Abstract
Purpose :
To assess the repeatability, agreement, and effects of learning on the new portable handheld heterochromatic flicker photometer, Zx Pro, a psychophysical test (Figure-1), in measuring Macular Pigment Optical Density (MPOD) in a wide age range of ocular healthy adults, compared to the MPOD measurements obtained using the clinically available QuantifEye device.
Methods :
The study included 76 eyes of 76 novice ocular-healthy subjects with visual acuity of 20/25 or better (Table 1). All participants performed one practice attempt and two study-related MPOD measurements with the new Zx Pro and the QuantifEye. The correlation between the first and second measurements was assessed using the Pearson Correlation coefficient for both devices. Agreement between the MPOD measurements was assessed using the Altman and Bland Plots for both devices' mean MPOD of the first and second study measures. The learning effects were assessed by calculating the mean difference between practice attempts and the study-related measurements using a paired samples t-test.
Results :
The mean correlation between the first and second study-related MPOD measurements for Zx Pro and QuantfEye devices was 90% and 85%, respectively (Figures 1 and 2). The correlation between Zx Pro and QuantifEye MPOD was 86.4%. There was excellent agreement between the mean Zx Pro and QuantifEye MPOD data, with the 95% limits of an agreement being -0.10 to +0.11 (Figure 3). The mean difference between the practice attempt and the study-related measurements 1 and 2 were not significant for both the devices (p-value 0.21, 0.1, and 0.44 and 0.20, respectively), indicating a non-significant learning curve despite the psychophysical nature of the tests.
Conclusions :
The Zx Pro provides excellent repeatable MPOD measurements, and the data is in good agreement with the predicate device QuantifEye. The learning effects are insignificant for Zx Pro and QuantifEye heterochromatic flicker photometers, and MPOD values are not statistically different and can be used interchangeably.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.