PURPOSE To determine the repeatability of real-time optical coherence tomography (OCT) measurements of tear film thickness (TFT) and variables of tear film menisci. METHODS Forty eyes were imaged with a custom-built, real-time OCT to obtain heights, curvatures, and cross-sectional areas of upper and lower tear menisci simultaneously. The central TFT was indirectly determined as the difference...

PURPOSE Kinetic analysis of sequential tear interference images was used to investigate how the precorneal lipid film spread and distributed in aqueous tear deficiency (ATD) dry eye. METHODS One eye of 17 patients with ATD was randomly selected for this noncomparative case series. Twelve patients also had noninflamed meibomian gland dysfunction (MGD). Sequential images were digitized and anal...

Biophysical properties of the tear film lipid layer are studied at the molecular level employing coarse grain molecular dynamics (MD) simulations with a realistic model of the human tear film. In this model, polar lipids are chosen to reflect the current knowledge on the lipidome of the tear film whereas typical Meibomian-origin lipids are included in the thick non-polar lipids subphase. Simula...

The cornea is the anterior most surface of the eye and plays a critical role in vision. A thin fluid layer, the tear film, coats the outer surface of the cornea and serves to protect, nourish, and lubricate the cornea. At the same time, the tear film is responsible for creating a smooth continuous surface, where the majority of refraction takes place in the eye. A significant component of visio...

This thesis deals with an interesting application of mathematics, tear film dynamics. Our goal is to understand and simulate the various observed tear film behaviors, such as film cooling, black line formation and lipid patterns etc. During this process, we build models to describe the fluid dynamics for several blink cycles, experiment on the choices of parameters, compare the simulation with ...

A lateral shearing interferometer designed and built for the study of the precorneal tear film topography dynamics and its effect on visual performance is presented. Simple data processing algorithms are discussed and tested on data illustrating different tear topography features: postblink tear undulation, tear breakup, eyelid-produced bumps and ridges, bubbles, and rough precontact lens tear ...

Purpose. To determine the dynamic pre- and postlens tear film (PLTF and PoLTF) thicknesses by using optical coherence tomography (OCT). Methods. Ultrahigh-resolution OCT was used to image the tear film of 22 subjects before and after contact lens wear. A soft lens with 1 drop of artificial tears on its concave surface was inserted onto one randomly selected eye. OCT images were taken before ins...

PURPOSE To derive the value of corneal epithelial barrier to fluorescein in humans from experiments in which the fluorophore in instilled in a single drop. METHOD A commercial scanning fluorophotometer, the Fluorotron Master, was used to scan through an anterior segment. It could not resolve the tear film from the cornea, but in the early stages of measurement, the tear component predominated...

PURPOSE To investigate meibomian gland and tear film function in patients with type 2 diabetes. METHODS This prospective study compared changes in meibomian gland and tear film function in type 2 diabetic patients with nondiabetic patients. Meibomian gland function was evaluated by measuring lipid layer thickness (LLT), grading of meibomian gland loss, lid margin abnormalities, and expression...

PURPOSE Extended wear of conventional hydrogel soft contact lenses (SCLs) is associated with adverse ocular responses. Some of these ocular events are thought to result from inadequate tear mixing in the postlens tear film (PoLTF). Therefore, strategies to increase tear mixing may improve the safety of extended-wear SCLs. Recently, it has been suggested that placing fenestrations in soft lenses...