Current Concepts and Recent Updates of Optical Biometry- A Comprehensive Review.

One of the most recent advancements in the field of cataract surgery is optical biometry. With the advent of optical biometry ocular measurements are now simpler, quicker, and more precise. The devices have made intraocular lens (IOL) power calculations easier in difficult situations too, such as in cases with extremes of axial lengths, silicone filled eyes, cataract surgery in post-keratoplasty eyes, post Laser-Assisted in Situ Keratomileusis (LASIK) eyes, etc. The gold standard for IOL power calculation in the present day is by the use of optical biometry devices. The anatomical measurements by these devices are highly precise and because of these measurements and the incorporation of various IOL power calculation formulas the optical biometry devices give the accurate power and the post-operative visual outcome is highly satisfactory among the patients. The growing use of these devices has made cataract the most commonly performed refractive surgical procedure nowadays. In the current scenario, optical biometry has widespread acceptance in almost all countries and has many advantages over ultrasound or immersion biometry. Cataract surgeons can obtain easy and reliable measurements from these devices. Refractive surprises have also decreased considerably with their use. This article will comprehensively review the principles of the various optical biometry devices, the parameters used in each of the devices, the advantages and disadvantages, and add more like what all this article will add.

Non-invasive flow mapping of parasagittal meningeal lymphatics using 2D interslice flow saturation MRI.

The clearance pathways of brain waste products in humans are still under debate in part due to the lack of noninvasive imaging techniques for meningeal lymphatic vessels (mLVs). In this study, we propose a new noninvasive mLVs imaging technique based on an inter-slice blood perfusion MRI called alternate ascending/descending directional navigation (ALADDIN). ALADDIN with inversion recovery (IR) at single inversion time of 2300 ms (single-TI IR-ALADDIN) clearly demonstrated parasagittal mLVs around the human superior sagittal sinus (SSS) with better detectability and specificity than the previously suggested noninvasive imaging techniques. While in many studies it has been difficult to detect mLVs and confirm their signal source noninvasively, the detection of mLVs in this study was confirmed by their posterior to anterior flow direction and their velocities and morphological features, which were consistent with those from the literature. In addition, IR-ALADDIN was compared with contrast-enhanced black blood imaging to confirm the detection of mLVs and its similarity. For the quantification of flow velocity of mLVs, IR-ALADDIN was performed at three inversion times of 2000, 2300, and 2600 ms (three-TI IR-ALADDIN) for both a flow phantom and humans. For this preliminary result, the flow velocity of the dorsal mLVs in humans ranged between 2.2 and 2.7 mm/s. Overall, (i) the single-TI IR-ALADDIN can be used as a novel non-invasive method to visualize mLVs in the whole brain with scan time of ~ 17 min and (ii) the multi-TI IR-ALADDIN can be used as a way to quantify the flow velocity of mLVs with a scan time of ~ 10 min (or shorter) in a limited coverage. Accordingly, the suggested approach can be applied to noninvasively studying meningeal lymphatic flows in general and also understanding the clearance pathways of waste production through mLVs in humans, which warrants further investigation.

Protein profiles in plasma: Development from infancy to 5 years of age.

PURPOSE: Little is known about the longitudinal development of different plasma protein levels during early childhood and particularly in relation to lifestyle factors. This study aimed to monitor the plasma proteome early in life and the influence of different lifestyles. EXPERIMENTAL DESIGN: A multiplex bead-based immunoassay was used to analyze plasma levels of 97 proteins in 280 blood samples longitudinally collected in children at 6, 12, 24, and 60 months of age living in families with an anthroposophic (n = 15), partly anthroposophic (n = 27), or non-anthroposophic (n = 28) lifestyle. RESULTS: A total of 68 proteins (70%) showed significantly altered plasma levels between 6 months and 5 years of age. In lifestyle stratified analysis, 59 of 97 (61%) proteins were altered over time within one or more of the three lifestyle groups. Nearly half of these proteins (28 out of 59) changed irrespective of lifestyle. The temporal changes represented four longitudinal trends of the plasma proteins during development, also following stratification of lifestyle. CONCLUSIONS AND CLINICAL RELEVANCE: Our findings contribute to understand the development of the plasma proteome under the influence of lifestyle exposures in early childhood.

Intrasession Repeatability of Biometric Measurements Obtained with a Low-Coherence Interferometry System in Pseudophakic Eyes.

