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Objective To evaluate the accuracy of intraocular lens (IOL) power calculation using IOL-Master in patients underwent phacoemulsification and vitrectomy for idiopathic macular epiretinal membrane (IMEM) concurrent with age-related cataract (ARC).Methods A prospective study was designed.A total of 32 patients (32 eyes) with ARC (ARC group) and 30 patients (30 eyes) with ARC and IMEM (ARC+IMEM group) were enrolled from March 2013 to July 2015 in the Hangzhou District of Eye Hospital of Wenzhou Medical University.All the surgeries were performed by the same experienced surgeon and the same IOL (Adapt-AO) was implanted.IOL power was calculated by both SRK-T and Haigis formulas.The central macular thickness was measured by OCT preoperatively and postoperatively.The mean postoperative refractive prediction error (ME),mean absolute postoperative prediction error (MAE) and percentage of eyes achieved target refraction within ± 0.25,± 0.50 and ± 1.00 D were compared between the 2 groups.The correlation between the refractive error and macular thickness change was evaluated.Results The ME and MAE calculated by Haigis were (-0.47±0.66)D and (0.63±0.44)D in ARC+IMEM group,and (-0.18±0.74)D and (0.68±0.65)D in ARC group.The ME and MAE calculated by SRK-T were (-0.60 ±0.59) D and (0.73 ±0.41) D in ARC +IMEM group,and (-0.23 ±0.85)D and (0.75 ±0.69)D in ARC group.No significant differences were found between the two groups in each formula (all at P＞0.05).There was no significant difference of MAE distribution between the two groups in Haigis formula.In SRK-T formula,the percentage of MAE≤0.25 D in the ARC+IMEM group was significantly higher than that in the ARC group (x2 =7.114,P=0.007).In the A RC+IMEM group,the change of the macular thickness was (-97.4± 115.3)μm,which was statistically correlated with the ME of H aigis and SRK-T formulas (r=0.369,P =0.045;r =0.421,P =0.021).Conclusions There is a tendency toward myopia shift in patients underwent phacoemulsification and vitrectomy compared with conventional phacoemulsification.The myopia shift shows a significant correlation with macular thickness changes.Haigis formula performs better than SRK-T formula with the condition of un-optimized parameters.
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Background Measurement of corneal thickness is of great significance for the design of refractive surgery and the diagnosis of eye diseases,measuring equipments and technology develop rapidly in recent years.Optovue iVue OCT is a new frequency-domain optical coherence tomography (OCT),to compare its results with those of Pentacam and Visante OCT is helpful to objectively assess the clinical value of Optovue iVue OCT.Objective This study was to investigate the repeatability of corneal thickness measurement with Optovue iVue OCT and the comparatbility with Pentacam three-dimensional anterior segment analysis diagnostic system and Visante OCT.In addition,this study attempted to analyze the distribution of average corneal thickness in each quadrant by Optovue iVue OCT.Methods The corneal thicknesses of the corneal thinnest point,the central point and 3:00,6:00,9:00,12:00 zones 1 mm away from the center of the cornea were measured in 45 right eyes of 45 subjects with myopia using Optovue iVue OCT,Pentacam and Visante OCT in Tianjin Eye Hospital.Interclass correlation coefficient (ICC) was used to analyze the repeatability of measurement by Optovue iVue OCT.The agreements between Optovue iVue OCT and Pentacam or Visante OCT were evaluated by Bland-Altman test.The corneal area of 1.0-2.5 mm away from the center was divided into eight quadrants and the average corneal thickness of each quadrant was measured and analysis with Optovue iVue OCT.Results No significant difference was found in corneal thickness values for 3 times by Optovue iVue OCT (P=0.546).The ICC by Optovue iVue OCT was 99.92％,99.99％,99.96％,99.99％,99.99％ and 99.97％ at the corneal thinnest point,the central point and 3:00,6:00,9:00,12:00 zones respectively.There were significant differences among the 3 kinds of methods (P =0.000,0.001,0.000,0.003,0.002,0.000).The measured values of Optovue iVue OCT were significantly lower mean 24.20 μm than those of Pentacam (P=0.000,0.001,0.000,0.003,0.004,0.000),but only the value at 12:00 zone of Optovue iVue OCT was evidently declined in comparison with that of Visante OCT (P =0.016),there were no significant differences between all the other zones (P =1.000,0.447,0.239,1.000,1.000).While the mean corneal thickness value from Pentacam lowed by 14.01 μm in comparison with Visante OCT,all zones had significant differences (P =0.009,0.005,0.034,0.017,0.008) except the central point (P =0.056).Based on the Optovue iVue OCT,the thinnest zone was at temporal quadrant in 23 eyes (accounting for 51.11％) and at superior quadrant or super nasal quadrant in 21 eyes (both at 46.66％).Conclusions Optovue iVue OCT measurement of corneal thickness is of high repeatability and is consistent with Visante OCT in myopic eye.Optovue iVue OCT shows evident difference from Pentacam in the measurement of corneal thickness.The thinnest point of the cornea is mainly in the inferior temporal quadrant and the thickest point is commonly in superior quadrant and nasal superior quadrant based on Optovue iVue OCT.
