PURPOSE To evaluate the use of tear osmolarity in the diagnosis of dry eye disease. DESIGN A prospective, observational case series to determine the clinical usefulness of tear osmolarity and commonly used objective tests to diagnose dry eye disease. METHODS A multicenter, 10-site study consisting of 314 consecutive subjects between 18 and 82 years of age. Bilateral tear osmolarity, tear fi...

PURPOSE To measure dynamic change characteristics of spatial and temporal variations in the post-blink tear film of normal eyes. METHODS A wavefront sensor was used to measure dynamic changes in wavefront aberrations, up to the seventh order, for 10 seconds in a group of 33 normal young adults. Tear menisci were imaged with an anterior segment optical coherence tomography (AS-OCT) system and ...

PURPOSE To report a novel method for pachymetry mapping of human precorneal tear film using Pentacam. METHODS Precorneal tear film is routinely undetected by Pentacam but could be well visualized with the aid of fluorescein. Twenty patients with dry eye and 20 age-matched control subjects with normal eyes were enrolled in this prospective study. The right eye of each subject was scanned once ...

Protease-activated receptor-2 (PAR-2) plays an extensive role in the regulation of digestive exocrine secretion. The present study examined whether PAR-2-related peptides could modulate tear secretion in rats and analyzed the underlying mechanisms. SLIGRL-NH(2), a PAR-2-activating peptide (PAR-2-AP) derived from mouse/rat PAR-2, when administered i.v. in combination with amastatin, an aminopept...

PURPOSE Serotonin, a neurotransmitter known to be involved in nociceptor sensitization, is present in human tears. The purpose of this study was to correlate tear serotonin levels, as a marker of nociceptor sensitization, to facets of dry eye (DE), including symptoms and signs. DESIGN Cross-sectional study. PARTICIPANTS A total of 62 patients with normal eyelid and corneal anatomy were pros...

PURPOSE To evaluate tear film stability in patients with tear dysfunction and an asymptomatic control group by using the novel, noninvasive Tear Stability Analysis System (TSAS). METHODS In this prospective case-control study, 45 patients with dysfunctional tear syndrome (DTS) were stratified into three groups (1, 2, and 3/4) based on clinical severity, with higher scores indicating more seve...

Tear hyperosmolarity is thought to play a key role in the mechanism of dry eye, a common symptomatic condition accompanied by visual disturbance, tear film instability, inflammation and damage to the ocular surface. We have constructed a model for the mass and solute balance of the tears, with parameter estimation based on extensive data from the literature which permits the influence of tear e...

The primary function of the lacrimal system is to produce and drain the tear film from the surface of the eye. The tear film is composed of three integrated layers: the aqueous, mucus, and lipid layers. The aqueous layer is produced by the orbital lacrimal gland and gland of the third eyelid and secreted onto the ocular surface through ductules that traverse the conjunctiva. The mucus layer is ...