Immune checkpoint inhibitor-associated ON appears to differ from typical ON

This retrospective case series describes 11 patients optic neuritis (ON) associated with immune checkpoint inhibitors.

Study design

Researchers assessed 18 eyes of 11 patients with ON associated with immune checkpoint inhibitors who were diagnosed at 3 centers between May 2017 and January 2020. They provide the details and outcomes from this rare but increasingly recognized complication.

Outcomes

Optic neuritis was associated with all 3 classes of immune checkpoint inhibitors (anti-cytotoxic T-lymphocyte associated antigen 4, anti-programmed cell death protein 1, and anti-programmed cell death ligand 1). Immune checkpoint inhibitor-associated ON occurred after a median of 4 drug cycles and 64% of cases were bilateral. Only 1 patient (10%), who also had coinciding uveitis, experienced eye pain. Dyschromatopsia was present in 67% of patients. Visual field defects were variable; patterns were diffuse (28%), arcuate or altitudinal (39%), central or cecocentral (22%), and no defect (11%). Ten patients had optic disc edema at presentation. Imaging by MRI often did not show enhancement of the optic nerve. The majority of patients received steroids and had improvement in vision.

Limitations

This was a retrospective study on a relatively small number of patients with variable treatment regimens.

Clinical significance

This study demonstrates that immune checkpoint inhibitor-associated ON tends to be different from typical optic neuritis in that it is more commonly bilateral, painless, spares color vision, is associated with disc edema, and lacks enhancement of the optic nerve on MRI. This complication should be on the differential diagnosis for any patient with new-onset vision loss while receiving checkpoint inhibitors.