripheral plus ring diameter (LPPRD) group consisting of 55 eyes with PD<PPRD-0.9 mm and smaller PPRD (SPPRD) group consisting of 45 eyes with PPRD-0.9 mm <PD<PPRD+ 0.9 mm based on PPRD and PD sizes in the tangential difference map.Differences in the above parameters before and after wearing orthokeratology lenses were compared between the two groups.The study followed the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Ineye Hospital of Chengdu University of Traditional Chinese Medicine (No.2021yh-008). All the subjects and their guardians understood the purpose and method of the study and signed the informed consent voluntarily.Results:The PPRD of LPPRD group was (5.15±0.37)mm 12 months after wearing orthokeratology lenses, which was significantly higher than (4.75±0.32)mm of SPPRD group ( t=0.214, P<0.01). The elongation of AL at 3, 6, 9 and 12 months after wearing orthokeratology lenses were (0.13±0.07), (0.23±0.11), (0.31±0.13) and (0.36±0.41)mm in LPPRD group, and (0.06±0.05), (0.11±0.06), (0.14±0.07) and (0.17±0.08)mm in SPPRD group, respectively.There were significant differences in AL elongation at different time points after wearing orthokeratology lenses between the two groups ( Fgroup=30.527, P<0.01; Ftime=16.528, P<0.01), and the AL elongation at different time points was smaller in SPPRD group than in LPPRD group, showing statistically significant differences (all at P<0.01). Compared to before wearing orthokeratology lenses, Ks and Kf were significantly smaller and CCT was thinner 3, 6, 9, and 12 months after wearing orthokeratology lenses in both groups (all at P<0.01). There was no significant difference in Ks, Kf, and CCT between the two groups (all at P>0.05). There was no significant difference in PD at different time points before and after wearing orthokeratology lenses between the two groups ( Fgroup=1.133, P=0.293; Ftime=231.427, P=0.112). Conclusions:The size of peripheral plus ring and its relationship with PD are key factors influencing the AL elongation rate in myopic patients after wearing orthokeratology lenses.With smaller PPRD, patients have slower AL elongation and better myopia control.
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Objective:To observe the corneal morphology and visual quality after transepithelial photorefractive keratectomy (Trans-PRK) with smart pulse technique (SPT) and 1 050 Hz cutting frequency in the correction of myopia and astigmatism.Methods:A self-controlled case series study was conducted.Sixty five eyes of 33 patients who underwent Trans-PRK surgery in Ineye Hospital of Chengdu University of TCM from July 2017 to June 2018 were followed up for 6 months.The uncorrected visual acuity (UCVA) converted to logarithm of the minimum angle of resolution (LogMAR) unit, best corrected visual acuity (BCVA) (LogMAR), and spherical equivalent (SE) of the subjects were recorded.The anterior corneal surface symmetry index (SI), the anterior corneal surface Q value in the range of 6, 7, 8, and 9 mm diameter, the spherical aberration, coma, trefoil and total higher-order aberration of the anterior corneal surface, the strehl ratio (SR), and the modulation transfer function (MTF) of 10, 20, 30, and 40 c/d in the horizontal and vertical meridian directions before and after surgery were measured with Sirius corneal topography analyzer.The differences of each index among different time points were compared, and the correlation between indexes was analyzed by Pearson correlation analysis.This study followed the Declaration of Helsinki.The study protocol was approved by the Medical Ethics Committee of Ineye Hospital of Chengdu University of TCM (No.2020yh-004). All patients signed the informed consent form before surgery.Results:The average preoperative BCVA and SE were -0.09±0.06 and (-4.24±1.24)D.The mean UCVA and SE at 7 days, 1, 3 and 6 months postoperatively were -0.10±0.08 and (0.03±0.63)D, -0.12±0.06 and (0.08±0.53)D, 1.16±0.06 and (0.02±0.79)D, -0.18±0.05 and (0.08±0.37)D, respectively.The SI at different time points after the surgery were significantly higher than that before operation (all at P<0.05). At 1, 3 and 6 months after surgery, the Q value of anterior corneal surface in different diameter ranges increased from negative to positive, showing statistically significant differences (all at P<0.05). At each time point after surgery, the trefoil and total higher-order aberrations of the anterior corneal surface increased to varying degrees.Coma at 7 days and 6 months after surgery were significantly higher than that before surgery, and spherical aberration at 3 and 6 months after surgery were significantly higher than that before surgery (all at P<0.05). The SR values at 3 and 6 months after operation were significantly higher than that before operation (all at P<0.05). At 6 months after