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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 Optical nerve damage of glaucomatous eyes is associated with intracranial pressure.Conventional method of evaluating intracranial pressure is to measure cerebrospinal pressure by lumber puncture.However,the measurement of intraorbital optical nerve parameters,a novel method of evaluating intracranial pressure,is introduced in this field.Objective This study was to measure and analyze the intraorbital optic nerve sheath diameter (ONSD) and cross sectional area (ONSA) in normal population using multi-slice spiral CT.Methods This study protocol was approved by Clinical Ethic Committee of Shenzhen Chinese Traditional Medical Hospital and followed Hersinki Declaration.Informed consent was obtained from each individual prior to any medical examination.One hundred and five eyes of 105 normal persons with normal cerebral CT image were enrolled in Shenzhen Chinese Traditional Medical Hospital from January 2012 to September 2013.Cerebral volume was scanned in all the individuals by 64 slice spiral CT.The brain images were obtained for the curve planar rebuilding of intraorbital optical nerve on image post-processing workstation.The maximum and minimum of ONSD and the ONSA in axial sections at 3,6,9,12 and 15 mm far away from globe wall were measured using a standardized technique to analyze the change of optical nerve parameters at different point locations.These parameters were compared in different gender or eyes.The correlation among age and the optical nerve parameters at 3 mm far away from globe wall was evaluated by multivariate regression analysis.Results The average maximal ONSDs were (6.24±0.47), (5.56±0.44),(5.18±0.43),(4.82±0.41) and (4.69±0.41) mm;the average minimal ONSDs were (5.56±0.50),(4.97± 0.41) ,(4.55±0.35),(4.26±0.39) and (4.10±0.40) mm;the average ONSAs were (27.68±4.40),(22.02±3.35) , (18.74± 2.75) , (16.34±2.72) , (15.40±2.68) mm2 at 3,6,9,12 and 15 mm far away from posterior eyeball wall,respectively, showing significant differences in the maximal/minimal ONSDs and ONSAs among the different point locations (F =218.329,215.906,246.924, all at P =0.001).No significant differences were found in the maximal/minimal ONSDs and ONSAs between male and female or between the right eyes and left eyes (gender:t=1.805,P=0.074;t=1.930,P=0.056;t=1.329,P=0.187;eyes:t=0.724,P=0.471;t=1.562,P=0.121;t=1.424,P=0.158).No significant correlations were seen between age and maximal/minimal ONSDs or ONSAs with the coefficients of 1.873,7.415 and-0.853 correspondingly (P =0.847,0.460,0.637).Conclusions Intraorbital section of optical nerve can be rebuilt using standardized technique after scanning of 64 slice spiral CT.The cross section of intraorbital optic nerve sheath is oval in shape and the optic nerve is thinning with the increase of distance far away posterior eyeball wall in normal populatuion.
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Background The simplex congenital blepharoptosis is the common blepharon motor dysfunction disease.Some researches have shown that congenital blepharoptosis is related to the hypoplasia of levator.Objective This study was to investigate the thickness and pathological features of levator palpebrae superioris aponeurosis in congenital blepharoptosis patients.Methods A prospective cohort study was carried out in Anyang Eye Hospital from March 2012 to April 2014.Eighty-five eyes of 56 patients with congenital blepharoptosis were divided into mild (15 eyes), moderate (25 eyes) and severe blepharoptosis (19 eyes) groups, and the fellow eyes of monocular blepharoptosis was used as fellow eye group (26 eyes).Twenty-six eyes of 13 normal subjects were recruited for the normal control group.The thickness of levator aponeurosis was measured by ultrasound biomicroscope (UBM) , and the shifting range of levator aponeurosis was detected by using measuring scale.Levator aponeurosis specimens were collected during the levator palpebrae superioris shortening surgery for the pathological examination.The study was approved by the medical ethics committee of Anyang Eye Hospital, and the patients or their guardian signed the informed consent.Results The thickness of levator aponeurosis was (0.331±0.018), (0.373±0.026), (0.539± 0.023) , (0.557 ± 0.024) and (0.547 ± 