Abstract
Abstract: :
Purpose: To quantify anterior chamber cells with a high–speed corneal and anterior segment optical coherence tomography (CAS–OCT) system. Methods: 37 eyes from 20 patients with uveitis were imaged with a high–speed (2000 a–scan/sec) 1.3–micron wavelength CAS–OCT prototype. Clinical grading of anterior chamber (AC) cells on a scale of 0–4 was performed at the slit–lamp biomicroscope by one uveitis specialist. Three OCT scans of the anterior chamber were obtained from each eye. The OCT scan pattern consists of 2 and 4–mm diameter concentric cylinders centered at the corneal apex and spanning the full AC depth. A computer algorithm was developed to automatically count AC cells in the OCT images, divided in 3 regions (central = 2–mm cylindrical scan, superior/inferior = top/bottom half of 4–mm cylindrical scan). Results: Inflammatory and pigmented cells in the AC are visualized as reflective spots in the OCT images. In the 28 non–granulomatous uveitis cases, signficant correlation was found between OCT cell count and clinical grading (central, 5.6 cells/grade, R2 = 0.76; superior, 4.3 cells/grade, R2 = 0.61; inferior, 7.7 cells/grade, R2 = 0.34). The 3 granulomatous uveitis eyes had low clinical AC cell grading (0–0.5) and surprisingly large numbers cells distributed inferiorly by OCT (central 3.8±3.3 cells, superior 5±2.5 cells, inferior 62.5±20.2 cells). In the 6 eyes with predominantly pigmentary particles, signficant correlation was also found between OCT particle count and clinical grading (central, 27 particles/grade, R2 = 0.77; superior, 23 particles/grade, R2 = 0.65; inferior, 24 particles/grade, R2 = 0.68). Conclusions: High–speed CAS–OCT provides quantitative information on anterior chamber inflammatory cells. The central cell count correlates best with clinical grading. A predominantly inferior distribution of cells is associated with granulomatous uveitis. OCT may be valuable for the diagnosis and management of anterior uveitis.
Keywords: anterior chamber • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • uveitis–clinical/animal model