Case Presentation
- Patient: 23-year-old White woman with worsening bilateral vision for 4-5 days.
- History: Recent travel to Georgia/Tennessee, multiple bug bites 1-2 weeks prior.
- Initial diagnosis: Acute posterior multifocal placoid pigment epitheliopathy (APMPPE).
- Progression: Evolved to relentless placoid chorioretinitis (RPC) over 2 months.
Clinical and Imaging Findings
- Clinical Exam: Posterior lesions (APMPPE-like) + vitreous cells.
- Fundus Photography:
- Initial: Creamy white lesions in macula and periphery (OS).
- Follow-up: Pigmented posterior lesions, increased peripheral white placoid lesions.
- Fundus Autofluorescence (FAF):
- Initial: Hyperautofluorescence of placoid lesions.
- Follow-up: Hyperautofluorescent lesions in posterior/midperipheral retina.
- Fluorescein Angiography (FA) (Ultra-widefield):
- Initial: Early hypofluorescence (blockage), late hyperfluorescence (staining).
- Follow-up: More peripheral lesions (window defects).
- Indocyanine Green Angiography (ICGA) (Ultra-widefield):
- Initial: Multifocal hypofluorescence (RPE lesions + choriocapillaris blockage).
- Follow-up: Stabilized hypofluorescence in posterior/peripheral lesions; detected new peripheral lesions not seen on FA/clinical exam.
- Optical Coherence Tomography (OCT):
- Initial: Outer plexiform layer hyperreflectivity (angular sign of Henle fiber layer, ASHH), ellipsoid zone (EZ) disruption, RPE disruption.
- Follow-up: Partial recovery of outer plexiform hyperreflectivity, persistent EZ/RPE disruption.
- OCT Angiography (OCTA):
- Initial: Choriocapillaris blockage/hypoperfusion.
- Follow-up: Healing mosaic with reduced hypoperfusion.
Disease Course and Management
- Initial APMPPE diagnosis based on posterior lesions and imaging.
- Progression to RPC: New peripheral lesions on ultra-widefield ICGA, increasing lesion number over 2 months.
- Treatment: Systemic corticosteroids + topical prednisolone acetate 1% for uveitis.
- Outcome: Lesions stabilized, suggesting milder RPC or benefit from early intervention.
- RPC therapies: Anti-TNF-alpha (adalimumab), anti-IL-6 (tocilizumab), intravitreal triamcinolone (long-term success reported elsewhere).
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Key Features and Differentiation
- APMPPE:
- Age: 20-30, often post-viral, self-limiting (weeks).
- Lesions: Posterior pole, rarely beyond equator, resolve with pigmentation.
- Prognosis: Good, unless foveal involvement.
- Imaging: FA (early hypo → late hyper), ICGA (hypo), OCT (outer retina/EZ disruption → recovery).
- RPC:
- Prolonged course (2-3+ months), multiple recurrences, lesions anterior to equator.
- Lesions: Creamy white, mid-/far-periphery, progress to choroidal atrophy.
- Prognosis: Poor with foveal involvement, requires immunosuppression.
- Imaging: Similar to APMPPE, but ultra-widefield shows peripheral extent.
- Spectrum: This case bridges APMPPE (initial posterior focus) and RPC (peripheral progression).
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Role of Ultra-Widefield Imaging
- Critical for differentiation: Detected peripheral lesions (ICGA) missed by standard FA/clinical exam, shifting diagnosis from APMPPE to RPC.
- Guides management: Early identification of RPC-like features prompted systemic corticosteroids, potentially halting progression.
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High-Yield Takeaways for Exams
- APMPPE: Acute, posterior, self-limiting; FA (early hypo → late hyper), ICGA (hypo), OCT (EZ disruption → recovery).
- RPC: Prolonged, peripheral, relentless; similar imaging but >50 lesions, poor prognosis without treatment.
- Ultra-widefield ICGA: Key to identifying peripheral lesions, distinguishing APMPPE from RPC.
- OCT findings: Angular sign of Henle fiber layer hyperreflectivity (ASHH), EZ/RPE disruption—hallmarks of placoid diseases.
- Management: APMPPE often observed; RPC requires early immunosuppression (corticosteroids, anti-TNF/IL-6, intravitreal steroids).
- Spectrum case: APMPPE can evolve to RPC—monitor with ultra-widefield imaging for peripheral progression.