Aimns-The purpose of this study was to assess whether the preservative benzalkonium chloride (BAC 0.01%) present in timolol induced a decrease in basal tear turnover and a deterioration ofprecorneal tear film in patients with glaucoma and ocular hypertension using topical timolol. Methods In a previous study7 we demonstrated a 36% lower mean basal tear turnover in patients with glaucoma using timolol+BAC in comparison with that of healthy controls. The preservative BAC is suggested as a possible cause for this decrease in tear turnover. The present follow up study was initiated to verify this assumption.In this study the tear turnover and break up time (BUT) of the precorneal tear film of patients with open angle glaucoma and ocular hypertension were evaluated when using timolol+BAC and subsequently when using timolol-BAC. In this way we expected to find out if BAC could be held responsible for a decrease in tear production and for a deterioration of tear film stability in patients with glaucoma who use timolol+ BAC. The study was set up in such a way that the same patient was measured when using timolol+BAC as well as when using timolol-BAC in order to avoid the effect of interindividual spread in tear turnover values. Note that the fluorophotometric measurement of tear turnover with a computer fluorophotometer is a quantitative method for the determination of tear production7 and is, because of its objectivity and reproducibility, suitable for unbiased outcomes of the measurements. The precorneal tear film integrity determined by the tear film BUT and the subjective acceptability of timolol+BAC and timolol-BAC were also assessed. Material and methods PATIENTS

Purpose We aimed to develop and evaluate the Computerized Glaucoma Visual Function Test (CoGVFT), among a cohort of glaucoma patients, and identify potential new items to optimize the test. Method A cross-sectional study involving 84 patients with open-angle glaucoma of varying severity and 18 controls without glaucoma were recruited. Better and worse eye visual field parameters, visual acuity, contrast sensitivity, 6-Part Cognitive Impairment Test (6CIT) and Glaucoma Activity Limitation-9 (GAL-9) questionnaire responses were recorded. The CoGVFT was administered to all participants. Rasch analysis was used to assess the psychometric properties of the CoGVFT, which was then evaluated with criterion, convergent, and divergent validity tests. Regression modeling determined factors predictive of CoGVFT performance. Results The 38-item CoGVFT demonstrated convergent validity with statistically significant differences in glaucoma severity groups ( P < 0.001, analysis of variance). The correlation coefficient for CoGVFT person measures (logits) with GAL-9 person measures (logits) and better eye (BE) mean deviation was 0.528 ( P < 0.001) and 0.762 ( P < 0.001), respectively, demonstrating convergent validity. Divergent validity was suboptimal as the 6CIT score demonstrated moderate correlation ( r = 0.463, P < 0.001) with CoGVFT person measures (logits). Multivariable analysis revealed that better BE contrast sensitivity, lower age, and better BE visual acuity were associated with better CoGVFT performance ( P < 0.001). Conclusions The CoGVFT retains most of the features of its predecessor to estimate vision-based activity limitation related to glaucoma. Translational Relevance The CoGVFT is an easily accessible tool that can potentially be used in the community to help detect undiagnosed glaucoma in the population.