Effects of tear substitutes on conjunctival epithelium of mice

Ophthalmic Res. 2007;39(5):265-75. doi: 10.1159/000108120. Epub 2007 Sep 12.


Aim: The effects of the administration of three tear substitutes on normal conjunctival epithelium of the mouse, with particular regard to goblet cells, were studied.

Methods: Three-month-old Swiss CD 1 mice were divided into four groups of 7 animals each. Group 1 was untreated (control). The other animals were treated with the instillation of 5 drops/day for 10 days as follows: group 2, 0.2% sodium hyaluronate (SH); group 3, 0.5% hydroxypropylmethylcellulose (HPMC); group 4, 0.9% NaCl. The entire conjunctiva was processed for light and electron microscopy. A morphometric study was performed to evaluate: the number and size of goblet cells and the number, size and optical density of mucin granules. Furthermore, Alcian blue/periodic acid-Schiff (AB/PAS) staining for goblet cells was carried out.

Results: The SH-treated group showed that the area and number of goblet cells were similar to the untreated group; the mucin granules were reduced in number and optical density but increased in size. The HPMC-treated group showed a reduced area of goblet cells with reduced optical density of mucin granules. The saline-treated group showed that goblet cells were reduced in area and number; mucin granules showed a reduction in number and optical density and an increased size. The AB/PAS stain showed that each treatment was able to induce a treatment-specific modification of the staining characteristics of goblet cells.

Conclusion: Our results strongly suggest that tear substitutes can induce treatment-specific modifications of the conjunctival epithelium with particular regard to goblet cell structure and ultrastructure.

MeSH terms

  • Alcian Blue
  • Animals
  • Coloring Agents
  • Conjunctiva / cytology
  • Conjunctiva / drug effects*
  • Epithelial Cells / drug effects
  • Epithelial Cells / ultrastructure
  • Epithelium / drug effects
  • Goblet Cells / drug effects
  • Goblet Cells / ultrastructure
  • Hyaluronic Acid / pharmacology
  • Hypromellose Derivatives
  • Methylcellulose / analogs & derivatives
  • Methylcellulose / pharmacology
  • Mice
  • Microscopy, Electron
  • Mucins / metabolism
  • Ophthalmic Solutions / pharmacology*
  • Periodic Acid-Schiff Reaction
  • Secretory Vesicles / metabolism
  • Secretory Vesicles / ultrastructure
  • Sodium Chloride / pharmacology
  • Staining and Labeling


  • Coloring Agents
  • Mucins
  • Ophthalmic Solutions
  • Hypromellose Derivatives
  • Sodium Chloride
  • Hyaluronic Acid
  • Methylcellulose
  • Alcian Blue