Purpose: To assess the agreement between anterior segment measurements obtained using swept-source optical coherence tomography (Anterion<sup>®</sup>, Heidelberg Engineering Inc., Heidelberg, Germany) and Scheimpflug partial coherence interferometry (Pentacam HR<sup>®</sup>, OCULUS, Wetzlar, Germany).Methods: We analyzed the anterior and posterior corneal keratometry, Cartesian astigmatism (J0), oblique astigmatism (J45), anterior chamber depth (ACD), and central corneal thickness (CCT) measurements obtained using the two devices in 65 eyes of 43 subjects.Results: The mean differences between the anterior flat K, anterior steep K, anterior mean K, anterior J0, anterior J45, posterior flat K, posterior steep K, posterior mean K, posterior J0, posterior J45, ACD, and CCT measurements were -0.13 ± 0.34, -0.02 ± 0.33, -0.05 ± 0.31, -0.03 ± 0.39, -0.06 ± 0.35, 0.12 ± 0.09, 0.07 ± 0.08, 0.10 ± 0.06, -0.02 ± 0.14, 0.01 ± 0.16, 0.04 ± 0.06, and -3.51 ± 7.42, respectively. All measurements except posterior J0 and J45 had interclass correlation coefficients greater than 0.75.Conclusions: The mean differences and 95% limits of agreement in this study are consistent with previously reported values. There was a high level of agreement between Anterion<sup>®</sup> and Pentacam HR<sup>®</sup>. However, considering the statistically significant differences and limits of agreement for certain measurements, caution should be exercised when assuming interchangeability between these devices.
In the present study, the retinal and choroidal vascular densities (VDs) in type 2 diabetes mellitus (DM) patients were analyzed using optical coherence tomography angiography (OCTA).The study included 282 eyes of 152 patients with type 2 DM (114 without retinopathy, 79 nonproliferative diabetic retinopathy (NPDR), 48 severe NPDR, and 41 proliferative diabetic retinopathy (PDR) eyes). The superficial and deep retinal vessel, choriocapillaris, and choroidal VDs were measured using a binarization method on OCTA images. VDs were compared based on retinopathy severity. Correlations among densities were analyzed.Retinal and choriocapillaris VDs were lower in PDR than in NPDR (all P < 0.05). Correlation analysis showed significant positive correlations among densities of superficial and deep retinal vessels and choriocapillaris (all P < 0.001). Choroidal VD showed a negative correlation with superficial and deep retinal vessels and choriocapillaris (all P < 0.001). Retinal and choriocapillaris VDs showed a negative correlation with diabetic retinopathy (DR) grade (all P < 0.001); however, the choroidal VD showed a weak positive correlation (P=0.030).Choroidal VD increased as retinal and choriocapillaris VDs decreased, indicating that the outer layer of the choroid is less affected by DR severity and VD of larger choroidal vessels may even be increased as a compensatory mechanism for decreased retinal and choriocapillaris VDs in type 2 DM patients.