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dc.contributor.advisorNjølstad, Inger
dc.contributor.authorErke, Maja Gran
dc.date.accessioned2013-05-16T07:55:31Z
dc.date.available2013-05-16T07:55:31Z
dc.date.issued2013-05-30
dc.description.abstractAge-related macular degeneration (AMD) is an important cause of visual impairment and blindness worldwide. The number of people affected by the disease is expected to rise due to increasing longevity. Development of adequate eye care for these patients should be based on knowledge about the prevalence of AMD. Further, preventive measures are the best strategy for any disease. The aims of this thesis were to estimate the prevalence of AMD and examine risk factors associated with AMD. We described prevalence rates of AMD among Caucasian elderly participants from the Tromsø Eye Study, a population-based study in Norway. The overall prevalence of late AMD was 3.5 % among the participants aged 65-87 years old. Neovascular AMD outnumbered geographic atrophy. Symmetry between eyes was relatively low. Prevalence increased strongly with age. No significant sex differences in prevalence rates of AMD were observed. Refractive error was lower in eyes with late AMD than in eyes without late AMD. We then analysed relationships between traditional cardiovascular risk factors and AMD. Daily smoking was a strong predictor for the presence of late AMD. We found a significant interaction between age and sex for late AMD, suggesting that age may be a stronger risk factor for late AMD in women than in men. Higher systolic blood pressure, higher pulse pressure, infrequent physical exercise and overweight or obesity were in adjusted analyses associated with late AMD in females, but this was not observed in men. Based on our observation of sex and AMD, we studied associations between female hormone related factors and AMD. We found a significant inverse relationship between duration of lactation and late AMD. No significant relationships were found between late AMD and exogenous oestrogen exposure in the form of contraceptives or hormone therapy. Nor did we find an association between late AMD and onset, end or length of fertile years, bilateral oophorectomy or parity as surrogate measures.en
dc.description.doctoraltypeph.d.en
dc.description.popularabstractAlders-relatert makuladegenerasjon (AMD) rammer skarpsynet og er en viktig årsak til redusert syn og blindhet blant eldre. Som en del av spesialundersøkelsene i den sjette Tromsøundersøkelsen, ble det tatt øyebunnsbilder. Bildene fra deltakere 65 år og eldre ble vurdert med tanke på AMD og dets forstadier. Blant de vel 2 600 deltakerne fant vi at totalt 3,5 % hadde de alvorlige senstadiene av AMD, mens forekomsten var 11 % blant de som var 80 år eller eldre. Litt under halvpartene av øynene med sen AMD hadde betydelig nedsatt syn tilsvarende definisjonen på svaksynt (Snellen ≤ 0,32). Bortsett fra høy alder var røyking sterkt forbundet med forekomst av sen AMD for begge kjønn. For kvinner var dessuten høy kroppsmasseindex og høyt systolisk blodtrykk forbundet med økt risiko. Likeledes, for kvinner, var fysisk aktivitet og langvarig amming av barn forbundet med lavere risiko for sen AMD.en
dc.description.sponsorshipNorthern Norway Regional Health Authorityen
dc.descriptionThe papers of this thesis are not available in Munin: <br/>1. Bertelsen G, Erke MG, von Hanno T, Mathiesen EB, Peto T, Sjølie AK and Njølstad I.: 'The Tromsø Eye Study: study design, methodology and results on visual acuity and refractive errors', Acta Ophthalmologica (2012), Online before print. Available at <a href=http://dx.doi.org/10.1111/j.1755-3768.2012.02511.x>http://dx.doi.org/10.1111/j.1755-3768.2012.02511.x</a> <br/>2. Erke MG, Bertelsen G, Peto T, Sjølie AK, Lindekleiv H and Njølstad I.: 'Prevalence of Age-Related Macular Degeneration in Elderly Caucasians: The Tromsø Eye Study', Ophthalmology (2012), vol.119(9):1737–1743. Available at <a href=http://dx.doi.org/10.1016/j.ophtha.2012.03.016>http://dx.doi.org/10.1016/j.ophtha.2012.03.016</a> <br/>3. Erke MG, Bertelsen G, Peto T, Sjølie AK, Lindekleiv H and Njølstad I.: 'Cardiovascular risk factors associated with agerelated macular degeneration: The Tromsø Study' (manuscript) <br/>4. Erke MG, Bertelsen G, Peto T, Sjølie AK, Lindekleiv H and Njølstad I.: 'Lactation, female hormones and age-related macular degeneration: The Tromsø Study' (manuscript)en
dc.identifier.urihttps://hdl.handle.net/10037/5155
dc.identifier.urnURN:NBN:no-uit_munin_4865
dc.language.isoengen
dc.publisherUniversity of Tromsøen
dc.publisherUniversitetet i Tromsøen
dc.relation.ispartofseriesISM skriftserie, nr 137
dc.rights.accessRightsopenAccess
dc.rights.holderCopyright 2013 The Author(s)
dc.subject.courseIDDOKTOR-003en
dc.subjectVDP::Medical disciplines: 700::Health sciences: 800::Epidemiology medical and dental statistics: 803en
dc.subjectVDP::Medisinske Fag: 700::Helsefag: 800::Epidemiologi medisinsk og odontologisk statistikk: 803en
dc.subjectVDP::Medisinske Fag: 700::Klinisk medisinske fag: 750::Oftalmologi: 754en
dc.subjectVDP::Medical disciplines: 700::Clinical medical disciplines: 750::Ophthalmology: 754en
dc.titleAge-related macular degeneration: Prevalence and risk factors - a cross-sectional study : The Tromsø Study 2007/2008en
dc.typeDoctoral thesisen
dc.typeDoktorgradsavhandlingen


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