Power Formula Research Articles

Bootstrap Outlier Identification in Clinical Datasets for Lens Power Formula Constant Optimization

PurposeBootstrapping is a modern technique widely used in statistics to evaluate the performance of model parameters. The purpose of this study was to develop a strategy to identify and eliminate outliers in a dataset used for optimizing formula constants for lens power calculation.MethodsIn a dataset with N = 888 clinical cases treated with a monofocal aspherical intraocular lens (XC1/XY1, Hoya) constants for the SRKT, Haigis and Castrop formula were optimized and the prediction error PE calculated. The PE was bootstrapped NB = 1000 times, and the mean and trimmed mean of the bootstrapped PE were derived to generate the Bootlier plot showing the probability density function of the mean minus trimmed mean. With outliers this Bootlier plot shows some multimodality, and a Bootlier Index was extracted as a measure for multimodality. Outliers were removed from the tails of the PE distribution in a stepwise fashion until the Bootlier Index fell below a threshold of 0.001.ResultsWith the entire dataset the mean/SD/median/mean absolute/root mean squared PE using the optimized formula constants were -0.0045/0.44415/0.0134/0.3406/0.4412 dpt with SRKT, 0.0065/0.3711/-0.0056/0.2830/0.3710 dpt with Haigis, and 0.0034/0.3452/0.0023/0.2683/0.3451 dpt with the Castrop formula. After identifying and removing outliers the respective metrics for the PE were -0.0036/0.4028/0.0134/0.3205/0.4026 dpt for the SRKT (13 cases removed), 0.0050/0.3375/-0.0056/0.2656/0.3373 dpt with Haigis (11 cases removed), and 0.0035/0.3168/0.0023/0.2531/0.3166 dpt with Castrop (11 cases removed). The multimodality in the Bootlier plots was reduced from 0/0.1567/0.0587/0.0258/0.0007/0 with SRKT, 0/0.0981/0.0261/0.0202/0.0003/0 with Haigis, and 0.0006/0.0006/0.0161/0.0191/0.0005/0 with Castrop for the entire dataset to values below 1e-3 for trimming both tails of the PE distribution by ⅛, ¼, ½, 1, 2.5, and 5% respectively.ConclusionWe were able to prove that bootstrapping with outlier identification based on Bootlier plots and the Bootlier Index is a powerful tool to clean a dataset of outliers for formula constant optimization.

Effect of air properties on a twin-shaft turbofan engine performance during start-up

When engines start in coastal areas in summer, the performance of turbofan engine and starter will be inevitably affected by ambient humidity and temperature. It is important to predict the change of start-up performance by capturing the effect of ambient humidity and temperature on the matching process between turbofan engine and starter. However, in the start-up model, starter model is usually simplified by look-up table of starter power and semi-empirical formulas. It is difficult to simulate the variation of transient performance of turbofan engine caused by the power change of the starter when the ambient humidity and temperature increase. In this paper, a new method for simulating the transient performance of start-up process is presented. The nonlinear transient model including turbofan engine and starter is developed based on real engine configurations. The power compatibility equation is established to correlate the turbofan engine and starter to predict the matching performance in the start-up stage. The model is validated using mature commercial software. The steady-state errors of the model are within 2 % and the dynamic errors are within 2.5 %. In this paper, the start-up process is divided into four stages, and the transient performance of turbofan engine and starter in each stage is analyzed. This paper simulates the transient performance of start-up process under different ambient temperature and humidity conditions. The results show that when the ambient temperature is 308.5 K and the relative humidity is 0.8, the starter power is reduced by 76.86 % and the start-up time is increased by 10.28 s.

