Correlation of Higher Order Aberrations in Anterior Corneal Surface and Degree of Keratoconus Measured by Scheimplug Camera
Purpose
To determine the correlation between high-order aberrations in the anterior corneal surface and degree of keratoconus measured by Scheimplug camera.
Methods
We conducted a descriptive, transversal and retrospective study in 152 eyes of patients with keratoconus from January 2009 to April 2014. We investigated the corneal aberrometry in the anterior corneal surface and used topographic mapping (by Muckenheim Amsler classification) to determine the degree of keratoconus. Statistical analysis was done with SPSS v.15; the Kendall´s tau was used to find the correlation between high-order aberrations in the anterior corneal surface and the degree of keratoconus.
Results
Coma aberration was significantly correlated with keratoconus severity (r=0.61, P <0.01). Trifoil and keratoconus were weakly correlated (r=0.34, P <0.01). Keratoconus severity was also weakly inversely correlated with spherical aberration in horizontal (r=-0.28, P <0.01) and vertical was (r=-0.24, P <0.01). Finally, keratoconus severity had a strong inverse correlation with ectasia type (r=-0.70, P <0.01).
Conclusion
Higher-order aberrations of the anterior corneal surface, but not the entire optical system, positively correlates with the severity of keratoconus.