title: Experimental histopathological study on retinal and renal cellular response to intravitreous antiangiogenic drugs.
abstract: OBJECTIVE
  To evaluate histopathological retinal and renal response after one single dose of intravitreous injection of antiangiogenic drugs ranibizumab and bevacizumab in rats.
  
  
  METHODS
  Experimental study in 60d of life adults Wistar rats. Ten animals were included. Group 1 included 5 animals that were injected with 1 µL ranibizumab 1.25 mg in the right eye and with 1 µL of balanced salt solution (BSS) in the left eye, as control; Group 2 included 5 animals that were injected with 1 µL of bevacizumab in the right eye and with 1 µL of BSS in the fellow eye. All injections were performed with Hamilton syringes. After 15d of the interventions, all animals were sacrificed in CO2 chamber. Both eyes were enucleated and one kidney was removed, fixed and embedded in paraffin for histopathological analysis by optic microscopy. For statistical purposes the initial expected abnormal histopathological responses were defined as 0%.
  
  
  RESULTS
  Atypical histopathological retinal response was detected in 2 eyes injected with ranibizumab (40%) as well as in 2 control eyes in group 1. Same was detected in 1 eye injected with bevacizumab (20%) as well as in 1 control eye, in group 2. The noted atypical findings were lymphocytes and eosinophils in the vitreous posterior cavity and mild retinal inflammatory reaction with ganglion cell layer edema but without clinical significance. No atypical histopathological renal response was detected.
  
  
  CONCLUSIONS
  Unexpected atypical histopathological retinal response without clinical significance was observed in 3 eyes injected with antiangiogenic drugs (2 in group 1 and 1 in group 2) as well as in 3 control eyes (2 in group 1 and 1 in group 2). No atypical renal response was detected suggesting no extra ocular involvement of the intravitreous injected antiangiogenic drugs.
authors: Department of Ophthalmology, Medical School, Federal University of Rio Grande do Sul and Hospital de Clínicas de Porto Alegre, Porto Alegre (RS) 90035-903, Brazil.
authors: João Borges
authors: JB
authors: Fortes Filho
authors: Department of Ophthalmology, Medical School, Federal University of São Paulo, São Paulo (SP) 040023-062, Brazil.
authors: Mauricio
authors: M
authors: Maia
authors: Department of Ophthalmology, Medical School, Federal University of São Paulo, São Paulo (SP) 040023-062, Brazil.
authors: Marcia Beatriz
authors: MB
authors: Tartarella
authors: Animal Experiment Unit of Hospital de Clínicas de Porto Alegre, Porto Alegre (RS) 90035-903, Brazil.
authors: Fabíola Schons
authors: FS
authors: Meyer
authors: Department of Ophthalmology, Medical School, Federal University of Rio Grande do Sul and Hospital de Clínicas de Porto Alegre, Porto Alegre (RS) 90035-903, Brazil.
authors: Bárbara Gastal Borges
authors: BG
authors: Fortes
authors: Department of Pathology, Medical School, Federal University of Rio Grande do Sul and Hospital de Clínicas de Porto Alegre, Porto Alegre (RS) 90035-903, Brazil.
authors: Lúcia Maria
authors: LM
authors: Kliemann
keywords: antiangiogenic drugs; bevacizumab; oxygen induced retinopathy; ranibizumab; retinopathy of prematurity; therapy