Decreased levels of soluble TNF-related apoptosis-inducing ligand (TRAIL) in the conjunctival sac fluid of patients with diabetes affected by proliferative retinopathy.

These data demonstrates for the first time that patients with proliferative diabetic retinopathy are characterized by decreased levels of soluble TRAIL in the conjunctival sac fluid. Although the relationship between soluble TRAIL released in the conjuctival sac fluid and TRAIL expressed in the retina or in the vitreous body are not known, our study strengthens the notion that TRAIL plays an important anti-inflammatory role in the eye. In addition, neither the duration of diabetes mellitus, nor the levels of glycated haemoglobin or the type of medications had significant impact on the levels of TRAIL measured in the conjunctival sac. In light of previous findings, it is plausible to suppose that a decreased production and ⁄ or release of TRAIL might contribute to worsening proliferative diabetic retinopathy by reducing the degree of apoptosis in retinal endothelial cells.