title: Induction of posterior capsule opacification by hyaluronic acid in an ex vivo model.
abstract: OBJECTIVE
  Because hyaluronic acid (HA) is found in many surgical viscoelastic agents, this study aimed to determine (1) if HA receptors are present in the canine lens, (2) if the rate of lens epithelial cell (LEC) migration is altered following treatment with HA, and (3) if introduction of exogenous HA into the lens capsule promotes lenticular migration, thus contributing to posterior capsule opacification (PCO).
  
  
  METHODS
  Normal and cataractous canine LECs were evaluated for expression of the HA receptor CD44 and the receptor for HA mediated motility (RHAMM) using immunohistochemistry, immunoblotting, and real-time PCR. Canine LEC were treated with various concentrations of HA, and induction of migration was monitored over time. Commercially available surgical viscoelastics were utilized ex vivo, and rates of PCO formation were analyzed.
  
  
  RESULTS
  Basal protein and mRNA expression of both CD44 and RHAMM was noted. Cataractous canine LEC demonstrated significantly (P < 0.01) higher expression of CD44 but not RHAMM. Treatment with higher concentrations of HA resulted in a significant (P < 0.01) increase in CD44 mRNA and increased LEC migration in vitro. Use of CD44-neutralizing antibodies confirmed the role of CD44 in HA-induced lenticular migration. Viscoelastic material containing higher concentrations of HA led to increased rates of ex vivo PCO.
  
  
  CONCLUSIONS
  Exogenous HA can induce lenticular migration and CD44 expression. Use of surgical viscoelastics that contained HA resulted in increased rates of ex vivo PCO suggesting that judicious selection and use of viscoelastic material during cataract surgery is warranted.
authors.affiliation: College of Optometry , The Ohio State University, Columbus, Ohio, USA. chandler.111@osu.edu
authors.forename: Heather L
authors.initials: HL
authors.lastname: Chandler
authors.forename: David J
authors.initials: DJ
authors.lastname: Haeussler
authors.forename: Anne J
authors.initials: AJ
authors.lastname: Gemensky-Metzler
authors.forename: David A
authors.initials: DA
authors.lastname: Wilkie
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Lutz
mesh_terms: D000818:Animals; D015153:Blotting, Western; D058442:Capsule Opacification / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology; D002465:Cell Movement; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004285:Dogs; D005786:Gene Expression Regulation / Q000187:drug effects; D018960:Hyaluronan Receptors / Q000096:biosynthesis / Q000235:genetics; D006820:Hyaluronic Acid / Q000008:administration & dosage / Q000633:toxicity*; D007150:Immunohistochemistry; D007903:Lens Capsule, Crystalline / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D009883:Ophthalmic Solutions; D011379:Prognosis; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D055675:Viscosupplements / Q000008:administration & dosage / Q000633:toxicity
chemical_list: D018960:Hyaluronan Receptors; D009883:Ophthalmic Solutions; D012333:RNA, Messenger; D055675:Viscosupplements; D006820:Hyaluronic Acid