TY - JOUR
T1 - OCT minimum intensity as a predictor of geographic atrophy enlargement
AU - Stetson, Paul F.
AU - Yehoshua, Zohar
AU - Garcia Filho, Carlos Alexandre A.
AU - Nunes, Renata Portella
AU - Gregori, Giovanni
AU - Rosenfeld, Philip J.
PY - 2014/1/9
Y1 - 2014/1/9
N2 - Purpose. We determined whether the minimum intensity (MI) of the optical coherence tomography (OCT) A-scans within the retina can predict locations of growth at the margin of geographic atrophy (GA) and the growth rate outside the margin. Methods. The OCT scans were analyzed at baseline and 52 weeks. Expert graders manually segmented OCT images of GA. The 52-week follow-up scans were registered to the baseline scan coordinates for comparison. The OCT MI values were studied within a 180-μm margin around the boundary of GA at baseline. Baseline MI values were compared in areas of progression and nonprogression of the GA, and sensitivity and specificity were assessed for prediction of growth at the margin. Average MI values in the margins were compared to overall growth rates to evaluate the prediction of growth outside the margins. Results. A statistically significant increase in MI (P < 0.05) was seen in areas of growth in 21/24 cases (88%), and 22/24 cases (92%) when the foveal subfield was excluded. Locations of growth within the margins at 52 weeks were predicted with 61% sensitivity and 61% specificity. The MI values correlated significantly with overall growth rate, and high and low growth rate subjects were identified with 80% sensitivity and 64% specificity. Conclusions. The MI may be increased at the margins of GA lesions before enlargement, which may indicate disruption or atrophy of the photoreceptors in these areas before GA becomes apparent. Increased MI may help predict areas of enlargement of GA, and may relate to overall growth rate and be a useful screening tool for GA. (ClinicalTrials.gov number, NCT00935883.).
AB - Purpose. We determined whether the minimum intensity (MI) of the optical coherence tomography (OCT) A-scans within the retina can predict locations of growth at the margin of geographic atrophy (GA) and the growth rate outside the margin. Methods. The OCT scans were analyzed at baseline and 52 weeks. Expert graders manually segmented OCT images of GA. The 52-week follow-up scans were registered to the baseline scan coordinates for comparison. The OCT MI values were studied within a 180-μm margin around the boundary of GA at baseline. Baseline MI values were compared in areas of progression and nonprogression of the GA, and sensitivity and specificity were assessed for prediction of growth at the margin. Average MI values in the margins were compared to overall growth rates to evaluate the prediction of growth outside the margins. Results. A statistically significant increase in MI (P < 0.05) was seen in areas of growth in 21/24 cases (88%), and 22/24 cases (92%) when the foveal subfield was excluded. Locations of growth within the margins at 52 weeks were predicted with 61% sensitivity and 61% specificity. The MI values correlated significantly with overall growth rate, and high and low growth rate subjects were identified with 80% sensitivity and 64% specificity. Conclusions. The MI may be increased at the margins of GA lesions before enlargement, which may indicate disruption or atrophy of the photoreceptors in these areas before GA becomes apparent. Increased MI may help predict areas of enlargement of GA, and may relate to overall growth rate and be a useful screening tool for GA. (ClinicalTrials.gov number, NCT00935883.).
KW - AMD
KW - GA
KW - Geographic atrophy
KW - Image processing
KW - Macula
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U2 - 10.1167/iovs.13-13199
DO - 10.1167/iovs.13-13199
M3 - Article
C2 - 24408973
AN - SCOPUS:84893862608
VL - 55
SP - 792
EP - 800
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
SN - 0146-0404
IS - 2
ER -