Case Presentation
- 52-year-old Chinese man with subacute bilateral blurred vision: 2 weeks OS, 1 week OD.
- No prior medical/ocular history, no travel, no pet exposure, systemically well.
- Best-corrected visual acuity (BCVA): 20/400 OD, 20/30 OS.
- Anterior segment: 1+ cells OU, otherwise normal.
- Fundus: Bilateral, multiple placoid whitish lesions at RPE level, involving macula and all peripheral quadrants.
Imaging Findings
- Fundus Photography: Multiple placoid whitish lesions throughout retina (macula + periphery).
- Fluorescein Angiography (FA):
- Early hypofluorescence (blockage).
- Late hyperfluorescence (staining).
- Indocyanine Green Angiography (ICGA): Hypofluorescence in early and late phases.
- Optical Coherence Tomography (OCT):
- Initial: Disruption/loss of inner segment/outer segment (IS/OS) junction (prominent in right fovea), outer nuclear layer hyperreflectivity, sub-RPE lesions with intact overlying RPE, RPE detachments.
- Post-treatment (10 weeks): Reduced number/height of sub-RPE lesions, IS/OS junction recovery.
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Clinical Course
- Treated with oral steroids (1 week): Lesions pigmented/consolidated, no new lesions.
- Vision improved with steroid response, supporting an inflammatory etiology.
- Follow-up critical to monitor for new lesions or atypical evolution.
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Differential Diagnosis
- White Spot Syndromes:
- Acute Posterior Multifocal Placoid Pigment Epitheliopathy (APMPPE):
- Acute onset, one eye followed by the other, centrifugal lesion pigmentation, no new lesions post-initial phase, good visual recovery.
- Atypical here: Large number of lesions, peripheral distribution.
- Serpiginous Choroiditis: Chronic, progressive, peripapillary/macula lesions, contiguous recurrences, poor prognosis without treatment—less likely due to acute onset and resolution.
- Persistent Placoid Maculopathy: Prolonged lesions (months-years), posterior pole only, CNV common—not seen here (rapid resolution).
- Relentless Placoid Chorioretinitis (RPC):
- >50 lesions across equator, prolonged course with sequential new lesions, poor prognosis without immunosuppression—less likely (no new crops over time).
- Infections:
- Tuberculosis (TB): Serpiginoid chorioretinitis, sub-RPE lesions possible, RPE predilection; negative PPD but Quantiferon gold recommended.
- Syphilis: Ocular syphilis can mimic placoid syndromes; negative VDRL insufficient—treponemal-specific test (e.g., FTA-ABS) needed.
- Neoplasms:
- Primary CNS Lymphoma: Sub-RPE lesions with intact RPE, less common acute vision loss/angiographic pattern—brain imaging warranted.
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Diagnostic Considerations
- APMPPE favored: Acute onset, bilateral sequential involvement, classic FA/ICGA pattern (early hypo → late hyper; persistent hypo), rapid pigmentation, IS/OS recovery, vision improvement.
- Atypical features: Numerous peripheral lesions, sub-RPE deposits with intact RPE—raise concern for RPC, TB, syphilis, lymphoma.
- Workup:
- Brain imaging (rule out CNS lymphoma).
- Fluorescent treponemal antibody (syphilis).
- Quantiferon gold (TB, given RPE involvement).
- Elevated CRP/ESR (if tested) supports systemic inflammation (e.g., APMPPE with CNS component).
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Management
- Initial oral steroids: Effective (lesion consolidation, vision improvement by 1 week).
- RPC requires early immunosuppression to halt progression—less likely here due to lack of relentless new lesions.
- Monitor closely for recurrence or atypical progression (e.g., CNV, atrophy).
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High-Yield Takeaways for Exams
- APMPPE: Acute, bilateral, placoid lesions, FA (early hypo → late hyper), ICGA (persistent hypo), OCT (IS/OS disruption → recovery), good prognosis with observation or steroids.
- Distinguish RPC: >50 lesions, prolonged course, new crops, poor prognosis without immunosuppression—key to early diagnosis/treatment.
- Sub-RPE lesions with intact RPE: Atypical for APMPPE, prompts workup for TB, syphilis, lymphoma.
- Rule out infectious masqueraders (TB, syphilis) with specific tests (Quantiferon, FTA-ABS) beyond initial negatives.
- OCT limitations: No specific diagnostic criteria for APMPPE—relies on clinical/angiographic correlation.