Age, gender, corneal diameter, corneal curvature and central corneal thickness in Nigerians with normal intra ocular pressure

AbstractPurposeTo investigate the relationship between age, gender, corneal diameter, central corneal curvature, central corneal thickness (CCT) and intraocular pressure in Nigerians with normal intraocular pressure.MethodsOne hundred and thirty eyes from 130 subjects (mean age=47.8±16.8 years) including 77 males and 53 females were recruited. CCT was measured by ultrasound pachymetry, intraocular pressure was determined by non-contact tonometry, horizontal and vertical corneal diameters were measured with a ruler and central corneal curvature was measured by keratometry.ResultsThe mean values obtained were as follows: CCT=548.97±34.28μm, IOP=15.61±2.69mmHg, average corneal curvature (AVK)=42.98±1.19 D, horizontal corneal diameter (HVID)=11.39±0.69mm and vertical corneal diameter (VVID)=10.51±0.50mm. There was a significant effect of age on CCT (r=−0.35, p<0.001). A 10-year-increase in age was associated with a 7.0μm decrease in CCT. Males had significantly wider HVID than females (p=0.03). Subjects in older age groups have narrower HVID and VVID. Corneal curvature, corneal diameter and gender did not significantly affect CCT.ConclusionCCT of normotensive Nigerian adults decreases with increasing age. There was no correlation between CCT and IOP in normotensive subjects. CCT was not significantly influenced by gender, corneal curvature and corneal diameter

The Effects of Vertical Yoked Prism on Horizontal Heterophoria

PURPOSE: Vertical yoked prisms (VYPs) have been recommended for the remediation of vergence dysfunction, but the evidence base for their use is mostly low level. This study investigates the effect of VYP on horizontal subjective dissociated heterophoria. METHODS: Phoria measurement was performed in primary gaze with the Modified Thorington technique at 3 m and at 40 cm on 40 nonpresbyopic young adults. Subjects were seated and head position was held constant. Baseline measures (without yoked prism) of distance and near phoria were measured. Phorias were measured again through the following range of VYP, randomly presented: 2 prism diopters (Δ) base up (BU), 2Δ base down (BD), 5Δ BU, and 5Δ BD. Twenty-six subjects also had their phorias measured with control lenses of +0.125 DS OU (because of unavailability of Plano trial lenses) randomly presented along the other conditions. RESULTS: There was no significant difference overall between phoria measured in any of the yoked prism conditions, including the baseline measure, at distance or near. Neither was there evidence of a predictable esophoric or exophoric shift with either BU or BD prism. CONCLUSIONS: Vertical yoked prisms did not exert any immediate effect on horizontal phoria in young adults when posture was controlled. This suggests that, if VYPs do indeed improve horizontal vergence problems, they do not do so by a direct or immediate impact on horizontal phoria

China Studies Review

Our edition begins with Shangsi Zhou’s exploration of the unconventional growth of market capitalism in China’s state-governed economy. Her essay is followed by Sam Boone’s timely review of China’s relationship with the International Criminal Police Organization (Interpol), reflecting on the ways in which China uses international organizations to fulfill domestic goals. The next article is Dominic Chiu’s review of the inefficiency of China’s state sector and the inherent difficulties that exist in reforming state-owned enterprises. The fourth entry is Anna Woods’ examination of China’s growing food insecurity and the ways in which China leverages international organizations and multilateral relationships in attempts to mitigate future shortages. Her work is followed by Brian Hart’s research regarding technological innovation in China in terms of strategic military development, and how this impacts U.S.-China technological competition. Next, Kevin Garrahan examines China’s path to becoming a world leader of innovation, and the challenges presented by China’s current economic structure to this transition. Finally, Michael Sutherland concludes this edition with his review of China’s transition from a “standards taker” to an international “standards maker,” and what this means for international governance organizations

Climate Change and its Oncoming Effects on Migration and Policy in the U.S. and France

