title: Lens cell populations studied in human donor capsular bags with implanted intraocular lenses.
abstract: OBJECTIVE
  Posterior capsule opacification is an ongoing cellular redistribution process. The level of viable cell coverage was therefore determined in human donor capsular bags with implanted intraocular lenses, and cellular morphology and ultrastructure were investigated in relation to cell type and level of differentiation.
  
  
  METHODS
  Donor capsular bags, retrieved at intervals of 4 months to 13 years after surgery, were investigated by phase optics before fixation. Postfixation techniques included scanning electron microscopy and transmission electron microscopy of sections and immunofluorescent staining of cytoskeletal proteins in wholemounts.
  
  
  RESULTS
  All the capsular bags contained a large population of viable cells on the capsular surfaces. Cells on the anterior face of the anterior capsule and in the spaces around the intraocular lens had an elongated morphology and expressed alpha-smooth muscle actin. The cells formed light-scattering, multilayered aggregates and strands that were surrounded by layers of extracellular matrix. The regions between the intraocular lens and the equator of the bags were populated by monolayers of epithelial cells of normal morphology and ultrastructure, on both the anterior and posterior capsules. In some regions the apical surfaces of the two epithelial monolayers were in contact, and in some parts of the equatorial regions, differentiation of cells into well-organized fiberlike cells was evident.
  
  
  CONCLUSIONS
  Human capsular bags contain a large population of viable cells for many years after cataract surgery. Cells in the regions around the intraocular lens undergo transition to a mesenchymal type. Cells peripheral to these regions can form a stable closed microenvironment in which both normal epithelial morphology and differentiation to fiberlike cells are maintained.
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich, United Kingdom. j.marcantonio@uea.ac.uk
authors.forename: J M
authors.initials: JM
authors.lastname: Marcantonio
authors.forename: J M
authors.initials: JM
authors.lastname: Rakic
authors.forename: G F
authors.initials: GF
authors.lastname: Vrensen
authors.forename: G
authors.initials: G
authors.lastname: Duncan
mesh_terms: D000199:Actins / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020346:Aquaporins; D002387:Cataract Extraction; D002454:Cell Differentiation; D002648:Child; D004847:Epithelial Cells / Q000378:metabolism / Q000648:ultrastructure*; D005136:Eye Proteins / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007903:Lens Capsule, Crystalline / Q000166:cytology* / Q000378:metabolism; D019654:Lens Implantation, Intraocular; D008562:Membrane Glycoproteins; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D014019:Tissue Donors; D014746:Vimentin / Q000378:metabolism
chemical_list: D000199:Actins; D020346:Aquaporins; D005136:Eye Proteins; D008562:Membrane Glycoproteins; D014746:Vimentin; C030328:aquaporin 0