operation, the MTF values at different spatial frequencies of the horizontal meridian and the MTF values at 30 and 40c/d spatial frequencies of the vertical meridian were lower than those before operation, and the differences were statistically significant (all at P<0.05). The correlation analysis showed that the Q value of different diameter ranges was positively correlated with spherical aberration ( r=0.798-0.925, P<0.05), total higher-order aberration ( r=0.596-0.630, P<0.05), SI ( r=0.235-0.303, P<0.05) and corneal ablation depth ( r=0.583-0.659, P<0.05) at 6 months after surgery.SI was positively correlated with spherical aberration ( r=0.307, P<0.05), coma ( r=0.424, P<0.05), total higher-order aberration ( r=0.300, P<0.05), corneal ablation depth ( r=0.227, P<0.05), and eccentric cutting amount ( r=0.281, P<0.05). There was no correlation between SR and aberration, corneal ablation depth, eccentric cutting amount, etc.(all at P≥0.05). Conclusions:Trans-PRK using SPT to correct myopic astigmatism can improve vision, stabilize diopter, enhance retinal imaging quality, increase the asymmetry of the anterior corneal surface, and introduce different degrees of higher-order aberrations.
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Objective To analyze the epidemiological characteristics and seasonal distribution of hand, foot and mouth disease (HFMD) in a suburban town in Shanghai from 2012 to 2018, and to provide a scientific basis for formulating effective prevention and control strategies. Methods The incidence data of a suburban town in Shanghai from 2012 to 2018 was collected through the Chinese disease prevention and control information system and analyzed by descriptive epidemiological methods. Results From 2012 to 2018, a total of 538 cases of hand, foot and mouth disease were reported in the suburban town in Shanghai, with an average annual incidence of 186.27/100,000. The difference in incidence between each year was statistically significant (χ2=107.95, P<0.05). The age of onset was mainly children under 5 years old. Peak incidence was from May to September. The main occupation was scattered children. HFMD outbreaks mainly occurred in nurseries and schools, accounting for 60.53% of the total number of outbreaks. Conclusion From 2012 to 2018, the incidence of HFMD in a suburban town in Shanghai had a certain seasonality. It is recommended to implement preventive measures against HFMD for key populations and key places before the high incidence period to reduce the occurrence of severe cases and epidemic situations.
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Objective:To compare the clinical outcome of transepithelial photorefractive keratectomy (TransPRK) using 1 050 Hz ablation frequency and intelligent pulse technique (SPT) and small incision lenticule extraction (SMILE) for myopia and astigmatism.Methods:A cohort study was performed.Eighty-five eyes of 43 patients who received TransPRK for myopia and 85 eyes of 46 patients who received SMILE for myopia in the Ineye Hospital of Chengdu University of TCM were enrolled from August 2017 to April 2018.The follow-up duration was 6 months.The changes of visual acuity and diopter were observed and compared before and after operation, and the predictability, stability, safety, effectiveness and long-term vision were compared between the different surgeries.This study complied with the Declaration of Helsinki and the study protocol was approved by the Ethics Committee of Ineye Hospital of Chengdu University of TCM.Results:The refractive power tended to be emmetropic and relatively stable in the TransPRK group, and the refraction varied from mild hyperopia to emmetropic gradually during 6 months after SMILE.There was no significant difference in the spherical equivalent (SE) between the two groups before and after operation (all at P>0.05). No significant difference was found in mean validity index between the two groups at 6 months after surgery (1.189±0.248 vs.1.120±0.205; t=1.862, P=0.065). The uncorrected visual acuity (UCVA) in the SMILE group was significantly higher than that in the TransPRK group at 7 days and 1 month after surgery ( P<0.05), and there was no significant difference in UCVA between the two groups at 3 months and 6 months after surgery ( P>0.05). The safety index at 6 months after surgery in the TransPRK group was 1.209±0.222, which was significantly higher than 1.143±0.178 in the SMILE group, with a significant difference between the two groups ( t=2.024, P=0.045). Conclusions:The predictability, stability, safety, effectiveness and long-term vision are good after TransPRK with SPT and SMILE for myopia and astigmatism.The safety index is better in TransPRK compared with SMILE, and the restoration of vision is faster after SMILE than that after TransPRK.
