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RETINAL INSIDER Edited by Carl Regillo, MDHow to Recognize And Treat PCVUnderstanding of polypoidal choroidal vasculopathy has undergone some changes in recent years.Hanna
Rodriguez-Coleman, MD, Richard Bryan, MD, and Lawrence A. Yannuzzi, MD
Background PCV is believed to be an inner choroidal vascular abnormality with two distinct components: a network of branching vessels predominantly external to the choriocapillaris, and terminal aneurysmal dilatations, sometimes clinically seen as reddish-orange spheroidal, or polypoidal, vascular lesions1 (See Figure 1). The nutrient, vascular branches of the abnormality may not always be seen, particularly if the lesion is in the inner choroid with no overlying exudative detachment of the pigment epithelium or neurosensory retina. When there are serosanguineous complications, the branching vessels are more clearly visible both clinically and angiographically. The polypoidal elements may be located tangentially at the margins of the vascular abnormality or anywhere overlying it.2
The assumption is that PCV represents a distinct form of choroidal neovascularization (CNV), specifically termed polypoidal CNV. Recent clinicopathological studies support the use of this term and show large, thin-walled choroidal vessels beneath the retinal pigment epithelium (RPE) usually, but not exclusively, external to the choriocapillaris with adjacent choroidal capillary proliferation.3 As seen in tumor angiogenesis, CNV ranges from a distinct, rapidly proliferating capillary network in the subretinal space, well-demarcated on fluorescein angiography (so-called classic-CNV), to a slower, gradual proliferation beneath the RPE, less distinct on fluorescein studies (so-called “occult” CNV). In polypoidal CNV, there are differences in risk factors, natural course, potential response to treatment, and visual prognosis compared to other forms of new vessels. Demographics Once described predominantly in black women, PCV is now known to occur in all races. There is a predilection for more heavily pigmented individuals, notably blacks, Asians and Hispanics. Men with PCV are as common as women, and Caucasians are not spared: Elderly whites with soft drusen have been described with polypoidal CNV, simulating the typical neovascularized form of age-related macular degeneration (AMD).6 In one series of consecutive patients with AMD, 7.8 percent had neovascularization of the polypoidal type. In another series in Asia, polypoidal CNV occurred in more than 60 percent of patients  presenting with hemorrhagic detachments of the
macula.4 The frequency and nature of polypoidal-CNV in Europe
corresponds to that described in the United States. The average age of onset of
PCV is significantly younger than in AMD, although the range in which the
abnormality may first appear is wider (<25 to >85 years).5
Figure 2. PCV in the peripapillary area, (left) and in the macula (right). Clinical Manifestations Polypoidal-CNV may lead to chronic-recurrent, acute serosanguineous detachments of the retina and RPE. If the polypoidal lesions are large enough, the pigment epithelium is thin and atrophic, and the location of the abnormality is in the innermost aspects of the choroid, the lesions may be seen quite easily with clinical slit-lamp biomicroscopy. Vascular abnormalities immediately adjacent to the RPE can be imaged distinctly with fluorescein angiography (FA), although this is a rare form of presentation (See Figure 6). In general, the overlying fluorescence of the choriocapillaris masks vascular lesions of the inner choroid on FA. Indocyanine Green (ICG) imaging, however, penetrates the RPE and serosanguineous complications and subtracts the choriocapillaris, providing a more enhanced angiographic delineation, not only of the active lesion, but also of the entire vascular component2 (See Figure 4). Curiously, bleeding may resolve spontaneously with little or no fibrous proliferation, and there may be a dramatic regression or even infarction of the membrane. This makes imaging of the polypoidal PCV virtually impossible during quiescent periods. The membranes may vary in size, ranging from large globular lesions to small serous pigment epithelial detachment-like abnormalities. There is a predilection for the peripapillary area, but they may also be seen in the paramacular region, the central macula and the peripheral fundus. (See Figure 2). Large, polypoidal vascular abnormalities in the far periphery may account for peripheral disciform disease or even be implicated in post-surgical choroidal hemorrhages, limited or expulsive in nature. Most cases are bilateral, though patients have been followed for more than 20 years with unilateral involvement. Eyes with polypoidal CNV have been misdiagnosed as the more typical neovascularized AMD in eyes with soft drusen or simply in elderly Caucasian patients. The assumption is that the serosanguineous complications are due to CNV of the more typical type. ICG angiography can identify the polypoidal lesions and help ascertain the form of CNV involved. In a study of a consecutive series of patients presumed to have typical neovascularized AMD, polypoidal CNV was present in 7.8 percent of the cases once ICG angiography was used. This figure is consistent with European studies mostly involving Caucasian patients. In Asia, the frequency of PCV in elderly patients may reach 60-70 percent.6  When the polypoidal vascular abnormality is small, the aneurysmal swellings may mimic tiny serous pigment epithelial detachments. Chronic neurosensory detachment, particularly those with lipids and/or blood, can be confused with chronic central serous chorioretinopathy (CSC) with secondary neovascularization (See Figure 5). The PCV lesion of these patients can be determined with ICG angiography. Figure 3. Large polypoidal choroidal vasculopathy at the margin of a massive serosanguineous detachment. On the other hand, polypoidal CNV may evolve as a secondary manifestation in patients with CSC, a reverse of the usual sequence of events. Keep in mind that regression of the neovascularization with resolution of the exudative manifestations can induce changes in the vascular abnormality so that polypoidal-CNV cannot be documented, even with ICG angiography.7 Natural Course PCV’s natural course has not been studied in a large series of patients with meaningful longitudinal experience. It is well-known that many patients with PCV and acute serosanguineous complications may experience spontaneous resolution and regression of the neovascularization. In contrast, proliferation of the vascular abnormality through tangential growth or even hypertrophy of the aneurysmal changes with associated alteration in their permeability and hemorrhagic diathesis can evolve. Independent polypoidal CNV may also develop at multiple sites. Above all, the complication of choroidal neovascularization of the more typical variety with capillary proliferation and fibrovascular scarring may occur, inducing damage to the central macula and severe vision loss. Bullous, even global, detachments of the RPE and neurosensory retina have been seen with or without severe vitreous hemorrhage (See Figure 3).  Figure 4. PCV with an active lesion noted in the mid-phase of the ICG (left), and full delineation of the lesion seen at the late phase of the ICG (right). Some of these eyes have proceeded to develop iris neovascularization with hemorrhagic glaucoma, eventually requiring enucleation. This is not so for AMD, where the neovascularization rarely results in a total retinal detachment. Systemic hypertension seems to be a driving force in the evolution of severe PCV complications and vision loss. Consider hypertension a significant risk factor in PCV, and advise patients to closely monitor and control their blood pressure when PCV is diagnosed.2,5 Treatment Beyond controlling systemic blood pressure, some eyes with serosanguineous complications are amenable to laser photocoagulation therapy. This is particularly true with leaking or bleeding vessels beneath the fovea associated with an active lesion outside the central macula. Laser treatment to the active polypoidal CNV or to the aneurysmal changes, but not to the entire vascular abnormality, obliterates the lesion and resolves the associated serosanguineous complications without stimulation or fertilization of the rest of the vascular abnormality. Treatment of eccentric active polypoidal CNV has the potential benefit of managing a subfoveal PCV complex without  treating the entire abnormality. This challenges traditional
treatment dogma regarding other forms of CNV that it is necessary to treat all
actively proliferating vessels. PCV is an exception. Recurrences may occur, but
unlike treatment of classic or well-demarcated CNV, they do not arise in the
form of capillary proliferation in front of the RPE, contiguous to the
photocoagulation site. Figure 5. PCV masquerading as central serous chorioretinopathy. At left, note a neurosensory detachment involving the central macula. Angiography (right) reveals the responsible PCV lesion. In fact, we have never seen such classic CNV recurrence in our experience at the Manhattan Eye, Ear and Throat Hospital. This is surprising, as mixed forms of neovascularization, PCV in the fundus with a focal area of classic CNV, have been noted in untreated patients. A non-specific disturbance of the RPE is thought to account for the new blood vessel formation of the classic type in patients with PCV. Some prefer feeder-vessel treatment of PCV. We believe this is unnecessary and only the active polypoidal lesion needs to be treated. Treatment should be of mild to moderate intensity, technically similar to laser treatment of retinal arteriolar macroaneurysm: There should be enough thermal energy to induce a fibrotic response in the aneurysm wall without inducing infarction. However, closure of the aneurysmal changes with  non-perfusion of the treated structures can be observed
in post-laser angiograms. Although we have not observed bleeding at the time of
treatment, this is definitely a theoretical consideration in laser
photocoagulation of the active form of the membrane. Photodynamic therapy has
been tried in a few patients with active PCV underneath the fovea with
promising success. Figure 6. PCV seen on fluorescein angiography (left) and ICG (right). Note the more marked delineation on FA secondary to overlying RPE atrophy and the location of the vessels immediately beneath the RPE. Ophthalmologists need to be aware that at least three forms of CNV may be present, singularly or in combination, in patients with serosanguineous subretinal complications. New vessel formation in AMD may occur with active proliferation secondary to growth of small capillaries from the choriocapillaris into Bruch’s membrane; a vessel complex that is well-demarcated on FA is referred to as classic CNV. A second form, occult CNV, is generally indicative of vessels proliferating slowly under the RPE and indistinctly evident on FA. Polypoidal CNV, a third form, in contrast, may occur in all races and both genders, with a wide age range. Drs. Rodriguez-Coleman and Bryan are vitreoretinal fellows at Manhattan Eye, Ear & Throat Hospital and New York Presbyterian-Columbia Hospitals. Dr. Yanuzzi is a professor of clinical ophthalmology at Columbia University. Contact Dr. Yanuzzi at (212) 861-9797, or fax (212) 628-0698.
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