Customized Contact Lens Treatments for in-the-Eye Medication

Hydrophilic polymer (polymacon, alphafilcon-A) and silicone-based (balafilcon-A) hydrogel contact lenses, before and after surface modification by radio-frequency glow-discharge treatment (RFGDT), were used to monitor methylene blue/silver nitrate drug-surrogate uptake and elution. Infrared spectroscopy revealed modified absorption peaks, accordingly. Energy-dispersive x-ray (EDX) analysis and inductively coupled argon plasma atomic emission spectroscopy (ICP) confirmed silver lens depot concentrations and were employed to measured eluate concentrations, while visible spectrophotometry and ICP spectrometry monitored methylene blue and silver elution rates in static versus simulated eye-blinking conditions. The conclusions reached are that (1) initial drug uptake of surface modified lenses increased in this order: polymacon