Signs appear bilaterally, and the fundus can initially appear normal. At a later stage, the patient may show retinal atrophy, vascular attenuation, and disc pallor. Using optical coherence tomography and autofluorescence may help to evaluate the patient better.
“Just looking at the retina may not do it,” added Dr. Lam. “You should go ahead and use other diagnostic tests.”
If you suspect autoimmune retinopathy, Dr. Lam advised starting with a detailed history.
For example, patients with previous small cell lung, gynecologic, and breast cancers, as well as melanoma, are likely to develop the condition. A history of autoimmune disease, hereditary retina degeneration, or inflammatory retinopathy–such as acute zonal occult outer retinopathy–are important to identify other retinal conditions that mimic autoimmune retinopathy.
A key test for autoimmune retinopathy is the full-field electroretinogram (ERG), Dr. Lam said. He recommended following the ERG testing standards set forth by the International Society for Clinical Electrophysiology of Vision. He also cautioned that it may be more difficult to interpret the findings in older patients, as ERG declines with age but the range of what is normal increases with patient’s age. Clinicians can repeat the full-field ERG to assess progression or also perform a multifocal ERG if needed.
Other ways to test for autoimmune retinopathy include retinal antibody testing and performing a work-up for cancer.
If the ERG results show the cones are primarily affected, Dr. Lam said to consider anti-enolase syndrome.
“Autoimmune retinopathy is tricky because patients without a history of cancer can develop autoimmune retinopathy,” explained Dr. Lam. “Some normal subjects may test positive for anti-retinal antibodies. We still don’t know as much as we like to know about the spectrum of autoimmune retinopathies.”