The QuantifEye-Macular Pigment Reflectometer (MPR) is a near commercial prototype that objectively measures lutein, zeaxanthin and overall macular pigment optical density (MPOD). We sought to evaluate the repeatability, intra and inter- observer variability and the effect of pupillary dilation on measurements obtained using the MPR and compare it with the subjective QuantifEye-MPS II, (MPSII). Experiment -1, thirty individuals were examined twice by a clinician. Measurements were performed for 40 seconds each eye and this dataset was parsed into various time intervals example 10-20, 10-30, 10-40 seconds etc. to evaluate the measurements’ repeatability and create clinical protocols that were utilized in the second experiment. Experiment-2 consists of two non-clinicians performing measurements on fifty individuals. Observer-1 performed measurements twice in the selected eye and once in the fellow eye both without and with pupillary dilation. The Observer-2 performed measurement only on the fellow eye both without and with pupillary dilation. Overall the MPR provides MPOD values that are well correlated with the MPSII. Of the various parsing of the data, the data 10-30 interval was the best at obtaining the MPOD, lutein and zeaxanthin values. The lutein and zeaxanthin optical densities were in the ranges of previously published histology results. Dilation was not needed to obtain the MPOD values but provided better lutein and zeaxanthin measurement repeatability. The intra and inter-observer repeatability in experiment-2 was excellent. The current studies have established the clinical protocols to use when measuring MPOD using the MPR and the MPR can provide repeatable and reliable measurements.
|