Article Text

Download PDFPDF
Polycarbonate membrane impression cytology: evidence for fluorescein staining in normal and dry eye corneas
  1. Sumeer Thinda1,
  2. Puneeta K Sikh1,
  3. Lawrence M Hopp1,
  4. Ben J Glasgow1,2
  1. 1Jules Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
  2. 2Department of Ophthalmology and Pathology, Jules Stein Eye Institute, Los Angeles, California, USA
  1. Correspondence to Dr Ben J. Glasgow, Department of Ophthalmology and Pathology, Jules Stein Eye Institute, 100 Stein Plaza, Room B-279, Los Angeles, CA 90095, USA; bglasgow{at}


Background/aims Corneal impression cytology is usually performed with mixed cellulose ester membranes and a limited array of stains. A method using polycarbonate membrane air-dried preparations led to the discovery of fluorescein staining in cells from patients with and without dry eye disease and a membrane-induced defect that was not due to cell removal.

Methods Impressions after fluorescein installation were performed using polycarbonate and mixed cellulose ester membranes with rapid staining protocols for Diff-Quick as well as haematoxylin and eosin stains. Prior to staining the air-dried material was examined for fluorescence.

Results Epithelia of both normal and dry eye corneas retained fluorescence from clinical instillation of fluorescein. Corneal defects created by the polycarbonate membrane could not be explained by membrane-induced cell removal. After rapid staining, polycarbonate membranes revealed less background, dissolved easily prior to coverslip application, but showed lower cellular yield compared with the mixed cellulose membranes.

Conclusion Polycarbonate membrane impression cytology enables immediate assessment with rapid stains. Topically applied fluorescein penetrates corneal epithelial cells in both normal and dry eye patients. Cells fluoresce on the cytology membranes. The impression-induced defect on the cornea is not due to cell stripping and may represent removal of mucins.

  • Diff-Quick, dry eye
  • impression cytology
  • polycarbonate
  • fluorescein

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Funding NIH R01-EY 11224 and the Edith and Lew Wasserman Professorship in Ophthalmology.

  • Competing interests None declared.

  • Patient consent Obtained.

  • Ethics approval Obtained.

  • Provenance and peer review Not commissioned; externally peer reviewed.