Wavefront: an additional tool for detection of keratoconus

Session Details

Session Title: Special Cases

Session Date/Time: Sunday 14/09/2014 | 14:30-16:00

Paper Time: 14:42

Venue: Boulevard B

First Author: : S.Mohan INDIA

Co Author(s): :    M. Rajan   B. John   S. Shah   A. Bhirud     

Abstract Details

Purpose:

Higher-order aberrations (HOAs) are small optical irregularities or imperfections of the eye which cannot be corrected by simple sphere and cylinder corrections. In the normal eye, 90% of total aberrations are caused by the cornea. New diagnostic technologies enable the detection and correction of ocular aberrations beyond defocus and astigmatism by applying the root mean square (RMS) of Zernike coefficient polynomials. The purpose of this study is to analyse & compare the higher-order aberrations in 3 groups of patients (Simple refractive errors, high astigmatism, and keratoconus) and to determine if wavefront can be used as an additional tool for detection of keratoconus.

Setting:

Rajan Eye Care Hospital Pvt. Ltd, Chennai, India

Methods:

It is a Prospective, observational analysis of higher order aberrations in patients in a refractive surgery clinic. 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. Zernike polynomials up to the fifth order were used for data analysis. Analyzed parameters included Zernike coefficients from third to fifth orders. Higher-order aberrations which were analysed were spherical aberration, total and vertical coma, trefoil and total aberration coefficient. Patients were divided into 3 groups, simple refractive errors, high astigmatism and keratoconus.

Results:

It is a Prospective, observational analysis of higher order aberrations in patients in a refractive surgery clinic. 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. Zernike polynomials up to the fifth order were used for data analysis. Analyzed parameters included Zernike coefficients from third to fifth orders. Higher-order aberrations which were analysed were spherical aberration, total and vertical coma, trefoil and total aberration coefficient. Patients were divided into 3 groups, simple refractive errors, high astigmatism and keratoconus.

Conclusions:

It is a Prospective, observational analysis of higher order aberrations in patients in a refractive surgery clinic. 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. Zernike polynomials up to the fifth order were used for data analysis. Analyzed parameters included Zernike coefficients from third to fifth orders. Higher-order aberrations which were analysed were spherical aberration, total and vertical coma, trefoil and total aberration coefficient. Patients were divided into 3 groups, simple refractive errors, high astigmatism and keratoconus.

Financial Interest:

NONE