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...

This study was performed to investigate the changes of tear film and ocular surface in diabetic patients, as well as the ocular and systemic factors related to these changes. We assessed the scoring of keratoepitheliopathy, corneal sensitivity test, tear film break-up time (BUT), Schirmer test, and conjunctival impression cytology in 94 eyes of 47 patients with noninsulin-dependent diabetes mel...

This study was designed to explore the influence of long-term corneal contact lens (CL) wearing on the stability and quality of tear film in Qinghai. Thirty subjects with CL over five years and thirty myopia subjects without CL as control were recruited in our study. Basic tear secretion test, tear film break-up time (TBUT), and corneal fluorescein staining were determined. For further evaluati...

We study the drainage of the precorneal tear film in humans. A fluid dynamic model for the drainage of the aqueous layer is developed that includes the effects of evaporation and gravity. The model may be reduced to a single nonlinear partial differential equation for the thickness of the aqueous layer. The equation is solved numerically and accurate times for film rupture are obtained for phys...

In Parkinson's disease (PD) patients, a wide range of ocular and visual disorders are present. Tear film instability, inflammation dysfunction the surface, presence symptoms disturbance characterize dry eye, multifactorial surface. Based on literature search, we discuss frequency, pathogenesis, influence quality life patients with eye in disease. Furthermore, review available means diagnosis ma...

RATIONALE Dry eye is the most prevalent condition seen by the ophthalmologist, in particular in elderly. The identification of new common risk factors (computer use and contact lens wear) extends the disease among the young people. The early diagnosis of dry eye is essential, but difficult, because the biochemical changes in tear film usually occur before any detectable signs. Due its advantage...

Schirmer's test and tear film break-up time (BUT) were studied in 56 eyes of patients with pterygium and compared with 50 eyes of normal healthy subjects representing the same age, sex and geographical distribution. Both the values were found to be significantly reduced in cases of pterygium indicating the inadequacy of tear film in these patients.