Tear meniscus volume in dry eye after punctal occlusion

PURPOSE. To use optical coherence tomography (OCT) to evaluate the effect of punctal occlusion on tear meniscus volume in dry eye patients. METHODS. Occlusion of both upper and lower puncta with collagen plugs was performed on one eye each in 20 dry eye patients and 20 normal subjects. The upper and lower tear menisci were imaged simultaneously by real-time OCT before punctal occlusion and on days 1, 4, 7, and 10 afterward. The heights, cross-sectional areas, and volumes of the menisci were obtained. Schirmer I test with anesthesia and tear break-up time (TBUT) testing were also performed. RESULTS. At baseline, both upper and lower tear meniscus heights and volumes in dry eye patients were lower than those in control subjects (P < 0.05). The volume of the lower tear meniscus was 0.28 ± 0.09 μL in dry eye patients and 0.55 ± 0.22 μL in control subjects at baseline (P < 0.05). After punctal occlusion, the Schirmer I test scores of dry eye patients did not change (P > 0.05), but the heights and volumes of the upper and lower tear menisci increased (P < 0.05). In control subjects, Schirmer I test scores decreased (P < 0.05), but the heights and volumes of the upper and lower tear menisci did not change (P > 0.05). CONCLUSIONS. Punctal occlusion induced increases in the upper and lower tear meniscus volumes in dry eye patients. The absence of change in the tear menisci of control eyes may indicate the presence of an autoregulatory mechanism in the tear system that maintains a balance in the tear volume.