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Objective:To evaluate the clinical reliability of ultra-wide field laser scanning ophthalmoscopy and indirect ophthalmoscopy for the fundus examination of myopia.Methods:A diagnostic test was performed.A total of 2 104 eyes of 1 052 myopic patients scheduled for corneal refractive surgery were enrolled from March to May in 2017 in Beijing Tongren Hospital, the subjects were firstly examined with ultra-wide field laser scanning ophthalmoscopy, then followed indirect ophthalmoscopy in full dilated pupil for the detection of fundus lesions.The total number of lesions, the number of lesion eyes, the lesions location and the missed diagnosis were analyzed and compared between the two examination methods.The consistency of the two methods was analyzed by Kappa test.This study followed the Declaration of Helsinki.and the written consent was obtained from the patients and their families.Results:A total of 186 fundus lesions in 137 eyes were screened out, of which 121 fundus lesions in 89 eyes were detected by both the two methods.For ultra-widefield laser ophthalmoscopy, 150 fundus lesions in 110 eyes were found and 36 fundus lesions in 27 eyes were missed; For indirect ophthalmoscopy, 157 of fundus lesions in 116 eyes were found and 29 fundus lesions in 21 eyes were missed.There was a good consistent of the detection rate of fundus leision between the two examination methods (kappa=0.776, P<0.001). There was a significant difference in the number for different kinds of retinal lesions between the two methods ( χ2=15.527, P=0.004). Compared with the indirect ophthalmoscopy, the ultra-wide field laser scanning ophthalmoscopy had a higher detection rate for lattice-like degeneration, retinal holes, and retinal detachment.There were no statistically significant differences between the two methods in the detection rate of fundus lesions, the number of fundus lesions among different ages, the number of fundus lesions among different quadrants, and the detection rate of fundus lesions among different diopters. Conclusions:Ultra-wide field laser scanning ophthalmoscopy is a reliable method for screening the fundus lesions of myopia in prerefractive surgery.The detection rate is similar to conventional dilated pupil indirect ophthalmoscopy.
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Objective@#To compare the visual quality after topography-guided customized femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and wavefront-optimized FS-LASIK treatment in myopic eyes.@*Methods@#A non-randomized controlled clinical study was performed.Seventy-eight eyes of 39 myopic patients undergoing FS-LASIK in Beijing Tongren Hospital from October 2016 to February 2017 were enrolled in this study and divided into two groups according to each patient's opinion, with matched demography between the two groups.Topography-guided customized FS-LASIK was performed on 42 eyes of 21 myopia in the topography-guided group, and wavefront-optimized FS-LASIK was performed on 36 eyes of 18 patients in the wavefront-optimized group.Visual acuity, refractive error, higher order aberrations (HOAs) and contrast sensitivity(CS) were compared between the two groups before and 6 months after surgery.Written informed consent was obtained from each patient before the operation.This study protocol was approved by Ethic Committee of Beijing Tongren Hospital (No.TRECKY2014-026).@*Results@#The postoperative uncorrected visual acuity (UCVA) levels were eaqual to or better than the preoperative best corrected visual acuity (BCVA) in 95.2% patients in the topography-guided group, and in 94.4% patients in the wavefront-optimized group 6 months after surgery, respectively.There were no significant differences in the spherical equivalent, sphere refraction and cylinder refraction between the two groups (all at P>0.05). The amount of induced coma was significantly lower in the topography-guided group than that in the wavefront-optimized group ([0.07±0.22]μm vs.[0.22±0.16]μm) at 6 mm pupil.LogCS improved under the 12.0 c/d in the background of mesopic in the topography-guided group and decreased under the 18.0 c/d both in the background of mesopic and mesopic + glare in the wavefront-optimized group 6 months after surgery, with signifcant differences between them (all at P<0.05). LogCS values under 6.0, 12.0 and 18.0 c/d in the background of mesopic and 18.0 c/d in the background of mesopic+ glare in the topography-guided group were significantly higher than those in the wavefront-optimized group 6 months after surgery, with significant differences between the two groups (all at P<0.05).@*Conclusions@#Topography-guided FS-LASIK has lower higher-order aberrations and better CS than wavefront-optimized FS-LASIK.
