Abstract
Purpose: :
To evaluate the utility of Cross Sectional B–Scan and Corneal C–Scan OCT for imaging lesions involving the anterior segment of the eye.
Methods: :
Forty patients were positioned in front of the non–contact AC Cornea OCT System (Ophthalmic Technologies Inc. [OTI], Toronto, Ontario, Canada), and were made to fixate at an internal or external target. The 1300nm light beam was centered over the lesion, and a series of images were obtained.
Results: :
A variety of anterior segment pathologies were included in the study. Imaging was ideal for lesions of the cornea, limbus, conjunctiva, sclera, iris, angle, central portion of the lens or IOL and pars plana. It was also useful for scanning through opaque corneas, as well as for imaging implants or foreign bodies within the anterior chamber. Maximum field of view was 15mm x 15mm. Scanning depth was up to 15mm, while scanning width was up to 20mm. The axial resolution was <10µ, whereas transverse resolution was <20µ. A 2x zoom feature was useful for examining specific small areas of interest. The measurement function provided data on corneal/lens thickness, anterior chamber depth, dimensions of normal and pathologic structures, as well as angular measurements. However, its imaging capability was limited by the vascular nature of the ciliary body for tumor imaging, and the posterior iris pigment layer for PCIOL/haptic position imaging. Overall, the procedure required minimal operator training, and was well tolerated by the majority of patients.
Conclusions: :
Anterior segment imaging using the AC Cornea OCT System offers a comprehensive high–resolution technique to examine normal and pathologic lesions involving the anterior part of the eye. Its ability to generate coronal scans in addition to the cross sectional scans also provided unique views of these lesions.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical • anterior segment