title: Topical silver nanoparticles result in improved bleb function by increasing filtration and reducing fibrosis in a rabbit model of filtration surgery.
abstract: OBJECTIVE
  To compare the effects of silver nanoparticles (AgNPs) and mitomycin C (MMC) on intraocular pressure (IOP) and external, histologic, and immunohistochemical bleb characteristics in a rabbit model of filtration surgery.
  
  
  METHODS
  Filtration surgery with concurrent topical application of either AgNPs or MMC was performed on 14 pigmented Dutch Belted rabbits. IOP and bleb characteristics were compared on postoperative day 1 and at weeks 1 through 6. Hematoxylin and eosin staining and smooth muscle actin (SMA) immunohistochemistry were performed at postoperative week 6.
  
  
  RESULTS
  Average IOP across all time points was reduced 5.8 and 3.8 mm Hg in AgNP- and MMC-treated eyes, respectively. At week 6, IOP was reduced 4.1 and 0.2 mm Hg in AgNP- and MMC-treated eyes, respectively. Blebs were smaller, thicker, and less ischemic in AgNP-treated eyes. AgNP-treated eyes showed less fibrosis and more stromal edema, suggesting increased filtration, and also had fewer SMA-positive myofibroblasts, suggesting reduced bleb contraction. AgNP-treated eyes showed more lymphocytes than MMC-treated eyes. There were few complications in both groups.
  
  
  CONCLUSIONS
  In a rabbit model of filtration surgery, AgNPs are a reasonable alternative to MMC as adjunctive therapy. Compared to MMC, AgNPs result in an improved and sustained reduction of IOP and promote blebs with decreased fibrosis and ischemia as well as increased filtration despite a smaller overall size. This combination may offer an opportunity to promote long-term surgical IOP reduction with an improved complication profile.
authors.affiliation: Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: Michelle R
authors.initials: MR
authors.lastname: Butler
authors.forename: Claudia M
authors.initials: CM
authors.lastname: Prospero Ponce
authors.forename: Y Etan
authors.initials: YE
authors.lastname: Weinstock
authors.forename: Silvia
authors.initials: S
authors.lastname: Orengo-Nania
authors.forename: Patricia
authors.initials: P
authors.lastname: Chevez-Barrios
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Frankfort
mesh_terms: D000287:Administration, Topical; D000704:Analysis of Variance; D000818:Animals; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage*; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage / Q000009:adverse effects; D001768:Blister; D004195:Disease Models, Animal; D018463:Filtering Surgery / Q000379:methods*; D005901:Glaucoma / Q000503:physiopathology / Q000601:surgery*; D007429:Intraocular Pressure / Q000187:drug effects; D053768:Metal Nanoparticles / Q000008:administration & dosage*; D016685:Mitomycin / Q000008:administration & dosage / Q000009:adverse effects; D011817:Rabbits; D012834:Silver / Q000008:administration & dosage*
chemical_list: D000891:Anti-Infective Agents, Local; D000903:Antibiotics, Antineoplastic; D012834:Silver; D016685:Mitomycin
keywords: filtration surgery; glaucoma; mitomycin C; rabbit; silver nanoparticle