Proteinuria in early referral to spectral domain optical coherence tomography for macular edema detection in type 2 diabetes individuals: results from the Brazilian diabetes study

Abstract

Background

Measurement of retinal thickness by optical coherence tomography (OCT) shows higher diagnostic accuracy for diabetic macular edema (DME) than fundus photography alone. The expanding gap between the rising number of type 2 diabetes (T2D) individuals and the availability of OCT devices demands a targeted selection of individuals at higher risk of DME who would benefit the most from early referral. We sought to appraise if proteinuria should be considered in a targeted referral of T2D individuals to OCT examination.

Methods

This study was a cross-sectional analysis of 576 consecutive patients enrolled in the Brazilian Diabetes Study between June/2016 and December/2021 who underwent OCT exam and urinalysis to assess ME and proteinuria status, respectively. Differences in the prevalence of DME between proteinuria groups and across a range of diabetic retinopathy (DR) stages were evaluated.

Results

Among 1134 eyes included in this analysis, the prevalence of proteinuria was 22% and 18.2% of eyes had DME. Proteinuria was related to an increased prevalence of DME (13.2% vs 38.7% for control vs proteinuria, respectively; p < .001), with an OR of 4.08 [95% confidence interval (CI): 2.50–6.64, p < .001), after adjustment for covariates. Proteinuria was independently related to DME also among eyes with non-apparent DR [OR: 2.82; 95%CI: 1.34–5.93; p = .003] and non-proliferative DR (OR of 5.94, 95%CI 2.13–16.62, p < .001). Fundus photography spotted only half of the DME cases detected by OCT.

Conclusion

In T2D individuals, early referral to OCT examination should be pursued for all individuals with concurrent proteinuria.

Trial registration

ClinicalTrials.gov Identifier: NCT04949152

Keywords:

• Macular edema
• type 2 diabetes
• optical coherence tomography
• proteinuria

Transparency

Declaration of funding

Andrei C Sposito is supported by a Research Career Awards grant from the Brazilian National Research Council (CNPq) (grant number 301465/2017-7).

Declaration of financial/other relationships

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

In this study, JB, FC, and VF assisted in sample collection, performed the experiments and were responsible for drafting the article. MAN, RPCL, WN, and ACS assisted in data interpretation and helped to revise the article, critically adding important intellectual contents. ACS was responsible for supervising the development of all its steps and contributing substantially to the preparation of the manuscript. All authors read and approved the final manuscript.

Acknowledgements

Authors wish to thank the Brazilian Diabetes Study participants.

Data  availability statement

The data that support the findings of this study are available from the corresponding author, ACS, upon reasonable request.

Ethics statement

The study was approved by the local ethics committee (CAAE: 89525518.8.1001.5404) and complied with the Declaration of Helsinki principles.

Notes

i NM/FA Carl Zeiss, USA.