What is retinal adenopathy?

Retinal Angiomatous Proliferation (RAP)

Definition

Retinal angiomatous proliferation (RAP) is a distinct variant of neovascular age-related macular degeneration characterized by proliferation of retinal capillaries in the paramacular area that may present as intraretinal, subretinal, or choroidal neovascularization. 1

---

Key Clinical Features

RAP represents a unique form of neovascular AMD with specific characteristics that distinguish it from typical choroidal neovascularization:

• Prevalence: Affects up to 15% of patients with neovascular age-related macular degeneration 2

• Bilateral disease: More commonly affects both eyes compared to other forms of neovascular AMD 2

• Associated findings: Frequently presents with pigment epithelial detachments and reticular pseudodrusen (also called subretinal drusenoid deposits) 1, 2

• High-risk complications: Greater propensity for developing retinal pigment epithelial tears and geographic atrophy, both leading to severe vision loss 2

---

Diagnostic Approach

Indocyanine green angiography remains the gold standard for diagnosis, though optical coherence tomography has significantly improved diagnostic precision and allows for accurate staging and monitoring 2

The condition involves:

• Proliferation of retinal capillaries originating from the retinal circulation 1
• Progressive stages from intraretinal to subretinal involvement, potentially culminating in retinal-choroidal anastomosis 3

---

Natural History and Prognosis

RAP carries a particularly poor visual prognosis with rapid progression to severe vision loss:

• Rapid deterioration: 81% of untreated eyes lose 2 or more lines of vision within 6 months 3
• Severe vision loss: 31% experience severe vision loss by 6 months, with 69% declining to 0.1 (20/200) or worse by final follow-up 3
• Legal blindness: 36% of patients become legally blind during follow-up 3
• Timeline: Progression to poor vision occurs within 3 months in faster cases and within 1 year in slower cases 3

---

Treatment

Anti-vascular endothelial growth factor (anti-VEGF) therapy is the first-line treatment 2

Alternative approaches include:

• Combination photodynamic therapy with anti-VEGF agents 2
• Intravitreal corticosteroids 2

Important caveat: RAP generally portends a more guarded visual prognosis than typical choroidal neovascularization due to variable treatment response and dependence on disease stage at presentation 2

---

Clinical Pitfalls

• High vasogenic potential: The exudative nature of RAP drives its poor visual outcomes 3
• Progression to fibrosis: 62% develop subretinal fibrosis, and 56% progress to retinal-choroidal anastomosis 3
• Monitoring requirement: Given the rapid progression, close follow-up is essential once diagnosed 3