The American Journal of Ophthalmology recently published imaging and consensus-based guidelines on the application of multimodal imaging in noninfectious multifocal choroiditis and panuveitis (MFCPU) and punctate inner choroiditis (PIC).
Give me some background.
In 2004, the first Standardization of Uveitis Nomenclature (SUN) Working Group met to initiate a process of systematizing the methods for reporting clinical data in the field of uveitis to develop diagnostic and therapeutic recommendations.
Since then, the SUN Working Group has defined MFCPU and PIC by the following criteria:
- MFCPU
- Absence of an associated infectious or systemic disease
- Presence of multiple lesions larger than 125 μm in diameter predominantly located outside the vascular arcades
- PIC
- Absence of appropriate infectious (e.g., toxoplasmosis retinitis or syphilis) or associated systemic diseases (e.g., sarcoidosis)
- Multiple punctate lesions smaller than 250 μm in diameter, predominantly located in the posterior pole, with very little to no intraocular inflammation
What was wrong with this criteria?
Importantly, the SUN classification criteria for both did not explicitly identify or define multimodal imaging biomarkers of activity specific to these conditions.
Consequently: The Multimodal Imaging in Uveitis (MUV) task force was developed by the International Uveitis Study Group (IUSG) to build upon the existing classification criteria by the SUN working group and address this gap in knowledge.
Gotcha. Now, talk about the basis for these new guidelines.
An expert committee applied a timed structured nominal group technique (NGT) to achieve consensus-based recommendations on MFCPU and PIC, including:
- Specific disease characteristics
- Biomarkers of activity
- Associated complications
They reviewed representative cases of noninfectious active and inactive MFCPU and PIC with the following imaging modalities:
- Color fundus photographs (CFP)
- Optical coherence tomography (OCT)
- Fundus fluorescein angiography (FFA)
- OCT angiography (OCTA)
- Indocyanine angiography (ICGA)
- Fundus autofluorescence (FAF)
Note: All recommendations were voted upon by the entire task force, which contained 50 experts.
Findings?
The task force agreed that lesions of MFCPU and PIC can be well-characterized using CFP, and OCT is the preferred modality for detecting active lesions.
Classic indicators of disease activity on CFP, OCT, and FAF include:
- CFP
- Active lesions: Multifocal choroiditis and PIC were characterized by multifocal lesions which appear creamy and ill-defined
- Inactive lesions: Atrophic/punched out and clearly defined (often with a pigmented border)
- OCT
- Active lesions: Fluffy subretinal hyper-reflective material (SHRM) overlying the retinal pigment epithelium (RPE)
- Ellipsoid zone (EZ) disruption extending beyond the borders of the lesion
- Potential presence of inflammatory pigment epithelial detachment (PED) or a discontinuous RPE band with elevated edges
- Active lesions: Fluffy subretinal hyper-reflective material (SHRM) overlying the retinal pigment epithelium (RPE)
- FAF
- Active lesions: New crops of uniformly hyper-autofluorescent (hyper-FAF) spots
- Inactive lesions: Typically evolve to hypo-autofluorescent (hypo-FAF) lesions corresponding to atrophy, but some can present with a hyper-FAF cuff
Anything else?
Late-phase ICGA was most valuable in recurrent disease when the lesions are not visible on FAF and CFP.
While OCTA and ICGA can successfully identify lesions and complications such as choroidal neovascularization, no imaging biomarkers were found to reliably distinguish between active and inactive lesions on these two modalities.
Expert opinion?
These guidelines “emphasize the importance of OCT as the primary imaging modality for evaluating active inflammation, with complementary roles for FAF, OCTA, and ICGA in specific scenarios,” the report authors explained.
Tie it all together for me.
The findings indicate that incorporating imaging findings—particularly OCT—into the SUN classification criteria for MFCPU and PIC enables more precise assessment of disease activity.
The consensus-based guidelines provide a framework for selecting optimal imaging modalities for diagnosis, monitoring, and identification of complications of MFCPU and PIC.