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Background The study on influences of gender,age and axial length (AL) on lens thickness (LT) and anterior chamber depth (ACD) in normal population is still lack in China.Objective This study was to measure LT and ACD in normal subjects and discuss their changes with age,gender and AL.Methods AL,ACD and LT were measured on 866 eyes of 433 normal population with Lenstar LS900 in Tianjin Eye Hospital from March through December in 2013,including 390 eyes in 195 males and 476 eyes of 238 females.ACD/AL,LT/AL and (ACD+LT)/AL were calculated after measurement.The subjects were grouped to the 10-20 years group,21-30 years group,31-40 years group,41-50 years group,51-60 years group and ≥61 years group based on age,or the 22 mm≤AL＜24 mm group,24 mm≤AL＜26 mm group and AL≥26 mm based on AL,and the measured parameters were compared and analyzed among the groups.Oral informed consent was obtained from each subject or child contutor prior to any medical examination.Results AL,ACD and LT values were (24.41±1.37),(2.89±0.42) and (4.05±0.52) mm in the males,and those in the females were (23.83±1.31),(2.72±0.40) and (4.20±0.44) mm,showing significant differences between them (t=6.278,6.102,-4.595,all at P=0.000).No significant differences were found in ACD,LT,ACD/AL,LT/AL and (ACD+LT)/AL values between the right eyes and the left eyes (t=-0.713,0.186,-0.754,0.296,-0.168,all at P＞0.05).As the increase of the AL,ACD was remarkable deepened but LT was declined,with the considerable difference among the 22 mm ≤ AL＜24 mm group,24 mm ≤ AL＜ 26 mm group and AL ≥ 26 mm group (F =176.640,94.569,both at P =0.000).ACD value was higher,but LT value was lower in the 24 mm≤AL＜26 mm group or AL≥26.00 mm group than that in the 22 mm≤AL＜24 mm group (all at P＜0.05).ACD value was gradually reduced,while LT value was elevated with aging,with significant differences among the different age groups (F =104.531,373.225,all at P =0.000).Significant correlations were found between age and ACD,LT or (ACD + LT)/AL,with the regression equations of ACD (mm) =-0.015 × age + 3.434 (F =-22.979,P =0.000);LT (mm) =0.024 × age + 3.122 (F =44.856,P =0.000),LT/AL =0.001 × age + 0.122 (F=37.982,P=0.000),(ACD+LT)/AL=0.001×age+0.259 (F=22.451,P=0.000).Conclusions Compared with normal females,males have thinner LT and deeper ACD.In the normal eyes,longer AL is,thinner LT is and the deeper ACD is.LT thickens and ACD deepens with aging.
