What is the difference between occult and classic cnv

Five-year outcomes and treatment patterns were not affected by the lesion type. Retina Philadelphia, Pa. Graefes Arch. We have detected that you are using an Ad Blocker. PracticeUpdate is free to end users but we rely on advertising to fund our site. Please consider supporting PracticeUpdate by whitelisting us in your ad blocker. Lesion size and leakage area are the same and are both measured from the late phase. Angiographic Subtypes of CNV.

In eyes with a combination of CNV, three angiographic subtypes are identified:. Minimally classic has 1 to 50 percent See Figure 6 of the total lesion area comprising a classic subtype. Occult with no classic has no classic component in it See Figure 4. At some reading centers an alternative definition of classic and minimally classic CNV is employed.

A lesion is classic if the CNV occupies more than 50 percent of the total CNV area which may be less than 50 percent of the total lesion area , and minimally classic is also based upon the proportion of the total CNV area occupied by classic. A combination of features such as superficial intraretinal hemorrhages, intraretinal leakage hot spot , cystoid spaces, serous PED and retinal anastamosis guide the diagnosis of RAP. RAP could occur in combination with other angiographic subtypes.

Non-CNV Components. An assortment of components is considered to constitute the neovascular lesion complex.

These include thick blood, elevated blocked fluorescence, and serous detachments of the RPE. Other lesions that occur during the follow-up of CNV such as fibrous or disciform scar, atrophic scar and RPE rips are also considered lesion components though the MPS protocol did not include them. Many clinical trial protocols specifically exclude subjects with either too many non-CNV components and with non-CNV components under the fovea.

Hyperplastic pigment or fibrous tissue can present with blocked fluorescence that is usually elevated above the RPE. Very proteinaceous, turbid fluid may be a cause.

Often, a correlation to blocked fluorescence on FA with clinical examination or color photos shows no visible lesion. S-PEDs tend to start pooling in very early phase and have a smooth contour surface with a semi-circular dome-shape. Pooling of dye and staining due to S-PEDs is not included as part of leakage. Important Measurements on FA. There are three main efficacy measurements derived from FA that are used for clinical trials of neovascular AMD: total lesion area, total CNV area and leakage area.

Clinical trials may specify a range of total lesion area for eligibility. The change in total lesion area, total CNV area, and leakage area over time are important morphology endpoints in clinical trials.

For classic lesions, this is the early phase and for occult, the early-mid phase. Fluorescein staining of the RPE, CNV or other structures is hyperfluorescence that may change in intensity but does not lose its sharp outlines. The distinction between mild leakage and staining is highly subjective and may be quite variable between clinicians.

Submitted for publication June 21, ; revised September 17, ; accepted January 26, Disclosure: U. Schmidt-Erfurth , None; K. Kriechbaum , None; A. Oldag , None. The publication costs of this article were defrayed in part by page charge payment.

F igure 1. View Original Download Slide. The peak of the curve represents the level of the choriocapillaris or large vessels with high concentration of dye i. B Gray-scale-coded 2D profile demonstrates the distribution of the axial fluorescence within the entire angiographic field: Brightness indicates prominent localization, darkness indicates deep localization.

In this example, the typical ring-crater configuration of a classic membrane is shown. F igure 2. A Early-phase conventional FA intensity image of a classic CNV demonstrating the distribution of fluorescence intensity, with central leakage of the CNV surrounded by subretinal hemorrhage.

C 3D topographic relief of the same lesion. The 3D perspective allows visualization of the lesion with sharp demarcation and a typical ring-crater configuration. F igure 3. A Late-phase conventional FA intensity image 10 minutes after dye injection showing the same classic lesion as in Figure 2 , with intensive central leakage, masking by blood and surrounding subsensory extravasate.

B Gray-scale-coded 2D depth image detecting the prominence of fluid pooling over the lesion site. C The topographic relief delineates the 3D distribution of fluorescent leakage with enhanced prominence of the hyperpermeable borders of the CNV.

