Repeatability of Noninvasive Break-Up Time Measurements using Keratograph Oculus 3.

Aim: The primary aim of this study is to evaluate the repeatability of noninvasive break-up time (NIBUT) measurement by keratograph when it is determined from one, two or three partial measurements, and to recommend a suitable methodology for practice. Another goal is to verify that repeated measurements do not affect the measured value.

Material And Methods: Thirty-eight healthy volunteers (30 women and 8 men) aged between 19 and 50 years old were included in the study, in which only one eye of each volunteer was measured.

EFFECT OF ACUTE HYDROGEN-RICH WATER INTAKE ON INTRAOCULAR PRESSURE IN HEALTHY SUBJECTS.

Purposes: The primary aim of the study was to assess the response of intraocular pressure (IOP) to the acute ingestion of hydrogen-rich water (HRW) compared to hydrogen-free water (placebo) in healthy subjects. The effect of HRW intake on central corneal thickness (CCT) was also monitored.

Subjects And Methods: Twenty-four healthy volunteers (5 men, 19 women) aged between 20 and 33 were included in the study, in which one eye of each subject was measured.

Crowding can impact both low and high contrast visual acuity measurements.

The adverse impact of adjacent contours on letter visual acuity is known as crowding but there is conflicting evidence that foveal crowding may be reduced or disappears under low contrast conditions. Potential differences in foveal crowding with contrast on clinical measurements of visual acuity, including test-retest repeatability, were assessed. Visual acuity was measured at the fovea on adult participants with normal vision under three different contrast levels (- 90, - 10 and - 5%).

Number of flankers influences foveal crowding and contour interaction differently.

Nearby flanking objects degrade visual resolution. If the flankers are similar to the acuity target, this influence is called crowding (CW), whereas if the flanking stimuli are simple bars then the phenomenon is known as contour interaction (CI). The aim of this study was to compare the influence of the number and position of flankers on foveal CW and CI to investigate possible differences in mechanism of these two effects.

Technical Report: The Mechanism of Contour Interaction Differs in the Fovea and Periphery.

Significance: Both foveal and peripheral contour interactions are based on, as yet, unexplained neural mechanisms. Our results show that, unlike foveal contour interaction, peripheral contour interaction cannot be explained on the basis of the antagonistic structure of neural receptive fields.

Purpose: Foveal contour interaction is markedly reduced for mesopic compared with photopic targets.