title: Quantitative analysis of subretinal injections in the rat.
abstract: BACKGROUND
  Experimental therapeutic approaches to retinal degenerations often require the subretinal injection of a therapeutic agent. The injected volume and the age of the animal can influence the proportion of the retinal surface affected by the subretinal injection. We have investigated the quantitative effect of a single injection in the subretinal space.
  
  
  METHODS
  Normal and Royal College of Surgeons rats aged 1 week, 3 weeks or 2 months received subretinal transscleral injections of 1, 3, 5 or 10 microl China ink. After 24 h, animals were killed, injected eyes were enucleated and fixated, and the retinas flattened. An image analyzing program was used to measure the total retinal surface and the retinal surface affected by the dye.
  
  
  RESULTS
  The mean retinal surface affected by the injection ranged from 5.24+/-2.76 mm2 to 14.8+/-2.3 mm2, depending on animal age and injected volume. The injection affected 8.79+/-0.89 to 36.9+/-8.13% of total retinal surface. There was no statistically significant difference between normal and Royal College of Surgeons rats. Intravitreal leakage of the dye was more frequent with increasing injection volumes.
  
  
  CONCLUSIONS
  The retinal surface affected by a single subretinal injection increases with the injected volume, but this increase is not proportional. Higher volumes lead to a loss of injected solution, either in the vitreous body or through the sclerotomy. In 2-month-old rats, a 3-microl subretinal injection appears to have the best reproducibility, with 20-30% of retinal surface covered by the injected dye.
authors.affiliation: Centre de Recherche Thérapeutique en Ophtalmologie, Université René Descartes Paris V, Faculté de Médecine Necker, France. pascal.dureau@nck.ap-hop-paris.fr
authors.forename: P
authors.initials: P
authors.lastname: Dureau
authors.forename: L
authors.initials: L
authors.lastname: Legat
authors.forename: M
authors.initials: M
authors.lastname: Neuner-Jehle
authors.forename: S
authors.initials: S
authors.lastname: Bonnel
authors.forename: S
authors.initials: S
authors.lastname: Pecqueur
authors.forename: M
authors.initials: M
authors.lastname: Abitbol
authors.forename: J L
authors.initials: JL
authors.lastname: Dufier
mesh_terms: D000818:Animals; D002244:Carbon; D004396:Coloring Agents / Q000008:administration & dosage*; D007267:Injections; D051381:Rats; D012160:Retina / Q000187:drug effects* / Q000473:pathology
chemical_list: D004396:Coloring Agents; C028433:chinese ink; D002244:Carbon