Abstract
Purpose: :
Document clinical features, histopathologic and immunohistochemical results in a population of 14 young cats with neovascular proliferative vitreoretinopathy.
Methods: :
Cases diagnosed as neovascular vitreoretinopathy were selected from a total of 7007 feline submissions from COPLOW. Information on breed, age, gender, laterality and clinical features were recorded. Slides were reviewed to describe the morphologic characteristics. Immunohistochemistry included GFAP, Factor VIII, Collagen IV, Laminin, SMA, and CD68 were performed on those globes available for further sectioning
Results: :
. Most cats presented at less than 1 year of age, with 8 of 14 of the study population less than 6 months old. Two Persian cats were represented, two domestic medium hair and the remainder domestic short hair. Among these breeds, 8 were female and 6 were male. The most common clinical sign was glaucoma. Histopathology: Retinal detachments were noted in 11/14 eyes. The retina was entirely avascular in one case, and 80-90% avascular in the remaining 13 cases. The course of retinal vessels traveled axially within the vitreous towards the lens in all cases. The consistency of the vitreous tended to be liquid. Iridal fibrovascular membranes were found in all 14 cases. Anterior uveal inflammation was noted in 12/14 cases.Immunohistochemical findings included an intense GFAP staining pattern throughout the retina. CD68 and Factor VIII confirmed that blood vessels extended into the vitreous but not the peripheral retina. Laminin and collagen IV demonstrated that the neovascular proliferation was confined to within the expanded inner limiting membrane and SMA demonstrated contractile spindle cells in the neovascular membrane.
Conclusions: :
Feline neovascular vitreoretinopathy is a vasoproliferative disorder with similarities to ROP. Retinal detachments lead to neovascular glaucoma in young cats.
Keywords: retinopathy of prematurity • vitreous • neovascularization