Vergleichende Untersuchungen zur circadianen Rhythmik des intraokularen Druckes (IOD) im Tagestensioprofil (TTP) und den Veränderungen der Druckwerte im Provokationstest "Wasserbelastungstest" (WBT) bei Patienten mit verschiedenen GLaukomformen

An important method in the glaucoma diagnosis is the determination of the intraocular pressure (IOD). This pressure underlies a circadian rhythm which is defective with many glaucoma patients. It is assumed that the maximum IOD and the increase in pressure are important factors for the further proceeding of the sickness. A competent diagnosis and therapy therefore requires in certain cases the preparation of a diurnal tension curve (DTC) over a period of 24 hours. In order to also gather the pressure values during the night, the DTC is performed under stationary conditions which make this examination method very time and cost consuming. Because of this we have analyzed the applicability and prognostic importance of the water drinking test (WDT) as an alternative model. In this testing method a rising pressure increase with glaucoma patients is achieved by having them drink a certain amount of water. We have formulated the hypothesis that the water drinking test can bring the same maximum daily pressure values and pressure variations like the DTC. In order to test the hypothesis we have analyzed retrospective 84 eyes of 44 patients who have been examined during the glaucoma consultation hours at the ophthalmic clinic in Marburg. The analyzed data allows the following conclusions: The maximum pressure values of the water drinking test are in our analysis on average higher than the values of the DTC; however, they show a positive correlation to one another. On average, the WDT is 2 mmHg higher which can - from a clinical perspective - be caused already by different examiners. A further reason for the difference of the measured values in the two methods can lay in the hospitalization of the patients in the DTC method. Due to the stationary stay, lower maximum values are seen as compared to the values which are present in daily routine activities. Further factors could be missed measurements during night times and too long measure intervals during the day. Whether the above factors are the main reason for the deviation or whether there are any other factors which explain the lower pressure values in DTC needs to be examined in further studies. The same applies for the pressure increase. Here, no correlation between the values of the two testing methods was identified which can, among other reasons, be due to our small patient sample size. Our study further showed that especially the WDT can be used effectively for the testing of normal pressure glaucoma patients. These patients often show normal pressure values during the glaucoma consultation hours despite proceeding visual field progressions. The quick procedure of a WDT can bring clearness because with the WBT method higher pressure values can be determined that with DTC. An explanation could be that the NTG is part of a generalized endothelium disfunction. It was already discussed in an earlier study that the increased inner eye pressure after the procedure of a WDT is the cause of an endothelium disfunction. Further studies regarding this topic should be done because this glaucoma version is increasing due to the rising age cascade. Due to the significant increase of health care costs the WBT should again be used in the glaucoma diagnosis as a cost effective testing method with high explanatory power. DTCs should therefore only be used for complex individual cases and at the same time a combined using of TTP and WBT is advisable.