Conjunctivochalasis and Tear Osmolarity Are Associated With Reduced Conjunctival Epithelial Thickness in Dry Eye

center dot PURPOSE: To investigate the hypothesis that ocular surface epithelial thickness is correlated with tear osmolarity, conjunctivochalasis (CCh), and dry eye clinical tests. center dot DESIGN: A case-control study. center dot METHODS: A total of 50 patients with different types of dry eye disease (DED) and 15 age-and sex-matched control subjects were enrolled in this study. We performed a detailed diagnostic assessment of tear film and ocular surface parameters, including Ocular Surface Disease Index questionnaire, visual analog scale questionnaire, topographic surface regularity and surface asymmetry indices, tear film break-up time, corneal and conjunctival dye staining, Schirmer I test, and tear osmolarity. The corneal and bulbar conjunctival epithelial thickness (CET) were obtained using the latest version of spectral domain optical coherence tomography (SDOCT). center dot RESULTS: Patients with aqueous-deficient DED (ADDED) had lower bulbar CET values, particularly in the temporal region, than those of normal subjects and patients with evaporative-type DED (EDED); however, the difference did not quite reach a statistically significant level. Patients with DED and CCh had lower bulbar CET values in temporal (38.52 +/- 9.58 & micro;m) and inferior regions (50.79 +/- 9.10 & micro;m) compared to those with DED without CCh (47.39 +/- 11.71 & micro;m, 60.38 +/- 14.36 & micro;m, respectively, P < .02). In the DED group, tear osmolarity was found to be negatively correlated with CET values in temporal bulbar region ( P = .006 and r = -0.403) and central corneal epithelial thickness values ( P = .029 and r = -0.325). center dot CONCLUSIONS: CCh and tear osmolarity are associated with reduced conjunctival epithelial thickness in DED. (Am J Ophthalmol 2021;227: 35-44. (c) 2021 Elsevier Inc. All rights reserved.)