Eyelid pressure and contact with the ocular surface

Area of Science:

• Ophthalmology
• Biomechanics
• Ocular Surface Disease

Background:

• Understanding eyelid pressure and ocular surface contact is crucial for diagnosing and managing dry eye disease and other ocular surface conditions.
• Previous studies have not precisely quantified the contact area and pressure exerted by the upper eyelid on the cornea.

Purpose of the Study:

• To investigate static upper eyelid pressure and its contact region with the ocular surface in young adult subjects.
• To establish a more accurate estimation of eyelid pressure based on direct measurements.

Main Methods:

• Utilized a piezoresistive pressure sensor integrated with a rigid contact lens to measure static upper eyelid pressure.
• Employed pressure-sensitive paper and lissamine-green staining of Marx's line to determine the contact width between the upper eyelid and the ocular surface.
• Derived eyelid pressure estimates by combining sensor readings with contact width measurements.

Main Results:

• The mean contact width between the eyelid margin and ocular surface, measured by pressure-sensitive paper, was 0.60 ± 0.16 mm, significantly larger than Marx's line (0.09 ± 0.02 mm).
• Calculated mean central upper eyelid pressure was 8.0 ± 3.4 mm Hg when derived using pressure-sensitive paper imprint widths.
• This pressure value is considered the most reliable estimate of static upper eyelid pressure.

Conclusions:

• The study suggests that a broader band of the eyelid margin, beyond Marx's line, is in primary contact with the ocular surface.
• The findings provide a more accurate understanding of the biomechanics of eyelid-ocular surface interaction.
• The estimated mean static upper eyelid pressure of 8.0 mmHg offers valuable data for clinical applications and further research in ophthalmology.