Ultrasound biomicroscopy enhances ophthalmic imaging applications

Take-home

Advances in ultrasound biomicroscopy enable the capture of higher quality images to ophthalmic surgeons who seek accurate diagnoses or anatomic measurements.

Dr. De La Torre Estremadoyro

By Mario Danilo de La Torre Estremadoyro, MD, Special to Ophthalmology Times

Lima, Peru-As an ultrasound and imaging specialist, the goal is to present the highest-quality images to colleagues when they seek accurate diagnoses or measurements. Accordingly, this can best be achieved using the highest-quality imaging devices.

The objective of this article is to explain the utilization of ultrasound biomicroscopy (UBM) for patients with glaucoma and trauma, as well as for obtaining anatomy measurements. Additionally, in using one such UBM platform (Aviso S, Quantel Medical) in practice, not only do recorded examinations reduce the amount of paper used, but surgeons are also offered a photograph as well as real-time video by electronic media of the anterior and intermediate segment.

Glaucoma

Traditionally, UBM is used with patients with glaucoma in order to image anatomical structures of the angle and their relationship. The technology is valuable not only for confirming what is visualized with the slit lamp examination, but also for visualizing behind the iris and the anterior and posterior capsule.

Often, UBM serves as an educational tool for patients with glaucoma. Patients may not understand why they may need to undergo phacoemulsification if they do not have a cataract. When the technology can be used to show patients they have a thick lens that is closing the angle and to explain how removing it and implanting an IOL will open it and reduce angle-closure glaucoma risk, they are extremely receptive.

It is also important to highlight that UBM is the best way to describe the angle configuration and it is important in the decision to perform an iridotomy or an iridoplasty in presence of pupillary block or a plateau iris.

Ocular trauma

UBM is commonly used in patients who have experienced eye trauma. In these cases, “clear scan“ film is used in order to avoid direct contact or pressure on the eye, which is especially important when looking for trauma in the ciliary body or posterior capsule.

In addition, UBM is effective as a means to rule out a foreign body in the anterior segment, especially behind the iris, and is accordingly helpful for the anterior segment surgeon.

In patients with blunt trauma, UBM is helpful with viewing the position of the ciliary body for the possibility of ciliary detachment or choroidal effusions. The capsule integrity is examined because the posterior capsule could have been broken by the trauma and it could cause a masqueraded anaphylactic glaucoma. Surgeons can also have a good representation of the anterior segment even if the patient has severe anterior chamber bleeding.

Anatomical measurements

Surgeons around the world look for optical media to view ciliary body tumors or segmental angle closure. With the use of UBM, surgeons are able to to rule out the possibility of cysts or tumors because they can look behind the iris. Very often, there are patients with tumors of the conjunctiva that go into the cornea and sclera, and the surgeon wants to know the depth of the tumor infiltration. Also, surgeons can now describe the anatomy of the anterior and intermediate segment of the eye.

UBM is also used in refractive surgery, especially phakic IOLs. The technology enables surgeons to determine the exact measurement of the sulcus-to-sulcus distance and plan the surgery based on the assessment of where the lens should be located. It is possible to control the position of the lens to avoid ciliary body irritation that may lead to anterior uveitis and measure the correct distance between the lens and anterior capsule.

Retinal surgeons-looking for more precision and for ways to decrease damage to the eye caused by pars plana incisions-can use UBM to view the pars plana or look at the port of vitrectomy pre- and postoperatively.

Additionally, patients with congenital disease-such as iridocorneal endothelial syndrome, Peters-plus syndrome, posterior embryotoxon, and Axenfeld-Rieger syndrome-can benefit from UBM imaging to view changes in the anatomy and the anterior segment structures.

In Latin America, UBM reimbursement from insurance companies is uncommon. This is because it is considered a new technology, and insurance companies often resist adding new procedures to their catalog. If colleagues realize I have a powerful tool to help them make a diagnosis and solve problems, however, patients typically have no problem paying out of pocket.

I work with all kinds of imaging modalities, including anterior segment optical coherence tomography (OCT) and video slit lamp. These are not competing technologies. Rather, they are inclusive, they are complementary, and they are unique. As an ultrasound specialist, I must be able to provide those who refer their patients to me with the most superb image that I am capable of providing.

Mario Danilo de La Torre Estremadoyro, MD, is chairman, Ocular Imaging, Ultrasound, and Radiology Department, Instituto Nacional de Oftalmologia, Lima, Peru and assistant professor of Ophthalmology, Universidad Nacional Mayor de San Marcos. Dr. de La Torre is a medical consultant for Quantel Medical.