Refitting long-term asymptomatic PMMA lens wearers into gas permeable lenses.

Controversy exists as to whether patients who are asymptomatic, long term PMMA contact lens wearers demonstrating an acceptable clinical ocular response should be routinely refit into hard gas permeable lenses. Corneal thickness, corneal curvature, and refractive changes were measured on eight such patients when their lenses were changed to a gas permeable lens material (Boston II) while all other lens parameters were held constant. Corneal thickness decreased dramatically, corneal curvature flattened slightly, and refractive findings showed no significant changes. A simple reorder of the current lens design in the gas permeable material has been recommended as a reasonable "refitting" method for this type of patient.