The pathogenesis and treatment of lacrimal obstruction: The value of lacrimal sac and bone analysis.

INTRODUCTION. The cause of primary acquired nasolacrimal duct obstruction (NLDO) has not been fully elucidated. In an attempt to determine the role of an inflammatory etiology, the pathology of nasolacrimal sac and bone specimens was assessed and correlated with clinical lacrimal variables. MATERIALS AND METHODS. Lacrimal sac and bone tissues from patients with known NLDO were sampled at the time of external dacryocystorhinostomy (DCR). Histopathological analysis was carried out to determine the presence and degree of inflammatory changes present in the tissues, and to correlate them with the clinical presentation. RESULTS. Of 104 cases analyzed, bony inflammatory changes were seen in 14% and lacrimal sac inflammatory changes in 94%. All cases of bony inflammation had accompanying lacrimal sac inflammation. The inflammatory changes were independent of the following variables: gender, duration of symptoms, a history of dacryocystitis, the presence of a lacrimal sac mucocele, the location of obstruction, and the presence of lacrimal sac calculi. CONCLUSIONS. Inflammatory changes are almost invariably present in all patients with NLDO. Its occurrence in bone is probably secondary to lacrimal sac inflammation. Although attempts are made to perform DCR surgery only in the absence of lacrimal sac inflammation, almost all cases exhibit subclinical inflammation. This may suggest that bypassing this 'critical area' of the sac-duct junction, as in a dacryocystorhinostomy, would be more reasonable than to re-canalize through an inflammatory obstruction.