We first conducted a genome-wide association study of 1007 individuals, comparing 570 subjects with ≥8 years duration without DR (controls) with 437 PDR (cases) in the Chinese discovery cohort.
The study population included 292 adults with diabetes, with and without DR. DR (better eye) was categorised as presence and absence of any DR; severity of DR (no vision-threatening DR (VTDR); severe non-proliferative DR (NPDR); PDR and/or clinically significant macular oedema and VTDR).
The prevalence of DR was 43.1% (95% confidence interval 39.6%-46.6%), with mild, moderate, and severe NPDR and PDR to be 9.41%, 7.46%, 11.1%, and 12.1%, respectively.
The diabetic cohort included four subgroups (35 eyes without diabetic retinopathy, 30 eyes with mild to moderate nonproliferative diabetic retinopathy [NPDR], 27 eyes with severe NPDR, and 26 eyes with PDR).
Serum levels of MCP-1 protein in patients classified as diabetic without retinopathy (DWR) and DR, including NPDR and PDR, were assayed by enzyme-linked immunosorbent assay.
sCD40L plasma concentrations were measured in 205 type 2 diabetes (T2DM) patients without DR (DWR; n=50) and with DR (n=155), the latter subdivided into non-proliferative diabetic retinopathy [NPDR; n=98 (63.2%)], or proliferative retinopathy [PDR; n=57 (36.8%)] patients.
Incidence rate ratios (IRRs) were estimated for patients with DME, PDR, and vision-threatening DR, compared with persons without these conditions, by using individual participant data followed by a standard inverse-variance meta-analysis (2-step analysis).
In this cross-sectional study, we examined 33 eyes from 33 patients with diabetes mellitus who underwent a vitrectomy (non-proliferative DR [NPDR, n = 8]; PDR with simple vitreous haemorrhage [VH, n = 17]; or PDR with a fibrovascular proliferative membrane [FVM, n = 8]).
IGF1 was found to increase the T2DM susceptibility as well as advanced DR, i.e., PDR, while VEGFA was found to be associated with early DR stage, i.e., NPDR.
Eighty-six eyes from 57 patients with diabetes (19 with no DR, 19 with non-proliferative DR [NPDR], and 19 with proliferative DR [PDR] who had undergone photocoagulation) and 10 eyes from 10 patients without diabetes were recruited.
Eight haplotype-tagging SNPs of SERPING1 and C5 were genotyped in 570 subjects with type 2 diabetes: 295 DR patients (138 nonproliferative DR [NPDR] and 157 proliferative DR [PDR]) and 275 diabetic controls.
During the follow up, 16 (5.84%) participants developed non proliferative DR and 9 (3.64%) progressed to PDR while the mean corpuscular volume (MCV) and red cell distribution width (RDW) MCV rose.
Conventional MRI was performed in 45 diabetic patients, 30 of whom had diabetic retinopathy (DR) involvement (half PDR, and half NPDR) and 15 of whom were diabetic patients without retinopathy and with normal ophthalmologic examination.
Any DR, vision-threatening DR (VTDR), treatment coverage rates (proportion of participants with proliferative DR [PDR], clinically significant macular edema [CSME], or both who had evidence of retinal scatter and focal laser treatment).
A total of 650 participants (495 [76.2%] nonproliferative DR [NPDR], 155 proliferative DR [PDR]) were analyzed; 302 (46.5%) were women and mean (SD) age was 61 (10) years; 425 (65.4%) were white.
Thr21Met (T21M) and Ser89Asn (S89N) polymorphisms of the UTS2 gene were associated with the risk of developing diabetes and DR. M21M genotype frequencies were high in PDR (8.9% in diabetic control vs. 54.6% in PDR, P = 0.0092) group.