Quantitative comparison of drusen segmented on SD-OCT versus drusen delineated on color fundus photographs

Spectral domain-optical coherence tomography (SD-OCT) may be useful for efficient measurement of drusen in patients with age-related macular degeneration (AMD). Areas identified as drusen from semiautomated segmentation of drusen on SD-OCT were compared to those identified from review of digital color fundus photographs (CFPs).

Twelve eyes with nonneovascular AMD were prospectively imaged with digital CFP and SD-OCT. For each eye, areas on CFP in which at least two of three retina specialists agreed on drusen presence produced the composite CFP drusen map. Automated image analysis produced another CFP map. Areas identified as drusen by segmentation on SD-OCT B-scans were plotted as the SD-OCT drusen map. The CFP and SD-OCT maps were compared and agreement was quantified. Disagreement was characterized into distinct types, and the frequency of each type was quantified.

There was general agreement between CFP and SD-OCT in identifying presence and absence of drusen, with mean agreement in 82% ± 9% of total image pixels. Most disagreement (80% ± 15%) occurred at drusen margins. There was a trend toward greater detection of drusen with SD-OCT in eyes with larger drusen and with hyperpigmentation. There was a trend toward greater detection of smaller drusen by CFP.

Good agreement was demonstrated in drusen detection between CFP and SD-OCT. Areas of disagreement underscore limitations of CFP-based measurement of drusen, particularly in the sizing of large, soft drusen. SD-OCT shows great promise as an adjunctive tool for assessing drusen burden in AMD. (ClinicalTrials.gov number, NCT00734487.).