Evaluation of total and corneal wavefront high order aberrations for the detection of forme fruste keratoconus.

PURPOSE To investigate the application of anterior corneal and ocular aberrations in detecting mildly ectatic corneas. METHODS This study retrospectively reviewed the data of 220 eyes separated into three groups by the NIDEK Corneal Navigator System automated corneal classification software: normal (N) (n = 123); forme fruste keratoconus (N topography with contralateral KC) (n = 34); and KC (n = 63). Anterior corneal and ocular aberrations were obtained with the optical path difference scan and compared using a Kruskal-Wallis test. Evaluation of these data to discriminate between the three groups was assessed using a Receiver-Operating Characteristic curve analysis. RESULTS Corneal and ocular tilt, vertical coma, and trefoil were significantly different in the FFKC as compared with the N group. The discriminant functions between the FFKC and the N group, and between the KC and the N group reached an area under the receiver operating characteristic curve of 0.98 and 0.96, respectively. CONCLUSION Indices generated from corneal and ocular wavefront can identify very mild forms of ectasia that may be undetected by Placido-based neural network programs.