PT  - JOURNAL ARTICLE
AU  - Bingyao Tan
AU  - Jacqueline Chua
AU  - Thiyagrajan Harish
AU  - Amanda Lau
AU  - Alfred Tau Liang Gan
AU  - Yar Li Tan
AU  - Damon W K Wong
AU  - Rachel Shujuan Chong
AU  - Marcus Ang
AU  - Rahat Husain
AU  - Leopold Schmetterer
TI  - Comparison of a commercial spectral-domain OCT and swept-source OCT based on an angiography scan for measuring circumpapillary retinal nerve fibre layer thickness
AID  - 10.1136/bjophthalmol-2019-314706
DP  - 2019 Oct 04
TA  - British Journal of Ophthalmology
PG  - bjophthalmol-2019-314706
4099  - http://bjo.bmj.com/content/early/2019/10/03/bjophthalmol-2019-314706.short
4100  - http://bjo.bmj.com/content/early/2019/10/03/bjophthalmol-2019-314706.full
AB  - Background/aims To assess the agreement in measuring retinal nerve fibre layer (RNFL) thickness between spectral-domain (SD; Cirrus HD, Carl Zeiss Meditec, USA) optical coherence tomography (OCT) and swept-source (SS; Plex Elite 9000, Carl Zeiss Meditec) OCT using an OCT angiography (OCTA) scanning protocol.Methods 57 participants (12 glaucomatous, 8 ocular hypertensive and 74 normal eyes) were scanned with two OCT instruments by a single experienced operator on the same day. Circumpapillary RNFL thicknesses were automatically segmented for SD-OCT and manually segmented for SS-OCTA scans. Agreement of global RNFL thickness, as well as average thickness in four quadrants was assessed using intraclass correlation coefficients (ICCs).Results There was excellent agreement in the inferior and superior quadrants and the global (all ICC >0.90), followed by good agreement in the temporal (ICC=0.79) and nasal (ICC=0.73) quadrants. The ICC values were similar in the subgroups except within the ocular hypertension group, where the nasal quadrant was less agreeable (ICC=0.31). SS-OCTA-derived RNFL thickness was on average 3 µm thicker than SD-OCT, particularly in the nasal (69.7±11.5 µm vs 66.3±9.3 µm; p<0.001) and temporal (75.6±13.7 µm vs 67.9±12.3 µm; p<0.001) quadrants.Conclusions RNFL measurements taken with SS-OCTA have good-to-excellent agreement with SD-OCT, which suggests that the RNFL thickness can be sufficiently extracted from wide-field OCTA scans.