Repeatability of a Combined Adaptive Optics Visual Simulator and Hartman-Shack Aberrometer in Pseudophakic Eyes With...

To evaluate the intrasession repeatability of wavefront aberrations obtained by a combined adaptive optics visual simulator and Hartman-Shack aberrometer in pseudophakic eyes with and without previous corneal refractive surgery.

Three consecutive measurements were performed in one eye of each individual. Total ocular aberrations were recorded up to the 5th Zernike order for a 4.5-mm pupil. Repeatability was assessed by calculating the within-subject standard deviation (S_w), the repeatability limit (R), and the intraclass correlation coefficient (ICC). Vector analysis was performed to assess astigmatism variability between scans.

The study enrolled 32 normal individuals and 24 individuals with a history of refractive surgery. In normal and eyes that had previous refractive surgery, respectively, the S_w values were 0.155 and 0.176 diopters (D) for sphere and 0.184 and 0.265 D for cylinder. The S_w values for all 3rd order terms ranged from 0.037 to 0.047 µm in normal eyes and 0.044 to 0.063 µm in eyes that had previous refractive surgery. The S_w for primary spherical aberration was 0.020 µm in normal eyes and 0.026 µm in eyes that had previous refractive surgery. ICC values for measurements of astigmatism yielded larger variability (ICC = 0.751 and 0.879). However, both groups demonstrated excellent repeatability (ICC > 0.9) for root mean square higher order aberrations (RMS-HOA) and total RMS values.

In pseudophakic eyes, the adaptive optics Hartmann-Shack device demonstrated acceptable repeatability for measurement of sphere and 3rd and 4th order HOAs with higher variability for astigmatism measurements, especially in eyes with a prior history of corneal refractive surgery. [.