Glutamic acid decarboxylase (GAD-65) and glycine receptor (GlyR) autoimmunity includes a wide range of clinical phenomena including stiff-person syndrome and epilepsy. Both GAD and GlyR interact with the retina. Optical coherence tomography (OCT) has previously been used in a variety of other neurological disorders to establish baseline characteristics and monitor disease course. This presents a noninvasive opportunity to evaluate for a biomarker that may assist with treatment of these rare but debilitating disorders.
To provide a description of the retinal nerve fiber layer (RNFL) in patients with GAD-65 and GlyR neurological autoimmunity.
OCT measures of RNFL were studied in patients with GAD-65 and GlyR neurological autoimmunity and compared to that of 148 healthy control eyes and 472 eyes from patients with multiple sclerosis.
The 15 patients were mostly female, in keeping with reported female preponderance in these conditions. We report initial post-diagnosis mean RNFL thickness and standard deviations, by sector, for the whole group, as compared with respective controls and patients with multiple sclerosis. Multiple sectors showed RNFL thinning, most apparent in the anti-GAD-65 group.
This study provides insight into baseline post-diagnosis RNFL thickness in a group with GAD-65 and GlyR autoimmunity, two conditions which may produce varied symptoms. While limited by sample size, RNFL thinning was most evident in the anti-GAD-65 group, and to a lesser extent, in the anti-GlyR group. This provides a baseline characterization and suggests that future studies should be done to determine the utility of OCT as a biomarker for these conditions.