Publications by authors named "Geir Bertelsen"
Background: To evaluate repeatability and agreement in measurements of total corneal astigmatism (TCA) in keratoconic eyes, using four optical coherence tomography (OCT)-based devices: Anterion, Casia SS-1000, IOLMaster 700, and MS-39.
Methods: Three consecutive measurements were taken with each device in 136 eyes. TCA values were converted into components J and J.
Introduction: Our main objective was to investigate whether retinal neurodegeneration, estimated from lower thickness of inner retinal layers, was associated with incident all-cause dementia and Alzheimer's disease (AD).
Methods: We performed an individual participant data meta-analysis using unpublished data from four prospective cohort studies with a total of 69,955 participants (n = 1087 cases of incident all-cause dementia; n = 520 cases incident AD; follow-up time median [interquartile range] 11.3 [8.
Purpose: To assess repeatability and agreement of corneal epithelial thickness mapping in eyes with keratoconus using three optical coherence tomography (OCT) devices featuring different technologies: spectral-domain (SD) OCT combined with Placido disk corneal topography (MS-39), swept-source OCT (Anterion), and SD-OCT (Avanti).
Methods: Three consecutive measurements were acquired with the three devices in 60 eyes with keratoconus. The mean epithelial thickness was calculated in the central 2-mm zone and in 2- to 5-mm and 5- to 7-mm diameter rings.
Purpose: To investigate the association of commonly used systemic medications with glaucoma and intraocular pressure (IOP) in the European population.
Design: Meta-analysis of 11 population-based cohort studies of the European Eye Epidemiology Consortium.
Participants: The glaucoma analyses included 143 240 participants and the IOP analyses included 47 177 participants.
Background/aims: To investigate the association of commonly used systemic medications with prevalent age-related macular degeneration (AMD) in the general population.
Methods: We included 38 694 adults from 14 population-based and hospital-based studies from the European Eye Epidemiology consortium. We examined associations between the use of systemic medications and any prevalent AMD as well as any late AMD using multivariable logistic regression modelling per study and pooled results using random effects meta-analysis.
Article Synopsis
- The study aimed to explore how cardiovascular risk factors like age, BMI, and blood pressure relate to the thickness of various retinal layers, like the ganglion cell-inner plexiform layer (GCIPL).
- The research included data from two rounds of the Tromsø Study, measuring retinal thickness and excluding individuals with diabetes or glaucoma, ultimately analyzing 8,288 participants cross-sectionally and 2,595 longitudinally.
- The findings revealed that GCIPL thickness was notably impacted by age and BMI, with significant relationships identified for blood pressure, emphasizing that weight and blood pressure are important factors for modifying retinal health.
Purpose: To assess the repeatability of corneal epithelial thickness mapping in virgin, post-laser refractive surgery (PLRS), and keratoconic eyes using a novel swept-source optical coherence tomographer (SS-OCT), and to determine the agreement of the measurements with a validated spectral-domain (SD) OCT.
Methods: Analysis of 90 virgin, 46 PLRS, and 122 keratoconic eyes was performed. Three consecutive measurements of each eye were acquired with the Anterion SS-OCT and Avanti SD-OCT devices, and averages of the epithelial thickness mapping were calculated in the central 2-mm zone and in the 2- to 5-mm and 5- to 7-mm diameter rings.
Background: Postoperative endophthalmitis is a rare but dreaded complication of intraocular surgery and often results in severe visual impairment or blindness. The present study describes the clinical course, treatment and visual outcome of an outbreak of Burkholderia contaminans endophthalmitis following cataract surgery.
Methods: Among 290 patients who underwent uneventful phacoemulsification cataract surgery at one outpatient clinic between January 4th and 28th 2019, 6 cases developed Burkholderia contaminans endophthalmitis.
Purpose: To assess the long-term outcome of uveitis in juvenile idiopathic arthritis (JIA).
Design: Population-based, multicenter, prospective JIA cohort, with a cross-sectional assessment of JIA-associated uveitis (JIA-U) 18 years after the onset of JIA.
Participants: A total of 434 patients with JIA, of whom 96 had uveitis, from defined geographic areas of Denmark, Finland, Norway, and Sweden.
Purpose: Genetic and epidemiologic studies have shown that lipid genes and high-density lipoproteins (HDLs) are implicated in age-related macular degeneration (AMD). We studied circulating lipid levels in relationship to AMD in a large European dataset.
Design: Pooled analysis of cross-sectional data.
Topic: To estimate the prevalence of nonrefractive visual impairment and blindness in European persons 55 years of age and older.
Clinical Relevance: Few visual impairment and blindness prevalence estimates are available for the European population. In addition, many of the data collected in European population-based studies currently are unpublished and have not been included in previous estimates.
Article Synopsis
- Unrecognized myocardial infarction (MI) is common, and this study investigates its association with small and large vessel diseases.
- The study involved 6128 participants using retinal photography, carotid ultrasound, and ECG to analyze the correlation between MI recognition and vascular health.
- Results showed that unrecognized MI was linked to narrower retinal arterioles (small vessel disease) and less associated with large vessel disease, suggesting differing underlying causes for recognized vs. unrecognized MI.
