Reproducibility of macular thickness measurement among five OCT instruments: effects of image resolution, image registration, and eye tracking.
OBJECTIVE
To study the effect of image resolution, eye tracking, and image registration on central macular thickness reproducibility (rCMT) among spectral-domain and time-domain optical coherence tomography (SD-OCT and TD-OCT) instruments.


METHODS
Seventy-six eyes were imaged (44 normal, 32 maculopathy) either twice using four SD-OCT and one TD-OCT devices or three times using Spectralis SD-OCT (with and without eye tracking) (Heidelberg Engineering, Inc., Heidelberg, Germany). Cirrus images (Carl Zeiss Meditec, Dublin, CA) were further analyzed with three-point image registration.


RESULTS
All instruments had superior rCMT in normal versus pathologic eyes (P < .001). No difference in rCMT was noted among instruments in normal eyes (P = .92), but TD-OCT was superior to SD-OCT (P = .017) in pathologic eyes. Cirrus image registration improved rCMT for normal eyes (P = .04), with borderline improvement in pathologic eyes (P = .06). Spectralis eye tracking improved rCMT in normal (P = .01) and pathologic (P = .004) eyes.


CONCLUSIONS
Higher image resolution with SD-OCT may not improve rCMT, but image registration and eye tracking options may improve rCMT.
Department of Ophthalmology & Vision Science, University of California Davis Eye Center, Sacramento, California 95817, USA.
Eric K
EK
Chin
Ragui W
RW
Sedeek
Yueju
Y
Li
Laurel
L
Beckett
Ellen
E
Redenbo
Karishma
K
Chandra
Susanna S
SS
Park
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D008266:Macula Lutea / Q000033:anatomy & histology* / Q000473:pathology; D008268:Macular Degeneration / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence / Q000295:instrumentation* / Q000592:standards; D055815:Young Adult