Accuracy of swept-source optical coherence tomography based biometry for intraocular lens power calculation: a retrospective cross–sectional study

BACKGROUND: To evaluate the accuracy of biometric measurements by a swept-source optical coherence tomography (SS–OCT) based biometry for intraocular lens (IOL) power calculation. METHODS: This retrospective observational study enrolled 431 patients undergoing cataract surgery. The charts were reviewed to investigate the failure rate of axial length (AL) measurement of the SS–OCT biometer, partial coherence interferometry (PCI), and A–scan ultrasonography (US) according to cataract type and severity. AL and keratometry in 164 eyes with the same IOL inserted were measured using the SS–OCT biometer, PCI, and A–scan US. The SRK/T formula was used to calculate IOL power. The mean absolute error (MAE) and percentage of eyes with a prediction error (PE) of ±0.50 D were compared. RESULTS: The AL measurement failure rate was 0.00% for A–scan US, 2.32% for the SS–OCT biometer, and 15.31% for PCI. The number of eyes measured using three devices (SS–OCT biometer, PCI, and A–scan US) was 128 (Group A) and the number of eyes measured using two devices (SS–OCT biometer and A–scan US) was 36 (Group B). The score of posterior subcapsular opacity was significantly different between two groups (p < .001). The SS–OCT biometer and PCI showed significantly lower MAE compared to A–scan US in Group A (p = 0.027). Using SS-OCT biometer, MAE showed no significant difference between Group A (0.36 ± 0.27) and Group B (0.36 ± 0.31) (p = 0.785). Whereas, MAE of A-scan US was significantly higher than Group A (0.47 ± 0.39) in Group B (0.64 ± 0.36) (p = 0.023). CONCLUSIONS: Using biometry with advanced OCT is useful in clinical practice as it is more effective in obtaining biometric measurements in the eyes with PSC and provides accurate measurements for IOL power calculation regardless of cataract type and severity. TRIAL REGISTRATION: Retrospectively registered. Registration number: KC16RISI1020. Registered 03 January 2018.