Hydrogel lens wettability during overnight wear

Area of Science:

• Ophthalmology
• Biomaterials Science
• Tear Film Dynamics

Background:

• Soft contact lens wear can impact the ocular surface environment.
• Understanding in vivo lens wettability is crucial for patient comfort and vision quality.
• Tear film stability is a key indicator of ocular surface health during lens wear.

Purpose of the Study:

• To evaluate the in vivo wettability of two soft contact lens materials over a 24-hour period.
• To compare tear film stability and structure between open and closed eye wear.
• To determine if lens material affects wettability and tear film characteristics.

Main Methods:

• Monitored in vivo wettability of Igel 67 (Prima) and Bausch & Lomb 70 lenses in 10 subjects over 24 hours.
• Measured pre-lens non-invasive break-up time (NIBUT) to assess tear film stability.
• Assessed pre-lens tear film structure, including lipid layer thickness and mucous coating.

Main Results:

• Both lens materials demonstrated good wettability throughout the study.
• No significant difference in wettability was found between the two lens materials.
• Tear film stability was significantly greater immediately upon waking (mean NIBUT 21.2 s) compared to open eye wear (mean NIBUT 11.2 s).
• A thicker pre-lens lipid layer and greater mucous coating were observed upon waking.

Conclusions:

• Soft contact lens wettability is not significantly different between the tested materials.
• Closed eye wear (during sleep) leads to a more stable pre-lens tear film compared to open eye wear.
• Differences in tear film structure upon waking are associated with enhanced stability, suggesting a protective effect after closed eye wear.