Summary of The Surface Properties of #ContactLenses: #Wettability and #Deposition | OOLS | Dr. Mera Haddad

Summary

The video features Dr. Mera Haddad discussing the surface properties of Contact Lenses, specifically focusing on wettability and deposition. Here are the key scientific concepts and discoveries presented:

Key Concepts

• Contact Lens Market Growth: There is a rising demand for Contact Lenses for vision correction, therapeutic uses, and cosmetic purposes, which drives research and development in contact lens materials.
• Material Development Timeline:
  • 1930s: Introduction of glass scleral lenses.
  • 1940s: PMMA (polymethyl methacrylate) lenses, which lacked oxygen permeability.
  • 1970s: Development of rigid gas permeable lenses that allowed more oxygen to the cornea.
  • 1960s-70s: Introduction of soft hydrogels and silicone hydrogels, which improved oxygen permeability and comfort.
• Surface Properties:
  • Wettability: Refers to how well a liquid spreads over a surface, measured by the contact angle. A lower contact angle indicates better wettability, which is crucial for a stable tear film and patient comfort.
  • Deposition: Refers to the accumulation of contaminants on the lens surface, which can lead to discomfort and potential health issues.

Methodologies for Measuring Wettability

• In Vitro Methods:
  • Cile Drop Technique: Measures contact angle by observing a drop of liquid on a lens surface.
  • Captive Bubble Method: Measures the displacement of an air bubble on the lens submerged in water.
  • Wilhelmy Plate Method: Involves immersing a lens in water and measuring the force acting on it as it is pulled out.
• In Vivo Methods:
  • Tear Breakup Time: Assesses the stability of the tear film and the wettability of the lens in a clinical setting.
  • Grading Scales: Developed to assess wettability and deposition severity on Contact Lenses.

Factors Affecting Wettability and Deposition

• Material Properties: Hydrophobic vs. hydrophilic characteristics of the lens material influence wettability.
• Lens Design: The design of the lens can affect its surface properties.
• Tear Film Variability: Individual differences in tear film can impact comfort and performance.
• Lens Care Solutions: The presence of preservatives and other components can affect deposition.

Recommendations for Contact Lens Selection

• Silicone Hydrogel Lenses: Generally preferred for their oxygen permeability and lower deposition rates, especially in patients with dry eyes or those requiring extended wear.
• Daily Disposable Lenses: Recommended to minimize deposition issues, provided they are used as intended.

Conclusion

Dr. Haddad emphasizes the importance of understanding the scientific principles behind contact lens materials and their surface properties to improve patient comfort and clinical outcomes.

Featured Researchers/Sources

• Dr. Mera Haddad, Jordan University of Science and Technology
• University of Manchester (where Dr. Haddad completed her studies)

Notable Quotes

— 00:00 — « No notable quotes »

Category

Science and Nature

Video