2M.D. Professor, Bozok University Faculty of Medicine, Department of Ophthalmology, Yozgat/TURKEY Purpose: To compare the anterior chamber angle measurements provided by spectral optical coherence tomography (OCT) and the combined Scheimpflug-Placido disk anterior segment evaluation system (ASES) and to assess the agreement of anterior chamber angle measurements using the two devices.
Materials and Methods: 80 eyes of 80 patients were evaluated in this prospective study. Nasal and temporal anterior chamber angle measurements of all eyes were taken three times by spectral OCT (RTVue, Optovue) with the cornea anterior module (CAM-L) and ASES (Sirius, CSO). After these measurements, the same ophthalmologist graded the anterior chamber angles of all patients according to Shaffer's grading system using gonioscopy. Bland and Altman plots were used to assess agreement among the devices.
Results: The mean anterior chamber angle measurements by Sirius and OCT were nasally 44.26±8.13º and 38.32±7.53º (p<0.001), and temporally 45.75±6.76º and 40.85±6.86º (p<0.001), respectively. Nasal and temporal anterior chamber angle measurements of the two devices were correlated (p<0.001, r=0.451 and 0.547). The Bland-Altman analysis showed that 95% limits of agreement ranged from -26.1 to 15.1 for the nasal angle, and from -9.8 to 18.9 for the temporal angle. There was a good correlation between gonioscopy and Sirius (r=0.587, p=0.032), and gonioscopy and OCT (r=0.689, p=0.005).
Conclusion: Although measurements of the anterior chamber angle using OCT and Sirius were easy to handle technically, angle measurements of these devices should not be used interchangeably.
Keywords : Anterior chamber angle, Sirius, Optical coherence tomography