OBJECTIVE: This study evaluates the accuracy of modern intraocular lens (IOL) calculation formulas using axial length (AL) data obtained by ultrasound biometry (UBM) compared to the third-generation SRK/T calculator.
METHODS: The study included 230 patients (267 eyes) with severe lens opacities that prevented optical biometry, who underwent phacoemulsification (PE) with IOL implantation. IOL power calculation according to the SRK/T formula was based on AL and anterior chamber depth obtained by UBM (Tomey Biometer Al-100) and keratometry on the Topcon KR 8800 autorefractometer. To adapt AL for new generation calculators - Barrett Universal II (BUII), Hill RBF ver. 3.0 (RBF), Kane and Ladas Super Formula (LSF) - the retinal thickness (0.20 mm) was added to the axial length determined by UBM, and then the optical power of the artificial lens was calculated. The mean error and its modulus value were used as criteria for the accuracy of IOL calculation.
RESULTS: A significant difference (p=0.008) in the mean IOL calculation error was found between the formulas. Pairwise analysis revealed differences between SRK/T (-0.32±0.58 D) and other formulas - BUII (-0.16±0.52 D; p=0.014), RBF (-0.17±0.51 D; p=0.024), Kane (-0.17±0.52 D; p=0.029), but not with the LSF calculator (-0.19±0.53 D; p=0.071). No significant differences between the formulas were found in terms of mean error modulus (p=0.238). New generation calculators showed a more frequent success in hitting target refraction (within ±1.00 D in more than 95% of cases) than the SRK/T formula (86%).
CONCLUSIONS: The proposed method of adding 0.20 mm to the AL determined by UBM allows using this parameter in modern IOL calculation formulas and improving the refractive results of PE, especially in eyes with non-standard anterior segment structure.
UNASSIGNED: Оценка точности современных формул расчета интраокулярных линз (ИОЛ) с использованием данных о длине переднезадней оси (ПЗО), полученных при ультразвуковой биометрии (УЗБ), по сравнению с калькулятором третьего поколения SRK/T.
UNASSIGNED: В исследование включено 230 пациентов (267 глаз) с выраженными помутнениями хрусталика, препятствовавшими выполнению оптической биометрии, которым была проведена факоэмульсификация (ФЭ) с имплантацией ИОЛ. Калькуляция оптической силы ИОЛ по формуле SRK/T основывалась на длине ПЗО и глубине передней камеры, полученных с помощью контактной УЗБ (Tomey Biometer Al-100) и кератометрии на авторефрактокератометре Topcon KR 8800. В целях адаптации ПЗО для калькуляторов нового поколения — Barrett Universal II (BUII), Hill RBF ver. 3.0 (RBF), Kane и Ladas Super Formula (LSF) — к определяемой с помощью УЗБ аксиальной длине добавлялась толщина сетчатки (0,20 мм), а затем вычислялась оптическая сила искусственного хрусталика. В качестве критериев точности расчета ИОЛ использовались средняя ошибка и модуль ее значения.
UNASSIGNED: Обнаружена значимая разница (p=0,008) в средней ошибке расчета ИОЛ между формулами. Попарный анализ выявил различия между SRK/T (–0,32±0,58 дптр) и другими формулами — BUII (–0,16±0,52 дптр; p=0,014), RBF (–0,17±0,51 дптр; p=0,024), Kane (–0,17±0,52 дптр; p=0,029), но не с калькулятором LSF (–0,19±0,53 дптр; p=0,071). Значимых различий между формулами по параметру модуля средней ошибки найдено не было (p=0,238). Калькуляторы новых поколений показали более частое попадание в рефракцию цели (в пределах ±1,00 дптр более чем в 95% случаев), чем формула SRK/T (86%).
UNASSIGNED: Предложенный метод добавления 0,20 мм к определяемой с помощью УЗБ длине ПЗО позволяет использовать данный параметр в современных формулах расчета ИОЛ и улучшать рефракционные результаты ФЭ, особенно в глазах с нестандартным строением переднего отрезка.

