Pearls for better uveitis workups

Uveitis does not have to be vexing. Here are some basic principles to make it easier for ophthalmologists to identify the disorder.

Reviewed by James Philip Dunn Jr., MD

It may feel like searching for a needle in a haystack when performing a uveitis workup, said James Philip Dunn Jr., MD. However, some guiding principles can make it easier to drill down for causes of uveitis, said Dr. Dunn, Retina Service, and director of the Uveitis Unit, Wills Eye Hospital, Philadelphia. 

Three important pearls when considering uveitis are:

• to distinguish infectious from non-infectious uveitis,

• to distinguish disorders that are purely ocular versus uveitis associated with systemic conditions, and

• to obtain additional testing only if it affects management of the disease.

For the latter, this could include medical management, referrals to other physicians, and prognostic implications, Dr. Dunn said. He also encouraged ophthalmologists to distinguish infectious versus non-infectious uveitis and ocular versus systemic disease.

“If you break that down, finding the needle in the haystack is not that intimidating,” he said. “Think first about a proper history, then a careful exam, and then going back and reviewing parts of the history. Finally, there is judicious use of lab testing.”¹

DEFINE UVEITIS CHARACTERISTICS 

A project called the Standardization of Uveitis Nomenclature (SUN) has attempted to better define uveitis characteristics. Dr. Dunn reviewed various findings from the SUN criteria to assist in creating a more precise differential diagnosis.² First, consider the disease history, onset, and duration (such as whether it has been present in a patient for under 3 months or for 3 months or more).

Also, consider if the patient has a sudden onset flareup with limited duration; recurrent disease, defined as occurring more than 3 months after stopping therapy; or chronic uveitis (lasting more than three months or requiring ongoing suppressive therapy for more than three months).

“Laterality is also important,” Dr. Dunn said. “It could be unilateral, unilateral and alternating, bilateral simultaneous, or bilateral and asynchronous.”

Anatomic location-including anterior, intermediate, posterior, or panuveitis-is another key indicator. However, the presence of certain structural complications-such as macular edema-does not in and of itself define that area of the eye as being involved, Dr. Dunn said. For example, iridocyclitis with macular edema is classified as anterior uveitis, not panuveitis. The presence of cell or flare is another finding to consider.

“However, cell is not the same as flare,” he said. “Some diseases have more cell, and some have more flare.”

Take some time to characterize the hypopyon- its color, size, and whether it shifts with change in head position, as may occur in Behcet’s disease Also, consider keratic precipitates (KP) and  whether they are granulomatous or non-granulomatous, Dr. Dunn said.

Remember that granulomatous diseases (such as sarcoidosis) may present with non-granulomatous KP, but non-granulomatous diseases (such as HLA B27-associated uveitis) almost never present with granulomatous features. If a patient has posterior uveitis, try to define if it is retinitis, choroiditis, retinal vasculitis (such as arterial or venous), or a combination. For any lesions that are present, make note of their size, shape, and colo -all of which can be important for diagnostic purposes.

ADDITIONAL DATA

Other information that can assist with a uveitis diagnosis includes ocular comorbidities, response to treatment, ethnicity, medical conditions, family history, and travel or geography. Regarding geography, Dr. Dunn gave the example of a patient from Connecticut with uveitis in whom Lyme disease testing may be critical.

“However, if you’re in San Antonio, Texas, a Lyme titer probably won’t be helpful,” he said. When deciding on lab testing, Dr. Dunn urged physicians to think about the cost involved and how helpful the information actually may be.

For instance, a full autoimmune antibody panel might cost as much as $700. In another example he gave, the positive predictive value of a PPD test for tuberculosis in a patient with no risk factors for TB would only be 1%, rendering the test almost useless.

ORDERING TESTING

In his patients, Dr. Dunn usually orders a chest X-ray (or chest CT scan) and syphilis serology, because sarcoidosis and syphilis are almost always in the differential diagnosis of any type of uveitis. There are other tests that he will request but only in the appropriate context, such as HLA-B27, Lyme antibody testing, or interferon gamma releasing assay.

When he suspects infection, Dr. Dunn is more likely to order PCR testing from aqueous or vitreous specimens, as in acute retinal necrosis or ocular toxoplasmosis, because serologic testing lacks specificity. Not all physicians who work with uveitis take the same approach. 

However, Dr. Dunn said that the rigorous use of the SUN criteria will improve the efficiency of uveitis workups. 

JAMES PHILIP DUNN JR., MD
E: jdunn@willseye.org
This article was adapted from Dr. Dunn’s presentation during Retina Subspecialty Day at the 2017 meeting of the American Academy of Ophthalmology

Disclosures:

^1. Jabs DA, Busingye J. Approach to the diagnosis of the uveitides. Am J Ophthalmol. 2013;156:228-236.

^2. Jabs DA, et al. Standardization of uveitis nomenclature for reporting clinical data. Results of the First International Workshop. Am J Ophthalmol. 2005;140:509-516.