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Background Corneal parameters (such as curvature,thickness,etc) are essential to the diagnosis of corneal related diseases,contact lenses fitting and corneal refractive surgery.Objective The aim of this study was to assess the repeatability and accuracy of corneal parameters obtained by RTVue Fourier-domain optical coherence topography (FD-OCT).Methods In this prospective study,77 eyes of 43 subjects with the refraction from-1.25 D to-10.00 D and astigmatism ＜2 D were enrolled in keratorefractive surgery center,Eye Hospital of Wenzhou Medical College.The anterior and posterior corneal curvature in 3 mm central zone (Ranterior and Rposterior),the ratio of posterior and anterior curvature (Rposterior/Ranterior),corneal central thickness (CCT),total corneal power(Knet),the simulated corneal power (Sim K),the anterior and posterior corneal power (Kanterior,Kposterior)were measured by FD-OCT.Corneal power (Km) was obtained by Topolyzer topography based on Placido ring.Three consecutive scans were acquired in every tested eye.Repeatability of FD-OCT measurement was assessed using the coefficient of variation CV),Cronbach Alpha and intra-class correlation coefficient (ICC).Repeated measure ANOVA was used to analyze the differences among SimK,Knet and Km.Pearson correlation analysis was used to analysis the correlation between SimK and K Knet and Km,SimK and Km.The agreement between Sim K and K Knet and Km,SimK and Km was assessed by Bland-Altman plots analysis.All the subjects understood the purpose of this investigation and written informed consent was obtained prior to the medical examination.Results The Ranterior,Rposterior,Rposterior/Ranterior,Kanterior,Kposterior,Sim K,Knet and CCT were (7.691 ±0.302) mm,(6.532±0.276) mm,0.849±0.014,(48.97±1.92)D,(-6.13±0.26)D,(43.95±1.72) D,(42.95±1.68) D and (545.20± 35.04) μm,respectively.The CV of all parameters was less than 1％.The Cronbach Alpha and ICC were both more than 0.9 except 0.802(ICC)of the Rposterior/Ranterior.SimK was (0.27±0.34) D higher than Km,and Knet was (0.73±0.37) D lower than Km.SimK was (1.01 ±0.11) D higher than K and all the differences showed a statistical significance (P＜0.001).There were close positive correlations between SimK and Km,Knet and Km,SimK and Knet(all r ≥ 0.976,P＜0.001).The Bland-Altman analysis showed a poor agreement between SimK and Km,Knet and Km,SimK and Knet.Conclusions The RTVue FD-OCT measuring corneal curvature and CCT performes good repeatability.The Sim K obtained by RTVue FD-OCT is slightly greater than that obtained by corneal topography,and the Rposterior/Ranterior obtained by RTVue FD-OCT is slightly lower than that from Gullstrand model eye.These results offer a basis for establishing a more accurate standardized model eye.
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Background The condition of the sclera is associated with many ocular diseases.The measurement of human scleral thickness in vivo is helpful for us to understand the features of the sclera and related diseases.Objective The present study was to measure the anterior sclera thickness(AST) in patients with senile cataract and to analyze the relationship among AST and other associated ocular parameters.Methods This study was approved by the Ethic Commission of First Hospital of Peking University.Written informed consent was obtained from each individual prior to examination.One hundred and five senile cataract patients were recruited in this study.Central corneal thickness (CCT),corneal curvature (CCV) and axial length were measured using ultrasonic pachymeter,keratometer,and A-scan unit,respectively.The AST was measured at 2 mm posterior to the scleral spur in the temporal meridian using ultrasound biomicroscope (UBM).The differences of CCT,CCV,ocular axial length and AST between bilateral eyes and the different sexes were compared by the Paired test and independent sample t test.The correlations among various parameters were assessed by the Pearson linear correlation analysis.The differences of CCT and AST among different axial length groups were evaluated by one-way ANOVA.Results No significant differences were found in the CCT,CCV,axial length and AST between bilateral eyes (t =0.584,P =0.561 ; t =1.161,P =0.248 ; t =0.140,P =0.889 ; t =0.342,P =0.773).Temporal AST at 2 mm posterior to the sclera spur was (0.589 ±0.051)mm in the right eyes.An insignificant decline in CCT was found in the male group compared with the female group (right eyes:t =0.469,P =0.641 ; left eyes:t =0.465,P =0.643).However,compared with the female group,the increase of axial length,reduction of the mean CCV value and enhancement of the mean AST were observed(right eyes:all P＜0.01 ;left eyes:all P＜0.01).CCV showed a negative correlation with ocular axial length (r =-0.50,P＜0.01),but no significant correlation was found among age,CCT,ocular axial length and AST(P＞0.05).No remarkable differences were found in CCT and AST among the various axial length groups (CCT:F =0.998,P=0.372;AST:F=1.919,P=0.383).Conclusions In senile cataract patients,correlation is not found between AST and CCT;the increase of axial length is not associated with the thinning of the eyeball wall to a certain extent.Differences exist in some ocular parameters between different sexes.