0.028) mm in the severe blepharoptosis group, moderate blepharoptosis group,mild blepharoptosis group, normal control group and fellow eye group, respectively, showing a significant difference among them (F =1.681, P =0.043).The thickness values of levator aponeurosis were considerably lower in the severe blepharoptosis group and moderate blepharoptosis group than those in the mild blepharoptosis group,fellow eye group and normal control group (all at P＜0.05) , and the thickness value of levator aponeurosis was significantly reduced in the severe blepharoptosis group compared with the moderate blepharoptosis group (P＜0.05).Pathological examination showed arranging disorder of muscle fibers,hyaline-like degeneration, connective tissue hyperplasia and interruption of endomysium.The number of eyes with severe hyaline-like degeneration and connective tissue hyperplasia was significantly increased in the severe blepharoptosis group than that in the moderate blepharoptosis group or the mild blepharoptosis group, as well as in the moderate blepharoptosis group than that in the mild blepharoptosis group(all at P＜0.01).The adipose cells in muscle in the mild blepharoptosis group, moderate blepharoptosis group and severe blepharoptosis group were (12.35±4.62), (17.58±7.46) and (26.19±10.81)/field,and adipose cells in the severe blepharoptosis group were significantly more than those in the mild and moderate blepharoptosis groups (t =5.60, P =0.00;t =2.71, P =0.01).A significant increase in the adipose cells also was seen in the moderate blepharoptosis group compared with the mild blepharoptosis group (t =2.44, P =0.02).Conclusions UBM can offer accurate thickness data of levator aponeurosis.The combination of thickness data and shifting range measurement of levator aponeurosis is helpful for the evaluation of muscle strength.The development of levator aponeurosis appears to be abnormal in congenital blepharoptosis patients.The histopathological change parallels to the severity of the disease.
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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 Choroidal thickness is closely associated with ametropia,and to study the influence of subfoveal choroidal thickness (SFCT) on refraction is very important for understanding the mechanism of refractive error more clearly.Objective This study was to investigate the relationship between SFCT and refraction.Methods A retrospective serial cases analysis was performed.Forty anisometrope patients were recruited in Zhongshan Ophthalmic Center from June 2012 to August 2012.The subjects were divided into 6-13 years group and 14-21 years group.Vision acuity was tested by the EDTRS visual acuity chart and ocular anterior segment was examined under the slit lamp microscope,and the fundus examination was performed by direct ophthalmoscope.Subjective and objective optometry was performed after pupils were dilated.EDI OCT was used to illuminate choroidal image.Ocular axial length (AL) was obtained by Lenstar 900.The difference in SFCT between myopic eyes and hyperopic eyes was compared using Student t test,and the correlations between SFCT and refraction were analyzed by Pearson linear analysis and linear regression analysis.Results The average SFCT was (307.82±88.47) μm in all the tested eyes,and the SFCT of myopic eyes and hyperopic eyes was (270.60±70.57) μm and (376.95±76.59) μm,respectively,with a significant difference between them (P =0.000).In the 6-13 years group,positive correlations were found between SFCT and diopters with the regression coefficient 18.60 and regression equation Y =18.60X +310.79 (r=0.345,F=21.110,P=0.000) as well as between SFCT and AL with the regression coefficient -31.76 and regression equation Y =-31.76X+1 039.97 (r=0.262,F=17.320,P=0.000).In the 14-21 years group,SFCT showed positive correlation with diopters,with the regression coefficient 23.38 and regression equation Y=23.38X+353.17 (r =0.430,F =27.210,P =0.000) and negative correlation with AL,with the regression coefficient-35.82 and regression equation Y =-35.82X+1 132.75 (r=0.237,F=15.650,P=0.000).Conclusions SFCT seems to be positive correlated with diopter.When the diopter shifts toward positive value,SFCT value increases,and whenever diopter increases-1 D,SFCT decreases 20 μm approximately.SFCT decreases with the increase of AL.
