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Wavefront aberrometry repeatability and agreement-A comparison between Pentacam AXL Wave, iTrace and OPD-Scan III
Kelvin H Wan1,2,3, Xu Lin Liao1, Marco Yu4
1Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong.
Summary
Three aberrometers showed good agreement for wavefront aberration measurements. However, individual Zernike components were not interchangeable between devices, indicating varied performance across ocular aberration parameters.
Area of Science:
- Ophthalmology
- Optical Engineering
- Metrology
Background:
- Accurate wavefront aberration measurements are crucial for understanding and correcting refractive errors.
- Different aberrometer technologies, including Hartmann-Shack, ray tracing, and automated retinoscopy, offer distinct approaches to wavefront sensing.
- Evaluating the intrasession agreement, repeatability, and interdevice agreement of these aberrometers is essential for clinical and research applications.
Purpose of the Study:
- To compare the intrasession agreement and repeatability of wavefront aberration measurements from three different aberrometers.
- To assess the interdevice agreement among these aberrometers using various measurement methods.
- To identify variations in performance across different ocular aberration parameters and Zernike components.
Main Methods:
- Three aberrometers (Pentacam AXL Wave, iTrace, OPD-Scan III) were used to obtain three consecutive measurements in 47 eyes.
- Wavefront data, including total aberrations (RMS total) and higher-order aberrations (HOA), were analyzed for 4-mm pupils.
- Intrasession agreement and repeatability were assessed using intraclass correlation coefficients (ICCs) and repeatability coefficients (RCs), while interdevice agreement was evaluated using the Bland-Altman method.
Main Results:
- Intrasession agreement and repeatability for RMS HOA were comparable across all three devices.
- The Pentacam AXL Wave and OPD-Scan III demonstrated superior intrasession agreement and repeatability for RMS total compared to the iTrace.
- Significant systematic differences and proportional bias were observed for most refraction power vectors and Zernike coefficients among the devices, with notable variations in intrasession repeatability for individual aberration orders.
Conclusions:
- All three aberrometers demonstrated good-to-excellent agreement for overall aberration measurements.
- Individual Zernike components were generally not interchangeable between the tested aberrometers.
- The relative intrasession performance in agreement and repeatability varied significantly depending on the specific ocular aberration parameter being measured.
