Sadda et al
Wet AMD: Lesion Changes with Ranibizumab
Table 1 (available online only). Glossary of Reading Center Definitions
Term
Definition
Classic CNV
Characterized by well-demarcated areas of hyperfluorescence discerned in the
early phase of the fluorescein angiogram. In the late phase of the angiogram,
progressive pooling of dye appears in the overlying subsensory retinal space and
usually obscures the boundaries of the CNV.
Occult CNV
Appearance varies. Fibrovascular PED is a type of occult CNV in which areas of
usually irregular elevation of the staining/leaking RPE are detectable on
stereoscopic angiography within 1 to 2 min after fluorescein injection.
Persistence of fluorescein staining or leakage within this area occurs within 10
min after fluorescein injection. These areas are not as bright as areas of classic
CNV or serous detachments of RPE in the early phase of the angiogram. Late
leakage of undetermined source is a rare type of occult CNV in which poorly
demarcated areas of leakage appear at the RPE level in the late phase of the
angiogram without well-demarcated areas of hyperfluorescence discernible in
the early phase of the angiogram that account for the leakage.
CNV lesion
An entire complex of components (e.g., CNV, elevated blocked fluorescence,
thick blood) is considered to constitute the neovascular lesion. Lesion
components may include CNV (classic or occult), thick blood, blocked
fluorescence (due to pigment or a scar that obscures the neovascular border),
and serous detachments of the RPE. Lesion components also include
contiguous flat blocked fluorescence, fibrous tissue, and thin flat scars. For
digital angiograms, lesion components are measured in millimeters squared
using the available planimetry tools. For film angiograms and color photographs,
lesion components are measured in disc areas using an acetate grid overlying
the image. All areas are converted to disc areas for analysis.
CNV leakage
An area of hyperfluorescence that increases over time and often displays illdefined or fuzzy borders. Total area of leakage includes intense progressive
RPE staining to capture fibrovascular PEDs (or parts of them) that show intense
staining in late frames while excluding fibrovascular PEDs that do not leak and in
which staining fades in late frames. Thin flat scars and serous PEDs that do not
leak but in which hyperfluorescence does not fade are also excluded.
An obvious white or yellow mound of fibrous tissue that is well defined in shape,
appears solid, and obscures the RPE and choroid. A disciform scar (or other
Disciform scar fibrous tissue) may demonstrate blocked fluorescence and/or staining on
angiography. If accompanied by CNV, scars also may demonstrate leakage on
angiography.
Subretinal
fibrous tissue
(or fibrin)
In color photographs, fibrous tissue is visible as sheets or mounds of white
material under the retina in eyes with age-related macular degeneration, usually
representing fibrous or fibrovascular tissue that has proliferated in areas
previously occupied by serous or hemorrhage subretinal fluid. Early in the
development of such scars, the white material may be fibrin. No attempt is made
to distinguish between fibrin and fibrous tissue in the classification.
SSRD
Caused by accumulation of fluid under the sensory retina and visible in
stereoscopic photographs as a separation between the retina and underlying
RPE. Retinal blood vessels provide the best landmark for determining its
position. Presence and extent are determined from an examination of color or
red-free photographs as well as an angiogram. When fluorescein leakage from
Sadda et al
Term
Wet AMD: Lesion Changes with Ranibizumab
Definition
CNV is intense, this hyperfluorescence helps to demonstrate presence and
extent of SSRD.
Table 1 (available online only). Glossary of Reading Center Definitions
(cont’d)
CNV = choroidal neovascularization; PED = pigment epithelial detachment; RPE = retinal
pigment epithelium; SSRD = serous sensory retinal detachment.