Clinicopathological correlation of choroidal neovascularization after external beam radiotherapy in age-related macular degeneration.
OBJECTIVE
To analyze the histopathology of choroidal neovascularization after external beam radiotherapy in age-related macular degeneration.


METHODS
A retrospective non-case-matched comparative histopathologic study. The histoarchitecture of nine surgically removed subretinal specimens from nine patients that had undergone external beam radiotherapy for exudative age-related macular degeneration was studied. Seven patients had received 20 Gy in 10 fractions and two 15 Gy in 5 fractions with an average time interval between radiotherapy and surgical extraction of 14 months (range 3-28). A consecutive series of classic, mixed and occult choroidal neovascular membranes served as controls.


RESULTS
Clinical findings. Radiation-associated choroidal neovasculopathy was angiographically suspected in four patients: a coarse net of vessels on fluorescein angiography developing at the border of previously irradiated choroidal neovascularization was observed in three patients; blebs at the margin of a plaque on indocyanine green angiography were observed in two patients. Pathological findings. Diffuse drusen as well as intra-Bruch's fibrovascular tissue was found in all irradiated specimens. In four specimens an edematous vascularized layer was seen between diffuse drusen and normal-appearing intra-Bruch's fibrovascular tissue. This lesion was not found in the control specimens. A particular correlation for the bleb lesion was not recognized.


CONCLUSIONS
The appearance of an edematous subretinal pigment epithelial vascularized layer between diffuse drusen and normal-appearing fibrovascular tissue in four of nine irradiated membranes may be secondary to previous irradiation. It may correlate with the unusual exudative manifestations observed after external beam radiotherapy.
Department of Vitreo-Retinal Surgery, Center of Ophthalmology, University of Cologne, Cologne, Germany.
S
S
Aisenbrey
B A
BA
Lafaut
S
S
Reynders
P
P
Szurman
S
S
Grisanti
C
C
Vanden Broecke
P
P
Walter
K U
KU
Bartz-Schmidt
D000368:Aged; D000369:Aged, 80 and over; D016570:Bruch Membrane / Q000473:pathology; D002829:Choroid / Q000098:blood supply / Q000528:radiation effects*; D020256:Choroidal Neovascularization / Q000175:diagnosis / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D008268:Macular Degeneration / Q000150:complications / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D010857:Pigment Epithelium of Eye / Q000473:pathology; D011832:Radiation Injuries / Q000175:diagnosis / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D011878:Radiotherapy / Q000009:adverse effects*; D012189:Retrospective Studies