Management of Single Choroiditis Foci
Critical First Step: Rule Out Central Serous Chorioretinopathy
The provided evidence focuses predominantly on central serous chorioretinopathy (CSC) with single focal leaks rather than true isolated choroiditis, which requires immediate clarification through multimodal imaging before proceeding with any treatment.
Essential Diagnostic Workup
Multimodal imaging is mandatory to establish the correct diagnosis and guide treatment:
- Optical coherence tomography (OCT) to identify subretinal fluid, outer retinal disruption, and distinguish between CSC and inflammatory choroiditis 1
- Fluorescein angiography (FA) to detect focal leakage points characteristic of CSC versus the pattern seen in inflammatory choroiditis 1, 2
- Indocyanine green angiography (ICGA) to assess choroidal hyperpermeability in CSC or hypofluorescent changes on late-phase imaging characteristic of inflammatory white dot syndromes 1, 2
- OCT-angiography to exclude neovascular networks and differentiate from pachychoroid neovasculopathy 1, 2
- Fundus autofluorescence (FAF) to characterize the lesion and assess for patterns suggestive of inflammatory versus degenerative processes 1, 2
Laboratory workup for true inflammatory choroiditis:
- Comprehensive infectious disease screening including tuberculosis (QuantiFERON-TB Gold), syphilis serology, and viral titers (HSV, VZV) given documented associations with serpiginous and multifocal choroiditis 3, 4
- Systemic inflammatory markers (ACE, lysozyme, chest imaging) to exclude sarcoidosis, which commonly presents with multifocal choroidal lesions 1, 4
- Recent COVID-19 infection history, as temporal associations with choroiditis have been documented 5, 6
Treatment Algorithm Based on Diagnosis
If Diagnosis is Acute CSC with Single Focal Leak:
For most patients, observation is the recommended initial strategy for the first 4 months, given the high rate of spontaneous resolution 1. This approach does not compromise long-term visual outcomes in first-episode acute CSC 1.
Immediate treatment is indicated if:
- Patient requires rapid visual recovery for professional reasons 1
- Recurrent episode of CSC 1
- Bilateral disease activity 1
- Patient preference after informed discussion 1
Treatment options when intervention is chosen:
- ICGA- and FA-guided half-dose photodynamic therapy (PDT) is the preferred treatment, targeting hyperfluorescent areas on ICGA that correspond to focal leakage on FA and subretinal fluid on OCT 1
- Argon laser photocoagulation may be used only if the focal leak is located at a safe distance from the fovea (not centrally located), though this carries risks of paracentral scotoma, neovascularization, and chorioretinal adhesion 1
- Discontinue corticosteroids if the patient is currently using them, as this is a critical reversible risk factor 1
If Diagnosis is True Inflammatory Choroiditis (Multifocal Choroiditis, Serpiginous Choroiditis):
Systemic corticosteroids combined with immunosuppressive agents should be initiated, never corticosteroids as monotherapy 2. This represents a fundamental difference from CSC management.
Initial treatment approach:
- Local corticosteroids (topical drops or periocular injections) for acute inflammation control 2
- Systemic immunosuppression is mandatory for the underlying inflammatory process, not optional 2, 7
- High-dose oral prednisolone at 1 mg/kg/day (maximum 60 mg/day) should be started immediately without waiting for complete diagnostic workup if inflammatory choroiditis is strongly suspected, as delay risks irreversible vision loss 7
Steroid-sparing immunosuppressive therapy:
- Add immunosuppressive therapy early (within 4-8 weeks) rather than waiting for steroid complications 7
- Mycophenolate mofetil is preferred for most cases due to favorable tolerability and efficacy 7
- Azathioprine is particularly effective for Behçet's disease-associated choroiditis with 90% inflammation control rate 7
- Methotrexate demonstrates comparable efficacy to mycophenolate mofetil 7
If choroidal neovascularization develops:
- Intravitreal anti-VEGF injections are the primary treatment 2
- Photodynamic therapy may be considered as adjunctive treatment in select cases 2
Common Pitfalls to Avoid
Do not confuse CSC with inflammatory choroiditis - these require fundamentally different treatment approaches despite both potentially presenting with single focal lesions 1, 2. CSC often requires observation or PDT targeting choroidal hyperpermeability, while inflammatory choroiditis requires systemic immunosuppression.
Do not treat underlying choroidal abnormalities in CSC with thermal laser photocoagulation - this modality should only target focal leaks away from the fovea, not the choroidal pathology itself 1.
Do not delay systemic workup for infectious etiologies in inflammatory choroiditis, as tuberculosis, syphilis, and viral infections can mimic idiopathic disease and require specific antimicrobial therapy rather than immunosuppression 3, 4.
Do not use local corticosteroid monotherapy for inflammatory choroiditis - systemic immunosuppression is required for the underlying disease process 2, 7.
Long-term Monitoring
For inflammatory choroiditis: Regular ophthalmologic surveillance is mandatory, with monitoring for at least 3 years after achieving remission to detect recurrence early 2.
For CSC: Follow-up OCT imaging at 1-3 months intervals to assess for complete subretinal fluid resolution, as residual fluid can cause progressive photoreceptor and RPE atrophy leading to vision loss over years 1.