To characterize how neurosarcoidosis (NS) affects the optic nerve (ON) using optical coherence tomography (OCT) and assess its diagnostic utility in NS patients with and without neuro-ophthalmic manifestations.

The ON is the second most commonly involved cranial nerve in NS, yet the role of OCT in this population remains largely unexplored.

In this cross-sectional study, people with NS and age, sex, and race-matched healthy controls (HC) underwent OCT. Clinical data and magnetic resonance imaging (MRI) data were retrospectively reviewed. Only OCT scans meeting recognized quality control criteria were included. Analyses used linear generalized estimating equations.

A total of 239 NS and 256 HC eyes were included: 32 with ocular sarcoidosis (OcS), 42 with known clinical and/or radiological sarcoidosis-associated optic neuropathy (SAON), 11 with both OcS and SAON, and 154 eyes with NS but no known ocular or ON involvement (NSNON). Four mechanisms of SAON were identified: leptomeningeal infiltration/compression (47%), optic neuritis (43%), perineuritis (23%), and secondary to elevated intracranial pressure (13%).SAON eyes had lower peri-papillary RNFL (pRNFL) and ganglion cell+inner plexiform layer (GCIPL) thicknesses, as compared to HC (-16.9 µm and -11.7 µm respectively, p < 0.001 for all) and relative to OcS eyes (-16.0 µm and -12.0 µm respectively, p < 0.001 for all). OcS eyes had increased GCIPL thicknesses compared to HC (3.18 µm; p=0.035). Retinal layer thicknesses did not differ between NSNON and HC (-1.52 µm; p=0.298 and -0.43 µm; p=0.609, respectively).Quadrantal analysis of SAON revealed lower pRNFL thickness in all quadrants except nasal,as compared to HC (p=0.140).

Neuroaxonal injury to the ON in NS can be quantified by OCT. OCT is valuable in the diagnostic assessment of neuro-ophthalmic manifestations of sarcoidosis. Our findings do not suggest the presence of subclinical optic neuropathy in NS, unlike some other neuroinflammatory disorders. Future work will analyze longitudinal retinal changes.