title: MMP expression in leaking filtering blebs and tears after glaucoma filtering surgery.
abstract: OBJECTIVE
  Glaucoma filtering surgery may be compromised by cystic blebs which develop more frequently when anti-metabolites are used to arrest wound healing. Matrix metalloproteinases (MMPs) and the naturally occurring tissue inhibitors of metalloproteinases (TIMPs) are essential in connective tissue remodeling and wound healing. This study aimed to determine whether filtering blebs display increased expression of MMP-2, MMP-9, TIMP-1 and TIMP-2, and whether it is reflected in tear fluid.
  
  
  METHODS
  Tissue samples from leaking blebs (n = 5) and control conjunctiva (n = 5) were evaluated by immunohistochemistry for MMP-2, MMP-9, TIMP-1 and TIMP-2. Tear fluid was collected from 12 patients (12 eyes) with cystic blebs and ten patients (ten eyes) with flat blebs following trabeculectomy with Mitomycin C applied and 16 controls. MMP levels were evaluated by zymography and TIMP levels by Western blot analysis.
  
  
  RESULTS
  Conjunctival tissue was obtained from five eyes with cystic leaking blebs and five control eyes undergoing cataract surgery. More extensive MMP-2 and MMP-9 expression was found in the epithelial and stromal layers of blebs than in control conjunctiva. TIMP-1and TIMP-2 were expressed in all layers of the blebs, but only in the epithelium of control conjunctiva. MMP-2 and proMMP-2 activity in tears from eyes with flat blebs was significantly higher than that of controls, while activity in tears of eyes with cystic blebs was significantly higher than in those with flat blebs. There was no difference in MMP-9 activity between tears of control and post-filtering surgery eyes.
  
  
  CONCLUSIONS
  Increased MMPs and TIMPs expression is associated with the formation of filtering blebs, suggesting involvement of MMPs in bleb remodeling. MMP-2 and ProMMP-2 levels in tear fluid may be markers for bleb configuration.
authors: Department of Ophthalmology, Carmel Medical Center, Haifa, 34362, Israel. matnurit@yahoo.com
authors: Nurit
authors: N
authors: Mathalone
authors: Sylvia
authors: S
authors: Marmor
authors: Michal A
authors: MA
authors: Rahat
authors: Nitza
authors: N
authors: Lahat
authors: Yoram
authors: Y
authors: Oron
authors: Orna
authors: O
authors: Geyer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000477:Alkylating Agents / Q000008:administration & dosage; D015153:Blotting, Western; D003228:Conjunctiva / Q000502:physiology* / Q000601:surgery; D005136:Eye Proteins / Q000378:metabolism*; D005260:Female; D005402:Fistula / Q000201:enzymology; D005902:Glaucoma, Open-Angle / Q000201:enzymology* / Q000601:surgery; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D045726:Metalloproteases / Q000378:metabolism*; D008875:Middle Aged; D016685:Mitomycin / Q000008:administration & dosage; D013666:Tears / Q000201:enzymology*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism; D014130:Trabeculectomy; D014945:Wound Healing / Q000187:drug effects
chemical_list: D000477:Alkylating Agents; D005136:Eye Proteins; D019715:Tissue Inhibitor of Metalloproteinase-1; C042434:tear proteins; D019716:Tissue Inhibitor of Metalloproteinase-2; D016685:Mitomycin; D045726:Metalloproteases; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9