Short-Time Changes of Intraocular Pressure and Biomechanics of the Anterior Segment of the Eye during Water Drinking Test in Patients with XEN GelStent

Purpose: Little is known about short-term changes in intraocular pressure (IOP) following minimally invasive glaucoma surgeries, such as post-XEN GelStent implantation. Although the importance of corneal biomechanics in glaucoma diagnostics has been reported, little work has been conducted on postoperative description of changes when the structure of the anterior segment is altered. The aim of presented study was to evaluate the changes in the biomechanical parameters of the anterior segment of the post-XEN GelStent implantation eyes. Patients and Methods: This investigator-initiated, open-label, prospective, single-center study recruited patients. Patients with primary open-angle glaucoma (POAG) after XEN GelStent implantation versus matched POAG controls (considered as control group/CG) treated pharmacologically were screened. Water loading was conducted using 10 mL of water per kilogram of body weight for ≤5 min. Goldmann applanation tonometry (GAT), corneal hysteresis (CH), and corneal resistance factor (CRF) were performed before water loading and after every 15 min up to 1 h. Results: The water drinking test (WDT) was positive in 3.7% (1 out of 27) of patients in the post-XEN group compared with 22.7% (5 out of 22) of patients in the control group (CG; p < 0.05). Mean fluctuations in GAT during the WDT were higher in the CG group (3.6 ± 2.5 mmHg vs. 2.9 ± 1.3 mmHg, p < 0.001). CRF and CH changed significantly only in the post-XEN group. The mean peak of CH and CRF occurred at 15 and 30 min of the test in the post-XEN group (p = 0.001). Conclusion: WDT is important to assess the ability of compensation mechanisms to reduce fluctuations in IOP after water upload. The relationship between biomechanics of the anterior segment and glaucoma may have substantial impact on surgical outcome evaluation.

Organophosphate Esters in Children and Adolescents in Liuzhou City, China: Concentrations, Exposure Assessment and Predictors

Dermal contact with dust is commonly considered an important pathway of exposure to organophosphate esters (OPEs), but the importance of OPE uptake from diet is unclear. Herein, we used hand wipes to estimate OPE exposure from indoor dust and examined whether urinary OPE metabolite concentrations were influenced by sociodemographic characteristics, OPE amount in hand wipes, and dietary factors. OPEs were measured in urine and hand wipes from 6–18-year old children and adolescents (n=929) in Liuzhou, China. Sociodemographic and dietary factors were obtained from questionnaire. Six OPE metabolites were detected in >70% of the urine samples, and seven OPEs were detected in >50% of the hand wipes. Estimated daily intakes (EDIs) were calculated using urinary OPE metabolites to investigate the total daily intake of OPEs, in which 0.36–10.1% of the total intake was attributed to the exposure from dermal absorption. In multivariate linear regression models, sex, age, and maternal education were significant predictors of urinary OPE metabolite concentrations. Urinary diphenyl phosphate (DPHP) is positively associated with its parent compounds 2-ethylhexyl-diphenyl phosphate (EHDPP) and triphenyl phosphate (TPHP) in hand wipes. High versus low vegetable intake was associated with a 23.7% higher DPHP (95% confidence interval (CI): 0.51%, 52.1%). Barreled water drinking was associated with a 30.4% (95% CI: 11.8%, 52.0%) increase in bis(1-chloro-2-propyl) 1-hydroxy-2-propyl phosphate (BCIPHIPP) compared to tap water drinking. Our results suggested the widespread exposure to OPEs in children and adolescents. In additional to dermal absorption, dietary intake may be an important exposure source of certain OPEs.

Water-drinking Test in Normal Tension Glaucoma Patients with and without High Myopia

This prospective study aims to evaluate the correlation between myopic severity and normal tension glaucoma (NTG) by investigating IOP changes following water-drinking test (WDT). We reviewed 61 patients with NTG during an interval of three years, of which 31 were highly myopic (HM) and 30 were non-highly myopic (NHM). Basic characteristics such as age, gender, spherical equivalence, baseline IOP, visual field parameters, and average retinal nerve fiber layer thickness were compared between NTG patients with and without high myopia. The IOP parameters obtained following WDT were then compared between the HM and NHM NTG groups. Intragroup analysis revealed significant IOP elevation following WDT within the 45-minute duration in both groups. However, no significant differences in IOP parameters were observed between the HM and NHM NTG groups. In conclusion, although the pattern of IOP fluctuations was different, the extent of IOP fluctuations and peak IOP following WDT was similar between the HM and NHM NTG groups, suggesting that myopic severity probably has a limited role in NTG. Lastly, WDT was an effective tool for eliciting IOP peaks when 24-hour IOP monitoring is not available.

