Ten-year longitudinal investigation of astigmatism: The Yamagata Study (Funagata)

Despite numerous investigations into ocular or corneal astigmatism, the dynamic nature of astigmatism remains poorly understood. To reveal potential associations between age and astigmatism, 264 Japanese participants who underwent systemic and ophthalmological examinations in Funagata Town (Yamagata Prefecture, Japan) were evaluated over a 10-year period. Astigmatism was evaluated with regard to the cylinder power, cylinder axis, and vector analyses. Whereas the refractive cylinders showed age-related increases in patients in their 40s to 60s, the corneal cylinders did not change over 10 years. Nevertheless, cylindrical axis of the cornea demonstrated a continuous shift toward against-the-rule (ATR) astigmatism. Vector analyses revealed that the astigmatic shift toward ATR progressed continually after patients reached their 40s, although the shift did not accelerate with age. These novel insights may pave the way for the development of potential strategies for vision correction, including refractive surgeries, and vision-quality maintenance in the elderly.

The medial condylar wall is a reliable landmark to kinematically align the femoral component in medial UKA: an in-silico study

Purpose Kinematic alignment (KA) aligns the femoral implant perpendicular to the cylindrical axis in the frontal and axial plane. Identification of the kinematic axes when using the mini-invasive sub-quadricipital approach is challenging in unicompartmental knee arthroplasty (UKA). This study aims to assess if the orientation of condylar walls may be suitable for use as an anatomical landmark to kinematically align the femoral component in medial UKA. It was hypothesised that the medial wall of the medial condyle would prove to be a reliable anatomical landmark to set both the frontal and axial alignment of the femoral component in medial UKA. Methods 73 patients undergoing medial UKA had pre-operative CT imaging to generate 3D models. Those with osteophytes that impaired visualisation of the condylar walls were excluded. 28 patients were included in the study. The ideal KA was determined using the cylindrical axis in the frontal and axial plane. Simulations using the medial wall of the medial condyle (MWMC) and the lateral wall of the medial condyle (LWMC) were performed to set the frontal alignment. To set the axial alignment, the MWMC, LWMC, medial wall of the lateral condyle (MWLC), and medial diagonal line (MDL) anatomical landmarks were investigated. Differences between the ideal measured KA values and values obtained using landmarks were investigated. Results Use of the MWMC let to similar frontal alignment compared to the ideal KA (2.9° valgus vs 3.4° valgus, p = 0.371) with 46.4% (13/28) of measurements being $$\le $$ ≤ 1.0° different from the ideal KA and only 1 simulation with greater than 4.0° difference. Use of the MWMC led to very similar axial alignments compared to the ideal KA (0.5° internal vs 0.0°, p = 0.960) with 75.0% (21/28) of measurements being $$\le $$ ≤ 1.0o different from the ideal KA, and a maximum difference of 3.0°. Use of the MWLC and MDL was associated with significant statistical differences when compared to the ideal KA (p < 0.001 for both). Conclusions The native orientation of the medial condylar wall seems to be a reliable anatomical landmark for aligning the femoral component in medial KA UKA in both the axial plane and frontal planes. Other assessed landmarks were shown to not be reliable. Clinical and radiographic assessments of the reliability of using the MWMC to set the frontal and axial orientation of the femoral component when performing a medial KA UKA are needed.

Comparison of Autorefraction, Cyclorefraction, and Subjective Manifest Refraction in Keratoconic Eyes

