Tear Break-up Time
Tear Break-up Time - Related Videos
01:29
The “Break-Even” Point
0 Views •
2025
The macroeconomic consumption function illustrates the relationship between aggregate consumption (C) and national income (Y). It is typically expressed as:C = a + bYwhere a denotes autonomous consumption—expenditures that occur regardless of income—and b, the marginal propensity to consume (MPC), indicates the fraction of additional income that is spent.The break-even point occurs where:C = YSolving for income yields the break-even level of national income:At this level, the entire output...
02:04
Fixing Double-strand Breaks
0 Views •
2020
The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
01:22
Break-Even Analysis
0 Views •
2026
Break-even analysis is a managerial accounting technique used to determine the level of sales at which total revenue equals total costs. At the break-even point, a business neither earns a profit nor incurs a loss because all fixed and variable costs are fully recovered. This analysis is widely used in planning, budgeting, pricing, and evaluating the financial feasibility of new products, projects, or business operations.The break-even point depends on three key factors: selling price per unit,...
04:38
A Novel Technique of Rescuing Capsulorhexis Radial Tear-out using a Cystotome
0 Views •
Cited by 4 •
2011
Capsulorhexis is an important step in phacoemulsification surgery. A surgeon creates a continous curvilinear tear on the anterior lens capsule by controlling the tearing vector forces. A peripherally extended tear is a serious complication. This video demonstrates a novel technique of rescuing capsular radial tear out using a cystotome.
07:45
Tear-Derived Exosomal miR-15a as New Diagnostic Tool for Diabetic Retinopathy
0 Views •
Cited by 1 •
2025
This article describes a protocol for the collection and detection of miR-15a from tears as a new diagnostic tool for diabetic retinopathy.
FAQs
The first dry spot represents the earliest visible loss of a continuous tear-film surface after blinking. Because the tear film normally helps maintain a smooth, protective ocular surface, this endpoint provides a practical indicator of how long that surface remains intact. An earlier dry spot therefore signals greater tear-film instability.
A complete blink establishes the starting point for the interval being measured. The clinician then observes the ocular surface until the first dry spot appears, creating a defined relationship between surface renewal and visible tear-film disruption. This timing approach allows the test to assess stability during the period between blinks.
A shorter interval indicates that the tear film becomes visibly unstable sooner. This finding can support evaluation of dry eye disease and other ocular-surface disorders, particularly when clinicians relate the measurement to a patient’s symptoms. The result provides information about tear-film dysfunction rather than simply describing the presence of ocular discomfort.
Tear Break-up Time helps clinicians relate reported symptoms to an observable feature of ocular-surface function. When symptoms occur alongside reduced tear-film stability, the measurement can support an assessment of tear-film dysfunction. This connection is useful because it links the patient’s experience with a measurable change seen during clinical examination.
The examination begins with placement of fluorescein dye on the ocular surface. Using a slit lamp, the clinician observes the eye after a complete blink and measures the interval until the first dry spot appears. The recorded time supplies the clinical measure used to judge tear-film stability.
The procedure requires fluorescein dye to make changes on the ocular surface visible and a slit lamp for observation. The clinician also needs a way to measure the interval between the complete blink and the first dry spot. Together, these components support a rapid assessment of tear-film behavior in the eye.
Clinicians use the measurement when evaluating dry eye disease and other ocular-surface disorders. It is especially useful when the goal is to connect symptoms with tear-film dysfunction or to examine whether tear-film stability changes during treatment. Its rapid and minimally invasive nature supports use in routine ophthalmic practice.
In ophthalmic research and clinical care, the measurement provides a way to assess tear-film stability at a given examination and to evaluate changes during treatment. Comparing the observed interval across assessments can help show whether tear-film behavior has changed, while still keeping the focus on ocular-surface function and patient symptoms.