This is a retrospective study between April and December 2017, of 22 rigid gas-permeable contact lens (RGP-CL) patients (31 eyes) and 15 non-CL patients (20 eyes) who fulfilled the criteria of: 1) >3 years follow-up and 2) Scheimpflug-based corneal imaging examination at each visit. The tomographic parameters for anterior (ARC) and posterior (PRC) radius of curvature in a 3mm zone, the thinnest corneal thickness (Tmin) and the maximum keratometry values (Kmax) were included. The multivariable nonlinear regression analysis did not show significant differences in all these parameters in these two groups of patients. The authors concluded that RGP-CL has no long-term effects on keratoconus progression over a five to six year period of observation. Limitations are small sample size and inhomogeneous nature of enrolled patients between the groups.
