Abstract:  Objective To observe the changes of the intraocular pressure (IOP) and anterior chamber morphology after water drinking test (WDT) in healthy volunteers. Design Prospective case series. Participants 23 healthy volunteers (23 eyes) aged 20-31 years-old. Methods All subjects underwent IOP(with Goldmann applanation tonometry) and anterior chamber morphology(with Pentacam three-dimensional anterior segment analyzer) measurement before and 15, 30, 45, 60 minutes after water drinking test(WDT)(drinking 1000 ml water within 5 minutes). Main Outcome Measures IOP, anterior chamber volume (AV), anterior chamber angle (ACA), central anterior chamber depth (CACD). Results The IOP before and at 15, 30, 45, 60 min after WDT was 12.3±1.5, 15.8±1.3, 17.6±1.5, 14.7±1.4, 13.3±1.6 mmHg, respectively (P=0.000). The peak IOP was at 30 min after WDT (P=0.000). The AV before and at 15, 30, 45, 60 min after WDT was 198.6±30.6, 190.6±28.2, 189.1±26.6, 195.0±27.9, 197.4 ±29.6 μl, respectively (P=0.000)). The minimum of AV was at 30 min after WDT (P=0.000). The ACA before and at 15, 30, 45, 60 min after WDT was 37.8±3.7°, 36.7±3.3°, 37.1±3.7°, 37.5±3.8°, respectively (P=0.000). The minimum of ACA was at 30 min after WDT (P=0.000). The CACD before and at 15, 30,45, 60 min after WDT was 2.66±0.37, 2.67±0.36, 2.64±0.33, 2.68±0.33, 2.706±0.39 mm, respectively (P=0.370). There was a significant correlation between the changes of IOP and AV(P=0.041). Conclusion The water drinking test can significantly decrease the anterior chamber volume and anterior chamber angle. The expansion of choroid caused by blood low permeability may play an important role in this process. (Ophthalmol CHN, 2013, 22: 30-33)

Key words:  water drinking test, anterior chamber morphology, Pentacam three-dimensional anterior segment analyzer