Using the OptiGlow Plasma Treatment for Contact Lens
(this is a summary….for complete report and tables contact Glow Research)
The Glow Research OptiGlow plasma system was used for increasing the wetability of gas permeable contact lens using room air as the processing gas.
Specifications/measurement and acceptance criteria
- Wetting Angle Measurement* Wetting angle must be no more than 40º on one face of the test disc.
- Sessile Drop Method used.
- Inspection Plan and Acceptance Criteria used for this Process Validation
- Inspection Plan for Wetting Angle Measurements: 100% testing of the test discs.
- Acceptance Criteria for Wetting Angle Measurements: All test disc wetting angles must be no more than 40º. (For one side of each test disc)
In this application, a layer of plasma is applied to the contact lens surface to enhance the wetability of the lens. The plasma was applied using a Glow Research Optiglow plasma system running the following plasma process conditions:
- Time: 5 Minutes
- Air Flow: 0.4 SCFH
- Vacuum: 0.25 Torr Chamber Atmosphere:
- Process Gas: Room Air
Manufactured test discs were used instead of lenses, so that a more accurate wetting angle measurement could be conducted. The polished faces are used to assimilate the polished front and base curve of a lens. Each test disc was installed into a CRT lens claw/vial lid assembly. For the sake of this validation, a maximum of 6 test disc/vial assemblies were placed on the plasma treatment chamber platform in various positions with the claw facing in a upward position and treated together with vial lid assemblies. This validation passed the acceptance specifications of a maximum of (18) contact lenses were treated during one cycle. The test discs did not receive any special cleaning prior to plasma treatment. The central area of both faces of the test discs were measured for wetting angle, by the Analytical Department immediately after plasma treatment.
- The Wetting Angle Measurement was measured in a range of 8 to 16 degrees (goal was <40 degrees)
The results contained in Table III (please contact Glow Research for complete report) demonstrates that the test discs assimilated a uniform and reproducible contact lens plasma treatment process that is under control to ensure contact lens product quality attributes. The Glow Research Optiglow Plasma System was validated by the documented test results and the fact that all of the test discs met the required specifications.
The OptiGlow plasma system can be easily set up in labs or medical offices worldwide since room air is used as the process gas for increasing the wetability of the contact lens
*Please contact Glow Research for complete reports on this application.