400 research outputs found
Age-related macular disease : studies on incidence, risk factors, and prognosis
Age-related macular disease (AMD) is a new name, recently coined by
Bird,25 for a progressive and degenerative disease in elderly persons
affecting the macula lutea. Dysfunction of this part of the retina, and
especially its centre, the fovea, results in the inability to read, recognize faces,
drive, and move freely.
Bird proposed to substitute the word disease for degeneration, probably
due to the pejorative ring of the latter and because the word degeneration does
not cover all pathological processes thought to play a role in AMD. According
to the current nomenclature of the International AMD Epidemiological Study
Group, all early and late signs of AMD are called age-related maculopathy
(ARM), while age-related macular degeneration indicates the two late stages of
ARM.24 These are the dry type, also called geographic atrophy, and the wet
type, also called neovascular or disciform AMD. The wet type often leads to
rapid loss of central vision while this may take years for the dry type.
The oldest image of disciform AMD, as far as we know, is from 1875
by Pagenstecher and Genth, while Haab was in 1885 the first to describe the
dry type of AMD that he called senile macular degeneration. I decided to
follow Bird’s example in the title of this thesis and used the word disease
instead of degeneration. However, the reader will find in the remainder of this
book the term ARM and AMD in the conventional sense, because most articles
included in the thesis were written at a time that we still used ARM as the
common denominator for this disease
7-Nitro indazole, an inhibitor of neuronal nitric oxide synthase, attenuates pilocarpine-induced seizures
7-Nitro indazole (25–100 mg/kg i.p.), an inhibitor of neuronal nitric oxide (NO) synthase, attenuated the severity of pilocarpine (300 mg/kg i.p.)-induced seizures in mice. This indicates that the decreased neuroexcitability of the central nervous system (CNS) following administration of 7-nitro indazole may be due to inhibition of neuronal NO synthase, implying that NO acts as an excitatory and proconvulsant factor in the CNS
Association of Rhegmatogenous Retinal Detachment Incidence With Myopia Prevalence in the Netherlands
Importance The incidence of rhegmatogenous retinal detachment (RRD) is partly determined by its risk factors, such as age, sex, cataract surgery, and myopia. Changes in the prevalence of these risk factors could change RRD incidence in the population. Objective To determine whether the incidence of RRD in the Netherlands has changed over recent years and whether this change is associated with an altered prevalence of RRD risk factors. Design, Setting, and Participants This cohort study included data from all 14 vitreoretinal clinics in the Netherlands, as well as a large Dutch population-based cohort study. All patients who underwent surgical repair for a primary RRD in the Netherlands from January 1 to December 31, 2009, and January 1 to December 31, 2016, were analyzed, in addition to all participants in the population-based Rotterdam Study who were examined during these years. Analysis began February 2018 and ended November 2019. Exposures RRD risk factors, including age, male sex, cataract extraction, and myopia. Main Outcomes and Measures Age-specific RRD incidence rate in the Dutch population, as well as change in RRD incidence and risk factor prevalence between 2009 and 2016. Results In 2016, 4447 persons (median [range] age, 61 [3-96] years) underwent surgery for a primary RRD within the Netherlands, resulting in an RRD incidence rate of 26.2 per 100 000 person-years (95% CI, 25.4-27.0). The overall RRD incidence rate had increased by 44% compared with similar data from 2009. The increase was observed in both phakic (1994 in 2009 to 2778 in 2016 [increase, 39%]) and pseudophakic eyes (1004 in 2009 to 1666 in 2016 [increase, 66%]), suggesting that cataract extraction could not solely account for the overall rise. Over the same period, the prevalence of mild, moderate, and severe myopia among persons aged 55 to 75 years had increased by 15.6% (881 of 4561 [19.3%] vs 826 of 3698 [22.3%]), 20.3% (440 of 4561 [9.6%] vs 429 of 3698 [11.6%]), and 26.9% (104 of 4561 [2.3%] vs 107 of 3698 [2.9%]), respectively, within the