title: Intravitreal memantine retinal toxicity in rabbits.
abstract: OBJECTIVE
  To histologically evaluate whether the intravitreal application of memantine produces retinal toxicity in rabbits.
  
  
  METHODS
  A cross-sectional design, experimental, descriptive study was performed on 16 eyes of 16 New Zealand rabbits of 3 kg, divided in 4 groups of 4 rabbits. A dose of 70 ng/ml of intravitreal memantine was administered in Group A, a dose of 150 ng/ml in Group B, a dose of 400 ng/ml in Group C, and Group D received 1 ml of balanced salt solution. The injected eye of half of each group was enucleated 15 days after the injection, and the rest within 30 days after injection. Following enucleation, each eye was placed in 10% formaldehyde. Histopathological analysis was performed on all enucleated eyes. The animals were treated according to the guidelines of the Association for Research on Vision and Ophthalmology (ARVO).
  
  
  RESULTS
  Groups A, B and D did not show any histopathological changes after their enucleation at 15 and 30 days. Group C showed changes in the photoreceptor layer after enucleation at 15 and 30 days.
  
  
  CONCLUSIONS
  In our study, it was observed that memantine concentrations at 70 ng/ml and 150 ng/ml are safe when administered intravitreally; however, doses of 400 ng/ml produced retinal structural changes. This research should continue to assess its clinical usefulness.
authors.affiliation: Servicio de Retina, Hospital General de México, México, D.F., México.
authors.forename: D
authors.initials: D
authors.lastname: Moreno Páramo
authors.affiliation: Servicio de Retina, Hospital General de México, México, D.F., México. Electronic address: any912@yahoo.com.
authors.forename: S
authors.initials: S
authors.lastname: Reyna Vielma
authors.affiliation: Servicio de Patología, Asociación para Evitar la Ceguera en México, México, D.F., México.
authors.forename: A
authors.initials: A
authors.lastname: Rodríguez Reyes
authors.affiliation: Servicio de Patología, Asociación para Evitar la Ceguera en México, México, D.F., México.
authors.forename: I
authors.initials: I
authors.lastname: Hernández Ayuso
authors.affiliation: Department of Ophthalmology, University of Colorado Denver, Denver, Colorado, EE. UU.
authors.forename: H
authors.initials: H
authors.lastname: Quiroz Mercado
mesh_terms: D000818:Animals; D003430:Cross-Sectional Studies; D015259:Dopamine Agents / Q000633:toxicity*; D004596:Electroretinography; D058449:Intravitreal Injections; D008559:Memantine / Q000633:toxicity*; D011817:Rabbits; D012160:Retina / Q000187:drug effects*; D014822:Vitreous Body
chemical_list: D015259:Dopamine Agents; D008559:Memantine
keywords: Conejos; Intravitreal; Intravítrea; Memantina; Memantine; NMDA receptor; Rabbits; Receptor NMDA; Retina; Toxicidad; Toxicity