The transit of Tc-99m pertechnetate through 122 lacrimal drainage systems was quantified. Systems were categorized as having presac, preduct, intraduct, or no delay. Scintigraphy indicated an obstruction in 81.3% of eyes with epiphora. Of the 18 eyes in whom only scintigraphy revealed an obstruction, all 3 who underwent surgery experienced symptom relief. In patients presenting with unilateral epiphora the mean canthus half-time (12.9 vs. 7.2 minutes), time-to-peak activity at the sac (11.6 vs. 3.1 minute), and sac half-time (19.0 vs. 10.3 minutes) were significantly prolonged in the symptomatic eye. Similarly, the sac-to-canthus (0.32 vs. 0.72), duct-to-canthus (0.32 vs. 0.99), and duct-to-sac ratios (0.48 vs. 0.79) of peak activity were all significantly reduced in the symptomatic eye. When compared with “no delay,” “presac,” “preduct,” and “intraduct” delay were significantly associated with attenuated clearance times or reduced ratios of peak activity corresponding to the level of obstruction. We conclude that there is a significant association between symptomatic epiphora and quantitative variables at the canthus and sac in lacrimal scintigraphy. Quantitative variables help locate the level of an obstruction.
From the *Sydney Eye Hospital, Sydney; †St. Vincent's Hospital, Sydney; ‡Department of Ophthalmology, Concord Repatriation General Hospital, Sydney; §University of Sydney, Sydney; ¶University of New South Wales, Sydney; ∥Sydney Oculoplastic Surgery, Sydney; **Department of Nuclear Medicine, Concord Repatriation General Hospital, Sydney; ††Department of Statistics, Macquarie University, Sydney; and ‡‡Department of Ophthalmology, Royal Prince Alfred Hospital, Sydney, Australia.
Received for publication July 23, 2007; accepted December 18, 2007.
Reprints: Hans Van Der Wall, MBBS, PhD, FRACP, Department of Nuclear Medicine, Concord Hospital, Hospital Road, Concord, NSW 2139, Australia. E-mail: email@example.com.