Search

To investigate the oxidative status in lens epithelial cells of patients with pseudoexfoliation (PEX) syndrome. Lens capsule samples obtained during cataract surgery of patients with PEX syndrome and normal age-matched control subjects were examined for changes in the levels of glutathione (GSH), glutathione disulphide (GSSG), protein concentration, and lipid peroxidation. Concentrations of GSH, GSSG, lipid peroxidation, and protein concentration were determined by specific fluorescent assays. This study shows a 2.2- and 2.0-fold decrease in GSH and GSSG levels, respectively, in PEX lens epithelial lens compared with non-PEX lens epithelial cells, as well as a 2.5-fold increase in lipid peroxidation product malondialdehyde (MDA) levels. The increased MDA and decreased GSH levels indicate high oxidative stress. On the other hand, GSSG usually increases in cases of high-oxidative stress, but this is not always the case, as it may not always accumulate in cells. Our findings suggest a role for oxidative stress in the pathogenesis and the progression of PEX syndrome.

Pseudoexfoliation syndrome (PEX) is an age-related condition, which may cause open-angle glaucoma and has increasing interest since it seems to affect additional human tissues, i.e., cardiovascular tissue, skin, and still lacks elucidated pathogenesis. Collagen type IX and HNK-1 epitope have been considered characteristic constituents of the aqueous humour of PEX patients, since their amounts were increased in PEX aqueous humour compared to normal eyes. Since it has been proposed that the initial manifestations of PEX syndrome occur in conjunctiva, the present study was undertaken to investigate the presence of the same antigens in tears of PEX patients and their possible use as the biochemical markers for early diagnosis. Tears of PEX patients and healthy individuals were subjected to western blotting analysis for various basement membrane components identified in aqueous humour. It was found that collagen type IX and HNK-1 epitope were present in tears, the amount of the former being increased 2.7 times compared to normal (P0.05), surprisingly high as compared with total protein or lysozyme activity in tears, which were found to be increased in PEX patients about 25% with no statistical differences (P approximately 0.4). The results suggest the possible use of tears' collagen type IX for the diagnosis of PEX syndrome.