Purpose: To evaluate the intrasession repeatability of the biometric measurements obtained with a low-coherence reflectometry optical biometer in pseudophakic eyes implanted with two different types of intraocular lens (IOL).Methods: Prospective, single-center, comparative study including 69 eyes of 69 patients with ages ranging from 51 to 92 years. Previous uncomplicated cataract surgery had been performed in all patients 1 to 2 months before measurements, with implantation of the Acrysof SN60WF IOL in 35 eyes (35 patients, group 1) and the IOL Akreos MI60 in 34 eyes (34 patients, group 2). A complete postoperative ophthalmological examination was performed including three consecutive measurements with the "Aladdin" system from (Topcon, Japan). Intrasession repeatability of axial length (AXL), anterior chamber depth (ACD) and IOL thickness (IOLT) were assessed with the within-subject standard deviation (Sw), intraobserver precision (1.96 × Sw), coefficient of variation (CV) and intraclass correlation coefficient (ICC). Results: The Sw for AXL measurements was 0.03 and 0.05 mm in groups 1 and 2, respectively, with ICC of 1.000 and 0.999 (CV: 0.14% and 0.22%) (p ≤ 0.031). Concerning pseudophakic ACD, the Sw was 0.03 and 0.09 mm in groups 1 and 2, respectively, with ICC of 0.992 and 0.956 (CV: 0.55% and 1.75%) (p ≤ 0.021). The variability of IOLT measurements was high in both groups, with Sw of 0.12 and 0.29 mm for groups 1 and 2 (p = .008), respectively, and ICC of 0.065 and 0.770 (CV: 20.84% and 62.39%).Conclusions: The optical biometer "Aladdin" (Topcon, Japan) provides consistent measurements of AXL and ACD in pseudophakic eyes. However, there is a limitation in the consistency of IOLT measurements that should be investigated further.

Histone Acetylation of Immune Regulatory Genes in Human Placenta in Association with Maternal Intake of Olive Oil and Fish Consumption.

Maternal diet modifies epigenetic programming in offspring, a potentially critical factor in the immune dysregulation of modern societies. We previously found that prenatal fish oil supplementation affects neonatal T-cell histone acetylation of genes implicated in adaptive immunity including PRKCZ, IL13, and TBX21. In this study, we measured H3 and H4 histone acetylation levels by chromatin immunoprecipitation in 173 term placentas collected in the prospective birth cohort, ALADDIN, in which information on lifestyle and diet is thoroughly recorded. In anthroposophic families, regular olive oil usage during pregnancy was associated with increased H3 acetylation at FOXP3 (p = 0.004), IL10RA (p = 0.008), and IL7R (p = 0.007) promoters, which remained significant after adjustment by offspring gender. Furthermore, maternal fish consumption was associated with increased H4 acetylation at the CD14 gene in placentas of female offspring (p = 0.009). In conclusion, prenatal olive oil intake can affect placental histone acetylation in immune regulatory genes, confirming previously observed pro-acetylation effects of olive oil polyphenols. The association with fish consumption may implicate ω-3 polyunsaturated fatty acids present in fish oil. Altered histone acetylation in placentas from mothers who regularly include fish or olive oil in their diets could influence immune priming in the newborn.

Efficiency and measurements agreement between swept-source OCT and low-coherence interferometry biometry systems.

PURPOSE: To compare and evaluate the agreement between the measurements obtained with a swept-source optical coherence tomography (OCT)-based biometer, the IOLMaster® 700 (IOLM), and those obtained by an optical biometer based on optical low-coherence interferometry (OLCI), the Aladdin (ALD); To evaluate the ability to perform biometric measurements in those eyes with transparency alterations. METHODS: Fifty-five eyes of 55 subjects were included in this study. Axial length (AL), corneal power (K, in diopters) and its astigmatism, anterior chamber depth (ACD), central corneal thickness (CCT), and lens thickness (LT) measures were obtained within both biometers, Zeiss IOLMaster 700 and Topcon Aladdin. Results were analyzed and compared using the Student's paired samples t-test, Bland-Altman analysis and intraclass correlation coefficient (ICC). RESULTS: Mean age was 73.12 ± 2.63 (62-89 years). The IOLM mean AL, K, and LT values did not show a statistically significant difference from ALD values and showed excellent agreement and correlation (ICC = 1.000, 0.970, 0.952). IOLM measured a lower mean ACD (-0.036 mm) and higher CCT measurements (9.296 µm). Those results were statistically different (p < 0.001 in both cases) but showed an excellent correlation coefficients (ICC = 0.994, 0.938). IOLM was able to obtain measures from all the eyes examined, while ALD did not measure in two cases with dense nuclear cataract. ALD showed spherical K measures in 7.27% of cases. CONCLUSION: Overall a quite good agreement between IOLM and ALD was found. ALD showed spherical keratometry measures in 7.27% of cases. IOLMaster 700 was more effective in obtaining AL measurements in eyes with dense cataracts.

