Patient Information Handout: Pachychoroid Neovasculopathy (PNV)
What is Pachychoroid Neovasculopathy?
Pachychoroid Neovasculopathy (PNV) is a condition where abnormal blood vessels grow under your retina in areas where the choroid (the blood vessel layer beneath the retina) is abnormally thickened. 1 This condition is part of a family of related eye diseases called the "pachychoroid spectrum" and typically affects people in their 50s and 60s 1.
PNV is often mistaken for age-related macular degeneration (AMD), but it is a distinct condition that requires different treatment approaches 2, 3.
What Causes PNV?
The exact cause is not fully understood, but PNV develops when:
- The choroid (blood vessel layer) becomes abnormally thick with enlarged blood vessels 1
- This leads to damage of the retinal pigment epithelium (the layer that supports your retina)
- Eventually, abnormal new blood vessels grow beneath the retina 4
PNV can develop either directly from early pigment changes or from chronic central serous chorioretinopathy (a condition causing fluid under the retina) 5.
What Are the Symptoms?
You may experience:
- Blurred or distorted central vision
- Difficulty reading or recognizing faces
- Dark or gray spots in your central vision
- Straight lines appearing wavy or bent
How is PNV Different from Age-Related Macular Degeneration?
PNV differs from AMD in several important ways 2, 3:
- Age: PNV typically occurs in younger patients (often under 60 years)
- Choroid thickness: Much thicker in PNV (typically over 250 micrometers)
- Drusen: PNV lacks the typical yellow deposits (drusen) seen in AMD, though it may have "pachydrusen" (different type of deposits)
- Response to treatment: PNV often requires fewer injections than AMD 2
How is PNV Diagnosed?
Your eye doctor will use several imaging tests:
- OCT (Optical Coherence Tomography): Shows the abnormal blood vessels and thickened choroid 4
- OCT Angiography: Reveals the pattern of abnormal blood vessels 4
- Fluorescein Angiography: Shows leakage from abnormal vessels
- Indocyanine Green Angiography: Best shows the enlarged choroidal vessels and helps distinguish PNV from AMD 6
What Are the Treatment Options?
The primary treatment for PNV is anti-VEGF injections (medications injected into the eye to stop abnormal blood vessel growth) 6, 7.
Anti-VEGF Injection Therapy
- Medications used: Aflibercept, ranibizumab, or bevacizumab 6, 7
- Treatment schedule: Most patients receive injections using a "treat-and-extend" approach, where the time between injections is gradually increased if the condition remains stable 7
- Expected outcomes: On average, vision improves by about 2-3 letters on the eye chart, and retinal fluid decreases significantly 7
- Duration: Most patients (about 79%) require ongoing treatment 7
Aflibercept may be more effective than ranibizumab for completely resolving fluid in PNV (83% vs 52% complete resolution) 6.
Photodynamic Therapy (PDT)
- May be used if anti-VEGF injections alone are insufficient 6
- Can be combined with anti-VEGF therapy in resistant cases 6
- Particularly useful when fluid persists or recurs despite injections 6
Treatment Cessation
- About 28% of patients may be able to stop treatment after initial control 7
- However, close monitoring is essential as recurrence is possible
What Can You Expect?
With treatment, most patients maintain or improve their vision 7:
- Average follow-up studies show vision improvement of 2-3 letters
- Central retinal thickness decreases by about 78 micrometers
- Choroidal thickness decreases by about 35 micrometers
Important: About 42% of patients experience recurrence when trying to extend the time between injections, requiring return to more frequent treatment 7.
Important Considerations
- Regular monitoring is essential: Even if your vision seems stable, regular eye exams and imaging are necessary
- Treatment differs from AMD: If you've been told you have "wet AMD" but are younger or have thicker choroid measurements, ask your doctor about PNV 2
- Fewer injections may be needed: PNV patients typically require fewer anti-VEGF injections than AMD patients (average 3 vs 5 injections) 2
- Avoid corticosteroids: If you're using steroid medications for other conditions, discuss this with your eye doctor, as steroids can worsen pachychoroid conditions 6
Questions to Ask Your Doctor
- What is my choroidal thickness measurement?
- Do I have drusen or pachydrusen?
- Which anti-VEGF medication is best for my case?
- How often will I need injections?
- When can we try extending the time between treatments?
- Should I consider photodynamic therapy?
Prognosis
The outlook for PNV is generally favorable with appropriate treatment 7, 4. Most patients maintain functional vision with ongoing anti-VEGF therapy. Early diagnosis and treatment are important to prevent permanent vision loss from chronic fluid accumulation or scarring.
This handout is for educational purposes. Always follow your eye doctor's specific recommendations for your individual case.