F igure 4. B In the gray-scale-coded 2D depth image the prominence of the neovascular net is highlighted by its brightness. C The 3D topographic image of the same lesion demonstrates the vascular configuration of the lesion as well as perfusion changes within the surrounding choriocapillary bed.

A halo, a dark ring zone that surrounds the lesion, is identified. F igure 5. The choriocapillary fluorescence appears homogenous without distinction of a vascular pattern due to extravasation of the dye molecules. B The 2D depth image identifies the prominence of the entire lesion as well as of individual areas within the lesion.

C A prominent ring of fluorescent leakage is seen along the borders of the lesion in the topographic relief. F igure 6. A Early-phase conventional FA intensity image of an occult lesion demonstrates mild hyperfluorescence without precise demarcation or pattern. B The gray-scale-coded 2D depth image identifies an area of fluorescence located within superficial layers and therefore appearing bright, regardless of the low overall intensity of fluorescence.

C The 3D topographic relief of the same occult lesion identifies a prominent fluorescent plaque with flat borders. F igure 7. A Late-phase conventional FA image of the identical occult lesion. Fluorescein was used as the dye. B , C Gray-scale-coded 2D depth image and 3D topographic images of the same lesion 10 minutes after dye injection. The occult lesion appears as a flat, well-demarcated area without a central crater or halo.

No prominent leakage with extravasation from the borders of the lesion is noted compared with the classic lesion seen in Figures 3 4 5 6. F igure 8. A Conventional intensity image of the occult lesion seen in Figures 6 and 7. B The gray-scale-coded 2D depth image demonstrates the site of the lesion and its superficial location compared with the surrounding physiological choriocapillaris.

C In the 3D topographic image, the prominence and flat configuration of the occult lesion is documented. F igure 9. A Fifteen minutes after ICG injection the choriocapillary pattern has faded, the lesion appears as late plaque by conventional angiographic intensity imaging.

C The topographic relief delineates the irregular pattern of the choriocapillary layer as well as the overlying neovascular CNV net. Distinct perfusion defects are recognized at the temporal aspect of the occult lesion. F igure A , B The characteristic shape of classic CNV: steep borders, ring crater configuration thin arrow and a halo thick arrows , defined as a sub-background area that surrounds the borders of the lesion and should be consistent with a relative defect in the vascular pattern of the choriocapillary layer.

T able 1. View Table. Lesion Characteristics Topographic Imaging. Lesion prominence was graded as flat barely detectable , moderate prominence reaching the elevation of a retinal vessel , or high exceeding a vein prominence. The configuration was described as a crater concave with a flat center surrounded by prominent borders or convex flat borders and a hill-like regular prominence in the center of the lesion.

T able 2. Imaging Characteristics. Masking phenomena hemorrhage, pigment, and exudate , which always influence the evaluation of conventional angiography, had no impact on topographic imaging, because even low fluorescence intensities were detected. The prevalence of age-related maculopathy in the Rotterdam Study.

Prevalence of age-related maculopathy. The Beaver Dam Eye Study. Key pathophysiologic pathways in age-related macular disease. Graefes Arch Clin Exp Ophthalmol. Retinal pigment epithelial tears through the fovea with preservation of good visual acuity.

Arch Ophthalmol. Pegaptanib for neovascular age-related macular degeneration. N Engl J Med. Confocal indocyanine green angiography with 3-dimensional topography: results in choroid neovascularization CNV in German. Three-dimensional topographic angiography in chorioretinal vascular disease. In these cases, the polyps were not visible at baseline.

BVN were detected in Plaques were detected in the late phase of ICGA in Subretinal fluid was noted in The proportion of subretinal fibrosis was prominent in the classic CNV group, which was also significantly different from that in the other groups Spectral-domain optical coherence tomographic OCT characteristics of patients according to the fluorescein angiography and indocyanine green angiography-based classification in neovascular age-related macular degeneration.

