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Comorbidity in patients with branch retinal vein occlusion: case-control study

BMJ 2012; 345 doi: (Published 30 November 2012) Cite this as: BMJ 2012;345:e7885
  1. Mette Bertelsen, medical doctor, clinical research fellow123,
  2. Allan Linneberg, senior researcher and head of department4,
  3. Thomas Rosenberg, consultant ophthalmologist23,
  4. Nynne Christoffersen, consultant ophthalmologist2,
  5. Henrik Vorum, professor of ophthalmology5,
  6. Else Gade, ophthalmologist6,
  7. Michael Larsen, professor of ophthalmology123
  1. 1Department of Ophthalmology, Glostrup Hospital, Nordre Ringvej 57, 2600 Glostrup, Denmark
  2. 2National Eye Clinic for the Visually Impaired, Kennedy Center, Gl. Landevej 7, 2600 Glostrup
  3. 3Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen, Denmark
  4. 4Research Centre for Prevention and Health, Glostrup Hospital, Glostrup
  5. 5Department of Ophthalmology, Aalborg University Hospital, Aalborg, Denmark
  6. 6Department of Ophthalmology, Odense University Hospital, Odense, Denmark
  1. Correspondence to: M Bertelsen mettebertelsen12{at}
  • Accepted 12 November 2012


Objectives To evaluate comorbidity before and after the diagnosis of branch retinal vein occlusion to determine whether it is a consequence of arterial thickening and therefore could serve as a diagnostic marker for other comorbidities and to evaluate the risk factors for the development of such occlusion.

Design Case-control study with prospective follow-up data from Danish national registries.

Setting Four secondary referral centres covering about 80% of the Danish population (4.4 million).

Participants 1168 patients with photographically verified branch retinal vein occlusion and 116 800 controls alive and aged ≥40 when the occlusion was diagnosed in the corresponding case.

Main outcome measures The risk of comorbidity 10 years and 1 year before the diagnosis of branch retinal vein occlusion and the incident comorbidity in a mean period of seven years after the diagnosis, with odds ratios and incidence rate ratios adjusted for age, sex, and year of diagnosis.

Results Risk factors present 10 years and 1 year before the diagnosis of branch retinal vein occlusion included peripheral artery disease (odds ratio 1.83, 95% confidence interval 1.14 to 2.95), diabetes (1.74, 1.40 to 2.17) and arterial hypertension (2.16, 1.86 to 2.51). After the diagnosis, patients had an increased risk of developing arterial hypertension (incidence rate ratio 1.37, 95% confidence interval 1.15 to 1.57), diabetes (1.51, 1.17 to 2.04), congestive heart failure (1.41, 1.12 to 1.68), and cerebrovascular disease (1.49, 1.27 to 1.76).

Conclusion Diabetes, hypertension, and peripheral artery disease are associated with an increased risk of developing branch retinal vein occlusion up to a decade later. Branch retinal vein occlusion was associated with an increased risk of subsequently developing hypertension, diabetes, congestive heart failure, and cerebrovascular disease, emphasising the importance of preventive initiatives. These results fit the assumption that branch retinal vein occlusion is a consequence of arterial thickening and that the arteriovenous crossing signs that precede it are hallmarks of arterial disease.


  • We acknowledge the support of the Danish Diabetes Academy.

  • Contributors: MB and ML developed the study design. MB, ML, AL, and TR analysed the data and drafted the manuscript. MB, NC, HV, ML, and EG contributed to the data collection. All authors contributed to the interpretation of the data and revision of the manuscript. MB is guarantor.

  • Funding: This study was funded by the Dag Lenards Foundation. The foundation had no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the reports; or in the decision to submit the article for publication.

  • Competing interests: All authors have completed the ICMJE uniform disclosure form at (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

  • Ethical approval: Not required.

  • Data sharing: No additional data available.

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license. See: and

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