Precision of High-Resolution OCT for Anterior Chamber Measurement: Agreement With Scheimpflug Imaging

To assess the precision of the new high-resolution optical coherence tomography (OCT) device to measure anterior segment distances and assess its agreement with a Scheimpflug camera.

Eighty patients with healthy and phakic eyes were included in this study, and only one eye per participant was analyzed. Each eye was measured three times with the Sirius topographer (Costruzione Strumenti Oftalmici, Florence, Italy) and the Cirrus HD-OCT 5000 (Carl Zeiss Meditec, Jena, Germany).

On average, the Sirius topographer measured statistically significantly (P < .05) deeper ACD (approximately 0.07 mm), larger angle-to-angle distance (approximately 0.30 mm), thicker pachymetry (approximately 11 µm), and wider temporal angle (approximately 6°) than the Cirrus OCT. Nevertheless, the Cirrus OCT measured statistically significantly (P < .05) wider nasal angle (approximately 2°) than the Sirius topographer. The repeatability and reproducibility metrics were similar between devices to measure the ACD (smaller than 0.05 mm), corneal pachymetry (smaller than 5 µm), and anterior chamber angles (smaller than 5 degrees). Nevertheless, the reproducibility of the Cirrus OCT to measure the angle-to-angle distance was worse than the Sirius topographer, which had values of 0.11 and 0.21 mm, respectively.

The Cirrus OCT and Sirius topographer showed good precision outcomes to measure the anterior segment of the eye. Nevertheless, clinical criteria are needed to judge whether these devices could be used interchangeably. [J Refract Surg. 2016;32(11):766-772.].