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The lacrimal drainage system: pressure changes in the canaliculus
American Journal of Optometry and Physiological Optics
|February 1, 1976
Summary
Tear drainage from the eye requires pressure changes in the nasal ducts. Various actions, including blinking and eye movements, were found to create these necessary pressure gradients in the lacrimal canaliculus.
Area of Science:
- Ophthalmology
- Fluid dynamics
- Anatomy
Background:
- Tear removal from the eye necessitates pressure gradients within the nasolacrimal ducts.
- Blinking is a known mechanism for tear drainage, but its contribution relative to other factors is not fully understood.
Purpose of the Study:
- To investigate the pressure dynamics within the lacrimal canaliculus during various ocular and facial actions.
- To determine if non-blinking related actions can also influence tear drainage pressure gradients.
Main Methods:
- Direct pressure measurements were taken within the lacrimal canaliculus.
- Recorded pressure changes during voluntary blinks, forceful eyelid closure (squeezing), and eye movements.
- Simultaneously monitored pressure variations within the nasal cavity.
Main Results:
- Voluntary blinks induced significant pressure changes in the lacrimal canaliculus.
- Forceful lid squeezing also generated measurable pressure fluctuations.
- Eye movements and nasal pressure alterations were correlated with pressure changes in the canaliculus.
Conclusions:
- Multiple mechanisms beyond blinking contribute to pressure changes essential for tear drainage.
- Eyelid and eye movements play a role in modulating lacrimal canaliculus pressure.
- Understanding these pressure dynamics is crucial for diagnosing and treating conditions affecting tear outflow.