Micropachometric investigation of rigid contact lens-induced corneal dystrophies.

We evaluated rigid contact lens associated changes in central corneal thickness using an improved method of pachometry. After altering one lens parameter (e.g., lens diameter or base curve) and keeping all other parameters constant, we evaluated 30 rigid lens patients at 4-hour intervals over 20-hour periods. Using micropachometry we were able to detect changes as small as 10-20 microns in the central cornea region. We found that the degree of corneal swelling from rigid contact lens wear can vary from one area to another. Thinning in one area can result from lens compression, while thickening in an adjacent area can result from lens-induced hypoxia. Using micropachometry for the early detection of corneal changes such as thinning may help to avoid problems associated with long-term lens wear.