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Background Evaluation of intra-retinal layer thickness plays an important role in the diagnosis and monitor of various eye diseases,and spectral domain optical coherence tomography (OCT) is a frequently used tool.Software analysis method was used to measure the retinal thickness in previous study,but the study on the reliability of automatic layered software is lack.Objective This study was to evaluate the repeatability and reproducibility of thickness profile measurement of intra-retinal layers determined by an automated algorithm applied to OCT images from RTVue100 OCT instrument.Methods In this prospective cross-sectional study,retinal thickness images at 6 mm around fovea were obtained from 18 right eyes of 18 normal subjects with RTVue100 OCT instrument.The retinal images were segmented into retinal nerve fiber layer (RNFL),ganglion cell layer and inner plexiform layer(GCL+IPL),inner nuclear layer (INL),outer plexiform layer (OPL),outer nuclear layer (ONL),inner segment (IS),outer segment (OS) and retinal pigment epithelial (RPE) layer using automated algorithm method.Then Matlab software was used to analyze the measuring outcome.Interclass correlation coefficient (ICC) and coefficients of reproducibility (COR) were calculated from the results of two-time examination by the same examiner to evaluate the repeatability and from the results of two different examiners to assess the reproducibility.Written informed consent was obtained from each subject prior to any medical procedure.Results The entire retinal thickness measured by RTVue-OCT was (303.22± 14.10) μm in the horizontal meridian and (306.68 ± 13.32) μm in the vertical meridian,with the maximum values of retinal thickness in the GCL+ IPL and ONL.Whether in the horizontal meridian or in the vertical meridian,the ICC and COR were ＜0.60 in the OPL,IS and OS;while those in the RNFL,GCL+IPL,INL,ONL and RPE layer were ＞0.70.Conclusions RTVue OCT with automated algorithm is a useful and reliable approach to the measurement of intra-retinal layer thickness.Automated segmentation can offer accurate and repeatable thickness profile of OCT retinal image.This method may improve the diagnosis and monitoring of retinal diseases.
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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 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 Clinical research showed that the corneal endothelial cell density value from different corneal specula microscopies exist diversity.The relevant literature of SP02,Tomey EM-3000 and SP3000P is still seldom up to now. Objective This research was to assess the repeatability of endothelial cell density measurements by SP02,Tomey EM-3000 and SP3000P respectively and the agreement among 3 kinds of endothelial microscopes.MethodsFifty-four healthy volunteers with the age 17-38 years old were included this research.The written informed consent was obtained from each subject before examination.The corneal endothelial cell densities in the right eyes were analyzed with SP02,Tomey EM-3000 and SP3000P respectively for 3 times under the automatic mode,and the analytical procedure of SP3000P measurement were divided into automatic mode SP3000P (A) and manual correction modes SP3000P( M).The repeatability of each specula microscopy was analyzed by calculating the intraclass correlation coefficients (ICC) and coefficient of variation ( CV ),and the 95％ confidence intervals and plotting Bland-Altman graphs were used to analyze the agreement among these methods.ResultsThe mean corneal endothelial cell densities in the population ＜24 years were significantly higher than the ones ≥ 24 years (t =3.692,P＜0.05 ),but no statistical difference was found between different gender ( t =0.335,P =0.739 ).The mean corneal endothelial cell densities were ( 3058 ± 260 ),( 2954 ± 229 ),( 2668 ± 258 ),( 2734 ± 268 ) cell/mm2 ; the ICCs were 0.957,0.940,0.972 and 0.972 and the CV were 0.063,0.061,0.056,0.058 for SP02,Tomey EM-3000,SP3000P (A) and SP3000P ( M ) respectively.The 95％ confidence intervals were ( - 100.8 - 306.8 ),( 162.6 - 617.4 ),( 109.9-494.1 ) and ( -0.6 - 132.6 ) cell/mm2 for between SP02 and Tomey EM-3000,SP3000P ( A ) and SP02,SP3000P(A) and Tomey EM-3000,SP3000P(A) and SP 3000P(M) respectively.ConclusionsSP02,Tomey EM-3000 and SP3000P(A) have good repeatability in the measurement of corneal endothelial cell density,however the outcome is different.Therefore,it is not interchangeable for the detection of corneal endothelial cell density.The differences of corneal endothelial cell density obtained from these instruments shall be paid high attention for their differences.SP3000P(A) and SP3000P(M) can be used interehangeably and SP3000P(A) is a preferable choice due to its convenience and quickness.
ABSTRACT
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.