Two clinicians use UBM for specific types of glaucoma management

One delegates most image capturing to a technician, while the other prefers administering the test himself to optimize its interactivity.

Ultrasound biomicroscopy is becoming more commonly used in the optometric practice to diagnose all types of glaucoma.

Two clinicians spoke to Primary Care Optometry News regarding how they use this technology in their practice and, specifically, how they administer the test.

PCON Editorial Board member J. James Thimons, OD, FAAO, said he has been using ultrasound biomicroscopy (UBM) to diagnose narrow-angle, suspected narrow-angle and mixed-mechanism glaucoma for 3 years. He also uses it to determine placement and wound healing for surgically implanted stents, tubes and other devices.

He considers it an indispensable technology for his practice.

“High-density anterior segment optical coherence tomography (OCT) is capable of visualizing the cornea and even, to some degree, the angle,” Thimons told PCON. “However, OCT is limited by the depth that it can penetrate into the eye and, because of this limitation, it can’t provide all the information we need to accurately diagnose and subsequently manage complex, or even moderately complex, glaucoma.”

J. James Thimons, OD, FAAO

J. James Thimons

He noted that when using light instruments, such as slit lamp and gonioscopy, the angle can be altered by the combination of room light and slit-lamp illumination.

Thimons shared a recent case of a patient with low hyperopic refraction and mildly elevated intraocular pressure who looked minimally narrow on slit-lamp examination analysis. Gonioscopy showed appositional touch in the superior angle only.

In a dark room, the UBM showed that the patient’s angle was 70% closed.

“This allowed me to identify that she had a form of narrow-angle glaucoma that was amenable to peripheral iridotomy, and not primary open-angle glaucoma,” Thimons said. “Following the procedure, UBM showed significant deepening of the angle and a lowering of IOP into the normal range.”

Technician performs testing

Thimons said that his technician, Joshua Escalera, primarily performs the UBM testing.

“I have found him to be quite skilled at doing a four-plane analysis of the anterior chamber and capturing the images that are pertinent to each individual case,” he said. “Occasionally I will be in the exam room while he is taking the images to assess a unique problem that requires real-time analysis. In those cases, I will use the foot pedal to freeze and store the images I like into the computer for later review. Allowing him to perform the test while I watch frees my time to focus on anatomy and amplifies my ability to truly analyze the data.”

Thimons said that having technicians perform testing saves the clinician time that can be given back to the patient.

“As practitioners move toward a more advanced medical model of practice, the goal is to effectively assess and treat as many patients as is reasonable and prudent in the course the day,” Thimons said. “If the doctor is doing most of the testing, he or she is limiting the number of patients being seen and the efficiency of his or her interface with the patient.

“I have chosen to extend and maximize my time by employing talented staff and moving them into a position of responsibility to utilize diagnostic equipment, acquire data and subsequently work with me in the disposition of the patient by setting appointments and instructing them on medical therapy,” he continued. “This has proven to be a an ideal way to maximize my time in that it gives me the opportunity to interact with patients in the exam room, finalizing the diagnostic and therapeutic plan, instead of tied up running routine tests.”

Thimons emphasized the importance of evaluating a specific technology’s impact on your unique patient base, how you will implement it and whether it will complement existing systems.

Elliot M. Kirstein, OD, FAAO, has also been using the UBM for more than 3 years for diagnosing and managing glaucoma.