PURPOSE: To examine the age- and gender-specific 5-year incidence of age-related maculopathy (ARM) and age-related macular degeneration (AMD) in citizens of Reykjavik. DESIGN: Population-based, prospective cohort study. PARTICIPANTS: The cohort was a population-based random sample of citizens 50 years and older. Of 1379 eligible subjects, 1045 had a baseline examination in 1996; 846 of the 958 survivors (88.2%) had a 5-year follow-up examination in 2001. METHODS: The incidence of various characteristics of drusen and pigmentary changes that are typical of ARM were determined using the international classification and grading system for ARM and AMD. MAIN OUTCOME MEASURES: Early ARM and AMD were assessed by masked grading of stereo fundus photographs. RESULTS: Hypopigmentation developed at 5 years in 10.7% of people 50 to 59 years of age (95% confidence interval [CI], 6.9-14.4) and in 25.7% those 70 to 79 years of age (95% CI, 18.4-33.0) at baseline. Age-related macular degeneration developed in no one who was 50 to 59 years of age at baseline. Geographic atrophy (GA) developed in 4.6% (95% CI, 1.2-7.9) and exudative AMD in none of those who were 70 years and older at baseline. CONCLUSIONS: Geographic atrophy is the predominant type of AMD in Iceland, and the ratio of GA to neovascular AMD is higher than in racially similar populations.
Over the past two decades, alcohol consumption of Icelandic adolescents has decreased dramatically. The aim of this study was to quantify the extent of this reduction and compare it with the trend in cannabis use over a 20 year period and to identify possible explanations.
We used data from the Icelandic participants to the European School Survey Project on Alcohol and Other Drugs study (collected via paper-and-pencil questionnaires in classrooms). The sample included all students in the 10th grade (54-89% response rate).
The percentage of participants who had never used alcohol during their lifetime rose from 20.8% in 1995 to 65.5% in 2015. Similarly, there was a decline in the proportion of students who had consumed alcohol 40 times or more, from 13.7% to 2.8%. During the same period, the number of students who had never used cannabis rose from 90.2% to 92.0%. In contrast, we found a small, but statistically significant, increase in the prevalence of those who had used cannabis 40 times or more, from 0.7% in 1995 to 2.3% in 2015. Parental monitoring increased markedly between 1995 and 2015, but availability of alcohol decreased. Perceived access to cannabis and youth attitudes towards substance use remained unchanged.
Although Iceland has enjoyed success in lowering alcohol use among adolescents over the past decades, and somewhat fewer claim to have ever tried cannabis, there has been a threefold increase among heavy users of cannabis. Increased parental monitoring and decreased availability of alcohol explain some of the changes seen.
PURPOSE: To establish a population profile of central corneal thickness (CCT), radius of the corneal curvature (CC) and intraocular pressure (IOP) and the relationships between them using non-contact techniques. METHODS: We used a population-based random sample of 415 male and 510 female Caucasians aged 50 years and older. CCT and the radius of CC were measured with Scheimpflug anterior segment photography. IOP was measured with air-puff tonometry. RESULTS: The mean IOP of right eyes was 15.1 mmHg (SD 3.3) among men and 15.8 mmHg among women (SD 3.1), which is a statistically significant difference. The mean radius of CC for male right eyes was 7.78 (SD 0.60) and for females 7.62 (SD 0.58) which is also statistically significant. Mean CCT for male right eyes was 0.528 mm (SD 0.041) and for females 0.526 mm (SD 0.037), which is not a significant difference. Linear regression analysis shows no relationship between the radius of CC and IOP or between age and radius of CC. Linear regression analysis of the relationship between CCT and IOP suggests higher IOP measurements with thicker corneas. There was no significant correlation between age and CCT. CONCLUSION: IOP was found to be independent of age and significantly higher in females than in males. Radius of CC was found to be age-independent and significantly steeper in females than in males. CCT appears to be independent of age and gender. Greater CCT is associated with higher mean IOP.
Glaucoma is a leading cause of irreversible blindness. A genome-wide search yielded multiple single-nucleotide polymorphisms (SNPs) in the 15q24.1 region associated with glaucoma. Further investigation revealed that the association is confined to exfoliation glaucoma (XFG). Two nonsynonymous SNPs in exon 1 of the gene LOXL1 explain the association, and the data suggest that they confer risk of XFG mainly through exfoliation syndrome (XFS). About 25% of the general population is homozygous for the highest-risk haplotype, and their risk of suffering from XFG is more than 100 times that of individuals carrying only low-risk haplotypes. The population-attributable risk is more than 99%. The product of LOXL1 catalyzes the formation of elastin fibers found to be a major component of the lesions in XFG.
Comment In: Am J Ophthalmol. 2007 Dec;144(6):974-97518036875
BACKGROUND: Aviation involves exposure to ionizing radiation of cosmic origin. The association between lesions of the ocular lens and ionizing radiation is well-known. OBJECTIVE: To investigate whether employment as a commercial airline pilot and the resulting exposure to cosmic radiation is associated with lens opacification. METHODS: This is a population-based case-control study of 445 men. Lens opacification was classified into 4 types using the World Health Organization simplified grading system. These 4 types, serving as cases, included 71 persons with nuclear cataracts, 102 with cortical lens opacification, 69 with central optical zone involvement, and 32 with posterior subcapsular lens opacification. Control subjects are those with a different type of lens opacification or without lens opacification. Exposure was assessed based on employment time as pilots, annual number of hours flown on each aircraft type, time tables, flight profiles, and individual cumulative radiation doses (in millisieverts) calculated by a software program. Odds ratios were calculated using logistic regression. RESULTS: The odds ratio for nuclear cataract risk among cases and controls was 3.02 (95% confidence interval, 1.44-6.35) for pilots compared with nonpilots, adjusted for age, smoking status, and sunbathing habits. The odds ratio for nuclear cataract associated with estimation of cumulative radiation dose (in millisieverts) to the age of 40 years was 1.06 (95% confidence interval, 1.02-1.10), adjusted for age, smoking status, and sunbathing habits. CONCLUSION: The association between the cosmic radiation exposure of pilots and the risk of nuclear cataracts, adjusted for age, smoking status, and sunbathing habits, indicates that cosmic radiation may be a causative factor in nuclear cataracts among commercial airline pilots.
