title: Intravitreally Injected Fluid Dispersion: Importance of Injection Technique.
abstract: The purpose of this study was to evaluate the dispersion of intravitreally injected solutions and investigate the influence of varying injection techniques.
  
  
  
  This was a prospective study using enucleated porcine eyes and ultra-high-resolution computed tomography (UHRCT) scanning to visualize iomeprol intravitreal dispersion. Sixty eyes were divided over 12 different groups according to the injection procedure: fast (2 seconds) or slow (10 seconds) injection speed and needle tip location (6- and 12-mm needle shaft insertion or premacular tip placement verified by indirect ophthalmoscopy). For each of these combinations, eyes were either injected with the combination of V20I (which is an analogue of ocriplasmin) and iomeprol or iomeprol alone. Distance to the macula and volume measurements were performed at 1, 2, 3, and 5 hours after injection.
  
  
  
  The measured contrast bolus volume increases slowly over time to an average of 0.70 (P = 0.03), 1.04 (P = 0.006), and 0.79 (P = 0.0001) cm3 5 hours after the injection for the 6-mm needle shaft insertion, 12-mm needle shaft insertion, and premacular needle tip placement, respectively. The distance to the macular marker was significantly lower for premacular needle tip placement injections compared with 6- and 12-mm needle shaft insertion depths.
  
  
  
  Ultra-high-resolution computed tomography with three-dimensional reconstruction offers the possibility to study the dispersion of intravitreally injected solutions in a noninvasive manner. Intravitreal premacular solution delivery is possible with an indirect ophthalmoscope-guided injection technique and significantly reduces the time to reach the posterior pole in respect to 6- and 12-mm needle insertion depths. The speed of injection does not influence dispersion significantly.
authors.affiliation: Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Koen
authors.initials: K
authors.lastname: Willekens
authors.affiliation: ThromboGenics NV, Leuven, Belgium.
authors.forename: Geert
authors.initials: G
authors.lastname: Reyns
authors.affiliation: ThromboGenics NV, Leuven, Belgium.
authors.forename: Marjan
authors.initials: M
authors.lastname: Diricx
authors.affiliation: ThromboGenics NV, Leuven, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: Vanhove
authors.affiliation: ThromboGenics NV, Leuven, Belgium.
authors.forename: Bernard
authors.initials: B
authors.lastname: Noppen
authors.affiliation: Department of Radiology, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Walter
authors.initials: W
authors.lastname: Coudyzer
authors.affiliation: Department of Radiology, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Yicheng
authors.initials: Y
authors.lastname: Ni
authors.affiliation: ThromboGenics NV, Leuven, Belgium.
authors.forename: Jean H M
authors.initials: JH
authors.lastname: Feyen
authors.affiliation: Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Stalmans
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D004338:Drug Combinations; D004596:Electroretinography; D004867:Equipment Design; D005341:Fibrinolysin / Q000008:administration & dosage* / Q000493:pharmacokinetics; D005500:Follow-Up Studies; D021621:Imaging, Three-Dimensional; D058449:Intravitreal Injections / Q000295:instrumentation*; D007479:Iopamidol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D023421:Models, Animal; D009887:Ophthalmoscopy; D010446:Peptide Fragments / Q000008:administration & dosage* / Q000493:pharmacokinetics; D010865:Pilot Projects; D011446:Prospective Studies; D013552:Swine; D014057:Tomography, X-Ray Computed; D014822:Vitreous Body / Q000000981:diagnostic imaging / Q000378:metabolism*
chemical_list: D003287:Contrast Media; D004338:Drug Combinations; D010446:Peptide Fragments; C057937:iomeprol; C054561:microplasmin; D005341:Fibrinolysin; D007479:Iopamidol