GENERAL ELECTIONS IN BOSNIA AND HERZEGOVINA

This article discusses the regular general election hold in Bosnia and Herzegovina (02.10.2022), the course of their electioneering, and the voting results. The analysis reveals the same main actors flashed on the political scene, the same principle collisions repeated, and even the methods of winning victory with the help of nationalist rhetoric remaining unchanged. However, the realignment of political forces has led to a new formula of power both in the Federation of Bosnia and Herzegovina and at the national level. The loser was the leading Islamist-nationalist Party of Democratic Action of the Bosniaks, which already bored its Western patrons with its destructive activity. Keeping up with these developments, an assessment of the prospects of the coalition government of Bosnia and Herzegovina formed by 21 political actors is suggested. Among them are the Croatian Democratic Union and the parties blocking with it, the Alliance of Independent Social Democrats with their partners from Republika Srpska and also eight secular Bosnian parties. A significant factor in maintaining the cabinet cohesion is the need to demonstrate to the EU its «cooperation», a sine qua non for Western support and funding. The Federation theoretically could face problems with the losers being able to block the process of authorities formation. However, according to the common understanding, Christian Schmidt, the High Representative of the international community in the country, will not allow this. It can be assumed that under the current international climate (when the Russian Federation is absorbed by the conflict in Ukraine, and Serbia is barely able to withstand Western pressure and the aggravation of the situation in Kosovo), even the allegedly pro-Russian President of the Republika Srpska, Milorad Dodik will be forced to take into account new political realities. If Brussels and Washington are smart enough to not push the Serbs «to the limit», the new Bosnia and Herzegovina government will finally have a chance to get down to business and do something useful for their citizens.

Refractive error after combined phaco-vitrectomy: A multicentric study.

To study the post-operative refractive error (RE) of patients undergoing combined phaco-vitrectomy and to find out which intraocular lens (IOL)-power formula had the best refractive outcomes. In this retrospective multicentric study we compared the preoperative expected target with the postoperative RE of patients undergoing combined phaco-vitrectomy due to vitreomacular traction, macular pucker, full thickness macular hole or lamellar macular hole. A multinomial logistic regression was performed to compare the postoperative REs and the differences between expected and postoperative REs among the SRK-T, Olsen's and Holladay-2 formulas. The correlation between the difference in REs and IOL-power was also studied. Sixty-seven eyes with a mean axial length of 23.73 ± 1.21 mm were included. Forty-two (63%), 14 (21%) and 11 (16%) eyes were implanted with an IOL that was calculated respectively with SRK-T, Olsen's and the Holladay-2 formula. The mean preoperative expected- and post-operative REs were -0.16 ± 0.12D and -0.48 ± 0.17, respectively (p = 0.045). SRK-T and Holladay-2 formulas led to a significant myopic shift whereas Olsen's caused a significant hyperopic error, independently from the IOL power. Independently from the IOL power, none of the analyzed formulas is precise at calculating the post-operative RE.

Precise measurement of the Bragg curve for 800 MeV/u 238U ions stopping in polyethylene and its implications for calculation of heavy ion ranges

Stopping power predictions in radiation transport codes are based on the Bethe-Bloch formula and different corrections. For very heavy ions at relativistic energies the available experimental data are scarce and therefore verification of stopping power predictions is only possible to a limited extent.In this work, a full experimental Bragg curve for 800 MeV/u 238U ions stopping in polyethylene is presented. The measurements were conducted at the experimental area Cave A at GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. The 800 MeV/u 238U beam was provided by the SIS18 heavy ion synchrotron. The Bragg curve was measured with a setup consisting of a binary range shifter and two large area parallel plate ionization chambers. Complementary Monte Carlo simulations using the FLUKA code were performed and compared with the experimental Bragg curve. The mean ionization potential of polyethylene was fine-tuned to match the measured primary ion range with FLUKA simulations. The impact of the Bloch and Mott corrections to the stopping power calculation were studied by switching them off intentionally in separate simulations. A detailed description of the implementation of the stopping power formulae and the Mott correction in FLUKA is provided.Supplementary data for this article is available online.

Direct Detection of Alpha Particles with Solid-State Electronics

Alpha-particle sources are widely used in industrial and medical applications. Such applications include smoke detectors, static charge eliminators, and radiation therapy. This paper is concerned with the detection of alpha particles. A number of techniques are known for the detection of alpha particles. Those techniques include the Geiger–Müller tube, the ZnS scintillator, the air-filled ionization chamber, and the spark chamber. All the techniques that are currently known are based on the interaction of the ionizing radiation with matter. Charged particles, such as alpha particles, upon entering a medium (such as air), encounter many collisions with bound electrons and lose kinetic energy in the process. The atoms of the medium also become ionized, and a large number of free electrons are released inside the medium. The theory describing the interaction of ionizing radiation with matter is well known and includes formulas such as the Bethe-Bloch formula for the stopping power of matter and formulas for calculating the range of the ionizing radiation in matter. Essentially, all the known techniques for the detection of alpha particles are based on detecting the presence of free electrons inside the medium. This paper presents a new technique for the detection of alpha particles that does not depend on the theory of the interaction of alpha particles with matter. Instead, the technique is based on the direct detection of the positive charge that is carried by the alpha particles. Furthermore, it is the objective of this paper to demonstrate that the direct detection of the charge carried by alpha particles can be done with a tiny and inexpensive component: a metal–oxide–semiconductor field-effect transistor (MOSFET).

