Distribution of preoperative angle alpha and angle kappa values in patients undergoing multifocal refractive lens surgery based on a positive contact lens test

Purpose To assess the preoperative objective angle alpha and angle kappa measurements of patients deciding to undergo multifocal refractive lens surgery based on a subjective positive multifocal contact lens test (MCLT). Methods Retrospective, consecutive case series. Alpha and kappa angles were measured using the iTrace aberrometer. All patients also performed a 1-week MCLT. Only patients with a positive MCLT underwent surgery. Visual outcome (UCVA) was obtained in the 1-year follow-up. We assessed the preoperative distribution of angle values within MCLT positive and negative patient groups. Results Two hundred seventeen eyes (111 patients) were included. Mean age was 56.4 years (SD 5.6) and 46.9% were female. In 71 eyes (38 patients), MCLT was positive. Of them, 12 eyes (17%) had an angle alpha and angle kappa ≥ 0.5mm. Of 146 eyes (73 patients) who refrained from surgery due to a negative MCLT, 71 eyes (48.6%) had both angles small (<0.5mm). In the 1-year follow-up, UCVA improved by 0.68 logMAR (SD 0.51; p<0.001) from baseline. Eyes with both small angle alpha and kappa sizes improved by 0.78 logMAR (SD 0.56), as did eyes with high (≥0.5mm) angle sizes (0.82 logMAR (SD 0.53). UCVA of eyes (n=24) with high alpha but low kappa sizes improved less (−0.31 logMAR (SD 0.13; p=0.019)). Conclusion Four out of five patients with a positive MCLT also had correspondingly small angle values. One-half of patients with low preoperative angle values refrained from surgery due to a negative MCLT result. One-year visual acuity improvement was substantial and independent from angle sizes.

THE IMPORTANCE OF THROMBOELASTOMETRY IN THE HEMOSTATIC DISORDERS DIAGNOSIS IN INTENCIVE CARE PATIENTS WITH TRAUMAS (CLINICAL CASE)

thromboelastometry and coagulogram in patients with polytrauma. Materials and methods. The results of thromboelastometry (TEM) and standard coagulogram of 12 patients aged 18 to 74 years with a diagnosis of trauma were analyzed. Analysis of thromboelastometry was performed using a ROTEM delta blood analyzer (Tem Innovations GmbH, Germany), which evaluates the physical properties of a clot. Patients' blood stabilized with sodium citrate was placed in special disposable microcuvettes with the addition of various activators of coagulation reactions. The following indicators of thromboelastometry were determined: CT, CFT, angle alpha (α), MCF, A5, A10 in the tests INTEM, EXTEM and FIBTEM. The determination of coagulogram parameters was carried out according to a standard method. The following parameters were identified: APTT, INR, fibrinogen A content, serum fibrin degradation products (SFDP) concentration. Results. Coagulogram and thromboelastometry data at different stages of treatment were compared. In patients with the development of traumatic shock, coagulogram indices were changed to varying degrees depending on the stage of a shock. At the first stage of shock, the analysis showed only a 2-fold increase in SFDP and a slight increase in fibrinogen in dynamics. In a patient with a third stage of traumatic shock, the coagulogram indices were within normal limits, but according to TEM (EXTEM and FIBTEM tests), hypocoagulation was observed due to platelets. Only a coagulogram was evaluated in dynamics, hypocoagulation was observed in parameters of internal and external hemostasis pathways (prolongation of APTT, decrease in IPT and increase in INR), increase in fibrinogen A and SFDP. In the group of male patients with closed craniocerebral injuries, an increase in SFMC in the coagulogram had always been combined with changes in the FIBTEM test during TEM. Conclusion. Thus, in most patients, there is no change in classic coagulogram tests immediately after the injury. At the same time, rotational thromboelastometry makes it possible to fill this deficiency at an earlier date, which indicates a high sensitivity of the method.

The structure of maps on the space of all quantum pure states that preserve a fixed quantum angle

Let $H$ be a Hilbert space and $P(H)$ be the projective space of all quantum pure states. Wigner’s theorem states that every bijection $\phi \colon P(H)\to P(H)$ that preserves the quantum angle between pure states is automatically induced by either a unitary or an antiunitary operator $U\colon H\to H$. Uhlhorn’s theorem generalizes this result for bijective maps $\phi $ that are only assumed to preserve the quantum angle $\frac{\pi }{2}$ (orthogonality) in both directions. Recently, two papers, written by Li–Plevnik–Šemrl and Gehér, solved the corresponding structural problem for bijections that preserve only one fixed quantum angle $\alpha $ in both directions, provided that $0 &lt; \alpha \leq \frac{\pi }{4}$ holds. In this paper we solve the remaining structural problem for quantum angles $\alpha $ that satisfy $\frac{\pi }{4} &lt; \alpha &lt; \frac{\pi }{2}$, hence complete a programme started by Uhlhorn. In particular, it turns out that these maps are always induced by unitary or antiunitary operators, however, our assumption is much weaker than Wigner’s.

