Purpose. To evaluate the Hartmann-Schack sphere and cylinder for pupil diameters of 3mm to 6mm, and to integrate higher order aberrations for patients undergoing myopic laser refractive surgery.

Methods. Prospective consecutive study of wavefront scanning with variable lighting conditions, with pupil size just larger than 6mm when processing Hartmann-Schack images. A wavefront scan series comprising four Harmann-Shark images was taken and the higher and lower aberrations were processed at 6mm, 5mm, 4mm and 3mm diameter of pupil and reprocessed with the higher order aberrations integrated into the sphere and cylinder derivations.

Results. 28 eyes of 29 patients were assessed and the data analysed. 2 of 29 (7%) were hyperopic by >=0.1D spherical equivalent (SE), measured at 6mm compared to 3mm. 8 of 29 (28%) were within 0.1D SE ; 19 of 29 (66%) were more myopic by >=0.1D SE. 3 of 29 (10%) were more myopic by >=0.5D SE. Assessed at 3mm pupil diameter, without higher order aberrations integrated, the mean SE was – 4.36D ; with higher order aberrations integrated is was – 4.38D SE. Assessed at 6mm pupil diameter, the mean SE was – 4.56D without higher order aberrations integrated, and was – 4.65D SE with higher order aberrations. When higher order aberrations are integrated, 7 out of 29 eyes (24%) were myopic by >=0.5D SE when assessed at 6mm compared to 3mm pupil diameter.

Conclusions. Wavefront scanning is a useful screening device prior to refractive surgery in order to detect those patients who have spherical aberration.