Color comparison measuring marker for more accurate measurement of tear film breakup time and tear volume based on the tear meniscus
By employing a color comparison measurement mark to maintain consistent tear film concentration, the variability in tear volume measurements is reduced, enhancing the accuracy of ophthalmic assessments.
Patent Information
- Application Number
- DE202024000843
- Authority / Receiving Office
- DE · DE
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2024-09-16
- Publication Date
- 2025-04-30
- Estimated Expiration
- 2034-09-30
AI Technical Summary
The measurement of tear volume using fluorescein dye under slit lamp microscopy is prone to variations due to differences in the cornea, conjunctiva, eyelid, and conjunctival sac, resulting in tear film concentration fluctuations of up to 50%.
Achieving consistent tear film concentration by using a color comparison measurement mark, which allows for more accurate assessments of tear volume, and ensuring the same concentration for simultaneous investigations of tear meniscus and tear volume.
This approach enables more reliable and consistent measurements of tear volume and meniscus, reducing variability and improving diagnostic accuracy in ophthalmic examinations.
Abstract
Description
[0001] In ophthalmological and optical practice, the above-mentioned measurements are performed using the dye liquid fluorescein under slit-lamp microscope observation, usually under ultraviolet radiation (wavelength approximately 496 nm). A drop or strip of fluorescein impregnated with approximately 1.0 µl is applied to the cornea and into the conjunctival sac. The applied amount of fluorescein is not always the same, and the key parameters of the eye—cornea, conjunctiva, eyelids, and conjunctival sac—variete greatly.
[0002] Thus, the concentration within the tear film is subject to fluctuations of up to 50%. By taking the colorimetric effect into account, a color reference marker can be used to obtain a more accurate measurement while maintaining a consistent concentration. The tear volume can be better estimated by the tear meniscus running along the lower eyelid. The same concentration is also advantageous for both tests; both tests can be performed simultaneously.
Claims
[1] The color reference mark can be integrated as a light-emitting diode (LED) into the beam path of the slit lamp microscope (intermediate image plane, focal plane on both sides of the objective lens, or object-side focal plane of the eyepiece). It can also appear on the display of a connected computer. [2] Time measurement. This can be done both on the computer display and in the slit lamp with a second display. [3] The use of short-wave LEDs as energy-saving lamps for better measurement of tear volume and tear film drainage into the nasolacrimal duct. This makes fluorescein particularly visible.