Evaluating intraocular lens power formula constant robustness using bootstrap algorithms.

Bootstrapping is a modern technique mostly used in statistics to evaluate the robustness of model parameters. The purpose of this study was to develop a method for evaluation of formula constant uncertainties and the effect on the prediction error (PE) in intraocular lens power calculation with theoretical-optical formulae using bootstrap techniques. In a dataset with N=888 clinical cases treated with the monofocal aspherical intraocular lens (Vivinex, Hoya) constants for the Haigis, the Castrop and the SRKT formula were optimised for the sum of squared PE using nonlinear iterative optimisation (interior point method), and the formula predicted spherical equivalent refraction (predSEQ) and the PE were derived. The PE was bootstrapped NB=1000 times and added to predSEQ, and formula constants were derived for each bootstrap. The robustness of the constants was calculated from the NB bootstrapped models, and the predSEQ was back-calculated from the NB formula constants. With bootstrapping, the 90% confidence intervals for the a0/a1/a2 constants of the Haigis formula were -0.8317 to -0.5301/0.3203 to 0.3617/0.1954 to 0.2100, for the C/H/R constants of the Castrop formula they were 0.3113 to 0.3272/0.1237 to 0.2149/0.0980 to 0.1621, and for the A constant of the SRKT formula they were 119.2320 to 119.3028. The back-calculated PE from the NB bootstrapped formula constants standard deviation for the mean/median/mean absolute/root mean squared PE were 5.677/5.735/0.401/0.318 e-3 dpt for the Haigis formula, 5.677/5.735/0.401/0.31829 e-3 dpt for the Castrop formula and 14.748/14.790/0.561/0.370 e-3 dpt for the SRKT formula. We have been able to prove with bootstrapping that nonlinear iterative formula constant optimisation techniques for the Haigis, the Castrop and the SRKT formulae yield consistent results with low uncertainties of the formula constants and low variations in the back-calculated mean, median, mean absolute and root mean squared formula prediction error.

Power Approximations for Overall Average Effects in Meta-Analysis With Dependent Effect Sizes

Meta-analytic models for dependent effect sizes have grown increasingly sophisticated over the last few decades, which has created challenges for a priori power calculations. We introduce power approximations for tests of average effect sizes based upon several common approaches for handling dependent effect sizes. In a Monte Carlo simulation, we show that the new power formulas can accurately approximate the true power of meta-analytic models for dependent effect sizes. Lastly, we investigate the Type I error rate and power for several common models, finding that tests using robust variance estimation provide better Type I error calibration than tests with model-based variance estimation. We consider implications for practice with respect to selecting a working model and an inferential approach.

Postoperative vault prediction for phakic implantable collamer lens surgery: LASSO formulas.

To develop and evaluate reliable formulas for predicting postoperative vault more accurately after implantable collamer lens (ICL) surgery in a White patient population with varying degrees of ametropia. Private clinical practice. Retrospective analysis on dataset split into a separate training and test set. 115 eyes of 59 patients were used to train regression models predicting postoperative vault based on anterior segment optical coherence tomography (OCT) parameters (Least Absolute Shrinkage and Selection Operator [LASSO]-OCT formula), ocular biometry data (LASSO-Biometry formula), or data from both devices (LASSO-Full formula). The performance of these models was evaluated against the manufacturer's nomogram (Online Calculation and Ordering System [OCOS]) and Nakamura 1 (NK1) and 2 (NK2) formulas on a matched separate test set of 37 eyes of 19 patients. The mean preoperative spherical equivalent was -5.32 ± 3.37 (range: +3.75 to -17.375 diopters). The mean absolute errors of the estimated vs achieved postoperative vault for the LASSO-Biometry, LASSO-OCT, and LASSO-Full formulas were 144.1 ± 107.9 μm, 145.6 ± 100.6 μm, and 132.0 ± 86.6 μm, respectively. These results were significantly lower compared with the OCOS, NK1, and NK2 formulas ( P < .006). Postoperative vault could be estimated within 500 μm in 97.3% (LASSO-Biometry) to 100% of cases (LASSO-OCT and LASSO-Full). The LASSO suite provided a set of powerful, reproducible yet convenient ICL sizing formulas with state-of-the-art performance in White patients, including those with low to moderate degrees of myopia. The calculator can be accessed at http://icl.emmetropia.be .