population-based Rotterdam Study. Conclusions and Relevance In this study, an increase was observed in primary RRD incidence in the Netherlands over a 7-year period, which could not be explained by a different age distribution or cataract surgical rate. A simultaneous myopic shift in the Dutch population may be associated, warranting further population-based studies on RRD incidence and myopia prevalence. This cohort study assesses whether the incidence of rhegmatogenous retinal detachment has changed over recent years and whether this change is associated with an altered prevalence of rhegmatogenous retinal detachment risk factors in the Netherlands. Question What is the incidence of primary rhegmatogenous retinal detachment (RRD) in the Netherlands and has it changed over recent years? Findings In this cohort study, 4447 individuals in the Netherlands underwent surgery for RRD in 2016, resulting in an incidence of 26.2 per 100 000 inhabitants, an increase of 44% compared with similar data from 2009. Over the same period, an increase in myopia prevalence in a Dutch population-based cohort study was observed. Meaning In the Netherlands, an increase in RRD incidence may be associated with a simultaneous myopic shift in the population
Hypernetted chain calculations for two-component plasmas
We have performed HNC calculations for dense beryllium plasma as studied
experimentally using x-ray Thomson scattering, recently. We treated
non-equilibrium situations with different electron and ion temperatures which
are relevant in pump-probe experiments on ultra-short time scales. To consider
quantum effects adequately, we used effective pair potentials to describe the
interactions. Results are compared with classical as well as quantum corrected
Debye model calculations.Comment: 7 pages, 4 figures. Contribution to the 12th International Workshop
on the Physics of Non-Ideal Plasmas PNP 12, Sept. 4 - 8, 2006, Darmstadt,
Germany. To appear in Contrib. Plasma Phy
Blood pressure, atherosclerosis, and the incidence of age-related maculopathy: the Rotterdam Study
PURPOSE: To determine whether blood pressure and subclinical
atherosclerosis are associated with incident age-related maculopathy
(ARM). METHODS: The study was performed within the Rotterdam Study, a
population-based, prospective cohort study in Rotterdam, The Netherlands.
A total of 4822 subjects who at baseline were aged 55 years more, were
free of ARM, and participated in at least one of two follow-up
examinations after a mean of 2 and 6.5 years, were included in the study.
At baseline, blood pressure and the presence of atherosclerosis were
determined. ARM was assessed according to the International Classification
and Grading System and defined as large, soft drusen with pigmentary
changes; indistinct drusen; or atrophic or neovascular age-related macular
degeneration. RESULTS: After a mean follow-up of 5.2 years, incident ARM
was diagnosed in 417 subjects. Increased systolic blood pressure or pulse
pressure was associated with a higher risk of ARM. Adjusted for age,
gender, smoking, total and high-density lipoprotein cholesterol, body mass
index, and diabetes mellitus, odds ratios (OR) per 10-mm Hg increase were
1.08 (95% confidence interval [CI]: 1.03-1.14) and 1.11 (95% CI:
1.04-1.18), respectively. Moreover, different measures of atherosclerosis
were associated with the risk of ARM. An increase in carotid wall
thickness (OR per 1 SD, 1.15; 95% CI: 1.03-1.28) increased the risk of
ARM. The lowest compared with the highest tertile of ankle-arm index had
an OR of 1.32 (95% CI: 1.00-1.75). A weak association was found between
aortic calcifications and the risk of ARM. CONCLUSIONS: Elevated systolic
blood or pulse pressure or the presence of atherosclerosis may increase
the risk of development of ARM
A view from the clinic – Perspectives from Dutch patients and professionals on high myopia care
