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Research on the stability of a rabbit dry eye model induced by topical application of the preservative benzalkonium chloride.

Li C, Song Y, Luan S, Wan P, Li N, Tang J, Han Y, Xiong C, Wang Z - PLoS ONE (2012)

Bottom Line: Compared with normal, there were still significant differences in the results of Schirmer's tests and fluorescein staining in Groups BAC-W3 and BAC-W4 on day 7 (P<0.05) and in Group BAC-W5 on day 14 (P<0.05).Decreases in goblet cell density remained stable in the three experimental groups at all time points (P<0.001).Decreased levels of mucin-5 subtype AC (MUC5AC), along with histopathological and ultrastructural disorders of the cornea and conjunctiva could be observed in Group BAC-W4 and particularly in Group BAC-W5 until day 21.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.

ABSTRACT

Background: Dry eye is a common disease worldwide, and animal models are critical for the study of it. At present, there is no research about the stability of the extant animal models, which may have negative implications for previous dry eye studies. In this study, we observed the stability of a rabbit dry eye model induced by the topical benzalkonium chloride (BAC) and determined the valid time of this model.

Methods and findings: Eighty white rabbits were randomly divided into four groups. One eye from each rabbit was randomly chosen to receive topical 0.1% BAC twice daily for 2 weeks (Group BAC-W2), 3 weeks (Group BAC-W3), 4 weeks (Group BAC-W4), or 5 weeks (Group BAC-W5). Fluorescein staining, Schirmer's tests, and conjunctival impression cytology were performed before BAC treatment (normal) and on days 0, 7, 14 and 21 after BAC removal. The eyeballs were collected at these time points for immunofluorescence staining, hematoxylin and eosin (HE) staining, and electron microscopy. After removing BAC, the signs of dry eye in Group BAC-W2 lasted one week. Compared with normal, there were still significant differences in the results of Schirmer's tests and fluorescein staining in Groups BAC-W3 and BAC-W4 on day 7 (P<0.05) and in Group BAC-W5 on day 14 (P<0.05). Decreases in goblet cell density remained stable in the three experimental groups at all time points (P<0.001). Decreased levels of mucin-5 subtype AC (MUC5AC), along with histopathological and ultrastructural disorders of the cornea and conjunctiva could be observed in Group BAC-W4 and particularly in Group BAC-W5 until day 21.

Conclusions: A stable rabbit dry eye model was induced by topical 0.1% BAC for 5 weeks, and after BAC removal, the signs of dry eye were sustained for 2 weeks (for the mixed type of dry eye) or for at least 3 weeks (for mucin-deficient dry eye).

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Representative images from scanning electron microscopy.Compared with normal eyes, there were fewer microvilli, and these microvilli were shorter and less regularly arranged on days 0 and 7 in Groups BAC-W2, BAC-W3 and BAC-W4, and on days 0, 7, and 21 in Group BAC-W5.
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pone-0033688-g007: Representative images from scanning electron microscopy.Compared with normal eyes, there were fewer microvilli, and these microvilli were shorter and less regularly arranged on days 0 and 7 in Groups BAC-W2, BAC-W3 and BAC-W4, and on days 0, 7, and 21 in Group BAC-W5.

Mentions: After the conclusion of BAC treatment, the number of microvilli on the corneal surface decreased significantly, the microvilli became shorter and irregularly arranged, and the micropores on the cell membrane decreased or even completely disappeared. This phenomenon was observable on days 0 and 7 in groups BAC-W2, BAC-W3 and BAC-W4 and on days 0, 7, and 21 in Group BAC-W5. As the amount of time that had elapsed after the cessation of BAC applications increased, the microvilli and micropores of the epithelial cells in Groups BAC-W2 and BAC-W3 gradually returned to normal levels by day 21. The number and morphology of microvilli in Group BAC-W4 recovered to normal on day 21, but the number of micropores was still slightly less than that it was prior to treatment. The numbers of both microvilli and micropores in Group BAC-W5 were still lower on day 21 compared with the numbers of microvilli and micropores in samples from the pre-treatment animals (Fig. 7).


