Oxidative Stress and Human Breath Hydrocarbons During Senile Macular Degeneration: A Preliminary Report

Abstract

Purpose: : Oxygen free radicals may play a role in the pathogenesis of age related macular degeneration, though the true significance and importance are still not clear. Breath concentration of ethane, propane, butane and pentane are now considered a specific and non invasive test for determining and monitoring the trend of lipid peroxidation in vivo. The present study was performed to evaluate in exhaled breath the pattern and concentrations of endogenous volatile hydrocarbons during age-related macular degeneration (AMD).

Methods: : Patients with AMD were enrolled in the study. Exclusion criteria were: diseases such as diabetes, liver disorders, neoplasias, collagen vascular disease, a recent history of acute illness, smoking, and antioxidant therapy. Breath analysis was carried out by a previously described and foresees various steps among which collection of end alveolar breath samples which are then adsorbed , desorbed, cryofocused and quantified using the TCT/PTIU CP 4001 injector mounted on the model CP 9001 gas chromatograph ( Chrompack; Varian, Lentini, Italy) fitted with an aluminium column and working under an appropriate temperature programme.

Results: : Thirty-six patients were analyzed . Breath ethane, propane, butane and pentane concentrations were found in normal range . Five of the evaluated patients showed a marked increase in breath ethane levels with mean values about 4 to 10 times higher than health normal controls. Alkanes levels in ambient air was negligible.

Conclusions: : These results suggest that free-radical-induced lipid peroxidation is not an usual finding during AMD. When analysis of breath alkanes is performed, only ethane levels was found increased in some patients, without statistical significance. Nevertheless these data deserve further investigations. Analysis of breath for alkanes could be helpful in identifying those patients where antioxidant therapy have benefit.Nevertheless these data deserve further investigations both in a larger number of patients and different stages of macular degeneration. The analysis of breath for alkanes could be helpful in identifying those patients who could mostly benefit from an antioxidant therapy.

Keywords: antioxidants