Clinical histopathologic characteristics of lacrimal glands in lacrimal gland prolapse with blepharochalasis

Objective: To analyze the clinical histopathologic characteristics of lacrimal glands and possible mechanisms of lacrimal gland prolapse in blepharochalasis (BC). Methods: A case-controlled study of 23 consecutive patients with prolapse of lacrimal glands in BC was performed. All samples were obtained during surgery from the Department of Ophthalmology, Beijing Tongren Hospital, Capital Medical University between January 2009 and December 2016. The lacrimal tissue included prolapsed lacrimal glands (30 samples) and controls from the donors in the eye bank of Beijing Tongren Hospital, Capital Medical University (8 samples). Hematoxylin-eosin staining, special staining, immunohistochemistry and colloidal gold-labeled pre-embedded indirect immunogold electron microscopy (Gold-IIEM) were performed to analyze the histopathologic characteristics of the samples. The nonparametric Wilcoxon signed-ranks test was carried out for statistical analysis. Results: Among the 23 patients with lacrimal gland prolapse in BC, there were 3 males and 20 females. The mean age of morbidity was 11 years old (7-16 years). In the 8 normal control cases, 3 males and 5 females were included. The mean age was 15 years (10-20 years). In the 30 prolapsed lacrimal gland samples, hematoxylin-eosin staining showed enlargement of glandular lumina accompanied by inflammatory infiltrates of interstitial tissue in 2 samples. Marked loosening of collagen fibers of the obtainable lacrimal fascia was observed. The results on immunohistochemical staining demonstrated an increased level of immunocytes in the 30 prolapsed lacrimal gland samples, including IgA (+++, ++, +, -; 12, 11, 4, 3 vs. 0, 0, 1, 7; Z=-3.892), CD3(+)T cells (+++, ++, +, -; 2, 19, 7, 2 vs. 0, 0, 1, 7; Z=-4.168), matrix metalloproteinase (MMP)-3 (+++, ++, +, -; 0, 0, 11, 19 vs. 0, 0, 0, 8; Z=-2.005) and MMP-9 (+++, ++, +, -; 14, 14, 0, 2 vs. 0, 0, 0, 8; Z=-4.552) (all P 0.05). Gold-IIEM showed zymogon granules in lacrimal glands were out of shape. MMP-3 and MMP-9 colloidal gold particles existed on the zymogon granules, and MMP-3 colloidal gold particles also existed on the surface of lacrimal gland epithelial cells. Conclusions: The histopathological changes in the lacrimal glands of lacrimal gland prolapse with BC include inflammatory infiltration, elastic fiber degeneration, marked loosening of the supporting fascia tissue, and an increased level of immunocytes, including IgA, CD3(+)T cells, MMP-3 and MMP-9. The results suggest that lacrimal gland prolapse with BC may result in the immuno-pathogenetic mechanisms with the involvement of cell-mediated immune responses. (Chin J Ophthalmol, 2020, 56: 205-210).