Abstract
Purpose:
To characterize the clinical, functional, and imaging features of patients with CAR and CAON, a form of autoimmune retinopathy and/or optic neuropathy secondary to cancer.
Methods:
Thirteen patients, age 45-76 yo (54% F, 31% AA), with CAR and/or CAON were retrospectively identified. Data analyzed included symptoms, visual acuity (VA), fundus features, Goldmann visual fields (GVFs), flash electroretinograms (ERGs), pattern-reversal visual evoked potentials (PVEPs), spectral domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF). Age of onset and AAb frequency were compared with those of 32 primary, not cancer-associated cases.
Results:
Compared to primary disease cases, CAR and CAON patients had significantly older onset. Patients >60yo were 11.3-fold more likely to have CAR/CAON (X2: 14.2, p=0.0002). The most common cancers were multiple myeloma, breast cancer, prostate cancer, and basal cell carcinoma (n=2 each). CAR/CAON patients also had fewer AAbs (1-2) than primary cases (up to 6, p <0.039). Patients with <3 AAbs were 5-fold more likely to have CAR/CAON (χ2 5.89, p= 0.015). Most patients (62%) had anti-alpha enolase AAbs. Photophobia (87%), nyctalopia (73%) and decreased VA (67%) were the most common symptoms at onset. VA ranged from 20/20 to count fingers. Cone ERGs were reduced and delayed in 100% of CAR cases. Changes at or around the disc, delayed PVEP timing, bundle-like/wedge-shaped defects and enlarged blind spots on GVFs were seen in all cases. Increased and/or reduced RNFL thickness on SD-OCT was also seen often. Four cases had CAON only. The most common retinal SD-OCT findings (n=10) were photoreceptor IS/OS junction loss (60%) and choroidal thinning (60%). FAF findings (n=10) included mainly hypo-AF changes with various patterns (focal, multifocal, diffuse, coarse mottling). In one case (rectal cancer with anti-alpha-enolase AAbs and CAON>CAR findings), IHC of intraoperative tumor tissue samples showed diffuse staining of cancer tissue by the patient serum.
Conclusions:
In addition to pure CAON, optic nerve involvement is also extremely common also in CAR. Signs of cone dysfunction prevail in CAR. Direct connection to cancer was shown in one case. Age >60 and <3 AAbs was predictive of higher likelihood of CAR or CAON compared to primary AIR or AON. These criteria may be useful to diagnose a paraneoplastic process.
Keywords: 432 autoimmune disease •
441 CAR •
695 retinal degenerations: cell biology