130
patients are younger), presence of exudative peripapillary
lesions (more frequent in PCV), prevalence of soft dru-
sen (greater in AMD patients) and ethnicity (PCV more
prevalent in non-white population). PCV also has less
tendency to develop fibrous proliferation and a higher
incidence of neurosensory and PE detachments.
PCV and AMD share common genetic factors, which
suggests that PCV and wet AMD are similar in some
pathophysiologic aspects. A common genetic back-
ground may exist between typical exudative AMD and
PCV patients. Complement pathway plays a substantial
role in the pathogenesis of PCV, like in AMD. The non-
synonymous variant I62V in the complement factor H
gene is strongly associated with polypoidal choroidal vas-
culopathy and may be a plausible candidate for a causal
polymorphism leading to the development of PCV,
given its potential for functional consequences on the
CFH protein
(21)
. The LOC387715/HTRA1 variants are
associated with PCV and wet AMD in the Japanese pop-
ulation. The associations are stronger in AMD than in
PCV
(22)
. The de1443ins54 polymorphism is a common
variant between White and Japanese populations and is
strongly associated not only with AMD but also with
PCV. Among the patients with AMD and PCV, those
with a homozygous HTRA1 rs11200638 risk allele seem
to have larger CNV lesions
(23)
. However, some genetic
differences seem to exist. A variation in the elastin gene
(ELN) may be associated with PCV but not with neo-
vascular AMD suggesting that a different pathogenic
process may be involved in the phenotypic expression of
neovascular AMD and PCV
(24)
.
PCV has been referred to be associated with other ocu-
lar disorders like macroaneurysms or inflammatory dis-
eases
(4,25)
. However, this association is still inconclusive
and deserves further investigation. A relation between
the retinal vascular changes in hypertensive retinopathy,
like vascular remodelling, aneurismal dilatations and
focal vascular constrictions, and choroidal alterations in
PCV was proposed by Ross et al.
(25)
.
4. Natural evolution
The disease has a remitting-relapsing course and is asso-
ciated with chronic, multiple recurrent serosanguineous
detachment of the neurosensory retina and RPE, with
long-term preservation of vision
(4,18,19)
. Visual acuity
(VA) loss is associated with central macular involvement
and may range from mild to severe VA loss or blindness.
Treatment of central macular lesions with PDT and more
whereas on its choroidal side an almost intact layer of dif-
fuse drusen was observed. A group of dilated thin-walled
vessels were found and located directly under diffuse
drusen within a sub-RPE, intra-Bruch’s fibrovascular
membrane. Dilatations appeared to be of venular rather
than arteriolar origin and some lesions were associated
with lymphocytic infiltration. The presence of choroidal
infiltration by inflammatory cells was also referred by
Rosa et al.
(11)
. Okubo et al.
(12)
described unusually dilated
venules adjacent to an arteriole with marked sclerotic
changes and newly formed capillaries within the wall
of the degenerate arteriole and near the dilated venule.
Therasaki et al.
(13)
described clusters of dilated thin-
walled vessels surrounded by macrophages and fibrin-
ous material in neovascular membranes obtained from
submacular surgery for PCV. Hyalinization of choroidal
vessels and massive exudation of fibrin and blood plasma
were observed in all the five specimens of PCV lesions
studied by Nakashizuka H et al.
(14)
. They also found
some blood vessels located above the RPE in two of the
five eyes. Immunohistochemically, CD68-positive cells
were described by them around the hyalinized vessels.
There were no alpha-SMA-positive cells in the vessels
of PCV. CD34 staining showed endothelial discontinu-
ity. Vascular endothelial cells within the PCV specimens
were negative for VEGF. HIF-1alpha positive inflam-
matory cells were located in the stroma of specimens
(14)
.
Hyalinization of choroidal vessels, like arteriosclerosis,
seems to be characteristic of PCV
(14)
.
All these previous histopathological studies identifying
a large spectrum features (like dilated choroidal vessels,
intra-Bruch’s neovascularization, inflammatory cells,
drusen material, thick membranes, single saccular dilata-
tions or clusters of dilated thin walled vessels) may par-
tially being expressing the influence of disease stage
(15)
.
For many authors
(4,6,10,16-19)
and following the results of
clinicopathological studies, PCVmay represent a subtype
of exudative AMD. Yannuzzi et al.
(18,19)
found a preva-
lence of 7.8% of PCV in a population with signs of exu-
dative AMD and Laffaut et al.
(10)
described the presence
of late ICG hyperfluorescent plaques in 58% of 45 cases
with PCV, proposing that PCV should be considered a
subtype of exudative AMD. Many other authors
(17,18,19)
describe PCV cases with subretinal neovascularization.
Ahuja et al.
(20)
described a prevalence of PCV in 47%
of a consecutive series with 16 eyes diagnosed as exuda-
tive AMD and showing a PED greater than 2 mm of
diameter, haemorrhage or retinal neurosensory exuda-
tion. According to Yannuzzi
(18,19)
PCV and exudative
AMD may differ in mean age of onset (PCV affected
