The Relationship between Retinal and Ganglion Layer Thickness and Perfusion in Patients with Type 2 Diabetes: A Cross-Sectional Study in Indonesia

Objective: To assess the differences and the relationship between retinal nerve fiber layer (RNFL) thickness, ganglion cell-internal plexiform layer (GCIPL) thickness, capillary perfusion density, and flux index in patients with type 2 diabetes (T2D) with and without diabetic retinopathy (DR). Materials and methods: This cross-sectional analytic study with consecutive sampling, which divided individuals into healthy, people with T2D without DR (no DR), and people with T2D with DR (DR) groups. The subjects were patients with T2D aged 40–75 years with or without DR. The collected data included age, gender, glycated hemoglobin test result (HbA1c), duration of diabetes, intraocular pressure (IOP), RNFL thickness, GCIPL thickness, peripapillary perfusion density, and peripapillary flux index. Results: This study included 137 eyes from 83 people with T2D. There were significant differences in minimum GCIPL thickness (p = 0.0001), peripapillary perfusion (p = 0.003), and peripapillary flux (p = 0.001) between the 3 groups, but no significant difference in RNFL thickness between the 3 groups (p = 0.222). There were significant positive correlations between RNFL thickness and peripapillary perfusion (p = 0.002, r = 0.264), RNFL thickness and peripapillary flux (p = 0.0001, r = 0.320), GCIPL thickness and peripapillary perfusion (p = 0.003, r = 0.256), as well as GCIPL thickness and peripapillary flux (p = 0.002, r = 0.268). Conclusions: There were relationships between RNFL thickness and peripapillary retinal perfusion, RNFL thickness and peripapillary flux, GCIPL thickness and peripapillary perfusion, and GCIPL thickness and peripapillary flux, in patients with T2D with and without DR.