Most GP solutions contain derivatives of which two polymers?

• A. polyvinyl alcohol and methylcellulose derivative
• B. sodium hyaluronate and polyacrylates
• C. guar gum and alginate
• D. polyethylene glycol and xanthan

Answer: (A)

Wetting and lubrication of the lens surface are central to how GP (gas-permeable) lens solutions comfort wear and ease handling. The two polymers most commonly present as derivatives in these solutions are polyvinyl alcohol (PVA) and methylcellulose derivatives. These hydrophilic polymers readily form a thin, even film on the GP lens, improving surface wettability and reducing friction during blinking. This coating helps the tear film spread more smoothly over the lens, enhances comfort, and can aid in easier insertion and removal.

Other polymers like sodium hyaluronate appear in some artificial tears, and guar gum, alginate, PEG, or xanthan may be used in different formulations as thickeners or lubricants, but the standard GP wetting solutions rely primarily on PVA and methylcellulose derivatives.