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Background Idiopathic macular epiretinal membrane (IMEM) combined with age-related cataract (ARC)is a common eye disease and the primary managing approach is the combination of phacoemulsification,intraocular lens (IOL) implantation and vitrectomy.However,whether the ocular length measured by IOL Master is accurate for the calculation of IOL refraction in the eye with IMEM remains unclear.Objective The aim of this study was to evaluate the refractive outcomes of combination surgery of phacoemulsification,IOL implantation and vitrectomy in IMEM eyes.Methods A prospective cohort study was designed.Forty-two eyes of 42 patients with IMEM combined with ARC (IMEM+ARC group) were enrolled in Peking University People's Hospital and the combination of phacoemulsification,IOL implantation and vitrectomy was performed from September 2010 to August 2011,and 47 eyes of 47 patients with ARC were included for the phacoemulsification combined with IOL implantation in the corresponding period (ARC group) under the approval of Ethic Committee of Peking University People's Hospital and informed consent of the patients.Ocular length and corneal curvature were measured using IOL Master,and the expected IOL diopter was calculated with SRK-T formula.Regular eye examination and medical optometry were performed 1 month and 3 months after operation to obtain the actual diopter and the refractive error.The outcomes were compared between the two groups.The correlations of refractive error with change of fovea thickness were evaluated after operation in the IMEM+ARC group.Results There were no statistically significant differences in the age,ocular length and corneal curvature between the two groups before operation (P =0.863,0.704,0.770).The visual acuity was improved 3 months after operation in comparison with before operation in both groups (P=0.001,0.000).The negative diopters were obviously higher 1 month and 3 months after operation than those before operation in both groups (all at P＜0.001),but no significant difference was seen between the IMEM+ ARC group and ARC group (Fgroup =0.417,P =0.520).The diopter deviations 1 month and 3 months after operation were (-0.727±0.666)D and (-0.628±0.627)D in the IMEM+ARC group,and those in the ARC group were (-0.664±0.644) D and (-0.642±0.550) D,showing insignificant differences between the two groups (Fgroup =0.036,P =0.849 ; Ftime =1.523,P =0.221).In IMEM + ARC group,the macular fovea thickness was (474.89 ± 135.76)μm in preoperation,and the shift values of macular fovea thickness were (-83.84 ±91.12)μm and (-158.53±113.03) μm in postoperative 1 month and 3 months.No positive correlations were presented between the diopter deviations and change of fovea thickness 1 month and 3 months after operation in the IMEM+ARC group (r=0.200,P =0.229 ; r =0.065,P =0.698).Conclusions Myopia shift after operation is similar in the IMEM combined with ARC patients to the only ARC patients,suggesting that the ocular length and corneal curvature measured by IOL Master is not affected by epiretinal membrane.
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Background Lowing intraocular pressure (IOP) is the only effective treating method in glaucoma.Making sure the change of optic disc parameters and retinal nerve fiber layer thickness(RNFLT) in primary open-angle glaucoma (POAG) patients after IOP reduced can provide objective evidence for evaluating the effect of lowing-IOP on the function of optic nerve.Objective The present study was to evaluate the change of optic disc parameters and RNFLT in POAG patients after trabeculectomy,and analyze the affecting factors of image parameters.Methods A serial case-observational study was adapted.Forty eyes of 39 patients with POAG underwent trabeculectomy were recruited in the study.IOP was examined and perimetry was performed before operation and 2 weeks,1 month,3 months,6 months and 1 year after surgery.Optical parameters and RNFLT were measured using Heidelberg retina tomography (HRT) and optical coherence tomography (OCT) in above-mentioned time points.The correlations between lowing-IOP range or disease severity and optical disc parameters or mean RNFLT (mRNFLT) were analyzed by Pearson linear correlation.Results Mean IOP of the 40 eyes was (32.77±8.64) mmHg before operation and (12.45 ±3.65) mmHg,(13.05±3.90) mmHg,(13.42± 3.33) mmHg,(14.22± 2.60) mmHg and (14.74±2.46)mmHg 2 weeks,1 month,3 months,6 months and 1 year after operation,with a significant difference among various time points (F=13.73,P =0.00).However,no significant difference was seen in the mean defect of perimetry among the different time points (F=1.02,P=0.41).The cup area (CA),cup/disc area ratio (C/DAR),cup volume (CV),mean cup depth (MCD),cup shape measurement (CSM),horizontal C/D,vertical C/D,rim area (RA),rim/disc area ratio (R/DAR),height variation contour (HVC),rim volume (RV),mRNFLT,RNFL cross sectional area (RNFLA) were gradually improved after operation in comparison with before operation.One year after operation,RV,CSM,mRNFLT,RNFLA were still increased,but vertical C/D was reduced after operation than that of before (P＜0.05).No significant differences were found in the whole mRNFLT and superior quadrant mRNFLT,inferior quadrant mRNFLT,nasal quadrant mRNFLT and temporal quadrant mRNFLT among before and after operation (F=1.63,P=0.16; F=0.51,P=0.77; F=1.44,P=0.20;F=1.02,P=0.32; F=1.31,P=0.30).Positive correlations were found between lowing-IOP range and the improvement of RV,CSM,vertical C/D (r =0.45,P =0.02; r=0.41,P=0.04; r=0.58,P=0.00),and negative correlations were seen between absolute value of MD and the improvement of RV,CSM 1 year after operation (r=-0.43,P=0.03; r=-0.62,P=0.00).Conclusions Reduction of IOP after trabeculectomy results in the reversal of optic disc parameters.The improvement of the optic disc parameters may be a protective factor for progression of glaucomatous optical nerve damage.
