title: Establishing an experimental rat model of photodynamically-induced retinal vein occlusion using erythrosin B.
abstract: OBJECTIVE
  To develop a reliable, reproducible rat model of retinal vein occlusion (RVO) with a novel photosensitizer (erythrosin B) and study the cellular responses in the retina.
  
  
  METHODS
  Central and branch RVOs were created in adult male rats via photochemically-induced ischemia. Retinal changes were monitored via color fundus photography and fluorescein angiography at 1 and 3h, and 1, 4, 7, 14, and 21d after irradiation. Tissue slices were evaluated histopathologically. Retinal ganglion cell survival at different times after RVO induction was quantified by nuclear density count. Retinal thickness was also observed.
  
  
  RESULTS
  For all rats in both the central and branch RVO groups, blood flow ceased immediately after laser irradiation and retinal edema was evident at one hour. The retinal detachment rate was 100% at 3h and developed into bullous retinal detachment within 24h. Retinal hemorrhages were not observed until 24h. Clearance of the occluded veins at 7d was observed by fluorescein angiography. Disease manifestation in the central RVO eyes was more severe than in the branch RVO group. A remarkable reduction in the ganglion cell count and retinal thickness was observed in the central RVO group by 21d, whereas moderate changes occurred in the branch RVO group.
  
  
  CONCLUSIONS
  Rat RVO created by photochemically-induced ischemia using erythrosin B is a reproducible and reliable animal model for mimicking the key features of human RVO. However, considering the 100% rate of retinal detachment, this animal model is more suitable for studying RVO with chronic retinal detachment.
authors.affiliation: Department of Ophthalmology, Shanghai First People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, Shanghai First People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Ophthalmology, Shanghai First People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080, China.
authors.forename: Mi
authors.initials: M
authors.lastname: Zheng
authors.affiliation: Department of Ophthalmology, Shanghai First People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Gu
authors.affiliation: Department of Ophthalmology, Shanghai First People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: Department of Ophthalmology, Shanghai First People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080, China ; Shanghai Key Laboratory of Fundus Diseases, Shanghai Jiaotong University, Shanghai 200080, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Xia
keywords: ischemia; laser photothrombosis; rat model; retinal vein occlusion