BACKGROUND: To evaluate the axial length acquisition success rates and agreement between various biometric parameters obtained with different biometers in dense cataracts.
METHODS: Fifty-one eyes were measured using Anterion®, Argos® and IOLMaster® 700 swept-source optical coherence tomography (SS-OCT) biometers, a Pentacam® AXL partial coherence interferometry (PCI) biometer, and an OcuScan® RxP ultrasound biometer. We measured keratometry (K1, flattest keratometry and K2, steepest keratometry), white-to-white (WTW), anterior chamber depth (ACD), lens thickness (LT) and axial length. Cataracts were classified according to the Lens Opacities Classification System III grading system, the dysfunctional lens index (DLI) and Pentacam® nucleus staging (PNS) metrics. Percentage of acquisition success rate and a Bland-Altman analysis for the agreement between biometers were calculated.
RESULTS: The mean LOCS III score was 3.63 ± 0.92, the mean DLI was 2.95 ± 1.30 and the mean PNS was 2.36 ± 1.20. The acquisition success rates for the Anterion®, Argos®, IOLMaster® 700, Pentacam® AXL and OcuScan® RxP biometers were 94.12%, 100%, 98.04%, 60.78% and 100%, respectively. There were significant differences in the success rates between biometers (P = 0.014). There were statistically significant differences between biometers for all parameters evaluated (P < 0.05). The range of the limit of agreement (LoA) for all comparisons of K1 and K2 were > 1.00 D. The LoA for WTW ranged from 0.095 to 1.050 mm. The LoA for ACD and LT ranged from 0.307 to 0.114 mm and from 0.378 to 0.108 mm, respectively. The LoA for axial length ranged from 0.129 to 2.378 mm.
CONCLUSIONS: Among optical biometers, those based on SS-OCT technology are more successful at measuring axial length in eyes with dense cataracts.
BACKGROUND: The study was registered with the National Institutes of Health (clinical trial identifier NCT05239715, http://www.
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OBJECTIVE: To systematically compare and rank ocular measurements with optical and ultrasound biometers based on big data.
METHODS: PubMed, Embase, the Cochrane Library and the US trial registry ( www.
BACKGROUND: gov ) were used to systematically search trials published up to October 22nd, 2020. We included comparative studies reporting the following parameters measured by at least two devices: axial length (AL), flattest meridian keratometry (Kf), steepest meridian keratometry (Ks), mean keratometry (Km), astigmatism (AST), astigmatism vectors J0 and J45, anterior chamber depth (ACD), aqueous depth (AQD), central corneal thickness (CCT), corneal diameter (CD) and lens thickness (LT). A network-based big data analysis was conducted using STATA version 13.1.
RESULTS: Across 129 studies involving 17,181 eyes, 12 optical biometers and two ultrasound biometers (with both contact and immersion techniques) were identified. A network meta-analysis for AL and ACD measurements found that statistically significant differences existed when contact ultrasound biometry was compared with the optical biometers. There were no statistically significant differences among the four swept-source optical coherence tomography (SS-OCT) based devices (IOLMaster 700, OA-2000, Argos and ANTERION). As for Ks, Km and CD, statistically significant differences were found when the Pentacam AXL was compared with the IOLMaster and IOLMaster 500. There were statistically significant differences for CCT when the OA-2000 was compared to Pentacam AXL, IOLMaster 700, Lenstar, AL-Scan and Galilei G6.
CONCLUSIONS: For AL and ACD, contact ultrasound biometry obtains the lower values compared with optical biometers. The Pentacam AXL achieves the lowest values for keratometry and CD. The smallest value for CCT measurement is found with the OA-2000.

UNASSIGNED: To assess the position of the haptics of the implantable collamer lens (ICL) in myopic eyes using a high-frequency ultrasound robotic scanner.
UNASSIGNED: This was a prospective, single-arm, observational study carried out at the Instituto Zaldivar SA (Mendoza, Argentina) in a sample of 52 eyes who have been submitted to successful ICL implantation prior to enrollment. Images of the eyes were obtained using a very-high frequency digital ultrasound robotic scanner (VHFDU) to establish the position of the ICL in the posterior chamber and its relation to the ciliary sulcus. New parameters for lens position analysis were also described.
UNASSIGNED: In 81% of cases (42 eyes), the ICL rests on the ciliary body (CB) in both temporal and nasal sides, being slightly lower than 6% (3 eyes) those that rest on the sulcus in both sides, with significant correlations between ICL position and vault values (p<0.05). Cases in which the ICL position was CB-CB yielded central vault values across the whole range determined within the sample, but most of the eyes where the ICL rests on both the sulcus in one side and the CB in the other yield greater central vault values. Correlation was significant between ICL position and retroposition distance on the temporal side (Spearman\'s rho -0.487, p<0.001). A significant but weaker correlation was also found between ICL position and retroiridian space (p<0.05).
UNASSIGNED: ICL for myopia footplates tend to locate outside of the sulcus in a significant percentage of patients after successful implantation. VHFDU assessment in eyes implanted with an ICL to properly study the lens footplate position and posterior anatomical relations provides important additional information besides post-surgery vault.

We developed an artificial intelligence (AI) method for estimating fetal weights of Japanese fetuses based on the gestational weeks and the bi-parietal diameter, abdominal circumference, and femur length. The AI comprised of neural network architecture was trained by deep learning with a dataset that consists of ± 2 standard devia-tion (SD), ± 1.5SD, and ± 0SD categories of the approved standard values of ultrasonic measurements of the fetal weights of Japanese fetuses (Japan Society of Ultrasonics in Medicine [JSUM] data). We investigated the residuals and compared 2 other regression formulae for estimating the fetal weights of Japanese fetuses by t-test and Bland-Altman analyses, respectively. The residuals of the AI for the test dataset that was 12.5% of the JSUM data were 6.4 ± 2.6, -3.8 ± 8.6, and -0.32 ± 6.3 (g) at -2SD, +2SD, and all categories, respectively. The residu-als of another AI method created with all of the JSUM data, of which 20% were randomized validation data, were -1.5 ± 9.4, -2.5 ± 7.3, and -1.1 ± 6.7 (g) for -2SD, +2SD, and all categories, respectively. The residuals of this AI were not different from zero, whereas those of the published formulae differed from zero. Though vali-dation is required, the AI demonstrated potential for generating fetal weights accurately, especially for extreme fetal weights.

