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

Abstract

Aims: To report the findings in a patient treated by repeated intravitreal bevacizumab (Avastin®) injections followed by macular relocation and excision of sub-foveal choroidal neovascular membrane (CNV).

Methods: Histopathological evaluation of the choroidal neovascular membrane (CNV) specimen, including immunohistochemical assessment.

Results: During surgical excision the CNV appeared to be avascular and its underlying bed did not bleed. Histopathological examination revealed that the CNV comprised avascular fibrous subretinal tissue containing fibroblastic RPE cells, fragments of irregular thickened Bruch's membrane and fibrotic choroidal tissue containing some medium size vessels but no choriocapillaris.

Conclusions: The development of an RPE rip during the course of avastin therapy may reflect contraction of the avascular subretinal tissue, while 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 rip.