Secondary Acquired Nasolacrimal Duct Obstruction as a Specific Complication of Treatment With Radioactive Iodine (Morphological Study)

Abstract

Purpose: To conduct a morphological study of structural changes in the nasolacrimal duct in secondary acquired nasolacrimal duct obstruction (SALDO) as a result of treatment with radioiodine. Methods: Twenty patients (20 cases) were involved: 10 cases with secondary acquired nasolacrimal duct obstruction at Hasner’s valve level due to the treatment with radioiodine (group 1) and 10 cases with primary acquired nasolacrimal duct obstruction (group 2). During surgery, a biopsy of nasolacrimal duct tissue from Hasner’s valve area was taken. A morphological study was performed using semi-fine sections technique. Results: Patients of group 1 showed the following: desquamation of columnar epithelium, pinpoint ulceration of nasolacrimal duct wall, collapse of a significant part of the capillary bed, and absence of blood cells in their lumen. State of secretory cells of mucous glands varied from necrobiotic to the different stages of dystrophic, decreased lumens of acini with abundant microvesicles in cell cytoplasm were revealed. A specific sign noted in patients of group 2 was mixed inflammatory infiltration of the mucosa of the nasolacrimal duct. The picture corresponds to the exacerbation of a chronic inflammatory process. Conclusions: Changes revealed in patients of group 1 include desquamation of nasolacrimal duct epithelium, mucous gland lesion, and moderate fibrosis that indicate a probable primary character of the lesion. In patients of group 2, fibrotic changes were more significant and were due to a chronic inflammatory process. Thus, secondary acquired nasolacrimal duct obstruction after treatment with radioactive iodine has a specific pathogenesis and should be classified as a separate nosological form.

Morphological Characteristics of the Lacrimal Apparatus in its Obstruction of Various Genesis

“…Previous studies on the comparative pathomorphological analysis of changes in Hasner's valve in PANDO and SALDO due to radioactive iodine therapy have shown that in the latter case speci c changes characterized as radiation damage to Hasner's valve develop [2]. It was found that in SALDO desquamation of the nasolacrimal duct epithelium and damage to the mucous glands are observed which is accompanied by moderate brosis, while in PANDO brosis is relatively more pronounced and is apparently a consequence of a long-running chronic in ammatory process.…”

“…Experience has shown that such obstruction develops most often in the distal segments of the nasolacrimal duct and is characterized by some pathomorphological features that distinguish primary and secondary acquired lacrimal drainage system obstruction [2]. A comparative study of changes in the lacrimal drainage system at various anatomical levels in patients with PANDO and SALDO due to radioactive iodine therapy has not yet been conducted, although the results of such a study would provide information concerning the pathogenesis of these conditions.…”

Topical Application of Perchlorate: A Toxicity Study in Rats

“…7 Fedorov et al reported the morphological changes associated with nasolacrimal duct obstruction as a complication from I-131, and observed desquamation of columnar epithelium, ulceration of nasolacrimal duct wall, and necrobiotic mucous glands. 13 Additionally, they compared the histologic changes observed to primary acquired nasolacrimal duct obstruction in which they report a mixed inflammatory reaction suggestive of chronicity. This highlights the molecular difference in the pathological process of developing nasolacrimal duct obstruction secondary to I-131.…”

Nasolacrimal Duct Obstruction in the Patients Receiving Treatment for Cancer

“…The tear fluid is a blood ultrafiltrate, where some components can be in higher concentrations than in blood. Once the drugs gain adequate access to the tear ducts, their toxicity on the mucous membranes results in undesirable effects 11,12 …”