Ultrasound biomicroscopy and anterior-segment optical coherence tomography are better at some tasks than others, but both are valuable imaging technologies.
This article was reviewed by Carol L. Shields, MD
When considering ultrasound biomicroscopy (UBM) or anterior-segment optical coherence tomography (AS-OCT), ophthalmologists are finding that they both are excellent in different scenarios because they complement each other.
UBM makes use of sound waves to obtain images of the anterior segment of the eye. In contrast, AS-OCT uses light waves for the same task, according to Carol L. Shields, MD, chief of the Ocular Oncology Service, Wills Eye Hospital, Philadelphia.
In her practice, she prefers UBM to get the best look at the iris stroma, iris pigment epithelium, and the ciliary body, in which the lesions are “deep and dark.” In contrast, AS-OCT, she noted, is better for lesions that are very “superficial and light.”
The technology also may be better for use in very young patients, those unable to cooperate, and in the presence of a thin cornea or infection. Some cysts in the iris stroma and lesions in the conjunctiva can be visualized by AS-OCT.
Dr. Shields described a comparative study that looked at the use of both of the technologies in 200 consecutive cases of anterior-segment tumors (Ophthalmology 2011;118:1297-1302).
“We found the UBM allowed better visualization of all margins and overall better images for the entire tumor configuration,” she said.
Dr. Shields demonstrated cases supporting these views.
“AS-OCT provides nice details in these cases,” she said. “Often, the posterior margin of the lesion is not visible. For solid iris lesions, UBM is better than AS-OCT. For iris/ciliary body lesions, UBM better displays all margins compared with AS-OCT. For iris tumors that extent into the ciliary body, we strongly prefer UBM.”