Purpose: To understand and compare perspectives of patients and professionals on current ophthalmologic care for high myopia, and to identify challenges and future opportunities. Methods: Self-reported data were collected through two online questionnaires. Patient perspective was obtained from highly myopic members of a patient organisation based in the Netherlands using a 17-item questionnaire consisting of open and multiple-choice questions regarding personal experience with myopia care. The ophthalmologist perspective was obtained from practising Dutch ophthalmologists with a 12-item questionnaire of multiple-choice questions on work-related demographics, myopia care in daily practice and need for improvement. The response rate for patients was 27% (n = 136/500) and for ophthalmologists, 24% (n = 169/716). Results: Patients were highly concerned about personal progressive loss of vision (69%) and feared their psychological well-being (82%) in case this would happen. The quality of performance of care provided by ophthalmologists was rated as excellent or satisfactory by 64% of the patients. These ratings for multidisciplinary care and insurance reimbursement were as low as 28% and 18% respectively. The mean concern among ophthalmologists about the rise in high myopia was 6.9 (SEM 0.1) on a 10-point scale. Sixty-nine per cent of the ophthalmologists reported that asymptomatic myopic patients should not be examined regularly at outpatient clinics. Ophthalmologists urged the development of clinical guidelines (74%), but did report (95%) that they informed patients about risk factors and complications. This contrasted with the view of patients, of whom 42% were discontent with information provided by ophthalmologists. Conclusions: These questionnaires demonstrated that the current clinical care delivered to highly myopic patients is in need of improvement. The expected higher demand for myopia care in the near future requires preferred practice patterns, professionals specifically trained to manage myopic pathology, accurate and comprehensive information exchange and collaboration of in- and out-of-hospital professionals across the full eye care chain.</p
Comparing the effectiveness and costs of Bevacizumab to Ranibizumab in patients with Diabetic Macular Edema: A randomized clinical trial (the BRDME study)
Background: The effectiveness of ranibizumab in the treatment of diabetic macular edema has been proven with large clinical trials. For bevacizumab only two clinical trials have been published and a head-to-head comparison is lacking to date. However, if proved non-inferior to ranibizumab, use of the off-label bevacizumab could reduce costs enormously without a loss in visual acuity. A cost-effectiveness study has been designed to substantiate this hypothesis. Aim: To compare the effectiveness and costs of 1.25 mg of bevacizumab to 0.5 mg ranibizumab given as monthly intravitreal injections during 6 months in patients with diabetic macular edema. It is hypothesized that bevacizumab is non-inferior to ranibizumab regarding its effectiveness. Design: This is a randomized, controlled, double masked, clinical trial in 246 patients in seven academic trial centres in The Netherlands. Outcomes: The primary outcome measure is the change in best-corrected visual acuity (BCVA) in the study eye from baseline to month 6. Secondary outcomes are the proportions of patients with a gain or loss of 15 letters or more or a BCVA of 20/40 or more at 6 months, the change in leakage on fluorescein angiography and the change in foveal thickness by optical coherence tomography at 6 months, the number of adverse events in 6 months, and the costs per quality adjusted life-year of the two treatments
Genotype-phenotype correlation in pseudoxanthoma elasticum
Background and aims: Pseudoxanthoma elasticum (PXE) is caused by variants in the ABCC6 gene. It results in calcification in the skin, peripheral arteries and the eyes, but has considerable phenotypic variability. We investigated the association between the ABCC6 genotype and calcification and clinical phenotypes in these different organs.
Methods: ABCC6 sequencing was performed in 289 PXE patients. Genotypes were grouped as two truncating, mixed, or two non-truncating variants. Arterial calcification mass was quantified on whole body, low dose CT scans; and peripheral arterial disease was measured with the ankle brachial index after treadmill test. The presence of pseudoxanthoma in the skin was systematically scored. Ophthalmological phenotypes were the length of angioid streaks as a measure of Bruchs membrane calcification, the presence of choroidal neovascularizations, severity of macular atrophy and visual acuity. Regression models were built to test the age and sex adjusted genotype-phenotype association.
