What is the likelihood of Central Serous Chorioretinopathy (CSC) developing into Choroidal Neovascularization (CNVM)?

Likelihood of Choroidal Neovascularization Development in Central Serous Chorioretinopathy

Choroidal neovascularization (CNV) develops in approximately 2-18% of patients with chronic central serous chorioretinopathy (CSC), with higher risk in older patients and those with prolonged disease. 1

Risk Factors for CNV Development in CSC

• Age: Higher risk in patients over 50 years
• Disease duration: Prolonged CSC increases risk
• Disease severity: More common in severe chronic CSC
• Treatment history: Laser photocoagulation can increase risk of iatrogenic CNV 2

Clinical Features Suggesting CNV in CSC

• Mid/hyperreflective signal below a flat irregular retinal pigment epithelial detachment (FIPED) on OCT
• Well-demarcated CNV "plaque" (with or without polypoidal component) on indocyanine green angiography (ICGA)
• Presence of a vascular network on optical coherence tomography angiography (OCT-A) 1

Diagnostic Challenges

• CNV can be present at the onset of CSC or develop gradually
• Detection can be challenging in small, early-stage CNV
• Up to two-thirds of CSC patients with CNV may have a polypoidal component, making ICGA particularly valuable for identification 1
• "Silent type 1 CNV" may be common in chronic CSC but only detectable on OCT-A 1

Prognosis and Clinical Course

• CNV detection occurs on average 1.65 ± 2.30 years after CSC diagnosis 3
• Most patients (73.3%) remain stable for more than 6 months without subretinal fluid recurrence after appropriate treatment
• Visual outcomes are generally favorable with proper management
• Some patients (20%) may not require treatment during observation 3

Management of CSC with CNV

• First-line treatment: Intravitreal anti-VEGF injections for active CNV 1
• Adjunctive therapy: Half-dose or half-fluence photodynamic therapy (PDT) may be combined with anti-VEGF 1
• Polypoidal component: If present, combination of PDT and anti-VEGF shows better results than monotherapy 1

Important Considerations

• Regular monitoring with multimodal imaging (OCT, FA, ICGA, OCT-A) is essential for early detection of CNV in chronic CSC
• "Silent type 1 CNV" may not require immediate treatment until active leakage becomes evident 1
• CNV secondary to CSC generally has better prognosis than CNV from age-related macular degeneration 3

Pitfalls to Avoid

• Misdiagnosis of CNV as uncomplicated CSC, especially in older patients
• Overlooking small CNV in patients with extensive chorioretinal abnormalities
• Failure to use multimodal imaging, particularly OCT-A and ICGA, which are crucial for detecting CNV in CSC
• Delaying treatment in cases with active CNV, which can lead to worse visual outcomes

Regular follow-up with comprehensive multimodal imaging is essential for patients with chronic CSC to detect CNV development early and initiate appropriate treatment promptly.