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.