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Chronologic Analysis of Tear Dynamics on Blinking Using Quantitative Manometry in Healthy Humans
Yohei Sato1, Masashi Mimura, Yasushi Fujita
1Department of Ophthalmology, Osaka Medical College, Takatsuki-City, Osaka, Japan.
Ophthalmic Plastic and Reconstructive Surgery
|March 12, 2021
Summary
The lacrimal pump uses pressure spikes during blinking to move tears. Higher pressure in the canaliculus suggests tears don't flow into the lacrimal duct during eyelid closure.
Area of Science:
- Ophthalmology
- Biomedical Engineering
- Fluid Dynamics
Background:
- Understanding tear dynamics is crucial for diagnosing and treating dry eye and other ocular surface diseases.
- The lacrimal drainage system's function during blinking is complex and not fully understood.
Purpose of the Study:
- To analyze tear dynamics during blinking by measuring the inner pressure of the upper lacrimal drainage system.
Main Methods:
- Direct manometry using a fiber optic pressure sensor in healthy volunteers.
- Pressure measurements in the conjunctival sac, canaliculi, and lacrimal sac during involuntary and intentional tight blinking.
- High-frequency pressure data (200 Hz) analyzed for pressure spikes and correlations.
Main Results:
- Positive and negative pressure spikes were observed during eyelid closing and opening movements.
- Maximum pressures (tPmax) in the canaliculus were significantly higher than in the conjunctival sac during blinking.
- Pressure changes in the lacrimal duct correlated with the conjunctival sac, indicating system synchronism.
Conclusions:
- The upper lacrimal drainage system acts as a unified lumen within the lacrimal pump.
- Pressure spikes are essential for efficient tear ejection and aspiration by the lacrimal pump.