Among the study participants, eyes from patients regularly visited the clinic and were treated for at least 12 months. The CST at baseline and final visit was not significant among the subtypes Fig. Treatments and month outcomes of neovascular age-related macular degeneration by angiographic subtypes.

Changes in the mean best-corrected visual acuity BCVA of eyes with neovascular age-related macular degeneration subtypes according to the fluorescein angiography and indocyanine green angiography at 3, 6, 9, and month examinations.

Results were analyzed only from the patients treated for at least 12 months. There were no significant differences at baseline between the 5 groups, although there was a significant difference at the final time point asterisk.

Changes in the mean central macular subfield thickness CST of eyes with neovascular age-related macular degeneration subtypes according to the fluorescein angiography and indocyanine green angiography at 3, 6, 9, and month examinations. However, we still see patients with unclear diagnoses regardless of advanced imaging technology. In this study, neovascular AMD was classified into five subtypes, including the novel MCV group, which was not present in the previous classification system.

This study provides several important issues in investigating the neovascular AMD. We can estimate the proportions of each subtype of neovascular AMD among the Asian population. Classic CNV was identified in However, the proportion of RAP was similar to that of previous studies 16 , This finding may explain the discrepancy in the proportion of PCV across studies, even those focusing on the same races In this regard, this novel classification system may contribute to improved categorization of neovascular AMD patients.

This method is strengthened by its comparatively high ratio of inter-observer correlation. Another advantage of this study is that we can compare the proportion of subtypes classified using FA and ICGA, respectively. Yannuzzi et al. The frequency of RAP in this study Lee et al.

Interracial differences in the proportion of neovascular AMD can be expected, because the YH variant plays a major role in the etiology of AMD and is obviously different between Caucasians and Asians Most Korean patients do not have the YH variant. Therefore, there are likely other, yet unidentified, genetic variants that also promote disease progression in RAP.

Moreover, Uzawa et al. These results are likely to be caused by the coexistence of different subtypes within the category we classify as PCV. In this regard, the refined classification system including MCV may reduce such debate and clarify the subtype of neovascular AMD. These results suggest that the MCV group has its own characteristics that distinguish it from other groups. Multimodal imaging of a year-old male with microaneurysmal choroidal vasculopathy MCV, left column and year-old male with polypoidal choroidal vasculopathy PCV, right column.

Note that there is no definite polyp, other than small aneurysmal dilations white arrow heads. The characteristics of the patients in MCV group, which includes male predominance, thickened choroid, alterations in RPE layer, and relatively good visual acuity at baseline, is quite interesting because it is comparable to CSC.

They demonstrated that it is a thickened choroid that drives the RPE changes seen in these eyes. In this regard, the features of MCV may correspond to the pachychoroid spectrum disease and its relevance seems even stronger than PCV. Given that choroid was most thickened in MCV group patients, it is possible that multiple microaneurysms along with the BVN is dominated by changes in the RPE, which, in tum, may be secondarily related to the chronicity of choroidal vascular hyperpermeability.

However, since this study is a cross-sectional study, it is difficult to identify the causal relationship between MCV and pachychoroid spectrum diseases. Further longitudinal research is needed in this regard.

There were several limitations in the present study. First, because of its retrospective nature, using data from a single tertiary hospital, our results may not be generalizable to the overall Korean population and microaneurysms of MCV subtype could not be identified histologically. A second limitation is that the classification was applied at the time of the review process; therefore, it did not influence the treatment regimens.

This may be the reason why there was no difference in treatment modality. Another limitation of this study is its relatively short follow-up period of 12 months.

Our results, therefore, may not reflect the final outcomes of neovascular AMD. Despite these limitations, our data provide evidence that are compared to results from other American, Asian, and even previous Korean studies.

The demographic, angiographic and OCT findings varied depending based on these subtypes.