RT Journal Article
SR Electronic
T1 Utilisation of poor-quality optical coherence tomography scans: adjustment algorithm from the Singapore Epidemiology of Eye Diseases (SEED) study
JF British Journal of Ophthalmology
JO Br J Ophthalmol
FD BMJ Publishing Group Ltd.
SP 962
OP 969
DO 10.1136/bjophthalmol-2020-317756
VO 106
IS 7
A1 Sahil Thakur
A1 Marco Yu
A1 Yih Chung Tham
A1 Shivani Majithia
A1 Zhi-Da Soh
A1 Xiao Ling Fang
A1 Carol Cheung
A1 Pui Yi Boey
A1 Tin Aung
A1 Tien Yin Wong
A1 Ching-Yu Cheng
YR 2022
UL http://bjo.bmj.com/content/106/7/962.abstract
AB Purpose To evaluate the effect of signal strength (SS) on optical coherence tomography (OCT) parameters, and devise an algorithm to adjust the effect, when acceptable SS cannot be obtained.Methods 5085 individuals (9582 eyes), aged ≥40 years from the Singapore Epidemiology of Eye Diseases population-based study were included. Everyone underwent a standardised ocular examination and imaging with Cirrus HD-OCT. Effect of SS was evaluated using multiple structural breaks linear mixed-effect models. Expected change for increment in SS between 4 and 10 for individual parameter was calculated. Subsequently we devised and evaluated an algorithm to adjust OCT parameters to higher SS.Results Average retinal nerve fibre layer (RNFL) thickness showed shift of 4.11 µm from SS of 5 to 6. Above 6, it increased by 1.72 and 3.35 µm to 7 and 8; and by 1.09 µm (per unit increase) above 8 SS. Average ganglion cell-inner plexiform layer (GCIPL) thickness shifted 5.15 µm from SS of 5 to 6. Above 6, increased by 0.94 µm from 7 to 8; and by 0.16 µm (per unit increase) above 8 SS. When compared with reference in an independent test set, the algorithm produced less systemic bias. Algorithm-adjusted average RNFL was 0.549 µm thinner than the reference, while the unadjusted one was 2.841 µm thinner (p<0.001). Algorithm-adjusted and unadjusted average GCIPL was 1.102 µm and 2.228 µm thinner (p<0.001).Conclusions OCT parameters can be adjusted for poor SS using an algorithm. This can potentially assist in diagnosis and monitoring of glaucoma when scans with acceptable SS cannot be acquired from patients in clinics.All data relevant to the study are included in the manuscript or uploaded as supplementary material. However, additional data can be made available on reasonable request to the corresponding author. The algorithm mentioned in the manuscript is available at https://seri-seed.shinyapps.io/Cirrus-OCT-SS-Adjustment.