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Laser corneal refractive surgery is currently the most mainstream surgery to correct refractive errors.In recent years,the laser corneal refractive surgery has been developed rapidly in China.Femtosecond laser small incision lenticule extraction (SMILE) and the femtosecond laser flap laser in situ keratomileusis (LASIK) are greatly improving the safety of the laser lamellar corneal refractive surgery,and trans-epithelial photorefractive keratectomy (Trans PRK) is also taking the surface ablation of excimer laser to a new level.Compared with traditional excimer laser corneal refractive surgery,the above methods are more safe,stable and reliable.Trans PRK,SMILE and femtosecond flap LASIK combined with riboflavin corneal cross-linking provides a safe guarantee for the myopicpatients with thin cornea and abnormal corneal topography.As rapid progress and upgrading of laser corneal refractive surgery technologies,selection of operation methods is a new challenge.Ophthalmologists should comprehensively evaluate the corneal anatomical characteristics,individual needs of patients,performance of operating equipment andindications of different surgeries to pay more attention to the precise and personalized selection of laser corneal refractive surgery to improve the postoperative visual quality of patients with ametropia.
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Objective This study was to evaluate the long-term clinical efficiency of allogeneic corneal intrastromal lenticule inlay for correction of moderate and high hyperopia.Methods A prospective self-controlled case series study was adopted.Twenty-nine hyperopic patients (53 eyes) were performed with allogeneic corneal intrastromal lenticule inlays.The range of preoperative spherical equivalent was +3.75 to + 10 D,with the mean value of (+6.84±2.95)D.All the cases were followed up for 1 year.Uncorrected and best corrected visual acuity and refraction were compared between before and after operation.Corneal topography and optical coherence topography were used to examine corneal topography.Ocular response analyzer was used to evaluate the shifts of corneal hysteresis.This study followed the Helsinki declaration,and the research process was approved by the Ethic Committee of Beijing Tongren Hospital,and informed consent was signed by each donor and receptor.Results Compared with the before surgery,the uncorrected distance visual acuity (UDVA) and uncorrected near visual acuity (UNVA) were obviously improved and the spherical equivalent (SE) was obviously decresed in 3 months,6 months and 1 year after surgery,with significant differences between them (all at P＜0.05),but no significant differences were found between each postoperative time points (all at P＞0.05).One year after surgery,14 eyes (26.4％) gained one line of best corrected distance visual acuity (BCDVA),and 12 eyes (22.6％) gained two lines of BCDVA.Only 2 patients (5.66％) lost lines due to opaque lenticules,and no eye lost lines after changing the opaque lenticules.There was no obvious hyperopic fallback phenomenon.Compared with the before surgery,the average corneal curvature value (Avek) was obviously improved,the surface regularity index (SRI),surface asymmetry index (SAI) and central corneal thickness (CCT) were obviously increased in 3 months,6 months and 1 year after surgery,with significant differences between them (all at P＜0.05),but no significant differences were found between each postoperative time points (all at P ＞ 0.05).The cornea optical coherence tomography (OCT) examination showed that,after the operation,the corneal stromal implant was in place and clear.One year after surgery,the dividing line of corneal graft was still clearly visible.No significant changes of corneal hysteresis (CH) and corneal resistance factor (CRF) were seen among different time points before and after surgeries (F =1.443,P =0.216;F =1.744,P =0.128).Conclusions Allogeneic corneal small incision intrastromal lenticule inlays can be used to correct moderate and high hyperopic eye with good safety,effectiveness and predictability.It provides a new choice for hyperopic patients.
