Scleritis and episcleritis in patients with idiopathic small fiber neuropathy

Purpose: To report the prevalence of scleritis and episcleritis in patients with idiopathic small fiber neuropathy (SFN).

Methods: The Mass General Brigham (MGB) hospital database was queried for patients with SFN, scleritis and episcleritis using diagnostic codes and natural language processing. Electronic medical chart review of patients diagnosed with SFN and episcleritis/scleritis who had at least one ophthalmology visit was conducted. The prevalence of scleritis and episcleritis in patients diagnosed with SFN was compared to those without SFN using logistic regression to adjust for covariates. All statistical analyses were performed in RStudio 4.2.1.

Results: From the 2100 SFN patients with an eye exam in the MGB database, 23 patients had episcleritis or scleritis (1.1 %) confirmed by chart review. Ten patients had episcleritis (0.48 %) and thirteen patients had scleritis (0.62 %). Of the episcleritis and scleritis patients, 16 (69.6 %) were women and 7 (30.4 %) were men. Ten (43.5 %) had bilateral ocular disease. The mean age of ocular diagnosis was 51.0 years (range, 22-77 years). Out of the 507,128 controls without SFN in the MGB database, 1481 (0.29 %) had scleritis and 1430 (0.28 %) had episcleritis. Episcleritis and scleritis were more prevalent in patients with SFN than in those without SFN: 0.48 % vs. 0.28 % for episcleritis and 0.62 % vs 0.29 % for scleritis (P values = 0.32 and 0.02, respectively).

Conclusions and importance: There were higher rates of scleritis in SFN patients compared to non-SFN patients. This potential systemic disease association had not been previously reported.