Macular Pigment Reflectometry: Developing Clinical Protocols, Comparison with Heterochromatic Flicker Photometry and Individual Carotenoid Levels.

Pinakin Gunvant Davey,Dennis L Gierhart,Richard B Rosen

doi:10.3390/nu13082553

Abstract

The study was designed to: (1) Analyze and create protocols of obtaining measurements using the Macular Pigment Reflectometry (MPR). (2) To assess the agreement of MPOD measurements obtained using the heterochromatic flicker photometry (MPS II) and MPR. (3) To obtain the lutein and zeaxanthin optical density obtained using the MPR in the central one-degree of the macula. The measurements were performed using the MPR and heterochromatic flicker photometry. The MPR measurements were performed twice without pupillary dilation and twice following pupillary dilation. The MPR measurements were performed for a 40-s period and the spectrometer signal was parsed at different time points: 10–20, 10–30, 10–40, 20–30, 20–40, and 30–40 s. The MPR analyzes the high-resolution spectrometer signal and calculates MPOD, lutein optical density and zeaxanthin optical density automatically. The MPR-MPOD data was compared with MPPS II-MPOD results. The MPR-MPOD values are highly correlated and in good agreement with the MPS II-MPOD. Of the various parsing of the data, the data 10–30 interval was the best at obtaining the MPOD, lutein, and zeaxanthin values (8–12% coefficient of repeatability). The lutein to zeaxanthin ratio in the central one-degree of the macula was 1:2.40. Dilation was not needed to obtain the MPOD values but provided better repeatability of lutein and zeaxanthin optical density. MPR generates MPOD measurements that is in good agreement with MPS II. The device can produce lutein and zeaxanthin optical density which is not available from other clinical devices.

Highlights

Measurement and the second macular pigment optical density (MPOD) measurement under undilated and dilated condition was not significantly different the data obtained from all six-time stamped intervals
Prior studies [49,50,51,52,53] have evaluated the laboratory slit lamp-based Macular Pigment Reflectometry (MPR) unit and have reported values of MPOD, lutein and zeaxanthin. They have reported that MPR was sensitive to measuring increased MPOD when carotenoid supplements were consumed for a given period [50]
Comparing the MPOD measurements obtained using the two devices MPS II and MPR we found that the limits of agreement were narrow but there were a consistent mean difference of 0.243 between the measures

Summary

Introduction

The National Institute of Health has taken a bold and much needed step known as the Precision Medicine Initiative [1,2,3]. Medicine, is defined as “an emerging approach for disease treatment and prevention, taking into account individual variability in genes, environment, and lifestyle for each person” [1]. This initiative is primarily focused on cancer and its management, the lessons learnt, and creative methodologies employed are applicable to other disease states [1,2]. The principles summarized are (a) phenotyping disease states with new definitions and latest technology; (b) discovery, validation and understanding of biomarkers; and (c) revamping epidemiological studies to discover and validate the risk factors that affect the onset and progression of the disease

Objectives

Methods

Results

Discussion

Conclusion