Abstract
Abstract: :
Purpose: Delayed tear clearance has been associated with the ocular surface inflammation in dry eye patients, however the presence of tear film dysfunction in patients with primary blockage of lacrimal drainage system is unknown. The aim of this study is to determine the correlation between tear film abnormalities and lacrimal drainage system blockage. Methods: Schirmer test I with anesthesia, tear film break-up-time and grading of Meibomian gland dysfunction were performed in 17 eyes of 17 patients with functional blockage of lacrimal drainage system, 13 eyes of 13 patients with anatomic blockage of lacrimal drainage system and 11 eyes of 11 age-matched normal controls. Results: The mean values of Schirmer test I were 11.6 ± 2.7 mm in patients with functional blockage, 15.0 ± 2.2 mm in patients with anatomic blockage and 15.3 ± 3.5 mm in normal controls (p=0.59). The mean values of tear film break-up-time were 9.1 ± 2.2 sec in patients with functional blockage, 9.4 ± 1.4 sec in patients with anatomic blockage and 12.0 ± 2.0 sec in normal controls (p=0.504). However, Meibomian gland dysfunction was detected in 76.5% of patients with functional blockage, 53.8% of patients with anatomic blockage and 9.1% of normal controls (p=0,027). Conclusion: The results indicate an association of blockage of lacrimal drainage system with Meibomian gland dysfunction, but not with tear secretion or tear film break-up-time. The authors hypothesized that this association may be caused by one or more of the following reasons: (1) extension of the inflammatory process of the ocular surface/Meibomian glands through the lacrimal drainage system; (2) retention of inflammatory mediators responsible for Meibomian gland dysfunction; (3) reduction of the lipid fraction of the tear film responsible for carry out the flow through the canaliculi leading to a vicious cycle of delayed tear clearance and progressive blockage of lacrimal drainage system. Future studies are necessary to clarify the initial events and better strategies to treat these chronic conditions.
Keywords: 376 cornea: tears/tear film/dry eye • 452 lacrimal gland • 437 inflammation