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Objective This paper reports a modified method for the isolation of rat thoracic aortic vascular smooth muscle cells based on combined enzyme double digestion.Methods An enzyme mixture containing collagenase II, soybean trypsin inhibitor and elastase was prepared and used to remove the aortic tunica intima and tunica adventitia, and then the tunica media was subjected to second digestion using the same enzyme mixture and to isolate vascular smooth muscle cells.Results The isolated VSMCs were cultured in vitro and the growing cells had an elongated spindle-shape, reached confluence within a week, and displaying a typical hill-and-valley pattern.After 1 week, the cells were passaged.Contractile smooth muscle markers(α-SMA, myosin-II and β-tubulin) were highly expressed in the isolated cells.More than 90% of the cells significantly expressed alpha smooth muscle actin and myosin-II.Conclusions Themethod established in this study has advantages of simple and easy to operate, and good reproducibility, with a high activity and purity of the separated cells.It can ensure to obtain a large amount of contraction-type vascular smooth muscle cells within a short time.
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Background Recently,small incision lenticule extraction (SMILE) procedure is used to correct myopia.The clinical safety and efficiency of SMILE have been approved,but its predictability to corneal ablation depth is brought into focus.Objective This study was to compare the predictability of ablation depth in central cornea between SMILE and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for myopia.Methods A nonrandomized controlled clinical study was performed.Two hundred and seventy eyes of 135 myopic patients who were going to receive corneal refractive surgery were included in Beijing Tongren Hospital from October 2015 to May 2016.SMILE and FS-LASIK were performed on 138 eyes of 69 patients and 132 eyes of 66 patients matched in demography respectively under the informed consent.Central corneal thickness was measured by RTVue FD-OCT before and 1 week after surgery.The refractive power,actual ablation depth (difference of central corneal thickness before and after surgery) and central corneal cutting error (difference between theoretically expected ablation depth and real ablation depth) were intergrouply compared,and the correlation of real ablation depth with theoretically expected ablation depth was assessed.Results No significant difference was found in spherical power,astigmatic power and spherical equivalent after surgery between SMILE group and FS-LASIK group (t =-1.826,-1.405,-1.420,all at P＞0.05).The actual ablation depth was (76.96± 15.27)μm in the SMILE group,which was significant lower than (96.76± 16.52) μm of theoretically expected ablation depth (t =-23.016,P ＜ 0.01);however,there was no significant difference in the FS-LASIK group between actual and expected ablation depth ([77.92 ± 18.69] μm versus [77.42± 15.60] μm) (t =-0.604,P =0.547).The central corneal cutting error was (20.55 ± 8.51) μm in the SMILE group and (7.17±5.97) μm in the FS-LASIK group,showing a significant difference between them (t=14.950,P＜0.01).The positive linear correlations were seen between actual and expected ablation depth in both SMILE group and FS-LASIK group (r=0.799,0.867,both at P＜0.01).The actual ablation depth was increased over expected ablation depth,with the regression equations of Y=3.892+0.749X in the SMILE group and Y=3.443 + 0.957X in the FS-LASIK group.Conclusions The actual corneal ablation depth is less than expected corneal ablation depth in SMILE procedure,while in FS-LASIK procedure,the actual corneal ablation depth appears to be consistent with the expected one,inferring a good predictability in corneal ablation depth in FS-LASIK surgery.
