Agreements’profile of Scheimpflug-based optical biometer with gold standard partial coherence interferometry

AIM:To determine the agreement of ocular biometric indices including axial length,keratometric readings,anterior chamber depth,and horizontal corneal diameter between the Pentacam AXL and IOL Master 500.METHODS:The study was a large cross-sectional population-based study(Tehran Geriatric Eye Study)conducted from Jan 2019 to Jan 2020.A total of 160 clusters were randomly selected proportional to size(each cluster contained 20 individuals)from 22 strata of Tehran city.All people aged 60y and above were invited to participate in the study.For all participants,preliminary ocular examinations were performed including the measurement of uncorrected and best-corrected visual acuity,objective and subjective refraction,anterior and posterior segment examinations.All participants underwent an ocular biometry using the Pentacam AXL and IOL Master 500.RESULTS:The 95%limits of agreement(LoA)between the two devices were-0.13 to 0.19,-0.15 to 0.17,and-0.13 to 0.19 in normal,pseudophakic,and cataractous eyes,respectively.With increasing the axial length,the difference between the two devices significantly increased in all three groups of normal,pseudophakic,and cataractous eyes(P<0.001).The 95% LoAs between the two devices regarding the mean keratometry shows that the best LoAs were seen in cataractous(-0.33 to 0.81)and followed by normal eyes(-0.36 to 0.86)and the pseudophakic eyes(-0.48 to 0.90)had the widest LoA.The 95% LoAs for horizontal corneal diameter measurements were-0.08 to 0.86,-0.03 to 0.83,and-0.07 to 0.87 in normal,pseudophakic,and cataractous eyes,respectively.The 95% LoAs of anterior chamber depth measurements between the two devices was-0.39 to 0.19 and-0.37 to 0.13 in normal eyes and cataractous,respectively.CONCLUSION:The Pentacam AXL has excellent agreement with the gold standard,IOL Master 500 in measuring axial length.In eyes with cataracts,the difference between the two devices is more scattered.With the increasing of axial length,the difference between the two devices increased,which should be considered when using Pentacam AXL.

Evaluation of corneal topographic,tomographic and biomechanical indices for detecting clinical and subclinical keratoconus:a comprehensive three-device study

AIM:To evaluate the diagnostic ability of topographic and tomographic indices with Pentacam and Sirius as well as biomechanical parameters with Corvis ST for the detection of clinical and subclinical forms of keratoconus(KCN).METHODS:In this prospective diagnostic test study,70 patients with clinical KCN,79 patients with abnormal findings in topography and tomography maps with no evidence on clinical examination(subclinical KCN),and 68 normal control subjects were enrolled.The accuracy of topographic,tomographic,and biomechanical parameters was evaluated using the area under the receiver operating characteristic curve(AUC)and cross-validation analysis.The Delong method was used for comparing AUCs.RESULTS:In distinguishing KCN from normal,all parameters showed statistically significant differences between the two groups(P<0.001).Indices with the perfect diagnostic ability(AUC≥0.999)were Sirius KCN vertex of back(KVb),Pentacam random forest index(PRFI),Pentacam index of height decentration(IHD),and Corvis integrated tomographic/biomechanical index(TBI).In distinguishing subclinical KCN from normal,Sirius symmetry index of back(SIb;AUC=0.908),Pentacam inferior-superior difference(IS)value(AUC=0.862),PRFI(AUC=0.847),and Corvis TBI(AUC=0.820)performed best.There were no significant differences between the highest AUCs within keratoconic groups(De Long,P>0.05).CONCLUSION:In clinical KCN,all topographic,tomographic,and biomechanical indices have acceptable outcomes in terms of sensitivity and specificity.However,in differentiating subclinical forms of KCN from normal corneas,curvature-based parameters(SIb and IS value)followed by integrated indices(PRFI and TBI)are the most powerful tools for early detection of KCN.

Comparison of anterior segment measurements using rotating Scheimpflug imaging and partial coherence interferometry

AIM:To compare central corneal thickness(CCT) and anterior chamber depth(ACD) measurements using rotating Scheimpflug imaging and partial coherence interferometry.·METHODS:As part of the first phase of Shahroud Eye Cohort Study with 5 190 subjects of 40 to 64 years of age,CCT and ACD were measured using Scheimpflug imaging with the Pentacam(Oculus,Inc.,Lynnwood,WA,USA) and partial coherence interferometry with the Allegro BioGraph(Wavelight,Erlangen,Germany).·RESULTS:After applying exclusion criteria,we had data of 4 387 subjects with a mean age of 50.7±6.2 years.Mean CCT with Pentacam and BioGraph were 528.6 ±33.2μm and 525.6 ±32μm respectively;the difference was statistically significant(P 【0.001),but the correlation was high(R=0.920).Mean ACD measurements using Pentacam and BioGraph were 2.68 ±0.35mm and 2.62 ±0.33mm respectively;the inter-device difference was significant(P 【0.001) with high correlation(R=0.944).The 95% limits of agreements between devices were-22.65μm to28.61μm and-0.16mm to 0.29mm for CCT and ACD measurements,respectively.·CONCLUSION:For both CCT and ACD,the BioGraph gave significantly lower values than the Pentacam(P 【0.05).Despite the high inter-device correlation,the 95%limits of agreements were wide,and this may limit their interchangeability in measuring the CCT and ACD.

