Which anterior segment structures cannot be visualized with optical coherence tomography?

Which anterior segment structures cannot be visualized with optical coherence tomography?

• A. Cornea
• B. Ciliary body
• C. Iris
• D. Lens

Answer: (B)

OCT imaging depth and tissue accessibility determine what parts of the anterior segment can be seen. Anterior segment OCT uses near-infrared light to image tissues that lie within its penetration range, so it can clearly show the cornea, the iris surface, the anterior surface of the lens, and the anterior chamber angle. The ciliary body, however, sits behind the iris and deeper in the eye, making it difficult for OCT light to reach and return with a usable signal. Its depth and the surrounding pigmented tissues limit visualization, which is why the ciliary body is not typically seen with OCT. When imaging the ciliary body specifically, ultrasound biomicroscopy is usually used instead.

OCT imaging depth and tissue accessibility determine what parts of the anterior segment can be seen. Anterior segment OCT uses near-infrared light to image tissues that lie within its penetration range, so it can clearly show the cornea, the iris surface, the anterior surface of the lens, and the anterior chamber angle. The ciliary body, however, sits behind the iris and deeper in the eye, making it difficult for OCT light to reach and return with a usable signal. Its depth and the surrounding pigmented tissues limit visualization, which is why the ciliary body is not typically seen with OCT. When imaging the ciliary body specifically, ultrasound biomicroscopy is usually used instead.