Understanding dengue solution and larval indices surveillance system among village health volunteers in high- and low-risk dengue villages in southern Thailand

BackgroundSuccessful dengue solutions require community collaboration between agencies engaged in human health, vector control and the environment. In Thailand, village health volunteers emphasize the need for a health working group to interact, collaborate, and coordinate actions. The objectives of this study were to acquire an understanding of dengue solutions, as well as the larval indices surveillance system of village health volunteers in high- and low-risk dengue villages. MethodsAfter 12 months of training in dengue prevention and setting larval indices surveillance systems, an analytical cross-sectional survey was conducted. A total of 117 villages were included in the 18 primary care facilities within one district in southern Thailand, and they were divided into 71 high-risk and 46 low-risk dengue villages. Sample size was determined using the G*power formula. The content validity index and reliability values of Cronbach's alpha coefficient for the questionnaires were 0.91 and 0.83, respectively. A random sampling approach was used to acquire data. The chi-square test, t-test, and odds ratio were used to assess the sample's level of understanding. ResultsThe study included 1302 village health volunteers, including 895 and 407 from high- and low-risk dengue communities, respectively. In total, 87.9% were female, 51.6% were 20–35 years old, 48.8% had worked as a village health volunteer for 11–20 years, 27.1% had an upper elementary education, and 59.1% had dengue in the previous 12 months. Understanding of the dengue solution and larval indices surveillance system varied across high- and low-risk dengue villages. Village health volunteers with a high level of understanding of the dengue solution and larval indies surveillance system were 1.064 and 1.504 times more likely to stay in high-risk dengue villages, respectively (odds ratio [OR] = 1.064, 95% confidence interval [CI]:0.798–1.419, p = 0.672 and OR = 1.504, 95% CI:1.044–2.167, p = 0.028). ConclusionsVillage health volunteers require ongoing training to understand the prevention and control of dengue and larval indices surveillance systems, promote awareness, and monitor dengue in both high- and low-risk dengue villages.

Power to Detect Moderated Effects in Studies with Three-Level Partially Nested Data

Comprehensive evaluation of treatment effects is aided by considerations for moderated effects. In educational research, the combination of natural hierarchical structures and prevalence of group-administered or shared facilitator treatments often produces three-level partially nested data structures. Literature details planning strategies for a variety of experimental designs when moderation effects are of interest but has yet to establish power formulas for detecting moderation effects in three-level partially nested designs. To address this gap, we derive and assess the accuracy of power formulas for detecting the different types of moderation effects possible in these designs. Using Monte Carlo simulation studies, we probe power rates and adequate sample sizes for detecting the different moderation effects while varying common influential factors including variance in the outcome explained by covariates, magnitude of the moderation effect, and sample sizes. The power formulas developed improve the planning of experimental studies with partial nesting and encourage the inclusion of moderator variables to capture for whom and under what conditions a treatment is effective. Educational researchers also have some initial guidance regarding adequate sample sizes and the factors that influence detecting moderation effects in three-level partially nested designs.

Bethe stopping-power formula and its corrections

The classical and quantum theories leading to the asymptotic Bethe formula of the stopping power of matter for charged particles heavier than the electron are briefly reviewed. Models and approximations for the practical calculation of various corrections that extend the validity range of the formula are described. The asymptotic formula and the associated shell correction were determined previously from an extensive database of atomic generalized oscillator strengths, calculated for an independent-electron model with the Dirac-Hartree-Fock-Slater (DHFS) self-consistent potential, with due account for relativistic departures from the Bethe sum rule. The nonrelativistic Bloch correction is extended to the relativistic domain by means of the Lindhard-S\o{}rensen formulation, and an accurate parametrization for point projectiles with small charges is proposed. The density-effect correction and the Barkas correction are obtained from a semiempirical model of the optical oscillator strength (OOS), built from the calculated DHFS contributions of inner electron subshells plus the OOS of outer-shell electrons represented by an analytical expression, which is determined by the composition, mass density, and empirical mean excitation energy, or $I$ value of the material. Inclusion of the shell, density-effect, Lindhard-S\o{}rensen, and Barkas corrections into the asymptotic formula leads to the corrected Bethe formula. A general strategy is proposed to determine the stopping power in terms of only the $I$ value of the material. It is shown that, with the empirical $I$ values recommended in Report 37 of the International Commission on Radiation Units and Measurements, the stopping powers calculated numerically from the corrected formula are in close agreement with available measurements of the stopping power of elemental materials for protons and alpha particles with energies higher than 0.75 and 5 MeV, respectively.

