Abstract
Purpose: :
To assess the validity of a new miniaturised, open-field wavefront device which has been designed to attach to a surgical microscope (the Aston Aberrometer).
Methods: :
The dynamic range of the Aston Aberrometer was assessed using a calibrated model eye. The validity of the Aston Aberrometer was compared to a conventional desk mounted Hartmann-Shack aberrometer (KR1W, Topcon) by measuring the refractive error and higher order aberrations of 156 dilated eyes of 78 patients with both instruments in random order. The Aston Aberrometer measurements were repeated 5 times to assess intra-session repeatability. Data was converted to vector form for analysis.
Results: :
The Aston Aberrometer had a wide dynamic range of at least +21.0 D to -25.0 D. The measurements from the Aston Aberrometer were similar to a conventional aberrometer for mean spherical equivalent (mean difference ± 95% confidence interval: 0.00 ± 0.51D; correlation: r=0.995, p<0.001), astigmatic components (J0: 0.01 ± 0.16D; r=0.97, p<0.001; J45: 0.04 ± 0.29; r=0.664, p<0.001) and higher order aberrations RMS (-0.02 ± 0.18D; r=0.736, p<0.001). Intraclass correlation coefficient assessments of intra-sessional repeatability for the Aston Aberrometer were excellent (spherical equivalent =1.000, p<0.001; astigmatic components J0 =0.998, p<0.001, J45=0.980, p<0.01; higher order aberrations RMS =0.961, p<0.001).
Conclusions: :
The Aston Aberrometer gives valid and repeatable measures of refractive error and higher order aberrations over a wide range. As it is able to measure continuously, it can provide direct feedback to surgeons as to the optical status of the visual system during intraocular lens implantations and corneal surgery.
Keywords: cataract • intraocular lens • cornea: clinical science