Comparison of spectral-domain optical coherence tomography biometry measurements with partial coherence interferometry optical biometry.

PURPOSE: This study aimed to evaluate the agreement and interchangeability between a spectral-domain optical coherence tomography (SD-OCT)-based biometer (REVO FC) and a partial coherence interferometry (PCI) device (AL Scan).

METHODS

This prospective comparative cross-sectional study included 60 right eyes of 60 patients aged 40-82 years, diagnosed with senile cataracts. Measurements of axial length (AL), anterior chamber depth (ACD), keratometry (K1, K2), and astigmatism vector components (J0, J45) were conducted using both devices. Paired comparisons were performed using appropriate statistical tests. Agreement was evaluated using Bland-Altman analysis, while correlation and reliability were assessed using Pearson correlation coefficients and interclass correlation coefficients (ICC).

RESULTS

No statistically significant differences were observed in AL (p = 0.507) or ACD (p = 0.218), with excellent correlations (AL: r = 0.998; ACD: r = 0.945). Bland-Altman analysis demonstrated excellent agreement for AL measurements, with a mean difference (bias) of - 0.01 mm and narrow 95% limits of agreement (LoA: -0.245 to 0.225 mm). For ACD, the mean difference was 0.02 mm, with a moderately wider LoA (- 0.244 to 0.288 mm), indicating an acceptable but less robust agreement compared to AL. The keratometric values were significantly higher with REVO FC (K1: +0.76 D; K2: +0.94 D; both p < 0.001), indicating a systematic bias. Despite strong correlations (K1: r = 0.980; K2: r = 0.924), the Bland-Altman analysis revealed wide limits of agreement. J0 exhibited no significant difference (p = 0.889), whereas J45 differed significantly (p = 0.028). Both vector components demonstrated moderate agreement, with relatively wide limits of agreement.

CONCLUSION

REVO FC and AL Scan demonstrate excellent agreement for AL and ACD measurements and may be used interchangeably for these parameters. However, significant discrepancies in keratometric and astigmatic measurements limit their interchangeability.