Research on the stability of a rabbit dry eye model induced by topical application of the preservative benzalkonium chloride.

Li C, Song Y, Luan S, Wan P, Li N, Tang J, Han Y, Xiong C, Wang Z - PLoS ONE (2012)

Representative images from scanning electron microscopy.Compared with normal eyes, there were fewer microvilli, and these microvilli were shorter and less regularly arranged on days 0 and 7 in Groups BAC-W2, BAC-W3 and BAC-W4, and on days 0, 7, and 21 in Group BAC-W5.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3306287&req=5

pone-0033688-g007: Representative images from scanning electron microscopy.Compared with normal eyes, there were fewer microvilli, and these microvilli were shorter and less regularly arranged on days 0 and 7 in Groups BAC-W2, BAC-W3 and BAC-W4, and on days 0, 7, and 21 in Group BAC-W5.
Mentions: After the conclusion of BAC treatment, the number of microvilli on the corneal surface decreased significantly, the microvilli became shorter and irregularly arranged, and the micropores on the cell membrane decreased or even completely disappeared. This phenomenon was observable on days 0 and 7 in groups BAC-W2, BAC-W3 and BAC-W4 and on days 0, 7, and 21 in Group BAC-W5. As the amount of time that had elapsed after the cessation of BAC applications increased, the microvilli and micropores of the epithelial cells in Groups BAC-W2 and BAC-W3 gradually returned to normal levels by day 21. The number and morphology of microvilli in Group BAC-W4 recovered to normal on day 21, but the number of micropores was still slightly less than that it was prior to treatment. The numbers of both microvilli and micropores in Group BAC-W5 were still lower on day 21 compared with the numbers of microvilli and micropores in samples from the pre-treatment animals (Fig. 7).

Bottom Line: Compared with normal, there were still significant differences in the results of Schirmer's tests and fluorescein staining in Groups BAC-W3 and BAC-W4 on day 7 (P<0.05) and in Group BAC-W5 on day 14 (P<0.05).Decreases in goblet cell density remained stable in the three experimental groups at all time points (P<0.001).Decreased levels of mucin-5 subtype AC (MUC5AC), along with histopathological and ultrastructural disorders of the cornea and conjunctiva could be observed in Group BAC-W4 and particularly in Group BAC-W5 until day 21.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.

ABSTRACT

Background: Dry eye is a common disease worldwide, and animal models are critical for the study of it. At present, there is no research about the stability of the extant animal models, which may have negative implications for previous dry eye studies. In this study, we observed the stability of a rabbit dry eye model induced by the topical benzalkonium chloride (BAC) and determined the valid time of this model.

Methods and findings: Eighty white rabbits were randomly divided into four groups. One eye from each rabbit was randomly chosen to receive topical 0.1% BAC twice daily for 2 weeks (Group BAC-W2), 3 weeks (Group BAC-W3), 4 weeks (Group BAC-W4), or 5 weeks (Group BAC-W5). Fluorescein staining, Schirmer's tests, and conjunctival impression cytology were performed before BAC treatment (normal) and on days 0, 7, 14 and 21 after BAC removal. The eyeballs were collected at these time points for immunofluorescence staining, hematoxylin and eosin (HE) staining, and electron microscopy. After removing BAC, the signs of dry eye in Group BAC-W2 lasted one week. Compared with normal, there were still significant differences in the results of Schirmer's tests and fluorescein staining in Groups BAC-W3 and BAC-W4 on day 7 (P<0.05) and in Group BAC-W5 on day 14 (P<0.05). Decreases in goblet cell density remained stable in the three experimental groups at all time points (P<0.001). Decreased levels of mucin-5 subtype AC (MUC5AC), along with histopathological and ultrastructural disorders of the cornea and conjunctiva could be observed in Group BAC-W4 and particularly in Group BAC-W5 until day 21.

Conclusions: A stable rabbit dry eye model was induced by topical 0.1% BAC for 5 weeks, and after BAC removal, the signs of dry eye were sustained for 2 weeks (for the mixed type of dry eye) or for at least 3 weeks (for mucin-deficient dry eye).

Show MeSH
Related in: MedlinePlus