Complement Factor P in choroidal neovascular membranes of patients with age-related macular degeneration.
OBJECTIVE
To evaluate whether complement Factor P (properdin) was present in surgically removed choroidal neovascular membranes of patients with age-related macular degeneration (AMD) and to investigate whether associated pre- and postoperative clinical characteristics can be correlated.


METHODS
The study population consisted of 26 AMD patients (26 eyes) with the exclusion criterion of prior treatment of the choroidal neovascular membranes. Factor P was detected immunocytochemically on paraffin sections (7 microm) by a polyclonal rabbit antihuman antibody.


RESULTS
Eleven of 22 assessable membranes showed a positive reaction for Factor P. The average percentage of Factor P-positive cells per membrane ranged from 0.65% to 4.09%. The duration of visual loss was significantly longer (8.6 +/- 2.7 vs. 3.9 +/- 0.8 months), and the size of postoperative measured area of atrophic retinal pigment epithelium was larger (27.6 +/- 7.6 vs. 15.0 +/- 6.9 mm2) in patients with Factor P-positive membranes compared with Factor P-negative ones.


CONCLUSIONS
Factor P was expressed in 50% of choroidal neovascular membranes of patients with AMD. The group with Factor P-positive membranes differed significantly from the Factor P-negative group in key clinical outcomes. Additional studies need to investigate the role of Factor P in the development of AMD for potential therapeutic intervention.
Wolf-Schnurrbusch
Ute E K
UE
Department of Ophthalmology, Inselspital, University of Bern, Bern, Switzerland.
Stuck
Anna K
AK
Hess
Roberto
R
Wolf
Sebastian
S
Enzmann
Volker
V
D020256:Choroidal Neovascularization / Q000209:etiology* / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D008268:Macular Degeneration / Q000150:complications*; D011184:Postoperative Period; D011414:Properdin / Q000378:metabolism*; D055213:Retinal Pigment Epithelium / Q000473:pathology; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014786:Vision Disorders / Q000209:etiology / Q000503:physiopathology; D014792:Visual Acuity
D011414:Properdin