Abstract
Purpose::
To evaluate the water drinking test (WDT) use, and compare the WDT with Intraocular Modified Pressure Curve (IMPC) in glaucomatous and normal patients
Methods::
39 patients (78 eyes) with glaucoma diagnosis (primary open angle or close angle) under antiglaucomatous treatment and 39 healthy individuals (78 eyes) classified according with criteria of the European Society of Glaucoma, underwent IMPC and WDT on different days. IMPC test consisted of IOP measurements each hour between 7am - 12m and WDT was performed at 7 am (under 6h minimum fast), drinking 900 ml of water in five minutes intraocular pressure was measured pre-water load and after load each 10min by 1hour. The IOP measurements were taken with Goldmann aplanation tonometer and were done by a masked independent ophthalmologist. The date correlation (IOP peak level and fluctuations) by each group of patients between test were measured with T student test but if some parameter didn’t has a normal distribution was used Mann-Whitney Rank Sum test, and the IMPC-WDT correlation was assessed by Pearson correlation coefficient.
Results::
IOP peak level, fluctuation and appearance peak time were measured among two groups with IMPC and WDT. No significant statistical differences (P<0.05) were found between IOP peak level and IOP fluctuations between patients groups with IMCP (P= 0.146 and P=0.317 respectively). We found significant statistical differences between IOP peak level and IOP fluctuations by groups with WDT (P= 0.002 and P=0.045 respectively). A small tendency to overvalue the peak levels with the WDT opposite to IMPC test (P= 0.046) was seen. The time average in WDT to IOP peak appearance was 20.0 minutes in healthy and 22.85 minutes in glaucomatous patients. IOP peak levels showed significant statistical differences between eyes -right/left- (P=0.025).Pearson correlation coefficient about IOP fluctuations by IMPC and WDT between eyes didn’t show a biological significant correlation (r>0.6) but, was different with the IOP peak levels (healthy 0R: r=0.61; OI: r=0.71; glaucoma OD: r=0.48, OI: r=0.48).
Conclusions::
The WDT measurements were similar like the IMPC measurements, with a slight tendency to overvalue the IOP peak level: Healthy 2.26 mmHg and glaucoma 3.44 mmHg. WDT allow assess IOP pecks level quickly (average 20minutes). It is exist a biological correlation between IOP peak level between IMPC and WDT we can use either, but it is different to IOP fluctuations.
Keywords: intraocular pressure • outflow: trabecular meshwork • aqueous