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Background Corneal refractive surgery has significant effects on corneal biomechanical properties.However,there are few study on large scale population with corneal biomechanical properties in the myopic population before corneal refractive surgery.Objective This study was to evaluate the change of corneal biomechanical properties and influence factors in myopic eyes using ocular response analyzer (ORA).Methods A prospective cohort study was carried out in Beijing Tongren Eye Center from April 2010 to January 2011.Corneal hysteresis (CH) and corneal resistance factor (CRF) were detected using ORA in 1 792 eyes of 896 myopic subjects who were going to receive corneal refractive surgery under the informed consent.According to different spherical equivalent (SE) the eyes were grouped into-0.25-＜-3.0 D group,-3.0-＜-6.0 D group,-6.0-＜-9.0 D group,-9.0-＜-12.0 D group,-12.0-＜-15.0 D group and ≥-15.0 D group and according to different central corneal thickness (CCT),the eyes were grouped into ＜500 μm group,500-＜550 μm group,550-＜600 μm group and≥600 μm group.The CH value and CRF value in different SE groups or different CCT groups were compared,and the factors influencing CH and CRF were analyzed by Pearson correlation analysis.Results The mean CH and CRF value were (9.84±1.52)mmHg (1 mmHg =0.133 kPa) and (10.46±1.71) mmHg,respectively in the myopic eyes.The CH values were (10.35±1.53),(10.07±1.55),(9.81±1.46),(9.71±1.59),(9.35±1.55) and (9.23±1.28) mmHg in the-0.25-＜-3.0 D group,-3.0-＜-6.0 D group,-6.0-＜-9.0 D group,-9.0-＜-12.0 D group,-12.0-＜-15.0 D group and ≥-15.0 D group,respectively,showing a significant difference among the groups (F=20.69,P＜0.01),and the CH values in the-6.0-＜-9.0 D group,-9.0-＜-12.0 D group,-12.0-＜-15.0 D group and ≥-15.0 D group were significantly lower than those in the-6.0-＜-9.0 D group,-9.0-＜-12.0 D group (all at P＜0.01).There was no significant difference in the CRF values among different SE groups (F =0.65,P =0.49).CH and CRF values were increasing with the raise of CCT,with evidently differences among the CCT＜500 μm group,500 μm ≤ CCT＜550 μm group,550 μm≤ CCT＜600 μm group and CCT≥ 600 μm group (CH:F=110.99,P＜0.01;CRF:F =84.35,P＜0.01),and the CH and CRF values were significantly higher in the 550 μm ≤ CCT＜600 μm group and CCT ≥600 μm group than those in the CCT＜500 μm group (all at P＜0.01).CH showed a positive correlation with SE (r =0.24,P＜0.01),and no significant correlation between CRF and SE (r =0.03,P =0.20).The CH and CRF showed the positive correlations with the CCT (r=0.42,0.57,both at P＜0.01).In addition,CH and CRF values increased as the increases of SE,corneal curvature (CC) and CCT values,with the regression equation of CH =-7.87+0.08SE+0.16CC+0.02CCT (R2=0.26,P＜0.01) and CRF=-11.42+0.14CC+0.03CCT (R2=0.34,P＜0.01),respectively.The CH and CRF did not change with the age and gender in the subjects.Conclusions Corneal biomechanical properties including CH and CRF were positively correlated with CCT,CC and SE.
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Background Laser in situ keratomileusis (LASIK) for myopia and/or myopic astigmatism still is one of primary surgeries.Femtosecond laser (FS)-LASIK offers several advantages over microkeratomes for flap creation including better safety,reproducibility,and predictability.However,the visual performance after FS-LASIK is of high clinical concern.Objective This study was to compare the visual performance between Intralase FS60 femtosecond laser flap and mechanical microkeratome Moria M2 flap in LASIK.Methods A prospective nonrandomized controlled study was performed.Two hundred and four myopic eyes of 102 patients were enrolled in this study and divided into two groups according to patients’ opinion,with matched demography between the two groups.LASIK with FS60 femtosecond laser flap was performed on 100 eyes of 50 myopia and/or myopic astigmatism in the FS group,and Moria M2 flap LASIK was performed on 104 eyes of 52 patients in the microkeratomes group.Zernike coefficients and the root-mean-square (RMS) of higher order aberrations were measured by Wavescan wavefront aberrometer before and 3,6 and 12 months after surgery,and the contrast sensitivity (CS) in different spatial frequencies under the scotopia and scotopia + glare background was detected using Optec 6500 visual function instrument before and 3,6,12 months after surgery.This study protocol was approved by Ethic Committec of Beijing Tongren Hospital,and written informed consent was obtained from each patient prior to surgery.Results The uncorrected visual acuity (UCVA) levels after surgery reached or was superior to the preoperative best corrected visual acuity (BCVA) in 95.1％,94.2％ and 93.9％ patients in the FS group and in 94.2％,93.8％ and 93.2％ patients in the microkeratomes group 3,6,12 months after surgery,respectively.The mean spherical equivalent (SE) was (-6.37 ±2.06)D,(-0.26±0.45)D and (-0.45± 0.51)) in the FS group,(-6.25± 2.43) D,(-0.44± 0.64) D and (-0.35±0.59)D in the microkeratomes group before surgery and 3,12 months after surgery,respectively.There were no significant differences in the SE in various time points between the two groups (u =1.194,1.429;both at P＞ 0.05).The root means square high order (RMSh) and RMS3-6 in the FS group were significantly lower than those in the microkeratomes group 3,6 and 12 months after surgery (all at P＜0.05).Under the background of scotopia or scotopia+glare,the LogCS values under different spatial frequencies were significantly higher in the FS group than those in the microkeratomes group 3 and 6 months after surgery (all at P＜0.05).In 12 months after surgery,no significant difference was found in the LogCS under the 1.5 c/d in the background of scotopia between FS group and microkeratomes group (P＞0.05),and the LogCS values under the 12.0 c/d and 18.0 c/d in the background of scotopia or scotopia+glare in the FS group were better than those in the microkeratomes group (all at P＜0.05).Conclusions Femtosecond laser assistant LASIK has better visual performance and lower higher-order aberrations than microkeratomes assistant LASIK.
