Nomdo M. Jansonius

Purpose OCT can be used for glaucoma assessment, but its usefulness may depend on image quality, disease stage and segmentation algorithm. We aimed to determine how layer thicknesses as assessed with different algorithms depend on image quality and disease stage, how reproducible the algorithms are, and if the algorithms (dis)agree. Methods Optic disc OCT data (Canon OCT‐HS100) from 20 healthy subjects and 28 early, 29 moderate, and 23 severe glaucoma patients were assessed with four different algorithms (CANON, IOWA, FWHM, DOCTRAP). We measured retinal nerve fibre layer thickness (RNFLT) and total retinal thickness (TRT) along the 1.7‐mm‐radius OCT measurement circle centred at the optic disc. In healthy subjects, image quality was degraded with neutral density filters (0.3–0.9 optical density [OD]); three scans were made to assess repeatability. Results were analysed with ANOVA with Bonferroni corrected t‐tests for post hoc analysis and with intraclass correlation coefficient (ICC) analysis. Results For all algorithms, RNFLT was more sensitive to image quality than TRT. Both RNFLT and TRT showed differences between healthy and glaucoma (all algorithms p < 0.001 for both RNFLT and TRT) and between early and moderate glaucoma (RNFLT: p = 0.001 to p = 0.09; TRT: p < 0.001 to p = 0.03); neither was able to discriminate between moderate and severe glaucoma ( p = 0.08 to p = 1.0). Generally, repeatability was excellent (ICC >0.75); agreement between algorithms varied from moderate to excellent. Conclusions OCT becomes less informative with glaucoma progression, irrespective of the algorithm. For good‐quality scans, RNFLT and TRT perform similarly; TRT may be advantageous with poor image quality.

Purpose The purpose of this study is to test the hypothesis that greater habitual water intake is associated with lower risk of dry eye disease (DED). Methods We included 51 551 participants from the population‐based Lifelines cohort (mean age = 51.2 years) in this cross‐sectional association study. DED was assessed using the Women's Health Study (WHS) dry eye questionnaire. Water intake was calculated from food frequency questionnaires. Logistic regressions were used to analyse the relationship between DED and water intake or 24‐h urine volume, corrected for age, sex, body mass index, physical activity, smoking status, education, income, 48 comorbidities, and 15 medication groups. The main outcome measure was WHS‐defined DED. Highly symptomatic dry eye and clinical diagnosis of DED were secondary outcomes. Results In total, 9.1% of the population had WHS‐defined DED. Higher water intake was associated with increased prevalence of WHS‐defined DED (OR: 1.011 per 100 ml/day, 95% CI: 1.004–1.017, p = 0.003). After excluding those with a clinical diagnosis, greater water intake was still tied to increased risk of having DED symptoms (OR: 1.010 per 100 ml/day, 95% CI: 1.006–1.015, p < 0.001). Higher 24‐h urine volumes were also associated with higher risk of WHS‐defined DED (OR: 1.010 per 100 ml/day, 95% CI: 1.005–1.015, p < 0.001). Conclusions In this large, population‐based study, higher water intake was not tied to reduced risk of DED. Rather, it was associated with a modest increased risk of DED. Interventional studies are needed to fully understand the effect of water intake on DED, but this study found no evidence that greater water intake is beneficial for DED.