Choroidal thickness measured using swept-source optical coherence tomography is reduced in patients with type 2 diabetes

Abstract

ObjectiveTo compare choroidal thickness between patients with type 2 diabetes (T2D) and healthy controls measured using swept-source optical coherence tomography (SS-OCT).MethodsThe sample comprised 157 eyes of 94 T2D patients, 48 eyes of which had diabetic macular edema (DME), and 71 normal eyes of 38 healthy patients. Subfoveal (SF) choroidal thickness, and choroidal thickness at 500-μm intervals up to 2500 μm nasal and temporal from the fovea were measured using the SS-OCT. Choroidal thicknesses were compared between groups using Student’s t-test. Additionally, Pearson correlations were calculated between diabetes duration, glycosylated hemoglobin (HbA1c) levels, and choroidal thickness.ResultsMean diabetes duration was 16.6±9.5 years, while mean glycosylated hemoglobin was 7.7±1.3%. Overall, the choroid was significantly thinner in T2D patients. Individuals with DME had reduced choroidal thickness in all measurements, except at 2000 and 2500-μm nasal positions, compared to healthy controls. There was a moderate correlation between choroidal thickness and HbA1c levels in DME patients (SF: r = 0.342; p = 0.017). Diabetes duration did not correlate significantly with choroidal thickness.ConclusionSS-OCT measurements revealed that the choroid was significantly thinner in T2D patients, moderate non-proliferative diabetic retinopathy patients, and DME patients than in healthy individuals. Further studies are needed to clarify the effect of diabetes on this layer and the relationship between choroidal thickness and DME.

Choroidal Changes of Long-Term Type 1 Diabetic Patients without Retinopathy

“…Kim et al [11] evaluated the subfoveal CT at a distance of 1500 µm superior, inferior, nasal and temporal to the fovea. Unlike the previously mentioned studies [11,28,33], they found that the subfoveal CT in the presence of proliferative DR was thicker than in eyes without DR, or with mild-to-moderate and severe non-proliferative DR. However, in comparison with healthy controls, the subfoveal, temporal, nasal, superior and inferior thicknesses of the choroid decreased slightly in eyes with DM2 without DR or with non-proliferating DR in more initial stages of the disease (mild/moderate), without reaching statistical significance.…”

“…This tendency was maintained with the DRI-Triton SS-OCT in which thinner CTs were obtained in seven of the nine areas in addition to the CV. In summary, CT diminishes with disease evolution as mentioned by other authors [11][12][13]33]. We divided the control group looking for the age influence on our results.…”

“…In this study we have only included DM1 without RD, but there are multiple studies showing that the presence of DME can modify CT. Regatieri [23], Abadía [33], Querques [29], Esmaeelpour [12] and Adhi [35] found a reduced choroidal thickness in different areas. Ünsal et al found that the CT decreases as the disease progresses from a mild to moderate non-proliferative DR, reaching a proliferative DR that correlates to prolonged deficient control of glycaemia and its influence on vascularization [24].…”

“…After development of DR, there is a tendency towards decreased CT that could correspond to vascular modifications and microvascular loss. Esmaeelpour [12] and Abadia [33] found that subfoveal CT was thinner in DM2 patients without DR and with non-proliferative DR compared to healthy controls. Kim et al [11] evaluated the subfoveal CT at a distance of 1500 µm superior, inferior, nasal and temporal to the fovea.…”

Familial retinal arteriolar tortuosity and quantification of vascular tortuosity using swept-source optical coherence tomography angiography

“…With newer advancements such as swept-source OCTA, the speed and resolution of image acquisition is greatly advanced, rendering highly detailed images of the retinal and choroidal vasculature. Prior studies have shown novel and useful applications of this technology to detect choroidal neovascularization, neovascular growth in proliferative diabetic retinopathy, or analyze in detail choroidal architecture 13, 14, 15…”