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Background Keratectasia after laser in situ keratomileusis (LASIK) is a rare but severe complication,which threatens the visual acuity and corneal strength.Corneal collagen crosslinking (CXL) is a new therapy that increases the security and decreases the risk of complication.However,the effectiveness and safety of LASIK-CXL is still need to be concerned.Objective This study was to evaluate the safety of LASIK-CXL for myopia and astigmatism with thin cornea.Methods A prospective cohort study was designed.A total of 128 eyes of 64 patients with thin corneal and myopic astigmatism enrolled in Beijing Tongren Eye Center from January 2014 to January 2015.The patients were assigned to LASIK group (74 eyes of 37 patients) and LASIK-CXL group (54 eyes of 27 patients).Refractive surgery was performed by Visumax femtosecond lasrer and VISX S4 excimer laser.Eyes of LASIK-CXL group applied accelerated CXL immediately after LASIK.The follow-up was 6 months.Manifest refraction,uncorrected (UDVA) and corrected distance visual acuity (CDVA),average keratometry values (AveK),anterior segment OCT (AS-OCT),corneal hysteresis (CH) and corneal resistance factor (CRF) were examined before and after operation.This research passed through Ethics Committee of Beijing Tongren Hospital.Results The spherical equivalent (SE) of the LASIK group and LASIK-CXL group were (-6.49 ±2.41)D and (-6.97 ±2.41) D before operation and decreased to (-0.68 ±0.88) D and (-0.75 ±0.94) D 6 months after operation.The UDVA (LogMAR) was 1.18±0.28 and 1.05±0.38 before operation and elevated to-0.06±0.09 and-0.03±0.186 months after operation in the LASIK group and LASIK-CXL group.The preoperative AveK values were (44.37 ±1.46) D and (44.47± 1.50)D in the LASIK group and LASIK-CXL group and reduced to postoperative (39.30±2.06) D and (38.66± 1.80) D.The preoperative SRI of LASIK group and LASIK-CXL group were 0.25 ±0.21 and 0.24±0.22,which increased to 0.29±0.24 and 0.28±0.24.The SAI values were 0.36±0.16 and 0.39±0.15 before operation,which increased to 0.57 ±0.31 and 0.75 ±0.376 months after operation,and the SAI value of the LASIK-CXL group was significantly higher than that of LASIK (F =10.220,P--0.002).CRF values of LASIK and LASIK-CXL were (8.44±1.44)mmHg and (8.63±1.35) mmHg in preoperation,which decreased to (5.74±1.31) mmHg and (6.25± 1.24) mmHg in postoperation.The result of LASIK-CXL was higher than that of LASIK (F=8.650,P =0.040).CH values were 8.78 ± 1.51 and 8.69 ± 1.62 in preoperation,which decreased to (7.23 ± 1.08) mmHg and (6.50±1.32)mmHg.The value of LASIK-CXL was lower than that of LASIK (F =5.860,P =0.017).The mean depth of demarcation line was (228.45±28.24) μm (range 165 to 310 μm) on OCT,which was presented in 45 eyes (81.82％) at 1 month in postoperation.Conclusions Accelerated CXL with FS-LASIK is effective and safe in improving visual acuity in myopic astigmatism patients with thin cornea,which also can increase the rigidity of the cornea.
