Elsevier

Ophthalmology

Volume 117, Issue 7, July 2010, Pages 1400-1405
Ophthalmology

Original article
Retinal Vascular Fractals and Microvascular and Macrovascular Complications in Type 1 Diabetes

https://doi.org/10.1016/j.ophtha.2009.10.047Get rights and content

Purpose

Fractal analysis is a method to quantify the geometric pattern and complexity of the retinal vessels. This study examined the association of retinal fractal dimension (Df) and microvascular and macrovascular complications in a population-based cohort of Danish patients with type 1 diabetes.

Design

Cross-sectional study.

Participants

This was a cross-sectional study of 208 long-term surviving type 1 diabetes patients from a population-based Danish cohort identified in 1973.

Methods

Retinal photographs were obtained at a clinical examination in 2007 or 2008. Df was measured with a semiautomatic computer-based program (International Retinal Imaging Software; National University of Singapore, Republic of Singapore; University of Sydney, Sydney, and University of Melbourne, Melbourne, Australia). Df of the retinal vasculature was measured within a predefined circular region of 3.5 optic disc radii centered on the optic disc. Line tracing of the vasculature was provided by the program. Any artifacts were removed by the grader, and the box-counting method then was used by the program to calculate Df.

Main Outcome Measures

The association of Df with proliferative retinopathy, nephropathy, neuropathy, and macrovascular disease (coronary heart disease, stroke, peripheral artery disease) was examined.

Results

Retinal fractals were gradable in at least 1 eye in 178 (86.6%) of 208 patients. Median age and duration of diabetes for these patients were 57.8 years and 42 years, respectively. Median Df was 1.4610 (range, 1.3774–1.5188). After adjustments for age, gender, duration of diabetes, systolic blood pressure, and smoking, persons with lower Df were more likely to have proliferative retinopathy (odds ratio [OR], 1.45 per standard deviation [SD] decrease in Df; 95% confidence interval [CI], 1.04–2.03) and neuropathy (OR, 1.42 per SD decrease in Df; 95% CI, 1.01–2.01). There was also a trend of an association between lower Df and nephropathy (OR, 1.39 per SD decrease in Df; 95% CI, 0.97–2.01) but not macrovascular disease. Furthermore, persons with lower Df were older.

Conclusions

This study adds to the evidence that Df may have some role as a global measure of retinal vasculature and its association with systemic disease. Prospective studies clarifying this role are needed.

Financial Disclosure(s)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Section snippets

Study Population

This study was a part of a cohort study of type 1 diabetes patients from Fyn County, Denmark. As previously described, the study participants were identified based on insulin prescriptions.15 All type 1 diabetes patients from Fyn County, Denmark, with an onset before the age of 30 years (n = 727) were identified as of 1 July 1973. In 1973, Fyn County had approximately 450 000 inhabitants and was considered a representative 9% sample of Denmark.15

In 2007, 208 (65.0%) of 320 surviving patients

Results

Of the 208 participants in the study, grading of retinal fractals was not possible in either eye of 30 patients (14.4%) because of severe media opacification (n = 10), fibrosis (n = 6), poor dilation (n = 5), missing pictures (n = 4), part of major vessel(s) missing (n = 3), or asteroid hyalosis (n = 2). Differences between patients with and without gradable retinal photos are shown in Table 1. In general, patients with ungradable fractals were older, had a longer duration of diabetes, were

Discussion

This study demonstrated an association between retinal fractal dimensions, a global measure of the retinal vascular pattern, and diabetes-related microvascular complications in long-term surviving Danish type 1 diabetes patients. Patients with eyes with smaller retinal fractals were more likely to have proliferative retinopathy, neuropathy, and nephropathy, while controlling for other risk factors including diabetes duration and glycemia levels. Retinal fractals were not related to

References (25)

  • S.L. Rogers et al.

    Retinal arteriolar caliber predicts incident retinopathy: the Australian Diabetes, Obesity and Lifestyle (AusDiab) study

    Diabetes Care

    (2008)
  • T.Y. Wong et al.

    Retinal vessel diameters and the incidence of gross proteinuria and renal insufficiency in people with type 1 diabetes

    Diabetes

    (2004)
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      In the present analysis significance was observed in age, systolic BP, BMI and waist length. Boxcounting (Grauslund et al., 2010) used in this work showed significance only in age and median fractal dimension is low for presence of diabetic retinopathy, neuropathy and nephropathy. In the present study also median fractal dimension was low for all diseased images.

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    Manuscript no. 2009-1020.

    Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

    Supported by the Velux Foundation, Copenhagen, Denmark; The Danish Eye Health Society, Copenhagen, Denmark; Sehested Hansen's Foundation, Copenhagen, Denmark; the Danish Diabetes Association, Odense, Denmark; the Synoptik Foundation, Copenhagen, Denmark; The A.P. Møller Foundation for the Advancement of Medical Science, Copenhagen, Denmark; The Danish Society of Ophthalmology, Copenhagen, Denmark; the Institute of Clinical Research at University of Southern Denmark, Copenhagen, Denmark; the Singapore National Medical Research Council, Singapore, Republic of Singapore (grant no.: STaR/0003/2008); and the Biomedical Research Council, (SBIC grant no.: C-011/2006) Singapore, Republic of Singapore. The funding organizations had no role in the design or conduct of this research.

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