Polypoidal Choroidal Vasculopathy

Polypoidal choroidal vasculopathy (PCV) is an increasingly recognized form of macular disease that causes central vision loss through abnormal blood vessel growth beneath the retina. What makes PCV clinically crucial — particularly for Asian and other non-Caucasian patients — is that it is frequently misdiagnosed as wet age-related macular degeneration (AMD). This diagnostic error has serious consequences: PCV and wet AMD require fundamentally different treatment approaches. A patient treated for wet AMD when they actually have PCV is unlikely to achieve optimal polyp closure or vision preservation. In Asia, where PCV prevalence is remarkably high, correct diagnosis is not a luxury — it is essential for clinical outcomes.

What Is Polypoidal Choroidal Vasculopathy?

PCV is characterized by an abnormal branching vascular network in the choroid — the layer of blood vessels that nourishes the outer retina — combined with polypoidal (grape-like) dilations at the termini of these branches. These polypoidal lesions are prone to rupture and leak, causing subretinal hemorrhage, exudate, and ultimately atrophy of overlying photoreceptors and retinal pigment epithelium.

Pathophysiologically, PCV is increasingly understood as part of the pachychoroid spectrum — a family of diseases characterized by thickened choroid and dilated choroidal vessels. Rather than a primary defect in retinal pigment epithelium (as in conventional AMD), PCV involves intrinsic abnormality of choroidal vasculature. This distinction explains why PCV differs from wet AMD in natural history, imaging appearance, and treatment response.

The disease typically affects the central macula — the region of highest visual acuity. This is why even small PCV lesions can cause marked visual disability. A patient with a 500-micron polypoidal lesion centered on the fovea will often have worse vision than a patient with a larger wet AMD lesion located parafoveally.

Why Is PCV Important in Asia?

The epidemiology of PCV is strikingly different across ethnic groups. In Caucasian populations, wet AMD is the predominant form of exudative macular disease, and PCV accounts for perhaps 5–10% of cases. In Asian populations — particularly in East Asia and Southeast Asia — this proportion is reversed: PCV may represent up to 40–50% of cases clinically diagnosed as wet AMD.

This is not merely a matter of statistical interest. In Singapore, where we see a diverse population of Chinese, Malay, and Indian descent, any patient presenting with presumed wet AMD requires careful diagnostic imaging to differentiate PCV from true AMD. The consequence of misdiagnosis is profound: a patient with PCV treated with anti-VEGF monotherapy (the standard for AMD) will have a markedly lower polyp closure rate and worse long-term visual outcomes than a patient treated with combination therapy.

The economic and social implications are equally important. Vision loss from untreated or under-treated PCV has the same impact on patient quality of life as any macular disease: difficulty reading, loss of independence, and psychological burden. Early, correct diagnosis and appropriate treatment can halt progression and preserve useful vision. Delayed or missed diagnosis leads to preventable vision loss.

Symptoms

PCV presents with symptoms nearly identical to wet AMD, which is why clinical presentation alone is insufficient for diagnosis:

• Central blur or haze — often described as a "fog" or mist over the center of vision, uncorrectable by glasses
• Distortion (metamorphopsia) — straight lines appear wavy, bent, or bowed, particularly noticeable when looking at architectural lines, grid patterns, or text
• Sudden vision loss — may occur rapidly (within hours to days) if a polyp ruptures and causes subretinal hemorrhage
• Dark spot in the center (scotoma) — typically representing active exudation or hemorrhage
• Difficulty reading — central vision loss makes reading impossible or severely impaired even with magnification aids
• Micropsia — objects in the affected eye may appear smaller than in the fellow eye
• No pain — as with all retinal conditions, vision loss from PCV is never accompanied by eye pain

The key clinical lesson: symptom presentation cannot reliably distinguish PCV from wet AMD. Imaging — specifically indocyanine green angiography (ICG-A) — is mandatory for accurate diagnosis.

How Is It Diagnosed?

Diagnosis of PCV rests on multimodal imaging, with ICG angiography being the gold standard.

Indocyanine Green Angiography (ICG-A)

ICG-A is the cornerstone of PCV diagnosis. Unlike fluorescein angiography (which highlights lesions in the early frame but loses contrast as dye leaks), ICG penetrates through blood and shows the deeper choroidal vasculature with outstanding clarity. In PCV, ICG-A reveals the characteristic findings:

• Branching vascular network (BVN) — a network of abnormal choroidal vessels
• Polypoidal lesions — grape-like dilations at the termini of the network, appearing as hyperfluorescent "knots" on ICG
• Early hyperfluorescence — polyps appear bright and hyperfluorescent in the early-mid phase of angiography, distinguishing them from simple choroidal neovascularization

In wet AMD, by contrast, ICG shows a more diffuse area of choroidal neovascularization without distinct polypoidal lesions.

