By Lucy Piper, Senior medwireNews Reporter
Researchers have found that idiopathic polypoidal choroidal vasculopathy (PCV) has significant clinical differences to neovascular age-related macular degeneration (AMD) and suggest that it should be considered a distinct entity.
“[O]ne could regard idiopathic polyps as a specific condition rather than a variant of type I [choroidal neovascularisation], and only one member in the large family of hemorrhagic maculopathies”, comments the team, led by Gabriel Coscas (Centre Hospitalier Intercommunal de Créteil, France).
Four examiners studied data and images for 52 eyes of 52 consecutive European Caucasian patients diagnosed with PCV according to scanning laser ophthalmoscope-indocyanine green angiography with fluorescein angiography and optical coherence tomography (OCT). They classified the patients into 34 with idiopathic polyps and 17 with neovascular AMD-related polyps.
One patient was excluded because their polyps were clearly associated with a diffuse retinal epitheliopathy.
A second group of examiners then assessed the data and images to determine objective features between the two groups.
They found a number of significant differences. The first of these was leakage origin on fluorescein angiography, which occurred only from the polyps in all the patients with idiopathic PCV, but in only 17.6% of those with neovascular AMD. For the latter group, most patients, at 70.6%, had leakage from both the polyps and choroidal neovascularisation. There was also a distinction in the presence of drusen, which were seen in all patients with neovascular AMD, compared with just 14.7% of those with idiopathic PCV.
Indocyanine green angiography showed that all neovascular AMD patients had type I choroidal neovascularisation networks, whereas nearly all of the patients with idiopathic PCV had branching vascular networks.
On OCT, the researchers detected pigmented epithelium detachment in all the patients, but while serous detachment was most prevalent in the idiopathic group (82.4%), fibrovascular detachment was seen in more than half (52.9%) of those with neovascular AMD.
OCT also confirmed the presence of branching vascular networks in 82.4% of patients in the idiopathic group and none of those in the AMD group, note the researchers, and showed a more than 100 µm thicker subfoveal choroidal thickness in the idiopathic group, at an average 278.3 µm versus 176.6 µm in the AMD group.
Other significant differences included solely unifocal involvement of the lesion in neovascular AMD, compared with a mix of unifocal and multifocal in PCV, and superior best-corrected visual acuity (BCVA) in PCV versus AMD, at 0.43 logMAR versus 0.58 logMAR.
The researchers comment in Investigative Ophthalmology & Visual Science that, despite idiopathic PCV and neovascular AMD sharing some similarities, mainly being located in the sub-retinal pigment epithelium, the two conditions show specific clinical patterns that may require distinct therapeutic approaches.
They recommend the use of photodynamic therapy as “the gold standard” for precisely targeting idiopathic polyps in both macular and extramacular areas, with anti-vascular endothelial growth factor (VEGF) injections added to reduce accumulated fluid and improve BCVA.
For neovascular-AMD polyps, they recommend: “[R]epeated anti-VEGF injections with the eventual use of limited [photodynamic therapy] to target the polyps in order to reduce hemorrhagic risk.”
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