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Safety,efficacy and predictability of corneal refractive surgery have greatly improved as the advancement of the operating technology and equipment.Laser corneal refractive surgeries include excimer laser photorefractive keratectomy (PRK),laser-assisted subepithelial keratomileusis (LASEK),laser in situ keratomileusis (LASIK) and small incision lenticule extraction (SMILE).No matter what kind of operation method,its ultimate goal is to increase the comfort level and improve visual quality.With the surgery skills improving,retinal drug use is a primary factor affecting the safety of laser corneal refractive surgery.Ophthalmologists should strictly master indications and administration of commonly used drugs in postoperative eyes to prevent drug-related eye diseases.In addition,eye doctors also should understand the postoperative complications and topical administration of eye drops.It is important to pay attention to the standard surgical operation and rational drug use after corneal refractive surgery,which can enhance the visual quality and comfort and reduce the complication.
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The all-in-one femtosecond laser corneal refractive surgery,especially small incision lenticule extraction (SMILE),has gained more and more attention in clinic,because of its small incision,“no flap” and corneal biomechanical stability advantages.However,like any other kind of corneal refractive surgery,the all-in-one femtosecond laser refractive surgery not only exists its clinical advantages,but also has its limitations.It is very important to put into perspective clinical advantages and limitations of all-in-one femtosecond laser corneal refractive surgery.
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Objective To optimize the RP-HPLC procedure for the determination of aristolochic acid. Method Different extraction solvents and methods have been screened to get the most efficient way for sample preparation. The influence of different mobile systems on quantitation were compared to choose an approprate mobile system for determination. Besides,the minimum limits of different detecting waves were measured to give the method to detect trace amount of aristolochic acid. Result Refluxing with 70% methanol was better than other ways in sample preparation. Both methanol-1% acetic acid (70∶30) solution and 0.3% ammonium carbonate solution (pH=7.5)-acetonitrile (75∶25) with wavelength of 250 nm and 319 nm can be used for quantitation while 0.3% ammonium carbonate solution (pH=7.5)-acetonitrile (75∶25) with wavelength of 224 nm for trace detection. The minimum detectable amount was 0.02 ng. Conclusion The method established can be applied to determinate aristolochic acid and detect trace amout exactly.
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The basic information,including the number of applications,dosage forms,indications,structure types,purification processes,medicinal materials,period of clinical trials,and dealing conclusions for registration of active fractions in Chinese materia medica(CMM) during 2004-2007,was analyzed.The numbers of registration for clinical trials and applications for production during 2004-2007 were 202 and 23,respectively.It could be found that the numbers of registrations of active fractions in CMM declined obviously since 2005 and the dosage form,indication,and purification process of those applications showed a trend of the relative concentration.From aspect of the stage conclusions,the rate of "not to approve" of applications for clinical trials and production were 48.0% and 8.7%,respectively.So,it could be concluded that the studies on the selection of dosage form,indication,and purification process of active fractions in CMM should be further strengthened.
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Object To optimize the best extraction of the total saponins in the root of Ophiopogon japonicus (Thunb.) Ker-Gawl. (RO). Methods The extract condition of total saponins in RO was observed by orthogonal design with ophiopogonis D as index. Results The optimum extract condition of RO was established. The more effective way was to smash RO to 5-10 mesh and extract total saponins in RO with ten times amount of 80% alcohol thrice by refluxing, one hour each time. Conclusion The total saponins in RO could be fully extracted in this condition.
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AIM: To choose the anti myocardial ischemic ingredients from polysaccharide of Ophiopogon Japonicus(PO), then to confirm their effects. METHODS: According to molecular weight, PO was separated to three portions by using ultrafiltration technique. The effects of each separated portion on myocardial ischemia induced by isoproterenol were studied. Then the effects of PO active portions (POAP) on the convulsion of coronary artery induced by pituitrin and acute myocardial ischemia caused by the ligation of coronary artery were further studied in rats. RESULTS: POAP could resist the elevation of Tand S T phase induced by pituitrin in rats, remarkably decrease the elevated S T phase and contents of CK and LDH in serum caused by the ligation of rat coronary artery. POAP also exerted some inhibition effects on the reduction of SOD and increase of MDA caused by myocardial ischemia. CONCLUSION: POAP can protect myocardial cells, inhibit the generation of free radicals, and scavenge the oxygen free radicals generated from myocardial ischemia.