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Introduction The purpose is to analyze the changes produced in subjects with an overdipper pattern of ambulatory blood pressure monitoring with the aim of understanding the pathophysiology of normal tension glaucoma.Methods A cross sectional study was performed in patients exhibiting overdipper and non-overdipper blood pressure patterns, respectively. Different optic parameters were assessed including the analysis of ganglion cell layer (GCL), peripapillary retinal nerve fiber layer (pRNFL) and Bruch's membrane opening-minimum rim width (BMO-MRW), as well as changes produced in choroidal thickness (CT) and lamina cribrosa (LC) position at two different periods of the day (early morning and evening).Results A total of 80 eyes (42 overdipper and 38 non-overdipper) were analyzed. A shortening of the distance at the beginning and end of the LC was objectified in the overdipper subjects (p< 0.003) as well as a statistically significant shift of the LC between morning and evening measurements in the overdipper subjects (p< 0.023). In addition, a significant thickening was found in 13 measurements of the horizontal and vertical plane CT (p< 0.029) of the overdipper subjects and a thickening of the CT in both groups in the morning. No significant differences in pRNFL, BMO-MRW and GCL measures were objectified.Conclusions Morning assessment in overdipper subjects showed a deeper LC and a LC shift in comparison to evening values. In addition, an increase in CT was found in these subjects. Altogether, these findings could illustrate an etiopathogenic mechanism of the damage produced in normal tension glaucoma associated to the overdipper pattern.

A method for the determination of lead in airborne particulates by graphite furnace atomic absorption spectrometry after extraction with HCl-HNO3 (120–150°C) is described. Particulate lead levels in the atmosphere have been measured in samples collected throughout a year, sampling has been made at eleven sites within the city of Valencia. The results obtained in this study show that annual means of lead levels are within the range of 0.526 to 7.033 µg/m3 depending upon the sampling site. Lead levels are higher in winter and autumn. Lead and nitrogen oxide levels are well correlated.