Purpose: Age-related macular degeneration (AMD) is a frequent, complex disorder in elderly of European ancestry. Risk profiles and treatment options have changed considerably over the years, which may have affected disease prevalence and outcome. We determined the prevalence of early and late AMD in Europe from 1990 to 2013 using the European Eye Epidemiology (E3) consortium, and made projections for the future.
View Article and Find Full Text PDFPurpose: To provide sex-stratified normative data on retinal thickness and study the relationship with sex, age and refractive status.
Methods: Population-based study including 2617 women and 1891 men, aged 38-87 (mean 61 ± 8) years, without diabetes, glaucoma and retinal diseases, and spherical equivalent refraction (SER) within ±6 dioptres. Retinal thickness was measured with optical coherence tomography (spectral domain Cirrus HD-OCT).
The European Eye Epidemiology (E3) consortium is a recently formed consortium of 29 groups from 12 European countries. It already comprises 21 population-based studies and 20 other studies (case-control, cases only, randomized trials), providing ophthalmological data on approximately 170,000 European participants. The aim of the consortium is to promote and sustain collaboration and sharing of data and knowledge in the field of ophthalmic epidemiology in Europe, with particular focus on the harmonization of methods for future research, estimation and projection of frequency and impact of visual outcomes in European populations (including temporal trends and European subregions), identification of risk factors and pathways for eye diseases (lifestyle, vascular and metabolic factors, genetics, epigenetics and biomarkers) and development and validation of prediction models for eye diseases.
View Article and Find Full Text PDFBackground/aims: Estimated glomerular filtration rate (eGFR) is used extensively in epidemiological research. Validations of eGFR have demonstrated acceptable performance, but the dependence of creatinine and cystatin C on non-GFR factors could confound associations with disease. Few studies have investigated this issue in direct comparison with measured GFR (mGFR).
View Article and Find Full Text PDFPurpose: To investigate whether myopia is becoming more common across Europe and explore whether increasing education levels, an important environmental risk factor for myopia, might explain any temporal trend.
Design: Meta-analysis of population-based, cross-sectional studies from the European Eye Epidemiology (E(3)) Consortium.
Participants: The E(3) Consortium is a collaborative network of epidemiological studies of common eye diseases in adults across Europe.
Article Synopsis
- The study estimates the prevalence of refractive errors like myopia, hyperopia, and astigmatism in adults across Europe using data from various cohort studies between 1990 and 2013.
- Participants included were mainly of European ancestry, with exclusions for those who had undergone eye surgeries that could affect results.
- Key findings highlighted that approximately 30.6% of adults have myopia, particularly high in younger individuals, while overall, more than half of the adult population in Europe experiences some form of refractive error.
Purpose: To examine associations between cardiovascular risk factors and age-related macular degeneration (AMD).
Methods: A population-based, cross-sectional study of Caucasians aged 65-87 years was conducted in Norway in 2007/2008. Retinal photographs were graded for AMD.
Article Synopsis
- A reduced glomerular filtration rate (GFR) is known to increase cardiovascular disease risk, but high GFR may also pose risks, which lacks consensus due to limited longitudinal studies.
- In a study of 1,521 healthy individuals, a high GFR (measured by iohexol clearance) was linked to greater carotid plaque area and signs of left ventricular hypertrophy, indicating potential cardiovascular issues.
- The study suggests that high GFR could be a risk factor for cardiovascular disease, warranting further longitudinal research to understand this relationship better.
Purpose: To investigate if markers of iron body stores and hemoglobin are associated with retinal vascular caliber.
Methods: This was a population-based study including 2993 participants of the fifth and sixth surveys of the Tromsø Study in Norway, conducted in 2001-2002 and 2007-2008. The association between levels of s-ferritin, transferrin saturation, and hemoglobin in the fifth survey and retinal vascular caliber in the sixth survey was assessed by multivariable linear regression models.
Purpose: To determine the prevalence and risk factors for retinopathy in a nondiabetic population.
Methods: The study population included 5869 participants without diabetes aged 38-87 years from the Tromsø Eye Study, a substudy of the population-based Tromsø Study in Norway. Retinal images from both eyes were graded for retinopathy.
Objective: Some risk factors for age-related macular degeneration (AMD) have been shown to act differently in women and men. The present study aims to investigate this disparity by examining associations between female hormones, reproductive history and AMD.
Methods: Women aged 65-87 years were invited to this cross-sectional, population-based study in Norway.
Purpose: To describe the association between retinal vascular calibres and cardiovascular risk factors.
Methods: Population-based cross-sectional study including 6353 participants of the Tromsø Eye Study in Norway aged 38-87 years. Retinal arteriolar calibre (central retinal artery equivalent) and retinal venular calibre (central retinal vein equivalent) were measured computer-assisted on retinal photographs.
The retinal vessel width relationship at vessel branch points in fundus images is an important biomarker of retinal and systemic disease. We propose a fully automatic method to measure the vessel widths at branch points in fundus images. The method is a graph-based method, in which a graph construction method based on electric field theory is applied which specifically deals with complex branching patterns.
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