Functional Retinal Impairment in Type 1 Diabetic Patients without any Signs of Retinopathy

Abstract

Purpose: To investigate functional and morphological retinal changes in the long-term follow-up in subjects with type 1 diabetes mellitus (DM1) without any signs of retinal vasculopathy. Methods: Functional testing included Humphrey Matrix perimetry (30-2 threshold program) and white-on-white Humphrey perimetry (HFA, 30-2 SITA standard), while retinal nerve fibre layer (RNFL) thickness was measured by scanning laser polarimetry with variable corneal birefringence compensator. Results: Data from 20 eyes of 20 subjects with DM1 were analysed. No changes of HFA mean deviation (MD: -2.20 ± 3.44 vs. -1.63 ± 2.47; p = 0.14) and pattern standard deviation (PSD: 2.50 ± 1.71 vs. 2.28 ± 1.36; p = 0.31), and Matrix MD (-1.06 ± 3.62 vs. -1.24 ± 2.99; p = 0.65) were found after 5 years. A significant change was found for Matrix PSD between baseline and the end of follow-up (2.76 ± 0.59 vs. 3.1 ± 0.68; p = 0.0078). RNFL parameters were not changed. A significant relationship was found between HbA1c levels and changes from baseline of Matrix PSD (R² 0.29, p = 0.02). Conclusions: Progressive retinal functional impairment could be detected in DM1 subjects by frequency doubling perimetry before the onset of any overt retinal vasculopathy and functional impairment seems to be significantly related to glycaemic control.

Cross-Sectional Analysis of the Involvement of Interleukin-17A in Diabetic Retinopathy in Elderly Individuals with Type 2 Diabetes Mellitus

“…20 Our previous research shows that the higher the serum IL-17A level, the higher the incidence and severity of DR. The underlying mechanism can be summarized as: (1) IL-17A can trigger the destruction of the fundus vascular barrier as well as increase the degree of inflammation of 10 Global DR research studies have revealed that a longer T2DM duration, increasing age, higher HbA1c levels, and poorer blood pressure control were strongly correlated with DR. 13,22 In this study, the longer the DM duration, the higher the prevalence and severity of DR, which is consistent with previous studies. 23 Many previous studies have shown that FCP is related to DR. 24 An earlier study showed that after adjustment for confounding factors, C-peptide and insulin levels were significantly correlated with extent of DR in Latinos with type 2 diabetes.…”

Retinal Neurodegeneration in Diabetes: an Emerging Concept in Diabetic Retinopathy

“…In addition to inner retinal thinning, functional deficits in contrast sensitivity, perimetry testing, multifocal electroretinogram (mfERG), and dark adaptation have also been described in diabetic patients without DR or with very early DR [8][9][10][11][12][13]. A correlation between GCL thinning and visual field deficits on Rarebit perimetry was demonstrated in type 1 DM patients with no DR [14].…”

Multidimensional Functional and Structural Evaluation Reveals Neuroretinal Impairment in Early Diabetic Retinopathy

“… 11 – 13 Contrast sensitivity is a nonspecific test of the inner retina, but different spatial frequencies favor specific neural pathways. 14 , 15 Parravano et al 16 , 17 showed that performance on multiple tests of inner retinal function, including FDP and SAP, is reduced in subjects with diabetes without evidence of DR. Additionally, Jackson et al 18 demonstrated that reduced contrast sensitivity and decreased performance on FDP and SAP correlate with nonproliferative diabetic retinopathy (NPDR). Hellgren et al 19 evaluated performance on SAP over 4 years and demonstrated progression of DR based on neuroretinal functioning and not microvascular-based grading.…”