Correlations between commonly used objective signs and symptoms for the diagnosis of dry eye disease: clinical implications

Purpose: To evaluate the relationship between signs and symptoms of dry eye disease (DED) in a clinic‐based population. Methods: In a retrospective analysis, clinical signs and symptoms were evaluated for 344 subjects (n = 82, normal; n = 263, dry eye), across 11 sites from the EU and United States. Pearson correlations between signs and symptoms (r²) and an independent components analysis (ICA) mixing matrix were derived from the data set. Similar analysis was performed on an independent data set from 200 subjects in a previous study in Munich, Germany. Results: No correlations above r² = 0.17 were found between any signs and symptoms, except for corneal and conjunctival staining, which reported an r² = 0.36. In the multisite study, the average r² for osmolarity (0.07), tear breakup time (0.12), Schirmer test (0.09), corneal (0.16) and conjunctival staining (0.17), meibomian grading (0.11) and Ocular Surface Disease Index^® (0.11) were consistently low. Among patients who showed evidence of DED by consensus of clinical signs, only 57% reported symptoms consistent with a diagnosis of DED. Similar results were observed in the Munich‐based study data set. Each component of the ICA mixing matrix exhibited minimal residual information. Conclusions: No consistent relationship was found between common signs and symptoms of DED. Each type of measurement provides distinct information about the condition of the ocular surface. These results also demonstrate that symptoms alone are insufficient for the diagnosis and management of DED and argue for a consensus of clinical signs that better reflect all aspects of the disease.