Purpose: This study aimed to estimate the agreement of astigmatism between an autorefractor (Topcon), cycloplegic refraction, subjective manifest refraction, front and back corneal astigmatism. Moreover, this study aimed to investigate which factors influence the difference between cycloplegic refraction and subjective manifest refraction in these keratonic eyes.Methods: subjective manifest refraction, Autorefractmeter were measured in 64 keratonic eyes of 43 patients (21-45 years old) before and after using cycloplegic drop. We measured Corneal values by using Scheimpflug tomography. Astigmatic power was converted to vectors. The agreement of astigmatism between an autorefractor (Topcon), cycloplegic refraction, subjective manifest refraction, front and back corneal astigmatism was measured overall and in each vector. The difference between Cycloplegic refraction and subjective manifest refraction was calculated in each vector axis. Factors were anticipated associated with discrepancy by using Multivariable Regression Analysis.Results: The maximum estimations of agreement were found berween autorefratometer and subjective manifest refraction in cylindrical power(Icc:0.703,P<0.026), cylindrical axis(Icc:0.943,P<0.0001) and astigmatic vestors of J0 (Icc:0.972,P<0.0001) and J45( Icc:827,P=0.006). The significant factors Associated With discrepancy between cyclorefraction and subjective manifest refraction in both vectors(J0 and J45) were Q-value(B Coefficient= -4.91, P<0.0001) (B Coefficient=1.01, P<0.0001), corneal astigmatism(B Coefficient= 0.66, P=0.001) (B Coefficient=0.11, P=0.001), Kmax(B Coefficient= -0.52, P<0.0001) (B Coefficient=0.07, P=0.02), IHA(B Coefficient=0.04, P=0.005) (B Coefficient= -0.03, P<0.0001). The significant associated factors for axis changes between cycloplegic refraction and subjective manifest refraction were cone location (B Coefficient= -33.34, P=0.001) and corneal astigmatism(B Coefficient= -0.1, P=0.04).Conclusion: Maximum agreement of subjective manifest refraction astigmatism is with auto refractometer in keratoconus patients, so it could be said that the result of the auto refractometer is the most appropriate starting point during subjective refraction in these patients. It can be predicted that the closer the keratoconus cone location relative to the center of the cornea and the lower the keratoconus patient's corneal astigmatism, the more the probability of axis changes by cycloplegic drop.

Comparison of photoscreeners and hand-held autorefractometer with cycloplegic autorefraction as a vision screening tool for children with newly diagnosed attention deficit hyperactivity disorder

Purpose: To compare non-cycloplegic refraction measurements of two photoscreeners and the hand-held autorefractometer with cycloplegic measurements of the autorefractometer in patients with attention deficit hyperactivity disorder (ADHD).Methods: This cross-sectional, comparative study consisted of 53 children who were newly diagnosed with ADHD. We compared spherical, cylindrical, cylindrical axis and spherical equivalent (SE) measurements in Plusoptix A12, Spot Vision Screener, and Retinomax K-plus Screen with Tonoref II. Reliability was analyzed by using the interclass correlation coefficient (ICC) and Bland-Altman plot was used to evaluate the agreement between devices.Results: The mean age of children was 9.45 ± 1.68. All of the devices measured spherical power and SE significantly more myopic than the Tonoref II. While The Spot Vision Screener, PlusoptiX A12, and Tonoref II provided similar cylindrical power, Retinomax K-plus Screen measured significantly lower than the Tonoref II. The excellent reliability was detected in spherical power, cylindrical power, SE and J0 between Tonoref II and PlusoptiX A12 (ICC:0.930, 0.921, 0.927 and 0.920, respectively. All of the hand-held devices showed excellent reliability in terms of cylindrical power and J0 (ICC>0.90, for all) and good reliability for J45 (ICC:0.75-0.90 for all).Conclusion: Despite all devices having advantages or disadvantages, Plusoptix A12 showed excellent reliability for detecting refractive errors in children with ADHD.

Comparison of photoscreeners and hand-held autorefractometer with cycloplegic autorefraction as a vision screening tool for children with newly diagnosed attention deficit hyperactivity disorder

Purpose: To compare non-cycloplegic refraction measurements of two photoscreeners and the hand-held autorefractometer with cycloplegic measurements of the autorefractometer in patients with attention deficit hyperactivity disorder (ADHD).Methods: This cross-sectional, comparative study consisted of 53 children who were newly diagnosed with ADHD. We compared spherical, cylindrical, cylindrical axis and spherical equivalent (SE) measurements in Plusoptix A12, Spot Vision Screener, and Retinomax K-plus Screen with Tonoref II. Reliability was analyzed by using the interclass correlation coefficient (ICC) and Bland-Altman plot was used to evaluate the agreement between devices.Results: The mean age of children was 9.45 ± 1.68. All of the devices measured spherical power and SE significantly more myopic than the Tonoref II. While The Spot Vision Screener, PlusoptiX A12, and Tonoref II provided similar cylindrical power, Retinomax K-plus Screen measured significantly lower than the Tonoref II. The excellent reliability was detected in spherical power, cylindrical power, SE and J0 between Tonoref II and PlusoptiX A12 (ICC:0.930, 0.921, 0.927 and 0.920, respectively. All of the hand-held devices showed excellent reliability in terms of cylindrical power and J0 (ICC>0.90, for all) and good reliability for J45 (ICC:0.75-0.90 for all).Conclusion: Despite all devices having advantages or disadvantages, Plusoptix A12 showed excellent reliability for detecting refractive errors in children with ADHD.