While the world carries on, the earth is changing. Climate change is a problem today that brings with it many effects on the modern world. The main effect down the line will be mass migration, which brings up an important question: How will migration due to climate change affect the law and public sentiments towards immigrants, refugees and asylum-seekers? Within this question, independent variables include climate change and migration while dependent variables are the law and public sentiments. For the purpose of this paper, the United States and France will be used as examples of Western nations that migrants may travel to. The laws pertaining to France within the E.U. and U.N. will be assessed along with U.S. immigration law that pertains to asylum-seekers and refugees. Since mass migration due to climate change has not yet occurred, only hypotheses can be made to intelligently assume what may happen in regard to how the topic/people will be handled. One includes that the United States is less likely to follow international law on asylum-seekers because of climate change migration that is to come. The second hypothesis focuses on how, due to climate change migration, public sentiments will grow negatively towards newcomers (immigrants, asylum-seekers, and refugees). Navigating the maze of the interconnected dynamics of this vital issue is important in order to understand where the world is headed in the near future is crucial

A new Gujarati language logMAR visual acuity chart: Development and validation

Aims: Gujarati is the main spoken language of a large proportion of the population of India. The aim of this study was to develop and validate a new Minimum Angle of Resolution (logMAR) visual acuity chart in the Gujarati language. Materials and Methods: A new Gujarati visual acuity chart was designed to logMAR specifications using Gujarati optotypes experimentally selected to have similar relative letter legibility under spherical and cylindrical defocus. The chart validation study was carried out using 153 adult subjects in a large clinical setting in India. Subjects who were literate in English and Gujarati participated in the study. Visual acuity was measured with the new Gujarati logMAR chart and a modified Early Treatment of Diabetic Retinopathy Study-(m-ETDRS) logMAR chart. The method of presentation was randomized between the charts. Repeat visual acuity was measured on a subsequent day with a second version of the Gujarati logMAR chart. Results: The Gujarati chart correlated highly with the m-ETDRS logMAR chart (r2 = 0.974). The mean visual acuity difference (Gujarati - m-ETDRS logMAR) was equal to three letters (-0.06 logMAR). The Gujarati logMAR chart also proved to be highly repeatable (r2 = 0.994, test-retest) with 95% CI of ± 0.04 logMAR. Conclusions: The new Gujarati logMAR visual acuity chart provides a valid and repeatable tool for the measurement of visual acuity in native Gujarati language speakers

A standardized logarithm of the minimum angle of resolution visual acuity chart in Hindi

Purpose: The purpose of this study to develop and calibrate a new Hindi logarithm of the minimum angle of resolution (logMAR) visual acuity chart. Methods: A new Hindi visual acuity chart was designed to logMAR specifications using Hindi optotypes experimentally selected to have similar relative legibility under equivalent spherical and cylindrical defocus. The chart calibration study was carried out in a large clinical setup in India. Participants who were literate in English and Hindi participated in the study. Visual acuity was measured with the new Hindi logMAR chart and a modified ETDRS (m‑ETDRS) logMAR chart. The method of presentation was randomized between the charts. Repeat visual acuity was measured on a subsequent day with a second version of the Hindi logMAR chart. Results: The Hindi logMAR chart correlated highly with the m‑ETDRS logMAR chart ( r 2 = 0.92); however, the mean visual acuity difference (Hindi logMAR‑m‑ETDRS logMAR) was nearly one and half lines (0.13 logMAR, 95% confidence interval [CI] = ±0.15 logMAR). The Hindi logMAR chart also proved to be highly repea table ( r 2 = 0.99; mean difference 0.005, 95% CI = ±0.04 logMAR). Conclusion: This study reports the first standardized visual acuity chart developed in Hindi incorporating equal letter legibility and logMAR chart design features. The Hindi logMAR visual acuity chart provides a valid and repea table tool for the measurement of visual acuity in native Hindi language speakers. Future use of the new Hindi chart should incorporate an increase in optotype size of 0.13 logMAR