Choroidal changes and associations with visual acuity in diabetic patients

Abstract

Background The variable visual function observed in diabetic retinopathy (DR) patients is not fully explained by the classic staging system. Our purpose was to evaluate choroidal changes, in standardized sectors, in DR patients and to find associations between choroidal measurements and visual function. Methods Cross-sectional study that included the right eye of diabetic patients (n = 265) without active edema, ischemia or neovascularization and age-matched controls (n = 73). Optical coherence tomography (OCT) imaging was performed with enhanced depth imaging protocol. Choroidal vascularity index (CVI) was calculated in a 5 mm scan centered in the fovea. Results CVI decreased with age (p < 0.001) but was not influenced by axial length. A multivariate analysis adjusting for age confirmed a significant difference in CVI between DR eyes that had previous treatments (intravitreal injections and/or photocoagulation) compared to control eyes (p = 0.013) and to DR eyes that never required treatment (p = 0.002). There was no significant difference between non-DR diabetic patients and normal controls. Considering the group of DR patients that had previous treatments, in eyes without optic media opacification, BCVA correlated with CVI (r = − 0.362, p < 0.001), whereas full retina thickness and individual retinal layer thickness did not (p > 0.066). Conclusions A reduction in CVI was observed in patients with a more advanced stage of DR. In treated DR patients with stable disease, choroidal biomarkers correlated with best-corrected visual acuity whereas retinal biomarkers did not. Trial registration: N/A

Vascular changes of the choroid and their correlations with visual acuity in diabetic retinopathy

“…However, no correlation was found between these parameters and CSME. Furthermore, CVI showed a strong negative association with BCVA, suggesting that patients with lower CVI exhibited poorer visual acuity, which was consistent with previous research findings (30). Consequently, CVI may serve as a reliable biomarker for monitoring the progression of DR; thus, preserving CVI could emerge as a novel clinical objective.…”

Choroidal Morphology and Photoreceptor Activity Are Related and Affected by Myopia Development

“… 74 , 75 The potential role of CVI in identifying myopes at risk of visual impairment has been suggested in the past, because young high myopes with and without chorioretinal complications were found to have lower CVI in turn related to reduced best corrected visual acuities. 76 , 77 …”

Choroidal Assessment in Patients with Type 2 Diabetes Mellitus and Non-Proliferative Diabetic Retinopathy by Swept-Source Ocular Coherence Tomography and Image Binarization

“…Of particular importance in the assessment of CT is the correct identification of the posterior limit of the choroid [ 28 , 33 , 34 ]. In our study, the identification of the CSJ was possible in all the examined subjects, a result similar to those reported in the literature [ 35 ].…”

“…In addition, SCL was not included in the polygonal selection of the ROI when we evaluated the choroidal parameters by binarizing the OCT images. Having a hyporeflective appearance on OCT images, SCL could lead to a false increase in vascular area after image binarization and modify CVI values [ 34 ]. After the binarization, if errors were observed at the posterior choroidal boundary, most often by not completely including the choroidal stromal area, the edges of the selection polygon were adjusted to include the choroidal stroma.…”

“…Agrawal et al defined the ratio between LA and TCA as CVI [ 25 ]. CVI is considered a better and stable quantitative parameter and a consistent indirect measure of choroidal vascularity assessment compared to CT, because it is less influenced by other factors [ 34 ]. In our study, there were no statistically significant differences between groups with respect to CT, but CVI was found to decrease significantly in diabetic patients with NPDR compared to DM patients for all three studied areas.…”