Association between nocturnal blood pressure reduction and progression of visual field defect in patients with primary open-angle glaucoma or normal-tension glaucoma.

PURPOSE: To assess prospectively the relationship between nocturnal blood pressure reduction (dip) and progression of the visual field defect in patients with normal-tension glaucoma (NTG) or primary open-angle glaucoma (POAG). PATIENTS AND METHODS: The subjects studied were 38 patients with glaucoma (23 patients with NTG, 15 patients with POAG), in whom 48-h ambulatory blood pressure monitoring was conducted, who were followed for at least 4 years, and in whom reliable visual field tests were performed at least 5 times. The progression was determined by the mean deviation (MD) slope analysis system installed in the Humphrey field analyzer Statpac program. Glaucoma patients with a dip of <10% were assigned to the nondipper group, those with a dip of 10%-20% to the tipper group, and those with a dip of >20% to the extreme dipper group. The dipper group was defined as physiologic dippers, while the nondipper and the extreme dipper groups were defined as nonphysiologic dippers, to study the relationship between the disturbance of the dip and progression of the visual field defect. RESULTS: Thirteen patients showed significant progression, while 25 patients did not. There were no significant differences in the mean intraocular pressure and follow-up period between the patients with progression and those without progression. Half (7/14) of the nondippers, 20% (4/20) of the dippers, and 50% (2/4) of the extreme dippers showed progression, indicating a tendency of progression in the nondipper and the extreme dipper groups. The nonphysiologic dippers had a higher incidence of progression compared with the physiologic dippers (P = 0.05). Among the glaucoma patients in the nondipper and dipper categories only, those with progression had significantly smaller dips (P = 0.02). CONCLUSION: These results suggest that disturbance in the physiologic dip may be involved in the progression of glaucoma.

Development of a genotoxicity detection system using a biosensor.

The umu-lux test is a genotoxicity test using the two genetically modified S. typhmurium TA1535 strains (TL210 and TL210ctl) transformed with the luxCDABE (luciferase gene and fatty acid reductase genes) of Vibrio fischeri as a reporter gene. The TL210 strain detects genotoxicants and the TL210ctl strain detects cytotoxicants. In order to develop a highly sensitive, simple and rapid genotoxicity detection system, we constructed a biosensor using these immobilized strains. The biosensor consists of two immobilized microbial membranes, a sample vessel and photodetectors, and the genotoxicity detection system consists of the biosensor, an isothermal box, a photodetector and an air pump. The total measurement time for genotoxicants using this detection system is about 4 h. When 2% (v/v) DMSO was used as a control, the TL210 strain was not emitting light while the TL210ctl strain was. When 0.3 mg/l 4NQO was used as a genotoxicant, TL210 strain and TL210ctl strain were both emitting light. When HgCl2 was used as a cytotoxicant, neither the TL210 strain nor the TL210ctl strain were emitting light. Therefore, the false negative prevention function of a biosensor using the TL210ctl strain has been checked. These results show that our proposed system can correctly detect genotoxicants.