Related Experiment Video
Updated: Feb 18, 2026
Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter
Published on: September 16, 2025
Agreement of anterior corneal aberrations between a Placido-disk-based wavefront analyzer and a Scheimpflug system in
Armin Doostparast1, Farbod Semnani2, Maryam Ghandhari3
1Eye Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Purpose:
We aimed to compare the anterior corneal aberrometry between Pentacam HR, a Scheimpflug-based imaging system, and Peramis, an aberrometer that combines a pyramidal wavefront sensor with Placido-disk topography.
Methods:
Myopic, otherwise healthy patients who were scheduled for refractive surgery were examined for anterior corneal aberration profiles using Pentacam HR and Peramis in a 4 mm pupil-centered analysis zone. This profile included corneal total aberrations (TAs), lower-order aberrations (LOAs), higher-order aberrations (HOAs), trefoil (Z(3,-3), Z(3,3)), coma (Z(3,-1), Z(3,1)), and spherical aberrations (Z(4,0)). Subgroup analysis was performed according to the laterality of eyes and the severity of myopia. In addition to the root mean square micrometer (RMS µm), the aberrometry data were simultaneously presented as equivalent diopters to facilitate clinical understanding. A difference of less than 0.5 diopter or 0.3 RMS µm was considered clinically interchangeable.
Results:
A total of 160 eyes from 80 patients were included. Pentacam HR consistently showed significantly higher corneal TAs, LOAs, HOAs, and SA in both eyes (p < 0.01). There was a moderate correlation for corneal TAs, LOAs, and coma aberrations (ICC: 0.39-0.59). In contrast, the correlation was poor for trefoil and spherical aberrations (ICC: 0.16-0.38) and almost non-existent for HOAs (ICC: 0.01-0.07). The width of the 95 % limits of agreement was too large across all comparisons, exceeding 2 RMS µm for TAs and LOAs and 1 RMS µm for HOAs. It was also approximately 0.5 RMS µm for trefoil, coma, and spherical aberrations. Similar patterns were observed in subgroups, regardless of eye laterality or myopia severity.
Conclusions:
Despite moderate correlations in some Zernike terms, the two systems could not be used interchangeably. This is important in pre-operative planning, where patients with higher HOAs might be/not be candidates for particular cataract or wavefront-based refractive surgeries.