Study of galaxies on large-scale filaments in simulations

ABSTRACT We use data from the Evolution and Assembly of GaLaxies in their Environment (eagle) cosmological simulation to study properties of galaxies in the cosmic web. Galaxies become more redder and form stars at a lower rate relative to their counterparts further away from the cylindrical axis of the large-scale filaments. These trends are particularly strong for galaxies with M*/M⊙ ≲ 1010. We also find that at distances &lt;0.5 Mpc from the spine of the filaments, the median gas and stellar mass fraction in filament galaxies rises sharply with decreasing distance from the spine of the filament. These results, together with matching trends in the SFR/M* and the g − r colour of filament galaxies suggest that (i) the intrafilamentary gas condenses into the filament galaxies thus fuelling star formation in them, and (ii) increased number density of galaxies closer to the central axis of the filament enhances the rate of gravitational interactions among filament galaxies closer to the spine.

The Symmetry of the Interior and Exterior of Schwarzschild and Reissner–Nordstrom Black Holes—Sphere vs. Cylinder

One can question the relationship between the symmetries of the exterior and interior of black holes with an isotropic and static exterior. This question is justified by the variety of recent findings indicating substantial or even dramatic differences in the properties of the exterior and interior of isotropic, static black holes. By invoking some of these findings related to a variety of the thought experiments with freely falling or uniformly accelerated test particles, one can establish the dynamic properties of the interior, which turn out to be equivalent to anisotropic cosmology, simultaneously expanding and contracting, albeit in different directions. In order to illustrate the comparison between the symmetry of the exterior vs. the interior, we apply conventional t, r, θ, φ coordinates to both of these ranges, although on the horizon(s) they display singular behavior. Using a simple approach based on co-moving and freely falling observers, the dynamics of the cylindrically shaped interior are explored. That enables us to present schematic snapshots of the interior of a Schwarzschild black hole, expanding along its cylindrical axis and contracting along its spherical base, as well as the interior of a Reissner–Nordström black hole, expanding first and then contracting along the cylindrical axis up to the terminal instant r =r−.

Mean difference of visual acuity with auto refraction and subjective refraction.

Purpose: To compare the mean difference of visual acuity as measured by auto refraction and subjective refraction. Study Design: Descriptive cross-sectional study. Place and Duration of Study: Department of ophthalmology, Services hospital Lahore from November 2013 to April 2014. Material and Methods: Using non-probability consecutive sampling 300 eyes of 300 patients fulfilling inclusion criteria were recruited through OPD registration slip. Demographic data including age and gender was recorded. Complete ophthalmic examination was performed. This included measurement of refractive error by auto-refraction as well as subjective refraction. Detailed anterior segment examination with slit lamp and dilated fundus examination with indirect ophthalmoscopy was performed. The collected data was analyzed by using software SPSS version 17. Results: The mean age of patients was 34.71 ± 7.45 years. There were 156 (52%) males and 144 (48%) females. There were 263 (87.69%) patients who had visual acuity of 6/6 and 37 (12.33%) had 6/9. Mean spherical auto-refraction and subjective refraction was 0.0290 ± 2.58 and -0.2842 ± 2.37 D with mean difference of -0.3133 ± 1.27 D. The mean cylindrical auto and subjective refraction in this study was -.9742 ± 0.78 D and -0.7500 ± 0.81 D and mean difference was 0.2242 ± 0.74 D. The mean cylindrical axis of auto and subjective refraction was 114.88 ± 49.75 and 115.60 ± 49.70 with mean difference as 0.72 ± 3.02 D (p-value < 0.05). Conclusion: Difference of spherical, cylindrical and cylindrical axis in auto and subjective refraction was significantly different.

UNIVERSAL METRIC BASE (RUMB), UNITS OF ANGLE MEASUREMENT IN GEODESY AND CARTOGRAPHY

Objective. Study of ancient cartographic documents in order to clarify the principle of working with a portolan map based on the RUMB metric base. Methodology. Analytical, graphic, mathematical, geodesic. Scientific novelty. For the first time, a table of interrelation of units of measurement of time, angles and distances in the metric base of RUMB is shown. It was found that the so-called portolan maps were built on the basis of RUMB, and their projection is similar to the oblique Mercator projection with a cylindrical axis oriented along the earth’s magnetic axis, with an additional network of rhomb rectangular coordinates, which allows the map to be used at any position of the poles. The Mercator projection is a simplified version of it with one coordinate system. Practical implications. It is shown that dividing the clock face, equator and meridians of the Earth into the same number of parts allows determining the coordinates of points on the Earth’s surface using any of the known parameters, which greatly simplifies the solution of geodetic and navigation problems. Key words: units of measurement, metric base, degree, bearing, portolan map, rose card, projection, coordinate.