Hypercoagulability as Measured by Thrombelastography May Be Associated with the Size of Acute Ischemic Infarct—A Pilot Study

Background: Thromboelastography (TEG®) measures coagulation function in venous blood. Previous studies have reported that this device providing an integrated data on dynamics of clot formation may be useful for predicting clinical outcome in ischemic stroke. We investigated whether a hypercoagulability detected by thrombelastography may be associated with larger size of acute ischemic infarct. Methods: We included 40 ischemic stroke subjects with large artery atherosclerosis or small-vessel disease to a cross-sectional pilot study. Thrombelastography parameters related to time of clot formation (R- reaction time, K-clot kinetics), clot growth and strengthening (angle-alpha and MA-maximum amplitude) and lysis (Ly30) were performed within first 24 h after the onset of stroke. A volume of ischemic infarct was assessed on the basis of diffusion-weighted imaging (DWI) sequence of magnetic resonance imaging. Results: In the entire group, we reported that subjects with a large ischemic focus (>2 cm3) had a higher diameter of a clot (measured as MA) than subjects with a small ischemic focus (p = 0.0168). In the large artery atherosclerosis subgroup, we showed a significant correlation between MA and size of acute infarct (R = 0.64, p = 0.0138), between angle (alpha) and size of acute infarct (R = 0.55, p = 0.0428) and stroke subjects with hypercoagulability (MA > 69 mm) had significantly higher probability of a larger size of acute ischemic focus compared to normalcoagulable subjects (5.45 cm3 vs. 1.35 cm3; p = 0.0298). In multivariate logistic regression hypercoagulability was a predictor of a large size of ischemic infarct (Odds ratio OR = 59.5; 95% confidence interval (CI) 1.08–3558.8; p = 0.0488). Conclusions: We emphasized that thrombelastography, based on the parameters related to clot strength, may have clinical utility to identify the risk of the extensive ischemic infarct.

Influence of Angle Alpha on Visual Quality after Implantation of Extended Depth of Focus Intraocular Lenses

Background: To assess postoperative changes in angle alpha, and to evaluate the postoperative visual quality of patients with different angle alpha values after implantation of extended depth of focus (EDOF) intraocular lenses (IOLs).Methods: Seventy-nine eyes of 79 patients who had phacoemulsification with EDOF IOLs implantation were enrolled. A cut-off value of 0.3 mm, 0.4 mm, and 0.5 mm in preoperative angle alpha was chosen to divide eyes into groups. Distance, intermediate, and near visual acuities, modulation transfer function (MTF), and aberrations were recorded during a 6-month follow-up. A patient questionnaire was completed. Results: There were no significant differences in angle alpha postoperatively compared to preoperatively. No significant differences were found in visual acuity and MTF between all groups. With 5mm pupil diameter, there were significant differences of higher-order aberrations and spherical aberration in ocular aberration and internal aberration between angle alpha＜0.4 mm and angle alpha≥ 0.4 mm. Additionally, significant differences of coma were also added in cut-off value of 0.5 mm. When the value of angle alpha is 0.4 mm or higher, there were significant differences in the score of halos and glare.Conclusions: Angle alpha did not affect visual acuity, but the value of 0.4 mm or higher in angle alpha affected the visual quality under scotopic conditions and occurrence of halos and glare. For patients with 0.4 mm or higher in angle alpha, the decision to implant a EDOF IOL should be carefully considered.

The Distribution of IOL Center and Its Relationship with Internal Ocular Objective Visual Quality in Cataract Patients

Background: To investigate the distribution of the center of the intraocular lens (IOL) after phacoemulsification, and to assess the correlation between the center of IOL and preoperative angle kappa, angle alpha, and objective internal visual quality, respectively, in cataract patients with monofocal and bifocal IOLs implantation. Methods: Prospective cross-section cases series. One hundred and thirty-seven eyes of 107 patients who underwent phacoemulsification were included. Preoperative angle kappa and alpha, postoperative internal ocular aberrations, internal objective visual quality, and the center of IOL relative to the visual axis (CIV) was evaluated using iTrace system. Independent sample t-tests and Pearson correlations were performed.Results: Locations of CIV were scattered in all directions centered on corneal light reflection for both C-Loop designed IOL and plate-haptic designed IOL. No correlations were found between CIV and preoperative angle kappa and alpha in both magnitude and orientation. No correlations were found between CIV and postoperative internal ocular aberrations (astigmatism, coma, and trefoil). In the bifocal IOLs group, the CIV was negatively correlated to the internal Strehl ratio at 3mm; however, it was not correlated to the Strehl ratio at 5mm. The magnitude of CIV was positively correlated to the length of the optic axis.Conclusions: CIV was not predictable according to angle kappa and alpha before cataract surgery. CIV was not related to internal ocular aberration, but large CIV may lead to light scattering due to steps between diffractive rings in patients with small pupil sizes. The magnitude of CIV may be greater in cataract patients with longer optic axis.Trial registration: retrospectively registered.