Status of serum VEGF and ICAM-1 and its association with external limiting membrane and inner segment-outer segment junction disruption in type 2 diabetes mellitus

PURPOSE: To correlate the serum levels of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1) with the severity of retinopathy and disruption of the external limiting membrane (ELM) and inner segment-outer segment (IS-OS) junction in type 2 diabetes mellitus (DM). METHODS: Study subjects included patients with type 2 DM [diabetes mellitus with no retinopathy (No DR; n=19); non-proliferative diabetic retinopathy (NPDR; n=19); proliferative diabetic retinopathy (PDR; n=20)] and healthy controls (n=19) between the ages of 40 and 65 years. Disruption of the ELM and the IS-OS junction was graded by spectral domain optical coherence tomography as follows: grade 0—no disruption of ELM and IS-OS junction; grade 1—ELM disrupted, inner segment-outer segment (IS-OS) junction intact; grade 2—both ELM and IS-OS junction disrupted. The serum levels of VEGF and ICAM-1were analyzed using the standard protocol. RESULTS: A significant difference was found between the serum levels of VEGF and ICAM-1 and the various study groups (p<0.001). A positive correlation was found between the grade of disruption and the levels of VEGF (r=0.45, p<0.0001) and ICAM-1 (r=0.40, p=0.0003). A significant positive correlation was found between logMAR visual acuity and grade of disruption (r=0.85, p<0.0001). CONCLUSIONS: An increase in serum VEGF and ICAM-1 levels is associated with an increase in the severity of diabetic retinopathy and the grade of ELM and IS-OS junction disruption.