AIM: To examine the age- and gender-specific prevalent and 5-year incident risk of developing exfoliation syndrome (XFS). METHODS AND PARTICIPANTS: In a population-based random sample of citizens 50 years and older, 1045 persons had baseline examination in 1996; 846 of the 958 survivors (88.2%) had a follow-up examination in 2001. Following maximum dilatation of pupils, a diagnosis of exfoliation was established on slit-lamp examination. An extensive questionnaire was administered at baseline and follow-up. Prevalent and incident risk was then calculated using a multivariate analysis. RESULTS: The following variables were found to correlate significantly with prevalence risk of XFS at baseline: age, female gender, increased iris pigmentation, moderate use of alcohol and self-reported asthma. We also found that, compared with those who consumed dietary fibre-rich vegetables, green or yellow vegetables, and fruit less than once a month in their 20s and 40s, those consuming the same food items once or twice every 2 weeks were found to be less likely to have XFS. The same applied to those consuming dietary fibre rich once or twice every 2 weeks in their 40s and 60s. CONCLUSION: Food items that are possibly surrogates for antioxidative effect may correlate with decreased risk of XFS and increased iris pigmentation may correlate with increased risk. Given the large number of comparisons, these findings require validation through additional clinical studies. Increased age and female gender increase the likelihood of XFS.
PURPOSE: To study refractive changes over the course of 5 years in citizens of Reykjavik 50 years and older at baseline. METHODS: The cohort was a population-based random sample of citizens 50 years and older. Eight hundred forty-six of the 958 survivors (88.2%) underwent a 5-year follow-up examination. Refraction and keratometry were performed using a Nidek (Gamagori, Japan) ARK 900 autorefractor keratometer. Typing and grading of lens opacification was carried out using Scheimpflug slit-lamp and retroilluminated images (Nidek EAS 1000), and axial length was measured by Nidek Echoscan 800. RESULTS: Seven hundred fifty-seven right eyes were available for refraction analysis. In the 50- to 59-year age group and the 60- to 69-year age group at baseline, there was a hyperopic shift of 0.41 diopters (D) and 0.34 D, respectively, during the 5 years. There was a 0.02-D myopic shift for those 70 years of age and older at baseline during the same period. Considering all right eyes, there was a hyperopic shift of +0.29 D over the 5 years, whereas eyes with nuclear lens opacification grade II or more at baseline had a mean myopic shift of -0.65 D. There was a mean change of 0.13 D in the astigmatism against the rule during the 5 years. The data on axial length are available from the follow-up study only. The mean axial length for those 50 to 59 years of age at baseline was 23.56 mm (standard deviation [SD], 1.08 mm), as compared with 23.23 mm (SD, 1.27 mm) for those 70 years of age and older at baseline (P
The transition from adolescence to young adulthood is marked by many changes. Mental well-being plays an important role in how individuals deal with these changes and how they develop their lifestyle. The goal of this study was to examine gender differences in the long-term development of self-esteem and other mental well-being variables from the age of 15 to the age of 23.
A baseline measurement was performed in a nationwide sample of 385 Icelandic adolescents aged 15, and a follow-up measurement was conducted eight years later, when participants had reached the age of 23. Standardized questionnaires were used to measure self-reports of self-esteem, life satisfaction, body image, anxiety, depression and somatic complaints.
Women improved their self-esteem significantly more than men from the age of 15 to 23 (p=0.004). Women were more satisfied with their life than men at the age of 23 (p=0.009). Men had a better body image, less anxiety, less depression and fewer somatic complaints than women, independent of age. Across gender, anxiety declined and somatic complaints became fewer (p
PURPOSE: To evaluate the use of disk diameter as an indicator in the identification of glaucomatous optic neuropathy. METHODS: We evaluated all available stereofundus photographs for 1,040 right eyes obtained in the Reykjavik Eye Study. Horizontal and vertical disk diameters were determined in a masked manner by a glaucoma specialist (K.F.D.). All disk diameters were corrected for refractive error. RESULTS: There were significant differences (P
Comment In: Am J Ophthalmol. 2003 Aug;136(2):398; author reply 39812888090
To study the correlation between ocular refraction and the refractive components (corneal power, lens power and axial length) in a population-based sample of normal subjects.
We analysed the refractive and biometric findings for 723 right eyes (325 males and 398 females) comprising a population-based random sample of citizens 55 years and older participating in the Reykjavik Eye Study. Measurements of refraction, corneal curvature (by keratometry), anterior chamber depth, lens thickness and axial length (all by ultrasound biometry) were used to calculate crystalline lens power. The correlation and regression between refraction and ocular refractive components (corneal power, anterior chamber depth, lens power and axial length) were studied by distributional statistical methods.
Refraction (spherical equivalent) showed a significant negative correlation with axial length (r = -0.59, P