title: Application of canaloplasty in glaucoma gene therapy: where are we?
abstract: OBJECTIVE
  Schlemm's canal (SC) inner wall is adjacent to the juxtacanalicular trabecular meshwork (TM) over their entire circumference. We seek to transfer reporter and therapeutic genes to these outflow-modulating tissues via canaloplasty surgery in live monkeys.
  
  
  METHODS
  A standard canaloplasty surgical approach was performed in cynomolgus monkeys using flexible canaloplasty catheters, modified for monkey eyes with a 175-μm outer diameter and an LED-lighted tip. A 6-0 prolene suture was used for the exact localization of SC. Trypan blue was injected during catheter withdrawal to document catheter placement within SC and to determine ease of injecting fluid into SC. Before, during, and after the injection, the position of the catheter and the anatomic details were video-captured with an externally positioned noncontact endoscopic imaging system and 50 mHz ultrasound biomicroscopy (UBM).
  
  
  RESULTS
  A 360° catheterization and injection of dye into SC was achieved. Suture, catheter, and trypan blue were imaged with the endoscope camera system and the catheter was also visualized with UBM. Trypan blue was seen in the SC over 5 clock hours after a 1 clock-hour insertion of the catheter.
  
  
  CONCLUSIONS
  A modified canaloplasty catheter device might be used for gene delivery to the SC/TM area without circumferential catheterization. Further studies comparing different delivery methods of the vector/transgene into the SC using canaloplasty are needed.
authors: 1 Department of Ophthalmology and Visual Sciences, University of Wisconsin , Madison, Wisconsin.
authors: Zeynep
authors: Z
authors: Aktas
authors: Baohe
authors: B
authors: Tian
authors: Jared
authors: J
authors: McDonald
authors: Ron
authors: R
authors: Yamamato
authors: Christine
authors: C
authors: Larsen
authors: Julie
authors: J
authors: Kiland
authors: Paul L
authors: PL
authors: Kaufman
authors: Carol A
authors: CA
authors: Rasmussen
mesh_terms: D000818:Animals; D002404:Catheterization / Q000379:methods*; D004724:Endoscopy; D015316:Genetic Therapy / Q000379:methods*; D005901:Glaucoma / Q000628:therapy*; D008252:Macaca fascicularis; D012590:Sclera / Q000601:surgery*; D014129:Trabecular Meshwork