Dacryolithogenesis or dacryolithiasis : the story so far

Abstract

The term dacryoliths refers to the concretions found within the lacrimal system. When the term dacryoliths is unspecified, it usually refers to the noninfectious dacryoliths commonly isolated from the lacrimal sac and the nasolacrimal duct. More often, they are diagnosed incidentally during a dacryocystorhinostomy, and the reported incidence among all dacryocystorhinostomy surgeries is 5.7% to as high as 18%. Dacryolithiasis is a complex process occurring within the lacrimal system, and current evidence suggests a multifactorial etiology. The sequence of events can be summarized broadly into 4 stages: stage of susceptibility, stage of initiation/trigger, stage of development, and stage of maintenance. The triggering event is the breach of the lacrimal sac or nasolacrimal duct epithelium, resulting in microtrauma with blood leakage. The blood clots act as a nidus for subsequent sequential laying of mucopeptides, cellular debris present locally, debris washed from the ocular surface, and extraneous agents in tears. This process is aided by altered rheology and composition of the tear film. After the formation of dacryoliths, extracellular neutrophil traps usually form on the surface, which help to maintain the dacryoliths (which do not dissolve). This review highlights and discusses the possible sequence of events during dacryolithiasis.