Predictive Accuracy of the Hill-RBF 2.0 Formula in Pediatric Eyes: Comparison of 5 Intraocular Lens Formulas.

To compare the predictive accuracy of the Hill-Radial Basis Function (Hill-RBF) 2.0 formula with the Barrett Universal II, Hoffer Q, SRK/T, and Holladay 1 formulas in pediatric eyes. In this observational study, 99 eyes of 70 children 4 to 18 years old with clinically significant congenital or developmental cataracts attending the pediatric ophthalmology clinic in Guru Nanak Eye Centre were included. Optical biometry was performed in all patients with the Lenstar LS-900 (Haag-Streit). Intraocular lens (IOL) power predicted by the Hill-RBF formula was selected. Mean absolute prediction error (MAE) at 8 weeks of follow-up was calculated for the Hill-RBF, Barrett Universal II, Hoffer Q, SRK/T, and Holladay 1 IOL power formulas. Percentages of eyes having residual refraction within ±0.50, ±0.50 to ±1.00, and greater than ±1.00 diopters (D) of target refraction were calculated. The MAEs were 1.08 ± 1.00 D for the Hill-RBF, 1.24 ± 1.20 D for the Barrett Universal II, 1.25 ± 1.06 D for the Hoffer Q, 1.25 ± 1.10 D for the SRK/T, and 1.28 ± 1.01 D for the Holladay 1 formulas. The Hill-RBF formula had the lowest MAE, which was significantly lower than the Holladay 1 and Hoffer Q formulas. However, the difference in MAE between the Hill-RBF and the SRK/T and Barrett Universal II formulas was not statistically significant (P > .05). The Hill-RBF group had the maximum percentage of eyes with residual error within ±0.50 D of the target refraction. The overall evidence from the studies indicates that the Hill-RBF method that uses artificial intelligence and works independent of specific anatomical features is non-inferior to the Barrett Universal II, Hoffer Q, SRK/T, and Holladay 1 formulas in pediatric eyes. [J Pediatr Ophthalmol Strabismus. 2023;60(4):282-287.].

Theoretical Relationship Among Effective Lens Position, Predicted Refraction, and Corneal and Intraocular Lens Power in a Pseudophakic Eye Model.

PurposeTo ascertain the theoretical impact of anatomical variations in the effective lens position (ELP) of the intraocular lens (IOL) in a thick lens eye model. The impact of optimization of IOL power formulas based on a single lens constant was also simulated.MethodsA schematic eye model was designed and manipulated to reflect changes in the ELP while keeping the optical design of the IOL unchanged. Corresponding relationships among variations in ELP, postoperative spherical equivalent refraction, and required IOL power adjustment to attain target refractions were computed for differing corneal powers (38 diopters [D], 43 D, and 48 D) with IOL power ranging from 1 to 35 D.ResultsThe change in ELP required to compensate for various systematic biases increased dramatically with low-power IOLs (less than 10 D) and was proportional to the magnitude of the change in refraction. The theoretical impact of the variation in ELP on postoperative refraction was nonlinear and highly dependent on the optical power of the IOL. The concomitant variations in IOL power and refraction at the spectacle plane, induced by varying the ELP, were linearly related. The influence of the corneal power was minimal.ConclusionsThe consequences of variations in the lens constant mainly concern eyes receiving high-power IOLs. The compensation of a systematic bias by a constant increment of the ELP may induce a nonsystematic modification of the predicted IOL power, according to the biometric characteristics of the eyes studied.Translational RelevanceOptimizing IOL power formulas by altering the ELP may induce nonsystematic modification of the predicted IOL power.

