Glaucoma Surgery Outcome in Rwanda De Smedt, Stefan K; Fonteyne, Yannick S; Muragijimana, Felicienne ...
Journal of glaucoma,
2016-August, Letnik:
25, Številka:
8
Journal Article
Recenzirano
Odprti dostop
PURPOSE:To assess long-term intraocular pressure (IOP) outcome after adult trabeculectomy surgery in Central Africa.
PATIENTS AND METHODS:All adult glaucoma patients who underwent trabeculectomy ...surgery in the Kabgayi Eye Unit, Rwanda between August 2003 and March 2008 were invited for a follow-up visit. Surgical and clinical data were collected from medical records. At the study visit, best-corrected visual acuity was measured and Goldmann applanation tonometry and biomicroscopy were done. Good IOP outcome was defined as both an IOP<21 mm Hg and achieving ≥30% reduction from the preoperative IOP. Considering first operated eyes, univariate and multivariate logistic regression was used to investigate risk factors for failure.
RESULTS:Of 163 individuals operated 3 had died, 118 (74%) participated. Preoperatively, the mean IOP was 31 mm Hg (SD=11; range, 12 to 60). At the time of the follow-up study visit the mean postoperative IOP was 13 mm Hg (SD=5; range, 4 to 35). Good IOP outcome was achieved in 132 eyes (84%). Univariate analysis suggested a protective effect against failure of use of antimetabolites odds ratio (OR)=0.39; 95% confidence interval (CI), 0.14-1.11; P=0.07 and a decrease in success with length of follow-up (OR=3.57; 95% CI, 1.09-12.50; P=0.03). The latter remained borderline significant with multivariate analysis. Seven eyes went from previously better vision (at least hand movements) down to perception of light or no perception of light after trabeculectomy. Particularly a flat anterior chamber in the first postoperative week (OR=0.07; 95% CI, 0.01-0.49; P<0.001) and late hypotony (OR=0.04; 95% CI, 0.002-0.99; P=0.004) were significant risk factors for severe visual loss.
CONCLUSIONS:Trabeculectomy with antimetabolites is one of the best available options for glaucoma management in Africa. However, the IOP control reduced at a follow-up duration beyond 2 years, highlighting the importance of regular long-term follow-up.
We sought to describe the clinical presentation, effect on visual acuity, impact on school attendance, and access to appropriate eye care in children with vernal keratoconjunctivitis (VKC) in Rwanda ...(Central Africa).
Case-control study nested within a cross-sectional survey.
We examined 3041 children; 121 had VKC.
Primary schools were randomly selected and children were interviewed using a questionnaire on VKC-related symptoms. Data on health-seeking behavior and school attendance were recorded. Children received a full eye examination, including visual acuity using a LogMar E Chart.
Description of the clinical findings, unaided visual acuity, prior attendance for medical eye care, and the impact of VKC on school attendance.
Of the 121 children with VKC, 119 (98.4%) had only limbal disease. Ocular itching (n = 101; 83.5%) was the predominant symptom and this was seasonal in 66 children (65.4%), constant but with variable intensity in 18 (17.8%), and constant with constant intensity in 17 children (16.8%). Children with VKC were >6 times more likely to have corneal astigmatism >2 diopters in their worse eye (odds ratio OR, 6.31; 95% confidence interval CI, 3.26-12.26; P<0.001) than controls. Eight affected eyes had astigmatism >4 diopters or irregular astigmatism incompatible with autokeratometry. Although 4 eyes (1.7%) had uncorrected low vision from VKC-induced corneal astigmatism or keratoconus, only 1 child was visually impaired in both eyes. School nonattendance for an ocular reason during the last 3 months was 5 times more likely in children with VKC (n = 44; 36.4%) than among those without (n = 297; 10.2%; OR, 5.04; 95% CI, 3.40-7.47; P < 0.001). Repeating a school year or having ever dropped out of school was not more common among children with VKC than those without. Medical eye care had been sought by 54 (44.6%) children with VKC.
This survey of prevalence and treatment of VKC in an African community adds to the argument for better primary eye care, including a safe topical medication. Long-term follow-up of this cohort is required to ascertain the overall risk of sight-threatening complications.