Distribution of intraocular pressure and its determinants in an Iranian adult population

AIMTo determine the distribution of intraocular pressure (IOP) and its determinants in an Iranian population.METHODSIn a cross-sectional survey, random cluster sampling was conducted from the 40-64 years old population of Shahroud, in the north of Iran. All participants had optometry and ophthalmic exams. IOP was determined using the Goldmann tonometry method and biometric components were measured.RESULTSOf the 6311 people selected for the study, 5190 (82.2%) participated. The mean age of the participants was 50.9&#x000b1;6.2y and 58.7% of them were female. Mean IOP was 12.87&#x000b1;2.27 mm Hg. In this study 0.3% of the participants had an IOP higher than 21 mm Hg. The multiple linear regression model revealed that sex (Coef=-0.30; 95% CI: -0.43 to -0.17), diabetes (Coef=0.43; 95% CI: 0.19 to 0.67), high systolic blood pressure (Coef=0.02; 95% CI: 0.01 to 0.02), high body mass index (BMI) (Coef=0.03; 95% CI: 0.01 to 0.04), higher education (Coef=0.02, 95% CI: 0.01 to 0.04), thicker central corneal thickness (Coef=0.01; 95% CI: 0.01 to 0.02), and myopic shift in spherical equivalent (Coef=-0.14; 95% CI: -0.18 to -0.10) significantly correlated with high IOP.CONCLUSIONThe IOP in this 40-64 years old population is low overall. In the north of Iran, average IOP is statistically significantly correlated with female sex, diabetes, higher BMI, systolic blood pressure, higher education, thicker cornea, and myopic refractive error.

Open globe injuries in geriatric population in Iran: characteristics and outcomes

AIM:To investigate the patterns and outcomes of open globe injuries in the elderly population in Iran.METHODS:In this retrospective cross-sectional chart review,medical records of 248 patients(aged 60 y and more)with the diagnosis of open globe injury from 2006 to 2016 were reviewed.Demographic features,type,and mechanism of open globe injury,ocular trauma score(OTS),visual acuity before and after treatment,the zone of injuries,and the associated injuries found at the presentation or thereafter were documented.RESULTS:A total of 248 eyes of 248 patients were included.The mean age was 69.2±5.8 y(range:60-90 y).Male/female ratio was about 3:1(187 vs 61).The three most common causes of injury were falling(25.2%),sharp objects(18.9%),and tree branches(13.9%).Penetrating injury accounted for most of the geriatric ocular trauma(50.4%),followed by globe rupture(40.3%),intraocular foreign body(IOFB;7.3%),and perforating injury(2.0%).The median raw OTS for the population was 60.5 and the most common OTS class was 3.The injuries tend to affect zoneⅠmore than zoneⅡand zoneⅢ.The only predictor of final visual acuity was the class of OTS(P<0.001).CONCLUSION:Geriatric open globe injury should be valued specifically.The most common type of open globe injury in Iran is penetrating injuries but falling remain the main cause.The OTS class must be considered as an important predictor of final visual acuity.

吸烟者与非吸烟者侧壁开窗上颌窦底提升术术中和术后并发症对比:系统综述和荟萃分析

目的:此系统综述和荟萃分析关注的科学问题是:烟草吸入是否会增加侧壁开窗上颌窦底提升术患者术中或术后的并发症。材料和方法:检索如下电子数据库:CENTRAL, MEDLINE, Google Scholar,Scopus. Sirous和Doaj,检索时间至201 5年12月.无语言限制。纳入分别记录吸烟者与非吸烟者侧壁开窗上颌窦底提升术术中或术后并发症发病率的文献。对如下并发症进行评估:上颌窦底粘膜穿孔.出血.创口裂开.创口感染.上颌窦炎、血肿和口腔上颌窦痿。采用文献严格评价项目评估纳入研究的偏倚风险。采用随机效应模型评估吸烟者与非吸烟者每种并发症的数量。结果:共929篇文献,最终纳入11篇。荟萃分析结果表明侧壁开窗上颌窦底提升术后吸烟者比非吸烟者发生创口裂开的风险显著增加(相对危险度[RR]: 7.82;95%置信区间[CI]: 2.38.25.74;P=0.0007) 0而且,当纳入前瞻性研究时.吸烟患者发生创口感染的风险也明显增加(相对危险度[RR]: 5.33;95%置信区间[CI]:1.34.21.25;P=0.02) o然而荟萃分析结果表明吸烟者与非吸烟者在上颌窦底提升术过程中发生上颌窦底粘膜穿孔和出血概率的差异没有统计学意义(分别为P=0.46和P=0.33)。结论:由于缺少随机对照试验以及纳入研究数量较少.结果提示吸烟可能与上颌窦底提升术后发生创口裂开和感染风险增加相关。