Abstract
Purpose:
Extracellular purines play important role in ocular physiology, diabetes, vascular remodelling and adaptation to inflammation. This study was aimed to evaluate intravitreal purine levels in patients with diabetic retinopathy (DR) and other nonvascular vitreo-retinal eye diseases.
Methods:
Vitreous samples were collected at the start of the 3-port pars plana vitrectomy. Study group comprised 55 eyes operated due to sight-threatening forms of DR, including 24 patients with proliferative DR (PDR). Of the 143 non-diabetic controls, 112 had rhegmatogenous retinal detachment (RRD) and 31 macular hole (MH) or pucker. Intravitreal purine concentrations were determined using a combination of bioluminescent (ATP, ADP) and fluorometric (AMP, adenosine, inosine) enzyme-coupled sensing assays.
Results:
Compared to control group, DR eyes contained significantly higher (p<0.01) concentrations of ATP (4.2±0.6 vs 34.5±13.7 nmol/L; mean±SEM), ADP (19.5±2.7 vs 43.7 nmol/L) and AMP (1290±115 vs 1876±190 nmol/L). Intravitreal adenosine and inosine levels varied within sum-micromolar to low micromolar range and their concentrations did not differ between the groups.
Conclusions:
High concentrations of intravitreal nucleotides ATP, ADP and AMP may be related to the pathogenesis of DR.
Keywords: 572 ischemia •
499 diabetic retinopathy