The role of cystoid macular edema as a marker in the progression of non-paraneoplastic autoimmune retinopathy.

PURPOSE: To determine the relationship between cystoid macular edema (CME) and disease severity and progression in non-paraneoplastic autoimmune retinopathy (npAIR).

METHODS: A retrospective study was conducted on patients seen between 2008 and 2016 with npAIR as defined by electroretinogram (ERG) dysfunction, visual field changes, presence of antiretinal antibodies, a negative malignancy workup, and no other apparent cause for visual dysfunction. Optical coherence tomography (OCT) scans were reviewed for each patient. A minimum follow-up of 1 year was necessary for study inclusion. The presence or absence of CME and the length of the preserved EZ on the centermost line scan of the SD-OCT images was recorded at each visit. The main outcome measure assessed was the rate of EZ loss (EZ final - EZ initial / days follow-up) over time, a marker for disease progression.

RESULTS: Thirty-two eyes (16 patients) were included with an average follow-up of 42 months. Twenty-one eyes (66%) had CME on initial presentation and final follow-up (group 1), eight eyes (25%) did not have CME on presentation or final follow-up (group 2), and three eyes (9%) did not have CME on presentation but developed CME during follow-up (group 3). Group 1 eyes had a lower maximal a-wave amplitude (59.0 vs. 220.9 mV, p = 0.012) and lower maximal b-wave amplitude (88.1 vs 256.9 mV, p = 0.017) on baseline ERG compared to Group 2 eyes. The rate of EZ loss over time was significantly greater for group 1 with CME compared to group 2 without CME both at 12 months (- 1.26 μm/day vs. - 0.26 μm/day, p = 0.022) and at final follow-up (- 1.03 μm/day vs. - 0.08 μm/day, p = 0.012).

CONCLUSIONS: CME was associated with decreased ERG amplitudes and greater velocity of EZ loss, suggesting that CME is a useful biomarker of more severe and more progressive disease in npAIR.