The Effect of Glycemia on Choroidal Thickness in Different Stages of Diabetic Retinopathy

Abstract

Objective: The purpose of this study was to evaluate the influence of renal and glycemic parameters on choroidal thickness (CT) in patients with diabetes with and without diabetic retinopathy (DR). Methods: This cross-sectional study included patients with and without diabetes. Patients underwent comprehensive ocular examination. CT was obtained using spectral-domain optical coherence tomography (SD-OCT) with enhanced depth imaging (EDI) mode. Clinical parameters were body mass index, mean arterial pressure, glycated hemoglobin, fasting plasma glucose, estimated glomerular filtration rate, and capillary plasma glucose (CPG) a few minutes before EDI-SD-OCT. Results: The study included 275 participants: 42 with diabetes and no DR, 43 with mild nonproliferative diabetic retinopathy (NPDR), 46 with moderate NPDR, 39 with severe NPDR, 24 with proliferative diabetic retinopathy (PDR), 40 with previous panretinal photocoagulation (PRP) treatment for DR, and 41 without diabetes. The diabetic patients had thinner subfoveal CT than the nondiabetic participants (280.5 ± 83.4 vs. 327.1 ± 48.8 µm, p < 0.001). After multivariable adjustment, CT was significantly correlated with age, DR stage, and CPG. In patients with mild and moderate NPDR, a higher level of CPG was associated with thicker CT. This relationship was not found in patients with PDR. Conclusion: CPG had the strongest correlation with CT in patients with NPDR (mild, moderate, and severe), but not in PDR and PRP PDR patients. Our study suggests that the glucose level at the time of the test should be aggregated to other systemic and ocular parameters, such as age and axial length, when studying the choroid using SD-OCT.

Prevalence and incidence of diabetic retinopathy in patients with diabetes of Latin America and the Caribbean: A systematic review and meta-analysis

“…The 43 prevalence studies included 47 585 participants and their characteristics are shown in Table 1 . With respect to scientific production by country, eighteen studies were conducted in Brazil [ 30 , 32 , 33 , 35 – 37 , 39 – 42 , 44 , 50 , 54 , 58 , 59 , 65 – 67 ], twelve in Mexico [ 27 – 29 , 38 , 45 , 47 , 49 , 51 , 55 , 57 , 60 , 64 ], four in Cuba [ 31 , 34 , 43 , 48 ], two in Peru [ 46 , 61 ] two in Chile [ 63 , 69 ], and one in Argentina [ 68 ], Costa Rica [ 62 ], Ecuador [ 56 ], Puerto Rico [ 52 ], and Suriname [ 53 ].…”

“…Regarding the populations assessed, in twenty-four studies the participants were assessed in the hospital [ 29 , 32 – 35 , 37 – 41 , 44 – 46 , 49 – 52 , 56 – 58 , 62 , 65 , 67 , 68 ], ten in the community [ 18 , 19 , 21 , 33 , 34 , 38 , 44 , 46 , 50 , 51 ], and nine in primary care [ 31 , 36 , 48 , 54 , 61 , 63 , 64 , 66 , 69 ]. For the type of DM, eight studies assessed T1DM [ 32 , 34 , 35 , 39 , 40 , 44 , 50 , 58 ], eighteen T2DM [ 27 , 33 , 37 , 41 , 42 , 45 , 46 , 48 , 49 , 51 , 54 –…”

“…Regarding the diagnostic criteria for diabetic retinopathy, seventeen studies used the ETDRS [ 27 , 30 , 32 , 33 , 35 – 38 , 42 , 43 , 51 – 53 , 56 , 63 , 65 , 67 ], thirteen used the GDRPG [ 39 – 41 , 44 – 46 , 50 , 54 , 58 , 61 , 66 , 68 , 69 ], six the SDRGS [ 47 , 53 , 57 , 60 , 62 , 64 ], three used the American Academy of Ophthalmology guidelines [ 28 , 29 , 49 ], three used the L’ Esperance classification [ 31 , 34 , 48 ], and one used the Revised English Diabetic Eye Screening Program Grading System (REDESPGS) [ 55 ].…”

Choroidal Thickness in Different Patterns of Diabetic Macular Edema

“…Other studies have also shown a change in choroidal thickness with fluctuation in plasma glucose levels. These findings indicate that the choroid is a more dynamic tissue than the retina [ 42 , 43 , 44 ]. However, our results show that the severity of microangiopathy is comparable in the retina and underlying choroid [ 45 ].…”

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

“…In our study, these two factors were associated with SF-CT both in univariable and multivariable analyses in patients with DM without DR. Fasting blood sugar was associated with a thinner SF-CT, and HbA1c was associated with thicker SF-CT. In a study evaluating the influence of glycemic parameters on CT in patients with DM without DR and in patients with DM and DR, Abalem et al found a positive correlation between capillary blood glucose and CT in patients with NPDR, but not in those with PDR [ 44 ]. However, they found no correlation of fasting blood sugar and HbA1c with CT. Torabi et al investigated the correlation between CT and HbA1c in patients with type 2 diabetes in an SD-OCT study in which both eyes from patients with diabetes were divided into three groups according to HbA1c values ( ≤7% good control, 7–8% moderate control and ≥8% poor control) and concluded that there is a significant correlation of CT with HbA1c in patients with DM, and an HbA1c ≤ 7% may prevent choroidal thinning [ 45 ].…”