Wavefront Analysis as Additional Tool for Detection of Keratoconus
Narrative Responses:
Purpose
To analyse & compare the higher-order aberrations in 3 groups of patients (Simple refractive errors, high astigmatism, and keratoconus) to determine if they can be used as an additional tool for detection of keratoconus.
Methods
All patients included in the study had a complete examination which included best spectacle corrected visual acuity, slitlamp and fundus examination, corneal topography for diagnosis of keratoconus and analysis of wavefront errors using the Wavelight analyzer II, a Tscherning aberrometry. Higher-order aberrations which were analysed were spherical aberration, coma, trefoil, and total aberration coefficient. Patients were divided into 3 groups, simple refractive errors, astigmats (> 1.5D ), and keratoconus.
Results
Total number of patients were 115, 75 with simple refractive error, 24 with high astigmatism and 16 with keratoconus. Spherical aberrations were highest in the patients with high astigmatism with a mean value of .149 which was statistically significant when compared with simple refractive errors(p value 0.046). Trefoil also was higher in the high cylinder group (mean value5.579) when compared to the other 2 groups but not statistically significant. Coma and total aberrations were highest in the keratoconus group (mean .314 and 2.058) which was statistically significant when compared to the other two groups (p value is 0.000).
Conclusion
Total aberrations and coma were significantly higher in patients with keratoconus when compared to patients with simple refractive errors and high astigmatism. Assessment of aberrations can be used as an additional tool in the diagnosis of keratoconus in addition to other standard methods.