Results: 158 patients (median age 51 years) had two truncating variants, 96 (median age 54 years) a mixed genotype, 18 (median age 47 years) had two non-truncating variants. The mixed genotype was associated with lower peripheral (13: 0.39, 95%CI:-0.62;-0.17) and total (13: 0.28, 95%CI:-0.47;-0.10) arterial calcification mass scores, and lower prevalence of choroidal neovascularizations (OR: 0.41 95%CI:0.20; 0.83) compared to two truncating variants. No association with pseudoxanthomas was found. Conclusions: PXE patients with a mixed genotype have less severe arterial and ophthalmological phenotypes than patients with two truncating variants in the ABCC6 gene. Research into environmental and genetic modifiers might provide further insights into the unexplained phenotypic variability
Stargardt disease:monitoring incidence and diagnostic trends in the Netherlands using a nationwide disease registry
PURPOSE: To assess the incidence of Stargardt disease (STGD1) and to evaluate demographics of incident cases. METHODS: For this retrospective cohort study, demographic, clinical and genetic data of patients with a clinical diagnosis of STGD1 were registered between September 2010 and January 2020 in a nationwide disease registry. Annual incidence (2014-2018) and point prevalence (2018) were assessed on the basis of this registry. RESULTS: A total of 800 patients were registered, 56% were female and 83% were of European ancestry. The incidence was 1.67-1.95:1,000,000 per year and the point prevalence in 2018 was approximately 1:22,000-1:19,000 (with and without 10% of potentially unregistered cases). Age at onset was associated with sex (p = 0.027, Fisher's exact); 1.9x more women than men were observed (140 versus 74) amongst patients with an age at onset between 10 and 19 years, while the sex ratio in other age-at-onset categories approximated one. Late-onset STGD1 (≥45 years) constituted 33% of the diagnoses in 2014-2018 compared to 19% in 2004-2008. Diagnostic delay (≥2 years between the first documentation of macular abnormalities and diagnosis) was associated with older age of onset (p = 0.001, Mann-Whitney). Misdiagnosis for age-related macular degeneration (22%) and incidental STGD1 findings (14%) was common in patients with late-onset STGD1. CONCLUSION: The observed prevalence of STGD1 in real-world data was lower than expected on the basis of population ABCA4 allele frequencies. Late-onset STGD1 was more frequently diagnosed in recent years, likely due to higher awareness of its phenotype. In this pretherapeutic era, mis- and underdiagnosis of especially late-onset STGD1 and the role of sex in STGD1 should receive special attention
Comparing the Efficacy of Bevacizumab and Ranibizumab in Patients with Diabetic Macular Edema (BRDME):The BRDME Study, a Randomized Trial
Purpose: To generate conclusive evidence regarding the noninferiority of intravitreal bevacizumab compared with ranibizumab in patients with diabetic macular edema (DME). Design: Comparative, randomized, double-masked, multicenter, noninferiority clinical trial. Participants: Eligible patients were older than 18 years, diagnosed with type 1 or type 2 diabetes mellitus, with glycosylated hemoglobin of less than 12%, central area thickness of more than 325 μm, and visual impairment from DME with a best-corrected visual acuity (BCVA) between 24 letters and 78 letters. Methods: From June 2012 through February 2018, a total of 170 participants were randomized to receive 6 monthly injections of either 1.25 mg bevacizumab (n = 86) or 0.5 mg ranibizumab (n = 84). Main Outcome Measures: Primary outcome was change in BCVA from baseline to month 6 compared between the 2 treatment arms. The noninferiority margin was 3.5 letters. Results: The difference in mean BCVA between treatment arms was 1.8 letters in favor of ranibizumab after 6 months of follow-up; BCVA improved by 4.9±6.7 letters in the bevacizumab group and 6.7±8.7 letters in the ranibizumab group. The lower bound of the 2-sided 90% confidence interval (CI) was –3.626 letters, exceeding the noninferiority margin of 3.5 letters. Central area thickness decreased more with ranibizumab (138.2±114.3 μm) compared with bevacizumab (64.2±104.2 μm). In a post hoc subgroup analysis, participants with a worse BCVA at baseline (≤69 letters) improved by 6.7±7.0 letters with bevacizumab and 10.4±10.0 letters with ranibizumab, and central area thickness decreased significantly more in the ranibizumab arm of this subgroup compared with the bevacizumab arm. Participants with an initially better BCVA at baseline (≥70 letters) did not demonstrate differences in BCVA or OCT outcomes between treatment arms. Conclusions: Based on change in BCVA from baseline to month 6, the noninferiority of 1.25 mg bevacizumab to 0.5 mg ranibizumab was not confirmed. Only the subgroup of patients with a lower BCVA at baseline showed better visual acuity and anatomic outcomes with ranibizumab. Our study confirmed the potential differential efficacy of anti–vascular endothelial growth factor agents in the treatment of DME as well as the difference in response between patient groups with different baseline visual acuities
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