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Article: The Retinal Vasculature as a Fractal: Methodology, Reliability, and Relationship to Blood Pressure

TitleThe Retinal Vasculature as a Fractal: Methodology, Reliability, and Relationship to Blood Pressure
Authors
Issue Date2008
PublisherElsevier Inc. The Journal's web site is located at http://www.elsevier.com/locate/ophtha
Citation
Ophthalmology, 2008, v. 115 n. 11, p. 1951-1956.e1 How to Cite?
AbstractObjective: Fractals represent a type of derived geometric pattern that permits the characterization of the branching pattern of retinal vessels. We examined a new semiautomated method to measure retinal vessel fractals. Design: Methodology study. Participants: Three hundred randomly selected participants from the population-based Blue Mountains Eye Study. Methods: We developed a semiautomated computer program to measure the fractal dimension (Df) of the retinal vessels from digitized images of disk-centered retinal photographs. Two trained graders masked to participant characteristics measured Df of right eye images of participants. Reliability was determined by repeat grading of the images from 60 participants, and association with systolic and diastolic blood pressure was examined in all 300 participants. Main Outcome Measure: Df of the retinal vessels. Results: Mean Df was 1.437 with a standard deviation of 0.025. Intragrader and intergrader reliability estimates were high with intraclass correlation ranging from 0.93 to 0.95. Df was inversely correlated with age (r = -0.42, P = 0.001) and systolic blood pressure (r = -0.29, P<0.0001). After adjustment for age and sex, mean Df was significantly lower in participants with than without hypertension (Df difference 0.01, P = 0.02). Conclusions: The Df of the retinal vessels can be reliably measured from photographs and shows a strong inverse correlation with blood pressure. These data suggest that the Df may be a measure of early microvascular alterations from elevated blood pressure. Further studies to examine the systemic and ocular correlates of the Df of the retinal vessels are needed. Financial Disclosure(s): The authors have no proprietary or commercial interest in any materials discussed in this article. © 2008 American Academy of Ophthalmology.
Persistent Identifierhttp://hdl.handle.net/10722/183559
ISSN
2015 Impact Factor: 6.75
2015 SCImago Journal Rankings: 4.745
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorLiew, Gen_US
dc.contributor.authorWang, JJen_US
dc.contributor.authorCheung, Nen_US
dc.contributor.authorZhang, YPen_US
dc.contributor.authorHsu, Wen_US
dc.contributor.authorLee, MLen_US
dc.contributor.authorMitchell, Pen_US
dc.contributor.authorTikellis, Gen_US
dc.contributor.authorTaylor, Ben_US
dc.contributor.authorWong, TYen_US
dc.date.accessioned2013-05-28T06:14:44Z-
dc.date.available2013-05-28T06:14:44Z-
dc.date.issued2008en_US
dc.identifier.citationOphthalmology, 2008, v. 115 n. 11, p. 1951-1956.e1en_US
dc.identifier.issn0161-6420en_US
dc.identifier.urihttp://hdl.handle.net/10722/183559-
dc.description.abstractObjective: Fractals represent a type of derived geometric pattern that permits the characterization of the branching pattern of retinal vessels. We examined a new semiautomated method to measure retinal vessel fractals. Design: Methodology study. Participants: Three hundred randomly selected participants from the population-based Blue Mountains Eye Study. Methods: We developed a semiautomated computer program to measure the fractal dimension (Df) of the retinal vessels from digitized images of disk-centered retinal photographs. Two trained graders masked to participant characteristics measured Df of right eye images of participants. Reliability was determined by repeat grading of the images from 60 participants, and association with systolic and diastolic blood pressure was examined in all 300 participants. Main Outcome Measure: Df of the retinal vessels. Results: Mean Df was 1.437 with a standard deviation of 0.025. Intragrader and intergrader reliability estimates were high with intraclass correlation ranging from 0.93 to 0.95. Df was inversely correlated with age (r = -0.42, P = 0.001) and systolic blood pressure (r = -0.29, P<0.0001). After adjustment for age and sex, mean Df was significantly lower in participants with than without hypertension (Df difference 0.01, P = 0.02). Conclusions: The Df of the retinal vessels can be reliably measured from photographs and shows a strong inverse correlation with blood pressure. These data suggest that the Df may be a measure of early microvascular alterations from elevated blood pressure. Further studies to examine the systemic and ocular correlates of the Df of the retinal vessels are needed. Financial Disclosure(s): The authors have no proprietary or commercial interest in any materials discussed in this article. © 2008 American Academy of Ophthalmology.en_US
dc.languageengen_US
dc.publisherElsevier Inc. The Journal's web site is located at http://www.elsevier.com/locate/ophthaen_US
dc.relation.ispartofOphthalmologyen_US
dc.subject.meshAgeden_US
dc.subject.meshAged, 80 And Overen_US
dc.subject.meshAging - Physiologyen_US
dc.subject.meshBlood Pressure - Physiologyen_US
dc.subject.meshFemaleen_US
dc.subject.meshFractalsen_US
dc.subject.meshHumansen_US
dc.subject.meshImage Processing, Computer-Assisted - Methodsen_US
dc.subject.meshMaleen_US
dc.subject.meshMiddle Ageden_US
dc.subject.meshPhotographyen_US
dc.subject.meshReproducibility Of Resultsen_US
dc.subject.meshRetinal Vessels - Anatomy & Histologyen_US
dc.titleThe Retinal Vasculature as a Fractal: Methodology, Reliability, and Relationship to Blood Pressureen_US
dc.typeArticleen_US
dc.identifier.emailCheung, N: dannycheung@hotmail.comen_US
dc.identifier.authorityCheung, N=rp01752en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1016/j.ophtha.2008.05.029en_US
dc.identifier.pmid18692247-
dc.identifier.scopuseid_2-s2.0-54949136464en_US
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-54949136464&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume115en_US
dc.identifier.issue11en_US
dc.identifier.spage1951en_US
dc.identifier.epage1956.e1en_US
dc.identifier.isiWOS:000260448900016-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridLiew, G=12796147900en_US
dc.identifier.scopusauthoridWang, JJ=55664024800en_US
dc.identifier.scopusauthoridCheung, N=8054683900en_US
dc.identifier.scopusauthoridZhang, YP=23977105700en_US
dc.identifier.scopusauthoridHsu, W=7402002763en_US
dc.identifier.scopusauthoridLee, ML=7409117252en_US
dc.identifier.scopusauthoridMitchell, P=7402933815en_US
dc.identifier.scopusauthoridTikellis, G=6602765289en_US
dc.identifier.scopusauthoridTaylor, B=14047527900en_US
dc.identifier.scopusauthoridWong, TY=7403531208en_US

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