Histological findings of a choroidal neovascular membrane removed at the time of macular translocation in a patient previously treated with intravitreal bevacizumab treatment (Avastin)

Abstract

Aim: To report the findings in a patient treated by repeated intravitreal bevacizumab (Avastin) injections, followed by macular relocation and excision of subfoveal choroidal neovascular membrane (CNV). Methods: Histopathological evaluation of the CNV specimen, including immunohistochemical assessment. Results: During surgical excision, the CNV seemed to be avascular and its underlying bed did not bleed. Histopathological examination revealed that the CNV comprised avascular fibrous subretinal tissue containing fibroblastic retinal pigment epithelial (RPE) cells, fragments of irregular thickened Bruch's membrane and fibrotic choroidal tissue containing some medium-sized vessels but no choriocapillaris. Conclusions: The development of an RPE tear during the course of Avastin treatment may reflect contraction of the avascular subretinal tissue, whereas the lack of capillaries in both choroidal and subretinal components may be caused by the increased access of Avastin to the choriocapillaris in the presence of the RPE tear.