Constant Power Factor Model of DFIG-Based Wind Turbine for Steady State Load Flow Studies

DFIG (Doubly Fed Induction Generator)-based WPP (Wind Power Plant) is the most popular type of wind-driven electric power generation configuration. The main reason for its popularity is that the DFIG system can capture wind energy more optimally than other WPP configurations. Due to the increasing penetration of WPP in power systems, the need to study its impact on power system performance is becoming increasingly important. To enable such a study to be conducted properly, the first and probably the most crucial step is to model all system components (including the WPP). This paper proposes a new steady state model of DFIG-based WPP for load flow analysis. The proposed model is derived based on DFIG power formulas (i.e., DFIG stator and rotor power formulas). The model in the present work is simple and can easily be incorporated into load flow analysis. Representation of the DFIG in both sub-synchronous and super-synchronous conditions can be carried out by using a single mathematical model. Furthermore, since DFIG can be operated at a constant power factor (i.e., unity, leading, or lagging power factor), this important feature is also considered in the proposed model development.

Investigating the Prediction Accuracy of Recently Updated Intraocular Lens Power Formulas with Artificial Intelligence for High Myopia.

The aim of this study was to investigate the prediction accuracy of intraocular lens (IOL) power formulas with artificial intelligence (AI) for high myopia. Cases of highly myopic patients (axial length [AL], >26.0 mm) undergoing uncomplicated cataract surgery with at least 1-month follow-up were included. Prediction errors, absolute errors, and percentages of eyes with prediction errors within ±0.25, ±0.50, and ±1.00 diopters (D) were compared using five formulas: Hill-RBF3.0, Kane, Barrett Universal II (BUII), Haigis, and SRK/T. Seventy eyes (mean patient age at surgery, 64.0 ± 9.0 years; mean AL, 27.8 ± 1.3 mm) were included. The prediction errors with the Hill-RBF3.0 and Kane formulas were statistically different from the BUII, Haigis, and SRK/T formulas, whereas there was not a statistically significant difference between those with the Hill-RBF3.0 and Kane. The absolute errors with the Hill-RBF3.0 and Kane formulas were smaller than that with the BUII formula, whereas there was not a statistically significant difference between the other formulas. The percentage within ±0.25 D with the Hill-RBF3.0 formula was larger than that with the BUII formula. The prediction accuracy using AI (Hill-RBF3.0 and Kane) showed excellent prediction accuracy. No significant difference was observed in the prediction accuracy between the Hill-RBF3.0 and Kane formulas.

Analysis of the Role of the Social Service in Distributing Social Aid as an Effort to Relieve Poverty in Wonogiri District

Poverty is also a classic problem in any country; there has not been a powerful formula that can deal with poverty quickly. This study uses qualitative methods with Case Study Analysis that explores a particular case in more depth by collecting various sources of information. The type of data used is primary data, the source of data taken from respondents through data collection techniques, interviews, observations, and documentation. The method of selecting respondents uses purposive sampling with six respondents, including three employees of the Social Service office and three recipients of social assistance in this social assistance program. From the results of interviews with 4 out of 6 respondents, it can be concluded that the existence of this social assistance distribution program can be said to be not fully on target. The recipients of the social assistance understand the purpose and purpose of this social assistance and how to get the social assistance. Keywords: poverty; social assistance; pandemic

Accuracy of IOL Power Calculation Formulas for AcrySof SN60WF versus Tecnis ZCB00 Intraocular Lenses.

PurposeTo compare the accuracy of various intraocular lens power formulas for two monofocal hydrophobic foldable lenses, the AcrySof SN60WF and the Tecnis ZCB00.MethodsThis retrospective study included 409 eyes from 409 patients who underwent uncomplicated cataract surgery (299 eyes with SN60WF and 110 eyes with ZCB00). Biometry was performed for all eyes with an IOLMaster 700. Predicted refraction from five different IOL power formulas (Barrett Universal II, Haigis, Hoffer-Q, Holladay 2, and SRK/T) was compared to postoperative refraction at one to three months for the following axial length strata: short eyes (22.5 mm), medium eyes (22.5–25.5 mm), and long eyes (25.5 mm).Results In patients with medium eyes, there were no significant differences in the mean absolute error (MAE) and the percentage of eyes within 0.5 D (%0.5 D) between both IOLs. In short eyes, although MAE was similar between both lenses, %0.5 D was significantly higher for Barrett Universal II in ZCB00 than in SN60WF (P = 0.01) while Hoffer-Q and Holladay 2 performed equally for both lenses. In long eyes, ZCB00 had a higher MAE than SN60WF for Barrett Universal II, Haigis, and Hoffer-Q. Additionally, in long eyes, the percentage of eyes within %0.5 D was significantly higher for SN60WF than ZCB00 for all formulas (P 0.001).ConclusionAlthough there were no significant differences in the formula accuracy between these two lenses in medium eyes for all formulas and in short eyes for most formulas, the accuracy decreased significantly in long eyes for ZCB00 compared to SN60WF. The effect of IOL model on the postoperative outcomes should be further investigated.