Comparison of intraocular pressure peak and fluctuations among Filipino patients with non-glaucomatous eyes and glaucoma suspects using water drinking test and diurnal intraocular pressure

AIM: To compare the intraocular pressure (IOP) peaks and fluctuations using water drinking tests (WDTs) and mean diurnal IOP among Filipino patients with normal eyes and glaucoma suspects METHODS: This prospective study included normal and glaucoma suspect patients. Each patient underwent both WDT and mean diurnal examination on separate visits. For mean diurnal examination, IOP was recorded every 2h for 8h while in WDT, IOP was recorded prior to WDT, and post-WDT at 5, 15, 30, 45, and 60min. IOP peak was recorded as the highest IOP for both methods, and IOP fluctuation was recorded as highest IOP minus lowest IOP. RESULTS: With the comparison of diagnostic tests, both normal eyes and glaucoma suspect groups, the peak IOP was caught at 15min. Comparative analysis of both groups also showed that the peak IOP measurements were statistically higher for the WDT compared to mean diurnal IOP (P=0.039, P=0.048 under normal group and P=0.032 and P=0.031 under glaucoma suspect group). Similarly, the WDT had a statistically higher mean IOP fluctuation score than the mean diurnal IOP method in both groups (P=0.003, P=0.011 under normal group; P=0.002 and P=0.005 under glaucoma suspect group). CONCLUSION: This study shows that WDT is a comparable diagnostic exam in predicting IOP fluctuations than mean diurnal measurement. WDT is a promising diagnostic procedure for risk assessment in glaucoma.

Evaluation of daily changes of Intraocular pressure in glaucomatous patients with modified diurnal tension curve versus water drinking test

Background Glaucoma is a chronic optic neuropathy characterized by the excavation of the optic disc due to atrophy of the retinal ganglion cells. A progression of such atrophy leads to reduction of the visual field and eventually to the loss of sight at the end-stage of the disease, Glaucoma is the second leading cause of blindness worldwide Objectives To study the correlation between intraocular pressure (IOP) fluctuation during water drinking test (WDT) and the IOP fluctuation of modified diurnal tension curve (mDTC) in glaucomatous eyes Patients and Methods Fifty participants (24 males and 26 females) were recruited in this prospective study; forty participants with known Primary Open Angle Glaucoma and the other ten participants with non- glaucomatous healthy eyes which served as control. Patients attending the outpatient clinic at Al-Demerdash Hospital and Cairo Fatemic Hospital from October 2018 to March 2019 were prospectively recruited. Four IOP measurements were taken at 8:00 am, 12:00 pm, 4:00 pm and 8:00 pm which represented the mDTC, while WDT was represented by a single measurement of IOP before ingestion of one liter of water over five minutes, followed by three IOP measurements after ingestion of this amount of water at thirty minute intervals. Results Distribution of the studied participants as regards Age and sex: 50 participants were included in the this study. 40 presented the case group (20 males and 20 females) and the mean age of the case group was 54.7 years, 10 presented the control group(4 males and 6 females) and the mean age of the control group was 51.2years. 59% of participants had a peak IOP at 8:00 am, while 10% had a peak IOP at 12:00 pm, 6% at 4:00 pm and 25% of the participants had IOP peak at 8:00 pm during the mDTC. In the WDT, 96% of the participants had a peak IOP after 30 minutes of ingesting one liter of water, while 4% had a peak IOP after 60 minutes. None of the participants had IOP peak after 90 minutes of ingesting one liter of water.. The IOP fluctuations detected during the WDT were significantly correlated to fluctuations observed during the mDTC. Conclusion The data of this study suggested that WDT can be used as a useful provocative test for the detection of the diurnal IOP peaks and fluctuation observed in the glaucoma patients.

Monitoring the human right to water in California: development and implementation of a framework and data tool

Ensuring the human right to water requires monitoring at national or subnational levels, but few comprehensive frameworks exist for industrialized contexts. This paper introduces a subnational-level framework – known as the California Human Right to Water Framework and Data Tool (CalHRTW) – developed by the authors at the California EPA's Office of Environmental Health Hazard Assessment. This paper has two objectives: (1) to present the theoretical foundations and methodology used to develop the first version of CalHRTW (CalHRTW 1.0) and (2) to showcase how results can be used. CalHRTW 1.0 measures three components of the human right to water: drinking water quality, accessibility and affordability for community water systems in California. Nine individual indicators grouped by component, and three indices that summarize component-level outcomes are used to quantify system-level results. CalHRTW allows users to: (1) summarize system-level conditions statewide and identify challenges, (2) explore social equity implications and (3) centralize information for planning. CalHRTW draws on approaches from existing international monitoring efforts and complements existing California efforts by being the first US effort to comprehensively and explicitly monitor the HRTW under one umbrella. This work offers other US states and countries a model to build monitoring efforts to realize the human right to water.

Use of reclaimed water for unreinforced concrete block production for the self-construction of houses

Experiments were conducted to evaluate the possibilities of using treated wastewater for the production of unreinforced concrete blocks. Compressive strength, water absorption and morphology tests of concrete blocks, produced from different makeups of mixing water, drinking water, drinking water spiked with ammonium and phosphate, and the effluent of the city's wastewater treatment plant, were evaluated. Results showed that the compressive strength of blocks manufactured using treated wastewater was as high as of the blocks produced using drinking water. Ammonium, phosphate and chlorine were found not to have a negative effect on the strength of the blocks. Water absorption tests confirmed the results of the compressive strength, as lower humidity was found in cases of higher strength. In the process of cement hydration, crystals of calcium silicate and calcium hydroxide were observed by morphology tests. From the variability in the results, it could be concluded that the quality of the mixing water was not the only factor that influenced the strength of the unreinforced concrete blocks. The observed differences in strength could, e.g. also be attributed to the manufacturing process.