From corneal shape to ocular wavefront in eyes with aspheric IOLs: the feasibility of IOL customisation.
OBJECTIVE
To determine if it is possible to predict the ocular wavefront aberrations of eyes with an aspheric IOL from the corneal shape and other readily available eye characteristics. A reliable prediction is a prerequisite for future IOL customisation.


METHODS
Sixty pseudophakic eyes with aspheric IOLs of 60 patients were included. The corneal shape and the ocular wavefront aberrations were measured postoperatively with a Scheimpflug camera and an aberrometer, respectively. The elevation data of the anterior corneal surface were fitted by Zernike polynomials. Linear regression models for the Zernike coefficients describing the ocular wavefront aberrations up till the fourth order were determined, with as independent variables the Zernike coefficients describing the corneal shape, the eye (right/left), IOL power, and axial length.


RESULTS
Linear regression equations with an explained variance (adjusted R-square) above 0.50 were found for five Zernike aberration terms: defocus (z(2,0); adjusted R-square 0.90), the astigmatism terms (0.81 for oblique astigmatism [z(2,-2)] and 0.88 for regular astigmatism [z(2,2)]), vertical coma (z(3,-1); 0.52), and spherical aberration (z(4,0); 0.71).


CONCLUSIONS
The defocus, astigmatism, vertical coma, and spherical aberration terms of the ocular wavefront are strongly associated with the corneal shape in pseudophakic eyes and may thus be predicted from the corneal shape and other eye characteristics.
Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
Tim
T
de Jong
AMO Groningen B.V., Groningen, the Netherlands.
Carmen
C
Canovas
AMO Groningen B.V., Groningen, the Netherlands.
Henk
H
Weeber
Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
Nomdo M
NM
Jansonius
D000328:Adult; D000368:Aged; D058452:Axial Length, Eye / Q000502:physiology; D002387:Cataract Extraction; D003315:Cornea / Q000033:anatomy & histology*; D019781:Corneal Topography; D057108:Corneal Wavefront Aberration / Q000503:physiopathology / Q000517:prevention & control*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular / Q000379:methods*; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D019591:Pseudophakia / Q000503:physiopathology*; D012044:Regression Analysis
IOL customisation; aspheric IOL; cataract; corneal wavefront aberration; ocular wavefront