Corneal Epithelial Thickness in Dry Eye Disease (DED) Patients: Association with Autoimmunity

Abstract

Purpose : Previous studies have shown that patients with DED display thinner superior corneal epithelium compared to normal controls. This retrospective, case-control study was designed to test our hypothesis that presence of autoantibodies is associated with superior epithelial thinning. We also assessed the link between corneal epithelial thickness and clinical findings and assessed the utility of including corneal epithelial thickness as a diagnostic tool for DED Patients.

Methods : This study includes around 200 patients who visited the DED clinic at UIC and had blood work results in their medical records for autoantibodies associated with DED related autoimmune diseases. If available, superior corneal epithelial thickness (ES), Schirmer’s I test, and corneal higher order aberrations (HOAs) were obtained from the patient's medical records. ES was determined with the RTVue XR OCT Avanti system and corneal HOAs were determined using the iTrace system. A two-tailed t-test was used for statistical analysis. A decision tree was used to determine feature variables and cutoffs necessary to accurately classify antibody positive and negative groups.

Results : Patients with antibody positive blood work (n = 208 eyes) had a significantly thinner superior corneal epithelial thickness (47.41 vs 49.73, p < 0.05) compared to patients with antibody negative blood work (n =181 eyes). Based on the decision tree, the top two most useful clinical indicators that a patient will have antibody positive blood work are a Schirmer’s < 15 and an ES < 45. Eyes with ES < 45 and Schirmer’s < 10 (n = 69 eyes) have significantly greater corneal HOAs (1.85 vs 0.1; p < 0.05) compared to eyes with ES ≥ 45 and/or Schirmer’s ≥ 10 (n = 164 eyes). If a patient’s eye has both ES < 45 and Schirmer’s < 10, the probability that they have autoantibody positive bloodwork is 81.16%.

Conclusions : Presence of autoimmune disease must be considered in patients who have superior epithelial thinning and reduced tear production because these patients are 5 times more likely to have antibody positive bloodwork, and associated visual compromise, as demonstrated by high corneal HOAs.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.