A Critical Step in Uveitis Diagnosis & Management | Ultra-Widefield Imaging

A Critical Step in Uveitis Diagnosis & Management | Ultra-Widefield Imaging

August 03, 2022

Uveitis is a notoriously challenging disease to manage. Among the leading causes of vision loss worldwide, it can stem from a wide variety of infectious and noninfectious etiologies.

Therefore, a multipronged assessment designed to gather as much information as possible regarding the cause and severity of the disease is critical to determine the most appropriate treatment regimen.

Fluorescein angiography (FA) and indocyanine green angiography (ICGA) are vital examinations in the evaluation of uveitis. Traditional angiography takes images of central retina 30°–55°.

The peripheral retina image is hard to obtain, and the quality is degraded due to the eye’s optical aberrations.

To overcome the limitations, 7 or 9field montage FA images are commonly used to demonstrate the findings of peripheral retina and can extend up to 96° under ideal circumstances.

However, montage FA images require highly skilled technicians, cooperative patients, and could not get simultaneous images of the posterior pole and the periphery.

Ultrawidefield (UWF) imaging is the imaging angles larger than the standard reference 30° and the widefield 55°. Several contact imaging systems have been developed for providing wider field retina image.

These include the Pomerantzeff camera, the Retcam (Clarity Medical Systems, Inc., Pleasanton, CA, USA), the Panoret1000™ camera (Medibell Medical Vision Technologies, Haifa, Israel), and the Staurenghi lens (Ocular Staurenghi 230 scanning laser ophthalmoscope (SLO) Retina Lens; Ocular Instruments Inc., Bellevue, WA, USA), allowing imaging up to the 100°–160° but with limited resolution.

With the introduction of the confocal SLO, UWF angiography (UWFA) has obtained the more distinct images of peripheral retina previously unavailable and moreover in a single shot. One of the most widely used UWF systems is the Optos®

Uveitis is a notoriously challenging disease to manage. Among the leading causes of vision loss worldwide, it can stem from a wide variety of infectious and noninfectious etiologies.

Therefore, a multipronged assessment designed to gather as much information as possible regarding the cause and severity of the disease is critical to determine the most appropriate treatment regimen.

GO BEYOND THE REFERRAL

An evaluation always begins with obtaining a thorough patient history. While notes from the referring physician are important, they cannot be relied upon solely.

We obtain a detailed ocular history, including symptom recurrence, duration, and severity as well as other ocular surgeries or trauma. We review the systemic history, including other illnesses or diseases as well as exposure to uveitis risk factors.

Such review is critical, as diseases afflicting other organs in the body such as the kidney or lungs might preclude the use of certain types of medication.

Finally, we document the patient’s treatment history, including the dosage of medication(s) and duration of therapy previously prescribed, as well as whether a certain course of therapy failed previously, or the patient experienced recurrences of disease.

SEEING “THE BIG PICTURE”

A thorough clinical examination must include both physical evaluations (ie, slit lamp, indirect ophthalmoscopy, and direct contact lens biomicroscopy) and retinal imaging, considering information garnered from both the anterior and posterior segments.

Performing an anterior segment OCT may be helpful for evaluating the cornea. For the posterior segment, ultra-widefield imaging (UWF) is the most efficient and effective tool.

While a typical fundus photograph captures 30 degrees of the retina and ETDRS 7 standard fields requires the compilation of 7 of these images to reach approximately 75 degrees, optomap UWF Imaging (Optos plc) captures 200 degrees (82%) in a single capture.

No other imaging platform offers the ability to see this far into the periphery. The ability to do so is essential, as lesions often occur in the peripheral retina and their presence would impact treatment decisions.

Utilization of wide angle imaging was demonstrated for the first time almost 10 years ago in 2 separate studies evaluating the use of UWF technology in the management of noninfectious posterior uveitis and noninfectious retinal vasculitis.

The first study, a prospective, observational case series, set out to determine how often disease management decisions changed based on the additional information garnered from UWF fundus images and UWF fluorescein angiography (FA).

The results showed that investigator review of UWF and UWF FA led to management changes in nearly half (48%) of the patients evaluated. In the second study, evaluation of UWF pseudocolor images led to a 14% increase in management changes, while UWF FA images led to a 51% increase.

When evaluating a UWF FA image, it is important to look at the perfusion or leakage of the vessels. The presence of retinal vascular leakage and peripheral ischemia can be important signs of significant posterior segment inflammation.

These are examples of peripheral findings that would go undetected with traditional fundus photography, but that UWF is able to capture. UWF retinal imaging also supports disease documentation.

Depending on the extent of peripheral pathology identified in an initial capture, it might be prudent to reexamine after a period of time and compare the images to assess disease activity and progression before initiating treatment.

Image comparison is especially beneficial when evaluating for both efficacy and safety following treatment initiation.

UNDERSTANDING POTENTIAL SYSTEMIC DISEASE FACTORS

A third critical element of uveitis evaluation is laboratory evaluations. Identifying any potential problems such as low platelet or low white blood cell count, for example, is important when considering the potential root cause of the disease and, subsequently, determining the most appropriate treatment regimen.

A thorough initial investigation may also help determine the need to obtain specimen(s) to understand more, such as in the case of intraocular lymphoma, where one needs to look at the vitreous of the eye and not just the fundus.

By improving our understanding of the disease process, we may be better informed regarding our treatment and management decisions, which will hopefully lead to the best possible outcomes for our patients.

This approach is particularly important in uveitis, which has a broad array of etiologies, each requiring different therapeutic approaches. In our clinics, this multifaceted approach with the addition of UWF imaging has greatly improved our ability to diagnose and manage patients with uveitis.

This critical tool not only helps guide our treatment decisions, but also allows patients to be better informed should the need for intervention or procedures arise.