Measurement of pH, Electrolytes and Electrophoretic Studies of Tear Proteins in Tears of Patients with Dacryoliths: A Novel Concept for Dacryoliths

Abstract

Dacryolithiasis is one of the causes of acquired nasolacrimal duct obstruction, although its origin is unclear. The purpose of this study was to investigate the differences in tear constituents between patients with nasolacrimal duct obstruction with dacryoliths and those without dacryoliths. In a prospective case-control study, undiluted tears were collected from 30 eyes from 30 patients with partial acquired nasolacrimal duct obstruction (PANDO) consisting of 17 PANDO patients with dacryoliths and 13 PANDO patients without dacryoliths. The pH, and the Na⁺, K⁺, Cl^–, total calcium and total protein concentrations were determined. The composition of the tear proteins was assessed by cellulose acetate electrophoresis. In the tear samples from 17 eyes with PANDO/dacryoliths, the mean ± SD K⁺ level was 15.6 ± 3.1 mEq/l. In the tear samples from 13 PANDO controls, the mean ± SD K⁺ level was 19.8 ± 4.9 mEq/l. The difference between the two groups was statistically significant (p = 0.02). In the tear samples from PANDO/dacryolith patients, the mean ± SD total protein level was 129.0 ± 72.9 mg/dl. In the tear samples from the PANDO controls the mean ± SD total protein level was 261.6 ± 132.5 mg/dl. The difference between the two groups was statistically significant (p = 0.00). In the tear protein fractions from electrophoresis, a low level of lysozyme was observed in the PANDO/dacryolith samples compared with the PANDO control samples (p = 0.03). The tears from patients with PANDO due to dacryoliths showed a change in the concentrations of electrolytes and protein, particularly lysozyme, compared with that of the patients with PANDO without dacryoliths, which may be related to the pathogenesis of dacryoliths.

Calcification associated with the nasolacrimal system of a horse: case report and mineralogic composition

“…4) indicate the presence of Ca, P, Cl, and Na (in that relative order of abundance), consistent with the observation that the dacryolith was composed of mainly hydroxylapatite with minor halite. As in other reports, this analysis did not reveal an etiology 1,2,5 …”

“…Dacryocystitis has been recognized as a significant predisposing factor; however, it remains unclear if the cause relates to the calculus or the inflammation. Stasis of secretions without preexisting dacryocystitis has also been considered significant to the formation of dacryoliths in idiopathic primary acquired nasolacrimal duct obstruction cases 5 . Unfortunately, a unifying theory to the existence and formation of dacryoliths does not exist.…”

TFF peptides and mucins are major components of dacryoliths

“…Atomic absorption spectrophotometric investigations demonstrate that dacryoliths consist almost entirely of organic proteins and, to a much lesser extent, of inorganic material [15]. According to Lew et al [13], lacrimal fluid from patients with dacryoliths contains a reduced amount of lysozyme and a lower calcium concentration than normal lacrimal fluid. Some stones reveal hyphae-like structures although no fungi are recovered by culturing [15].…”

Lesions of the lacrimal drainage system: a clinicopathological study of 643 biopsy specimens of the lacrimal drainage system in Denmark 1910−1999

“…The mechanism of dacryolith formation is still not well understood (Yazici et al 2001), but concrements in the lacrimal drainage system have been associated with Candida (Jones 1965) and Actinomyces (Smith & Henderson 1980; Font 1996). These micro‐organisms may possibly act as a nidus for calculus formation, and their presence is more likely in tears with reduced levels of potassium and proteins (Lew et al 2004). The increased frequency of dacryolithiasis in our study could be the result of changes in the referral pattern among ophthalmic surgeons (Fig.…”