PURPOSE To develop a safe, noninvasive, noncontact, continuous in vivo method to measure the dehydration rate of the precorneal tear film and to compare the effectiveness of a viscoelastic agent in maintaining the precorneal tear film to that of a balanced salt solution. METHODS Software was designed to analyze the corneal reflection produced by the operating microscope's coaxial illumination...

BACKGROUND Diabetic patients often complain of dry eye symptoms, such as burning and/or foreign body sensation. The aim of the present study was to investigate whether diabetes mellitus is correlated with tear film dysfunction and/or tear hyposecretion. METHODS In 86 consecutive insulin dependent diabetics with retinopathy and 84 non-diabetic controls (age and sex matched) we performed fluoro...

PURPOSE To investigate whether the tear film thinning between blinks is caused by evaporation or by tangential flow of the tear film along the surface of the cornea. Tangential flow was studied by measuring the movement of the lipid layer. METHODS Four video recordings of the lipid layer of the tear film were made from 16 normal subjects, with the subjects keeping their eyes open for up to 30...

Extensive studies have explored the dynamics of the ocular surface fluid, though theoretical investigations are typically limited to the use of the lubrication approximation, which is not guaranteed to be uniformly valid a-priori throughout the tear meniscus. However, resolving tear film behaviour within the meniscus and especially its apices is required to characterise the flow dynamics where ...

PURPOSE The purpose of this work was to gather preliminary data in normals and dry eye subjects, using a new, non-invasive imaging platform to measure the thickness of pre-corneal tear film. METHODS Human subjects were screened for dry eye and classified as dry or normal. Tear film thickness over the inferior paracentral cornea was measured using laser illumination and a complementary metal-o...

PURPOSE To synthesize an interference color chart for the specific tear lipid layer interference camera, DR-1, for the conversion of the tear film lipid layer thickness into color graphic information--that is, for the quantification of the tear interference image--by a colorimetric approach. METHODS Because the color of the tear lipid layer interference image is visualized by a white light so...

PURPOSE To examine tear film, contact lens, medical, and patient-related factors associated with self-reported contact lens-related dry eye. METHODS Four hundred fifteen contact lens wearers were recruited and enrolled in this phase of a larger cross-sectional study. A variety of tear film (e.g., interferometry, osmolality, phenol red thread, meibography, fluorescein, and lissamine green stai...

PURPOSE To compare quantitative changes induced in the tear film of patients submitted to photorefractive keratectomy and LASIK over a year. METHODS A prospective, longitudinal, comparative, post-interventional study was designed to distinguish tear film changes before and one year after refractive surgery procedures in 48 patients submitted to PRK and 36 patients submitted to LASIK, using ty...

Menthol is thought to stimulate lacrimation via activation of cold-sensitive primary afferent neurons in the cornea. We evaluated a warm compress containing menthol as a potential treatment for dry eye by examining its effects on the tear film in healthy subjects (n = 20) and dry eye patients (n = 35). Disposable eyelid-warming steamers that either did (MH) or did not (HO) contain menthol were ...