OCT and OCT Angiography (OCTA)

Optical coherence tomography reveals:

• Subretinal hyperreflective material (SHRM) — often more solid and sharply demarcated than in wet AMD
• Characteristic "double-layer" or "mushroom" appearance — polyps may create a distinctive shape on vertical sections
• Retinal pigment epithelium elevation — the RPE is pushed upward by subretinal exudation
• Disruption of photoreceptor layers — ellipsoid zone may be interrupted or attenuated

OCTA (optical coherence tomography angiography) can visualize the abnormal vascular network without dye injection, though ICG remains superior for definitive polyp identification.

Fluorescein Angiography (FA)

FA is less specific for PCV diagnosis but may show:

• Hyperfluorescent spots in the early phase corresponding to polyps
• Late leakage (as dye leaks from the lesion)
• Pooling of dye in subretinal space

The Critical Point: Why ICG Matters

A patient presenting with central vision loss and subretinal exudation on OCT is presumed to have wet AMD unless ICG angiography is performed. Many clinics worldwide — and some in Asia — diagnose and treat "wet AMD" based on clinical presentation and OCT alone, without ICG. This is a diagnostic trap. The only way to reliably distinguish PCV from wet AMD is ICG angiography. In my practice, I obtain ICG for all patients with presumed wet AMD who are of non-Caucasian descent, and increasingly for all such patients regardless of ethnicity, because the treatment implications are so significant.

How Is PCV Different from Wet AMD?

Although PCV and wet AMD share superficial similarities — both cause central vision loss through abnormal choroidal blood vessel growth — they differ fundamentally in pathophysiology, imaging, and treatment response:

The practical implication is stark: a patient with PCV treated as wet AMD will undergo repeated anti-VEGF injections with suboptimal response, accumulating unnecessary injection burden and continuing to experience visual decline due to inadequately controlled polyps. The same patient treated with combination therapy (PDT + anti-VEGF) achieves superior polyp closure and better visual outcomes.

Treatment Options

Treatment of PCV has evolved considerably over the past decade. The emergence of strong evidence for combination therapy has changed the management paradigm for this condition.

Combination Therapy: PDT + Anti-VEGF

This is the recommended first-line approach for PCV in most guidelines and consensus statements. Photodynamic therapy (PDT) with verteporfin is administered as an intravenous infusion followed by targeted laser application to the angiographically-identified polypoidal lesions. Anti-VEGF injection (ranibizumab, aflibercept, or bevacizumab) is given concurrently or shortly after PDT.

Why combination therapy? Because verteporfin PDT directly ablates the polypoidal lesions and abnormal vasculature, while anti-VEGF addresses the vascular permeability and leakage. Together, they achieve polyp closure rates of 70–90% — substantially superior to anti-VEGF monotherapy alone. The visual and functional benefits are correspondingly better.

Typical protocol: Initial PDT session followed by anti-VEGF injection (same visit or within 1 week). Repeat cycles at 3-month intervals based on ICG angiography findings. Most patients achieve polyp closure within 1–3 cycles. Maintenance anti-VEGF therapy may be continued depending on OCT findings and disease activity.

Anti-VEGF Monotherapy

Anti-VEGF injection alone (ranibizumab, aflibercept, or intravitreal bevacizumab) can be used but is generally considered less effective than combination therapy. Polyp closure is achieved in only 20–40% of cases with anti-VEGF monotherapy. This approach may be considered in:

• Patients who cannot tolerate or wish to avoid PDT (rare)
• Cases with small, non-central polyps
• Patients with limited financial resources (anti-VEGF is more affordable than PDT in some settings)

However, long-term visual outcomes are inferior with monotherapy, and this should not be first-line for most PCV patients.

Photodynamic Therapy (PDT)

Verteporfin PDT involves a photosensitizing dye (verteporfin) injected intravenously, followed by laser application targeted to the angiographically-identified polypoidal lesions. The laser activates the dye, causing endothelial damage and thrombosis of the abnormal vessels.

Mechanism: PDT directly occludes polypoidal lesions, whereas anti-VEGF reduces vascular permeability. This complementary action explains the superiority of combination therapy.

Side effects: PDT can cause transient visual blurring on the day of treatment, and rarely, RPE atrophy at the treatment site if lesions are central. This is why accurate ICG angiographic targeting is essential.

What to Expect with Treatment

The treatment trajectory for PCV differs from wet AMD, largely because combination therapy addresses the underlying pathology more aggressively.

