Multimodal Imaging Device Comparison for Central Corneal Thickness Assessment in Primary Open-Angle Glaucoma and Non-Glaucomatous Eyes

Abstract

Purpose:  To compare central corneal thickness (CCT) in eyes with primary open-angle glaucoma (POAG) and non-glaucomatous eyes using four different devices, and to evaluate the agreement and comparability of these devices in both groups. Study Design:  Cross sectional study. Place and Duration of Study:  Tertiary hospital in Semarang City from May 2025 to February 2026. Methods:  CCT in right eye was measured using standard ultrasonic pachymetry (USP), optical coherence tomography (OCT), non-contact tono-pachymetry (NCT), and specular microscopy (SM). Differences, correlation levels, and agreement between the measurement results were assessed. Result:  A total of 69 participants participated in this study (33 patients with glaucoma and 36 without glaucoma).The mean CCT measured using NCT (580.50±27 mm), USP (578.50±26 mm), SM (569.50±28 mm), and OCT (564.50±27 mm) did not differ statistically in the non-glaucoma group. Similar results were seen in glaucoma group with NCT (528±22 mm), USP (527±22 mm), SM (518±25 mm), and OCT (518±27 mm)(p>0.05). The difference between the two groups was statistically significant (p < 0.001). A strong positive correlation was observed among the four devices within each group (p<0.001). Bland-Altman analysis comparing each device to the USP gold standard showed bias values of 2.6 (NCT), -12.03 (SM), and -6.03 (OCT) in the glaucoma group, and 9.8 (NCT), -9.1 (SM), and -14.6 (OCT) in the non-glaucoma group. Conclusion:  The CCT measurements using NCT, SM, and OCT were aligned with the USP measurements in both groups. This finding highlights that CCT monitoring may be interchangeable between devices. Keywords:  Central Corneal Thickness, Non-Contact Tono- Pachymetry, Optical Coherence Tomography Specular Microscopy, Ultrasound Pachymetry.