Key result
The Zx Pro portable photometer demonstrated excellent agreement with the QuantifEye device for measuring macular pigment optical density (95% limits of agreement -0.10 to +0.11 du).
Why the study?
Macular pigment optical density is a key clinical biomarker, but the repeatability, agreement, and learning curve of the new portable handheld Zx Pro device compared with the clinically available QuantifEye device had not been established.
Does the Zx Pro portable handheld heterochromatic flicker photometer provide repeatable and agreeable MPOD measurements compared to the QuantifEye device in ocular-healthy adults?
Cross-Sectional (n=76)
Does the Zx Pro portable handheld heterochromatic flicker photometer provide repeatable and agreeable MPOD measurements compared to the QuantifEye device in ocular-healthy adults?
Effect estimate: 95% limits of agreement -0.10 to +0.11 du
The Zx Pro provides repeatable MPOD measurements with an insignificant learning curve and good agreement with the clinically available QuantifEye device.
Background/Objectives: Macular pigment optical density (MPOD) is an important clinical biomarker for ocular conditions like macular degeneration, diabetic eye disease, and digital eye strain. Additionally, its measurements can be essential in health assessment for visual function, systemic diseases, and brain health. We aimed to assess the repeatability, agreement, and effects of the learning curve of the new portable handheld heterochromatic flicker photometer, Zx Pro, in measuring MPOD in a wide age range of ocular-healthy adults, compared to the MPOD measurements obtained using the clinically available QuantifEye device. Methods: Seventy-six participants performed one practice attempt and two study-related MPOD measurements with the Zx Pro and the QuantifEye. Results: The Pearson correlation between the study-related MPOD measurements for Zx Pro and QuantifEye devices was 90% and 85%, respectively. Bland and Altman plots show excellent agreement between the device’s MPOD data, with 95% limits of an agreement being −0.10 to +0.11 du. The mean difference between the practice attempt and the study-related measurements was not statistically significant for Zx Pro but was significant for QuantifEye (Repeated measures ANOVA p = 0.325 and p = 0.015, respectively). Conclusions: The Zx Pro provides excellent repeatable MPOD measurements, has an insignificant learning curve, and is in good agreement with the predicate device.
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Davey et al. (2025) conducted a cross-sectional in ocular-healthy adults (n=76). Zx Pro portable handheld heterochromatic flicker photometer vs. QuantifEye device was evaluated on Macular pigment optical density (MPOD) measurement agreement (95% limits of agreement -0.10 to +0.11 du). The Zx Pro portable photometer demonstrated excellent agreement with the QuantifEye device for measuring macular pigment optical density (95% limits of agreement -0.10 to +0.11 du).
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