Comparative evaluation of 3D exophthalmometry and Hertel exophthalmometer for measuring ocular protrusion

This study evaluates the reliability and agreement of 3D exophthalmometry, combined with OA2000 measurements, in comparison to traditional Hertel exophthalmometry for assessing ocular protrusion. This study included 110 healthy volunteers assessed for ocular protrusion using both Hertel exophthalmometry and 3D exophthalmometry, complemented by precise measurements of anterior chamber depth (ACD) and central corneal thickness (CCT) via the OA2000. Data were analyzed for intra-operator and inter-operator variability and agreement using paired T-tests, correlation coefficients, and Bland-Altman plots. The 3D exophthalmometry method demonstrated high intra- and inter-rater reliability, with agreements of ±0.53 mm and ±0.69 mm for right and left eyes, respectively. Comparisons between the two methods showed no significant differences (P > 0.05), with a moderate correlation (R = 0.63). Bland-Altman analysis revealed minimal bias (0.3 mm) and consistent agreement between methods. The 3D exophthalmometry technique, supported by OA2000 measurements, provides reliable and reproducible results, and serves as a complementary tool to traditional methods. Further research involving diverse patient populations and comparisons with a gold standard, such as computed tomography, is required to establish its clinical applicability.