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Observational Study
. 2020 Oct 13:2020:8880586.
doi: 10.1155/2020/8880586. eCollection 2020.

Optical Coherence Tomography Biomarkers of the Outer Blood-Retina Barrier in Patients with Diabetic Macular Oedema

Ioana Damian  1   2 , Simona Delia Nicoara  1   3
Affiliations
Observational Study

Optical Coherence Tomography Biomarkers of the Outer Blood-Retina Barrier in Patients with Diabetic Macular Oedema

Ioana Damian et al. J Diabetes Res. .

Abstract

Background: Numerous studies confirmed the main role of the inner blood-retinal barrier in the development of Diabetic Macular Oedema (DMO). Lately, the focus of research shifted towards the external retinal barrier with potential involvement in the pathogenesis of DMO.

Objective: We aim to identify the OCT changes of the external blood-retinal barrier in patients with DMO and to define them as biomarkers with predictive value. Materials and method. We set up retrospectively 3 groups of patients diagnosed with nonproliferative diabetic retinopathy (NPDR) and DMO, proliferative diabetic retinopathy (PDR) and DMO, and controls. We compared the RPE thickness in every quadrant between groups and performed correlations between best-corrected visual acuity (BCVA) and the thickness of the retinal layers. The Social Science Statistics platform was used for statistical tests.

Results: The NPDR-DMO group consisted of 18 eyes, the PDR-DMO group consisted of 19 eyes, and the control group included 36 eyes. In the PDR-DMO group, RPE thickness was decreased in almost all quadrants (p < 0.001); in the NPDR-DMO group, only the central minimum and central maximum values of the RPE thickness were significantly different from the control group. We did not find any strong correlation between BCVA and the thickness of the retinal layers.

Conclusion: The thickness of the RPE layer is an OCT biomarker able to predict the functioning of the outer BRB. Eyes with PDR-DMO exhibited decreased thickness of the RPE layer in almost all quadrants, highlighting the degenerative changes occurring in a hypoxic environment. The thickness of a specific layer could not be identified as a biomarker to correlate significantly with BCVA, most likely because we did not analyze specific morphologic features, such as continuity and reflectivity. The analysis of the RPE thickness could clarify the unexplained decrease of BCVA and predict early the evolution of DR.

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Conflict of interest statement

The authors declare that there is no conflict of interest regarding the publication of this paper.

Figures

Figure 1
Figure 1
Flow diagram illustrating the study selection process. AMD: age-related macular degeneration; anti-VEGF: anti-vascular endothelial growth factor; PPV: pars plana vitrectomy; ERM: epiretinal membrane, Q: OCT segmentation quality; NPDR-DMO: nonproliferative diabetic retinopathy-diabetic macular oedema; PDR-DMO: proliferative diabetic retinopathy-diabetic macular oedema.
Figure 2
Figure 2
Retinal layer segmentation.
Figure 3
Figure 3
Mean RPE layer thickness difference (%) between the eyes from the control group and NPDR-DMO or PDR-DMO.
Figure 4
Figure 4
Scatterplots between different variables: (a) CMT and central RPE in NPDR-DMO; (b) CMT and central RPE in PDR-DMO; (c) central RPE and BCVA in NPDR-DMO; (d) central RPE and BCVA in PDR-DMO; (e) inner retina and central RPE in NPDR-DMO; (f) inner retina and central RPE in PDR-DMO; (g) central RPE and photoreceptors' thickness in NPDR-DMO; (h) central RPE and photoreceptors' thickness in PDR-DMO.
See this image and copyright information in PMC

References

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