Which anterior segment structure cannot be visualized with OCT?

Which anterior segment structure cannot be visualized with OCT?

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

Answer: (C)

OCT in the anterior segment images structures that lie in front of or near the iris-sus lens region with light that penetrates relatively well and doesn't scatter much. The iris, cornea, and the anterior surface of the lens sit in this accessible zone, so they can be visualized routinely. The ciliary body, however, is located behind the iris and lens, in the posterior part of the anterior segment, and OCT light cannot reach or adequately penetrate to image it. Pigmentation and scattering further limit depth. For visualization of the ciliary body, ultrasound biomicroscopy is used instead, since it can image deeper anterior-segment structures.

OCT in the anterior segment images structures that lie in front of or near the iris-sus lens region with light that penetrates relatively well and doesn't scatter much. The iris, cornea, and the anterior surface of the lens sit in this accessible zone, so they can be visualized routinely. The ciliary body, however, is located behind the iris and lens, in the posterior part of the anterior segment, and OCT light cannot reach or adequately penetrate to image it. Pigmentation and scattering further limit depth. For visualization of the ciliary body, ultrasound biomicroscopy is used instead, since it can image deeper anterior-segment structures.