Context. The unparalleled photometric data obtained by NASA's Kepler Space Telescope has led to improved understanding of red giant stars and binary stars. Seismology allows us to constrain the ...properties of red giants. In addition to eclipsing binaries, eccentric non-eclipsing binaries that exhibit ellipsoidal modulations have been detected with Kepler. Aims. We aim to study the properties of eccentric binary systems containing a red giant star and to derive the parameters of the primary giant component. Methods. We applied asteroseismic techniques to determine the masses and radii of the primary component of each system. For a selected target, light and radial velocity curve modelling techniques were applied to extract the parameters of the system and its primary component. Stellar evolution and its effects on the evolution of the binary system were studied from theoretical models. Results. The paper presents the asteroseismic analysis of 18 pulsating red giants in eccentric binary systems, for which masses and radii were constrained. The orbital periods of these systems range from 20 to 440 days. The results of our ongoing radial velocity monitoring programme with the Hermes spectrograph reveal an eccentricity range of e = 0.2 to 0.76. As a case study we present a detailed analysis of KIC 5006817, whose rich oscillation spectrum allows for detailed seismic analysis. From seismology we constrain the rotational period of the envelope to be at least 165 d, which is roughly twice the orbital period. The stellar core rotates 13 times faster than the surface. From the spectrum and radial velocities we expect that the Doppler beaming signal should have a maximum amplitude of 300 ppm in the light curve. Fixing the mass and radius to the asteroseismically determined values, we find from our binary modelling a value of the gravity darkening exponent that is significantly larger than expected. Through binary modelling, we determine the mass of the secondary component to be 0.29 + or - 0.03 M sub(middot in circle). Conclusions. For KIC 5006817 we exclude pseudo-synchronous rotation of the red giant with the orbit. The comparison of the results from seismology and modelling of the light curve shows a possible alignment of the rotational and orbital axis at the 2sigma level. Red giant eccentric systems could be progenitors of cataclysmic variables and hot subdwarf B stars.
We present an asteroseismic approach to study the dynamics of the stellar interior in red giant stars by asteroseismic inversion of the splittings induced by the stellar rotation on the oscillation ...frequencies. We show preliminary results obtained for the red giant KIC4448777 observed by the space mission Kepler.
Aims
. Over the past decades, libraries of stellar spectra have been used in a large variety of science cases, including as sources of reference spectra for a given object or a given spectral type. ...Despite the existence of large libraries and the increasing number of projects of large-scale spectral surveys, there is to date only one very high-resolution spectral library offering spectra from a few hundred objects from the southern hemisphere (UVES-POP). We aim to extend the sample, offering a finer coverage of effective temperatures and surface gravity with a uniform collection of spectra obtained in the northern hemisphere.
Methods
. Between 2010 and 2020, we acquired several thousand echelle spectra of bright stars with the Mercator-HERMES spectrograph located in the Roque de Los Muchachos Observatory in La Palma, whose pipeline offers high-quality data reduction products. We have also developed methods to correct for the instrumental response in order to approach the true shape of the spectral continuum. Additionally, we have devised a normalisation process to provide a homogeneous normalisation of the full spectral range for most of the objects.
Results
. We present a new spectral library consisting of 3256 spectra covering 2043 stars. It combines high signal-to-noise and high spectral resolution over the entire range of effective temperatures and luminosity classes. The spectra are presented in four versions: raw, corrected from the instrumental response, with and without correction from the atmospheric molecular absorption, and normalised (including the telluric correction).
Erratum: The WISE view of RV Tauri stars Gezer, I.; Van Winckel, H.; Bozkurt, Z. ...
Monthly notices of the Royal Astronomical Society,
11/2015, Letnik:
454, Številka:
1
Journal Article
Background Eczema is a growing problem in Africa, particularly amongst children.
Objectives To investigate the point‐prevalences of eczema by physical examination in schoolchildren living in rural ...and urban areas and with different socioeconomic backgrounds in Ghana, Gabon and Rwanda. In Ghana period‐prevalences were also estimated by questionnaire and compared with the point‐prevalences.
Methods In total, 4839 schoolchildren in Ghana, Gabon and Rwanda were seen by at least one dermatologist. The point‐prevalences of eczema were estimated on the basis of physical examination. Period‐prevalences were measured in Ghana with questionnaire based‐interviews adapted from the International Study of Asthma and Allergies in Childhood (ISAAC).
Results The point‐prevalences were 1.5% and 1.6% in the two Ghanaian studies; 4% in Gabon and 0.8% in Rwanda. The period‐prevalences were 2.6% and 4.4% in the two Ghanaian studies. The prevalences of eczema were not significantly different when comparing the urban and rural groups as well as the different socioeconomic levels. The sensitivity and positive predictive value to identify eczema cases based on the questionnaires compared to the diagnoses by physical examination were only 33% and 22% in the first Ghanaian study and 10% and 4% in the second Ghanaian study respectively.
Conclusions The point‐prevalences of eczema in the three African countries studied were low compared with industrialized countries. Physical examination by a dermatologist is still the gold standard to identify eczema cases because the sensitivity and the positive predictive value to identify eczema cases with questionnaires were low in the two Ghanaian studies.
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