Alterations in Tear Biochemistry Associated with Postanesthetic Chronic Dry Eye Syndrome.

Perioperative dry eye syndrome (DES) is a common ocular complication of long-term general anesthesia. Chronic DES can lead to permanent damage to the cornea and disturbance of visual function, up to total loss of vision. Here, a relationship between the duration of general anesthesia and the risk of chronic DES in patients was demonstrated. Using an experimental model of perioperative corneal abrasions in rabbits, it was found that introduction of animals to 3-h general anesthesia resulted in clinically significant chronic damage to the cornea in 50% of cases. The development of the complication was not associated with irreversible or long-term impairment of tear secretion, but it was accompanied by a decrease in tear film stability and growth of the total protein content as well as decrease in total antioxidant activity of the tear induced by low molecular weight antioxidants. In addition, anesthesia-induced changes in activity of tear antioxidant enzymes including superoxide dismutase and enzymes providing homeostasis of reduced glutathione (glutathione peroxidase, glutathione-S-transferase, glutathione reductase) were observed. All these alterations were protracted (up to 1-2 weeks) and therefore might account for transition of the perioperative DES into the chronic form. These findings can be useful in the development of novel approaches for the prevention and treatment of chronic forms of DES in the postanesthetic period.

[Device for analyzing roentgen images]. / Ustanovka dlia analiza rentgenovskogo izobrazheniia.

Analyzer of X-ray images includes a photodetector array with online memory, a single-purpose computer and an imager for the memory contents. The photodetector array incorporates 2 X (64 X 128) bistable photocells, their action potentials are adjusted for brightness. The analyzer is the most useful in verifying parallelism of absorbing plates in X-ray grids, in checking protective devices, and in processing mammograms.

[Methods of detecting defects in x-ray protective equipment]. / Metody vyiavleniia defektov v rentgenovskikh zashchitnykh ustroistvakh.

A comparison of five different methods of quality control for X-ray protective devices has shown that electroradiogrpahic control is the most efficient. It allows reliable disclosure of defects and is economically profitable. Roentgenoscopic approach proved to be more reasonable for rapid checking of protective devices.