Scrutinizing the Therapeutic Promise of Purinergic Receptors Targeting Depression.

Antidepressant use has resulted in a variety of negative consequences, including permanent brain damage and erectile dysfunction. So, the purpose lies in developing something more productive with minimal side effects and consequently improved efficacy. A growing body of evidences indicated a remarkable purinergic signalling system, which helped in dealing with this complication. This has been found to be a powerful formula in dealing with psychiatric disorders. P1 (adenosine), P2X, and P2Y (ATP) are the receptors, involved in the pathology as well as exhibiting the therapeutic action by triggering the purinergic pathway. It was found that A2A and P2X7 receptors specifically were involved and recognized as possible targets for treating depression. Further, the development of biomarkers for the diagnosis of depression has also been attributed to accelerate the process. One such biomarker includes serum uric acid. Many clinical studies reveal the importance of antagonizing P2X7 and A2A receptors, for promising research in understanding the molecular premises of depression. However, further investigations are still needed to be done to open several unfolded mysteries for a better and safe upshot. The selective antagonists for A2A and P2X7 receptors may have antidepressant effects showing positive results, in agreement with non-clinical testing. In this review, efforts are being devoted to the targeted receptors in bringing out antidepressant effects with a possible link involving depression and defined purinergic signalling. Additionally, the overview of various receptors, including their functions and distribution, is being explored in a representative way along with the biomarkers involved.

Evaluation of Refractive Accuracy of ORA and the Factors Impacting Residual Astigmatism in Patients Implanted with Trifocal IOLs During Cataract Surgery: A Retrospective Observational Study

PurposeTo assess the refractive accuracy of the intraoperative aberrometer Optiwave Refractive Analysis (ORA) and evaluate factors impacting residual astigmatism in eyes implanted with PanOptix (TFNT) trifocal intraocular lenses (IOLs) during cataract surgery.Patients and MethodsThis retrospective study examined 180 eyes implanted with a toric or non-toric trifocal IOL during cataract surgery. The mean refractive prediction error (RPE), median absolute RPE, and percentage of eyes with an absolute RPE ≤0.25, ≤0.50, ≤0.75, and ≤1.00 diopter (D) were determined for ORA and each of the IOL power formulas (Sanders–‍Retzlaff–Kraft/Theoretical [SRK/T], Barrett Universal II, and Haigis). Correlation analysis of postoperative residual astigmatism and factors associated with it was performed using Pearson’s and Spearman correlations in eyes with non-toric trifocal IOLs.ResultsAfter optimization, the median absolute RPE was 0.19 D, 0.25 D, 0.20 D, and 0.26 D in eyes measured using ORA and the SRK/T, Barrett Universal II, and Haigis formulas, respectively. An absolute RPE ≤0.50 D after optimization was noted in 92.8%, 83.3%, 88.3%, and 81.1% of the eyes using ORA and the SRK/T (p=0.0093), Barrett Universal II (p=0.2071), and Haigis (p=0.0018) formulas, respectively, showing significant differences between ORA and the SRK/T and Haigis formulas. The mean±standard deviation subjective residual astigmatism in non-toric IOL eyes (N=76) was 0.46±0.39 D and showed a strong positive correlation with preoperative objective refractive astigmatism (r=0.2925, p=0.0109), intraoperative ORA–measured astigmatism (r=0.5555, p<0.0001), postoperative objective refractive astigmatism (r=0.8188, p<0.0001), and postoperative total corneal astigmatism (TCA) (r=0.4051, p=0.0003) and a negative correlation with preoperative anterior corneal astigmatism (r=−0.3541, p=0.0017).ConclusionORA is a salient tool for improving the postoperative refractive accuracy of trifocal IOL power calculations and may help in determining the need for toric IOL use in astigmatic eyes with cataracts. Residual astigmatism correlated with objective refractive astigmatism, ORA-measured astigmatism, and postoperative TCA.