Corneal desiccation in rigid contact lens wear: 3- and 9-o'clock staining.
The current knowledge of treatment options together with signs and symptoms, classification, prevalence, and etiology of 3- and 9-o'clock staining in rigid contact lens wear are described in this review article. In total, 11 treatment options for the management of 3- and 9-o'clock staining were found in the literature. Five of these treatment options are related to lens parameters, namely edge lift, edge thickness and shape, back surface geometry, total diameter, and back optic zone radius. Three other options are related to lens performance: movement, centration, and surface wettability. Three more variables can be identified: blinking habits, tear supplements, and, finally, switching to a hydrogel material. There is controversy on how to adjust the most important individual variables for management of 3- and 9-o'clock staining. The advocated treatment options are often related to the fitting techniques used: lid attachment or interpalpebral fit. Implications for practice and for further research are discussed.