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Background The accuracy of biometric measurement is critical for precise diagnoses and prognosis evaluation of ocular diseases.Objective The present study was to evaluate the differences of Lenstar with A-scan ultrasound biometry or keratometer in ocular bio-measurement.Methods Written informed consent was obtained from each subject before examination.Total 43 eyes of 40 age-related cataract patients were enrolled in this study.Axial length,corneal curvature (K1,K2,Km) and intraocular lens (IOL) power were measured with Lenstar,A-scan ultrasound biometry and keratometer,separately.The differences of measuring outcomes were compared between these two methods according to a paired samples t test,and the agreement analysis of measuring outcomes between Lenstar and A-scan ultrasound biometry or keratometer was performed by Blant-Altman plots.Results Thirty-five eyes finished the clinical bio-measurement.The axial length was (23.341 ± 1.208) mm and (23.268 ±1.157)mm based on Lenstar method and A-scan ultrasound biometry method,respectively,with a insignificant difference between them(t =0.260,P=0.796).No significant differences were found in the K1,K2 and Km values between Lenstar and keratometer methods (t =0.526,P =0.601 ; t =0.927,P =0.357 ; t =0.213,P =0.832).The IOL power was (20.371 ±2.827) D and (20.729 ± 2.672) D,respectively in Lenstar method and keratometer method,without statistically significant difference between them (t =0.543,P =0.589).Bland-Altamn agreement analysis showed that the dots of 11％ (4/35),0％ (0/100),9％(3/35),9％ (3/35),6％ (2/35) were out of 95％ confidence limit,and the absolute values of maximal difference value between Lenstar and A-scan ultrasound biometry or keratometer methods was 0.39 mm,1.31 D,1.30 D,0.77 D and 1.00 D in ocular axial length,K1,K2 and Km values and IOL power,respectively.Conclusions As a new bio-measuring method,Lenstar can offer multiple biometric parameters by single procedure.However,an inconsistent measuring outcome is seen between Lenstar and Ascan ultrasound biometry or keratometer.So whether Lenstar can replace A-scan ultrasound biometry or keratometer still need further large simple clinical trail.
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Background Measurement of ciliary sulcus distance is important for phakic intraocular lens implantation.Suowei panoramic 50-MHz digital ultrasound biomicroscopy makes it possible for the direct measurement of ciliary sulcus distance.Objective The aim of this study was to investigate the correlation between anterior chamber(AC)angle diameter and ciliary sulcus distance in different AC depth population and offer a clinical guide.Methods The anterior chamber angle diameter and ciliary sulcus distance were measured in 30 right eyes with shallow anterior chamber caused by suspect glaucoma and 30 right eyes with deep anterior chamber dut to the high myopia with Suowei panoramic 50-MHz digital ultrasound biomicroscopy.Three horizontal B-scans with the focal plane approximately at a depth corresponding to the iris plane were acquired for each eye.The differences of the anterior chamber angle diameter and ciliary sulcus distance were calculated and compared between the two groups.The correlation of the anterior chamber angle diameter and ciliary sulcus distance were evaluated in respective group.Results In shallow AC group,the mean angle diameter was(11.49+0.75)mm,the mean ciliary sulcus distance was (10.97±0.86)mm with the mean standard deviation of the difference of(-5.14± 0.55)mm,showing a statistically significant difference(t =-5.092,P =0.000).In shallow AC group,linear regression analysis showed a statistically significant correlation between ciliary sulcus distance and angle diameter(R2=0.593,P=0.000)and the Pearson's correlation coefficient was 0.767.In deep AC group,the angle diameter was(12.69±0.67)mm;while ciliary sulcus distance was(12.31 ± 0.61)mm with the mean slandard deviation(-0.38 ± 0.17)mm,which was statistically significantly different(t=-5.531,P=0.000).The ciliary sulcus distance was found to be linear correlation with the angle diameter(R2 =0.699,P=0.000)and Pearson' s correlation coefficient of 0.836.Conclusions Panoramic ultrasound biomicroscopy is an useful tool to the measurement of ciliary sulcus distance.This study exhibited that the ciliary sulcus distance is significant associated with the anterior chamber angle diameter,which may offer a guide for phakic intraocular lens implantation.