Clinical relevance of OCT artifact depends on data analysis
KOLOA, Hawaii — Some artifacts seen on optical coherence tomography have clinical importance but others do not depending on how the OCT measurements are being used, a speaker said here.
In a quantitative analysis of glaucoma, for example, where very small changes in retinal nerve fiber layer are significant, artifacts are clinically important.
“If you’re making your diagnosis or your patient management decisions based on numbers, you need to be sure the numbers are right,” Jay S. Duker, MD, professor and chairman, department of ophthalmology, New England Eye Center, told colleagues at Retina 2014.
Jay S. Duker
Artifacts occur with all OCT devices and they occur for various reasons, Duker said. Artifacts common to both time-domain and spectral-domain OCT are due to misalignment, software breakdown, shadowing, blink, motion and out-of-range error. Of these, the most common, he said, is software breakdown.
Software breakdown errors that result in inaccurate mapping and quantitative measurements can result from a poor quality scan, media opacity and segmentation errors, particularly in retinal pathology, he said.
Software breakdown of inner line imaging is not necessarily clinically important, Duker said, because most of these diseases are being screened based on how thick the retina is, but surgical management does not depend on thickness of the retina.
However, software breakdown of the outer line imaging can be critically important clinically, he said, if quantified data are being used to treat the retinal disease.
Manual correction can be time-consuming, and when quantitative data are needed, rescan may be best, Duker said. —by Patricia Nale
Disclosure: Duker is a stock shareholder in EyeNetra; Hemera Biosciences; Ophthotech, and Paloma Pharmaceuticals; he is a consultant for EMD Serono, Novartis, Optos, QLT and ThromboGenics; he receives research funds from Carl Zeiss Meditec and Optovue.