OBJECTIVE: To analyse the impact of ultrasound and optical intraocular lens (IOL) calculation methods on refractive outcomes of cataract phacoemulsification performed after penetrating keratoplasty (PK) in keratoconus.
METHODS: Phacoemulsification cataract surgery was performed on 42 eyes of 34 patients with keratoconus who had previously undergone PK. The IOL power was determined by using both standard and corneal topography-derived keratometry using the SRK/T formula. We used two independent methods-ultrasound biometry (UB) and interferometry [optical biometry (OB)] for IOL calculation. The analysed data from medical records included demographics, medical history, best corrected visual acuity (BCVA) on Snellen charts, technique of IOL calculation and calculation formula and its impact on final refractive result.
RESULTS: BCVA ranged from 0.01 to 0.4 (mean 0.09±0.19) before surgery and ranged from 0.2 to 0.7 (mean 0.38±0.14) at 1mo and from 0.2 to 1.0 (mean 0.56±0.16) (P<0.05) at 3mo, postoperatively. The refractive aim differed significantly from the refractive outcome in both the UB and OB groups (P<0.05). There was no statistically significant difference in the accuracy of the two biometry methods.
CONCLUSIONS: The refractive aim in keratoconus eyes post-PK is not achieved with either ultrasound or OB.

OBJECTIVE: To ascertain if optical biometry determination of axial length (AL) and intraocular lens (IOL) power is significantly different compared to ultrasound (US) biometry in cases with borderline signal-to-noise ratio (SNR).
METHODS: Sixty patients who had cataract and IOL Master biometry with borderline SNR (1.6-2.0) were included. A retrospective chart review was performed to compare data collected with optical biometry and US biometry in cataract cases with borderline SNR.
RESULTS: Results showed that optical biometry IOL and AL measurements were not significantly different from the US measurements. Analysis also demonstrated good agreement between the two methods.
CONCLUSIONS: Our study suggests that, in cases of borderline quality data, IOL power and AL measurements with optical biometry are still useful in surgical planning and that additional US measurements may be used more as a corroborative tool.

Historically, pregnancy dating has been based on self-reported information on the first day of the last menstrual period. In the 1970s, ultrasound biometry was introduced as an alternative for pregnancy dating and is now the leading method in Nordic countries. The use of ultrasound led to a reduction of post-term births and fewer inductions, and is considered more precise than last menstrual period-based methods for pregnancy dating. Nevertheless, differences in early growth and specific situations, such as maternal obesity, can render its estimates less precise, leading to gestational age misclassification. Clinical implications of ultrasound dating include effect on timely induction in case of post-term pregnancies, treatment with corticosteroids in cases of anticipated preterm delivery and decision on viability in cases of extreme prematurity. Furthermore, gestational age misclassification may influence the numbers and the magnitude of some adverse perinatal outcomes, closely related to gestational age, which are recorded in the Nordic birth registers.

The question of whether universal growth charts can be used in multi-ethnic settings is of general interest. The Intergrowth-21st fetal growth and newborn size standards are suggested to represent optimal fetal growth regardless of country origin. Our aim was to examine whether women fulfilling the strict Intergrowth-21st inclusion criteria were healthier, showed less ethnic differences in fetal growth and newborn size, and less adverse perinatal outcomes.
Data were drawn from a population-based multi-ethnic cohort of 823 presumably healthy pregnant women in Oslo, Norway. We assessed differences in fetal and neonatal gestational age specific z-scores and compared maternal health parameters, pregnancy and birth complications between pregnancies fulfilling and not fulfilling the Intergrowth-21st criteria.
Only 21% of pregnancies enrolled in our cohort fulfilled the Intergrowth-21st criteria. Fetal growth deviated substantially from the new standards, in particular for ethnic Europeans. Ethnic differences persisted in pregnancies fulfilling the criteria. In South Asian fetuses, estimated fetal weight was -0.60 SD (95% confidence interval -1.00, -0.20) lower at 24 gestational weeks, and birthweight was -0.62 SD (-0.95, -0.29) lower, compared with ethnic Europeans. Corresponding numbers for Middle-East/North Africans were -0.13 (-0.62, 0.36) and -0.60 (-1.00, -0.20). Maternal health indicators and birth complications were similar in women fulfilling and not fulfilling the criteria, but the relation depended on ethnic origin.
In an urban multi-ethnic Norwegian population, applying an extensive list of criteria to define \"healthy\" pregnancies excludes the majority of women but does not cancel ethnic differences in fetal growth.