Upper and lower tear menisci in the diagnosis of dry eye

Purpose: To measure the upper and lower tear menisci in patients with aqueous tear deficiency (ATD) dry eye by realtime optical coherence tomography (OCT) and to determine the most effective meniscus variables for the diagnosis of dry eye. Methods: Eyes of 48 pre-screened ATD patients were compared with those of 47 healthy subjects. Upper and lower tear menisci were imaged simultaneously by real-time OCT immediately after blinking. The height, radius, and cross-sectional area of upper and lower tear menisci were obtained. Results: The tear meniscus radius, height, and cross-sectional area were significantly smaller in patients with dry eye than in healthy subjects (P<0.01). The lower tear meniscus variables were higher than the upper menisci (P<0.01) in normal subjects; however, no significant differences between menisci were found in ATD patients. In both groups, the upper and lower tear meniscus variables were strongly correlated with each other. Good dry eye diagnostic accuracies were obtained with cutoff values for an abnormal lower tear meniscus radius (LTMR) of 182 μm and a lower tear meniscus height (LTMH) of 164 μm. The LTMR diagnostic sensitivity and specificity were 0.92 and 0.87, respectively. The LTMH diagnostic sensitivity and specificity were 0.92 and 0.90. Conclusions: Upper tear meniscus variables in ATD patients were assessed by real-time OCT. The tear meniscus was smaller in ATD patients than in healthy subjects. LTMR and LTMH may have potential in the diagnosis of ATD.