Vaccination and Allergic Sensitization in Early Childhood - The ALADDIN Birth Cohort.

BACKGROUND: The increasing incidence of allergic diseases highlights the importance of finding underlying mechanisms. Early vaccination has been suggested as one influential factor. However, it is difficult to find a study group with a large variation between subjects concerning compliance to the official vaccination program. The anthroposophic lifestyle is of interest in this context. Moreover, cohort studies show that children of families with this lifestyle run a lower risk of allergic sensitization and allergy-related disease. METHODS: From the prospective birth cohort ALADDIN we included one group from the anthroposophic community, with restrictive attitudes concerning vaccinations, and two other groups of age-matched children with more conventional parental lifestyles. In all, 466 children were followed from birth to five years of age. Detailed vaccination data and blood samples were collected at six months, one, two, and five years. Information was also obtained on risk factors for allergy. The outcome variable, allergic sensitization was defined as allergen-specific serum IgE levels ≥ 0.35 kUA/L. FINDINGS: In a logistic regression model adjusted for socio-demographics and established allergy risk factors, vaccination at later age or having a lower number of injections or vaccines were associated with low OR for allergic sensitization during the first year of life. However, after adjustment for anthroposophic lifestyle, no statistically significant associations remained. The adjusted OR for sensitization at five years of age in children not receiving any vaccinations (n = 54) was 0.98 [95% CI 0.38-2.57]. INTERPRETATION: We found no support for an association between early childhood vaccination and subsequent allergic sensitization. Our findings do not support scepticism towards early childhood vaccination motivated by allergy risk.

Comparison of Anterior Segment Measurements Obtained by Aladdin Optical Biometer and Sirius Corneal Topography.

OBJECTIVES: To assess the agreement of anterior segment parameter measurements derived from Aladdin optical biometer using optical low coherence interferometer and Sirius corneal topography using combined Scheimpflug-Placido disk. MATERIALS AND METHODS: Data obtained using the Aladdin and Sirius systems from 110 eyes of 59 subjects who had no health problems other than refractive errors were retrospectively evaluated. Anterior chamber depth (ACD), flat (K1) and steep (K2) keratometry readings, and white-to-white distance (WTW) measurements taken with both devices were noted. RESULTS: The mean age of the patients was 47.31±18.57 years (range, 25 to 79 years). Mean ACD was 3.35±0.4 mm using Aladdin and 3.42±0.44 mm using Sirius. Mean difference in ACD was 0.075 mm greater with Sirius than Aladdin (p<0.001). K1 measurement obtained by Aladdin was an average of 0.409 D higher (p<0.001). No statistically significant differences were detected between the two devices in respect to K2 and WTW measurements (p=0.18, p=0.85 respectively). Pearson correlation analysis showed high correlation between the two devices for all measurements (r=0.985, 0.895, 0.961 and 0.766 for ACD, K1, K2 and WTW respectively; p<0.001). CONCLUSION: Anterior segment parameters obtained by Aladdin optical biometer and Sirius anterior segment analysis system correlated well with each other and measurement differences between the devices were clinically negligible except for K1 values.

Comparison of different formulas for intraocular lens power calculation using a new optical biometer.

PURPOSE: To evaluate and compare the predictability of different formulas for intraocular lens (IOL) power calculation using a new optical biometer (Aladdin). METHODS: This prospective cross-sectional study included 70 eyes of 70 patients who underwent uneventful phacoemulsification with IOL implantation. Preoperative IOL power calculations were performed using the Aladdin optical biometer. Postoperative actual refractive errors and errors predicted by the SRK/T, SRK II, Holladay 1, Hoffer Q and Haigis formulas were analyzed. The mean estimation error (EE), mean absolute estimation error (AEE) and the percentage of eyes within ± 0.50 and ± 1.00 D of the target refraction for each of five formulas were calculated and compared. This analysis was also repeated in three groups formed based on axial length (AL) (group 1: <22.5mm, group 2: 22.5-24 mm, group 3: >24 mm). RESULTS: In the overall study group, the smallest mean AEE was provided by the Holladay 1 formula, however there was no statistically significant difference in the mean AEE's predicted by the five formulas (P=0.34). The highest percentage of eyes within ± 0.50 and ± 1.00 D of the target refraction was also found by using Holladay 1 (71% and 97%). SRK/T provided smallest mean AEE for groups 1 (n=13) and 3 (n=16). In group 2 (n=41), the smallest mean AEE was obtained using Holladay 1. CONCLUSIONS: Based on the Aladdin biometric data used in our study, better results can be obtained using SRK/T formula in eyes with short or long AL. The Holladay 1 formula may be preferred in eyes with moderate AL.