• After PDT: Some patients report transient blurring or mild discomfort on the treatment day. Vision may improve, remain stable, or rarely, temporarily worsen (if central polyps are treated and cause transient RPE disruption).
• After anti-VEGF injection: Vision may improve, stabilize, or remain unchanged in the short term. The main benefit accrues over weeks to months as the combination therapy takes effect.
• Weeks 1–4: Active resorption of subretinal fluid often begins. OCT shows reduction in SHRM and decreased intraretinal edema.
• Weeks 4–12: Period of most significant improvement. Polyp closure typically evident on ICG by 3 months. Visual acuity often improves during this phase.
• Months 3–6: Continued improvement as residual exudation resorbs and RPE repairs. Metamorphopsia improves.
• Beyond 6 months: Polyp closure is typically durable; however, disease recurrence can occur in 20–30% of cases within 2–3 years. Long-term monitoring is essential.

Cost, MediSave & Insurance

Treatment of PCV — particularly combination therapy — is not inexpensive. A single PDT session costs SGD 3,000–4,500 depending on lesion characteristics. Anti-VEGF injections range from SGD 1,000–2,500 per injection depending on the agent (bevacizumab being least expensive, ranibizumab and aflibercept more so). A typical initial treatment course of 3 cycles of combination therapy would total SGD 12,000–21,000.

MediSave claims: Both PDT and anti-VEGF injections are approved claims under Integrated Shield plans in Singapore. Verify your plan details, claim limit, deductible, and annual ceiling with your insurer or through your MediSave statement.

Subsidies: Patients with low household income may be eligible for government subsidies through the clinic. Ask during your consultation.

For detailed, personalized information on costs, payment plans, and insurance claiming, please visit our fees page or contact the clinic.

Frequently Asked Questions

Is PCV the same as wet age-related macular degeneration?

No. Although PCV and wet AMD both involve abnormal blood vessel growth under the retina and cause similar symptoms, they are distinct conditions with different pathophysiology, imaging findings, and treatment responses. PCV is characterized by polypoidal lesions and a branching vascular network, whereas wet AMD involves choroidal neovascularization. Crucially, combination therapy (anti-VEGF plus PDT) is often required for PCV, whereas wet AMD typically responds to anti-VEGF monotherapy. Misdiagnosis leads to inadequate treatment and poor outcomes.

Why does ethnicity matter for PCV diagnosis?

PCV is significantly more prevalent in Asian, Hispanic, and African populations compared to Caucasians. In Asia, PCV accounts for up to 50% of cases clinically diagnosed as wet AMD. This ethnic predisposition means that any patient of Asian descent presenting with presumed wet AMD requires ICG angiography to confirm the diagnosis. Failure to diagnose PCV correctly results in treatment with anti-VEGF monotherapy alone, which is less effective for PCV than combination therapy. This is why we have a much lower threshold for ordering ICG angiography in Asian patients with presumed wet AMD.

Will I go blind from PCV if untreated?

PCV can cause significant central vision loss, but immediate blindness is not typical. However, untreated PCV tends to progress over time through repeated episodes of polyp bleeding and leakage, leading to gradual deterioration of central vision and eventual legal blindness if left unmanaged. Early diagnosis and appropriate treatment — combination therapy in most cases — can halt progression and preserve vision. The prognosis is considerably better with timely, correct treatment than without it. I have seen patients who delayed treatment suffer progressive vision loss; conversely, patients diagnosed and treated promptly have much better visual outcomes.

How many treatments are usually needed for PCV?

Treatment protocols vary, but the typical approach is combination therapy: photodynamic therapy (PDT/verteporfin) followed or accompanied by anti-VEGF injections. An initial course of combination therapy usually involves 1–3 cycles of PDT spaced 3 months apart, with anti-VEGF injections given at baseline and repeated as needed based on imaging. Some patients achieve polyp closure and stable vision with fewer cycles, while others require extended therapy. The goal is polyp closure on ICG angiography and stable or improving vision. I individualize the treatment schedule based on ICG findings at each 3-month interval.

Can PCV recur after successful treatment?

Yes, PCV can recur after an initial period of stability. Recurrence rates vary depending on treatment intensity and follow-up duration, but approximately 20–30% of successfully treated eyes experience recurrence within 2–3 years. This is why long-term monitoring with OCT and periodic ICG angiography is essential. Patients with recurrence can be re-treated with the same or adjusted combination regimen. Close surveillance allows early detection of recurrence before significant vision loss occurs. I recommend OCT imaging every 4–6 weeks initially, then every 3 months once stable, with repeat ICG angiography at 6 months post-treatment and then annually if stable.

Does MediSave cover PCV treatment?

MediSave can be used to claim anti-VEGF injections and photodynamic therapy as approved treatments for age-related macular degeneration, which includes polypoidal choroidal vasculopathy. However, individual MediSave balances, claim limits, and specific treatment protocols may vary. I recommend confirming your MediSave eligibility and claim amount directly with your clinic or MediSave account statement. For details on treatment costs and MediSave claiming, please visit our fees page or contact the clinic directly.