연령 관련 황반변성에서의 망막 안저 플라보단백질 형광 (FPF in AMD)

실험적: FAF(Fundus autofluorescence) 이미징

장치: 오큐멧 비콘

OcuMet Beacon은 FPF를 감지, 캡처, 평가할 수 있는 새로운 안저 카메라입니다.

Optical Coherence Tomography (OCT) Variables

Ellipsoid Zone (EZ) loss refers to damaged photoreceptors in the eye. Retinal Pigment Epithelium (RPE) are cells that nourish photoreceptors in the eye, RPE loss is a measure of the degradation of these cells. Geographic Atrophy (GA) is an advanced stage of macular degeneration. These OCT variables are measured in millimeters squared from images taken with the Heidelberg Spectralis.

Flavoprotein Fluorescence (FPF) Intensity

Average pixel intensity over a 5.5 mm-diameter region centered at the macula, a measure of oxidative stress. Data range from 0-100 where higher numbers indicate more severe disease. This is measured with the OcuMet Beacon.

FPF Heterogeneity

This is a measure of variability in retinal mitochondrial flavoprotein fluorescence (FPF) across the macula. It is a parameter that measures distribution and spatial variability of fluorescent signal by quantifying signal distribution of energy in localized hotspots, normalized to background. Normal values are less than 1 AU (arbitrary units), with values higher than 1 AU (in the range of 1-10 AU) corresponding to increased levels of metabolic distress due to oxidized mitocondria within the particular area of the retina that was imaged. This is measured with the OcuMet Beacon.

Correlation Between FPF-intensity, FPF-heterogeneity and OCT Continuous Variables

Spearman's rank coefficient was chosen as the primary metric due to the relatively small number of eyes in our sample as well as the lack of normally-distributed data (confirmed by Shapiro-Wilk tests, evaluated at α=0.05). Correlations were calculated between both FPF biomarkers and all FAF/OCT variables (i.e. areas of GA, EZ loss, and RPE loss). To account for correlation between eyes belonging to the same patient, p-values were obtained via nonparametric bootstrap resampling at the patient level.

Compare the Cross-sectional Associations Between FPF Intensity to FAF Area at the Time of Measurement

FPF Intensity is the average pixel intensity over a 5.5 mm-diameter region centered at the macula (measured in gray scale units) compared to are of Geographic Atrophy (measured in millimeters squared). Spearman's rank coefficient was chosen as the primary metric due to the relatively small number of eyes in our sample as well as the lack of normally-distributed data (confirmed by Shapiro-Wilk tests, evaluated at α=0.05).

Compare the Cross-sectional Associations Between Best Corrected Visual Acuity (BCVA - Using Early Treatment Diabetic Retinopathy Study, Greater Number of Letters Read Correctly Equals Better Vision) to FAF Area at the Time of Measurement

Correlation Between FPF-intensity, FPF-heterogeneity and Participant Variables

Spearman's rank coefficient was chosen as the primary metric due to the relatively small number of eyes in our sample as well as the lack of normally-distributed data (confirmed by Shapiro-Wilk tests, evaluated at α=0.05). Correlations were calculated between both FPF biomarkers and all continuous demographic and FAF/OCT variables (i.e. age and logMAR values). To account for correlation between eyes belonging to the same patient, p-values were obtained via nonparametric bootstrap resampling at the patient level. Participant variables are reported in the baseline characteristics section.