Lacrimal imaging findings in fellow asymptomatic eyes of unilateral epiphora.

To investigate the prevalence of subclinical anatomical and functional abnormalities of lacrimal drainage in fellow asymptomatic eyes of unilateral epiphora using dacryocystography and dacryoscintigraphy. Retrospective case note review of lacrimal imaging of adult patients presenting to a hospital Oculoplastic clinic with unilateral epiphora over 10 years. A total of 172 patients with unilateral epiphora were included. The median age was 67 (range 18-96 years). A dacryoscintigraphy (DSG) abnormality was present in 54 (42%) asymptomatic eyes, and dacryocystography (DCG) abnormality in 10 (10%). The most common finding on DSG was no delay in 76 eyes (58%), and most common DSG abnormality was post sac delay in 51 (39%) eyes. The most common finding on DCG was no obstruction in 88 (90%) eyes, and the most common DCG abnormality was post sac stenosis (7.1%). Of the 92 asymptomatic eyes with both DCG and DSG, 53 (57%) showed neither an obstruction on DCG or delay on DSG, and 28 (30%) showed a post sac delay on DSG and no abnormality on DCG. Greater than a third of asymptomatic eyes displayed post sac delay on DSG, frequently without accompanying anatomical obstruction on DCG. Subclinical DSG delay in asymptomatic eyes may represent physiological variation in tear transit time, subclinical lacrimal drainage dysfunction or anatomical stenosis undetected by DCG. Furthermore, the DSG results of fellow asymptomatic eyes in unilateral epiphora may not represent a normal standard that can be utilised for comparison. Further investigation with dacroyendoscopy, the use of control eyes, and long term follow up is required.