Comparison of dacryocystography and lacrimal scintigraphy in the diagnosisof functional nasolacrimal duct obstruction

Aim-It appears from the literature that no standardised examination exists for patients with functional nasolacrimal duct obstruction. The role of dac ryocystography and lacrimal scintigraphy was compared in the diagnosis and management of these patients. Method-Patients who were clinically diagnosed as having unilateral or bilat eral functional nasolacrimal duct obstruction were prospectively entered in to the study and data collected over 12 months in Moorfields Eye Hospital a nd Whipps Cross Hospital, London. All cases had, on separate occasions, a s tandardised dacryocystogram with delayed erect films and a lacrimal drainag e scintigram. Results-45 lacrimal systems of 32 patients (mean age 62 years; 59% male) fu lfilled the inclusion criteria. Abnormalities were detected with dacryocyst ography in 93% of systems and with lacrimal drainage scintigraphy in. 95% o f systems, Based on the results of previous quantitative studies, the posit ive scintigrams were subdivided into those demonstrating prelacrimal sac de lay (13%), delay at the lacrimal sac/duct junction (35%), or delay within t he duct (47%). Combining the two imaging techniques increased the sensitivi ty to 98%. Conclusions-Bath investigations are very sensitive at detecting abnormaliti es in patients with a clinical diagnosis of functional nasolacrimal duct ob struction. Lacrimal drainage scintigraphy is a slightly more sensitive test , but missed an abnormality detected by dacryocystography in two (4%) syste ms. A combination of the two techniques gives the highest sensitivity with maximum anatomical and physiological information but, in clinical practice, his reasonable to perform a dacryocystogram initially and proceed to scint igraphy only if contrast radiography is normal.