Differentiation between presumed ocular histoplasmosis syndrome and multifocal choroiditis with panuveitis based on morphology of photographed fundus lesions and fluorescein angiography.
OBJECTIVE: To evaluate whether inactive cases of presumed ocular histoplasmosis syndrome (POHS) and multifocal choroiditis with panuveitis (MFC) can be differentiated from each other by their appearance on fundus photography and fluorescein angiography. METHODS: Two masked observers classified 50 patients' photographs (27 with fluorescein angiograms) as POHS, MFC, or "indeterminate." Twenty-five patients had known POHS and 25 had known MFC. Statistical analysis was performed to assess agreement and interrater reliability. RESULTS: Observer A classified 33 patients and was indeterminate on 17. Of the 33, he was correct on 26 (79% crude accuracy; kappa = 0.560; 95% confidence interval [CI], 0.286-0.834). Observer B classified 40 patients and was indeterminate on 10. Of the 40, he was correct on 33 (82% crude accuracy; kappa = 0.650; 95% CI, 0.422-0.878). Both observers ventured a diagnosis on 28 common patients. Of these, they selected the same diagnosis on 26 (93% crude agreement). When the 2 observers' diagnoses were compared and indeterminate patients were factored in, the kappa value was 0.408 (95% CI, 0.215-0.601). When the indeterminate patients are excluded, the kappa agreement increased to 0.825 (95% CI, 0.592-1). When pictures only were available, observer A and observer B kappa values against the gold standard were 0.625 (95% CI, 0.270-0.980) and 0.588 (95% CI, 0.235-0.940), respectively. The pictures-only kappa values for observer A vs observer B were 0.582 (95% CI, 0.316-0.848) with indeterminate patients factored in and 1.0 (95% CI, 1.0-1.0) when indeterminate patients were excluded. Pictures and fluorescein angiogram kappa values were 0.493 (95% CI, 0.076-0.909) for observer A and 0.706 (95% CI, 0.413-0.999) for observer B against the gold standard. For observer A vs observer B, the kappa value was 0.261 (95% CI, -0.002 to 0.524) with indeterminate patients factored in and 0.567 (95% CI, 0.032-1) excluding indeterminate patients. Sensitivity for all cases for observer A was 60% (+/-13%) for POHS and 94% (+/-6%) for MFC. For observer B, the sensitivity for all cases was 70% (+/-10%) for POHS and 95% (+/-5%) for MFC. CONCLUSIONS: Given adequate funduscopic information, the experienced observer can often accurately distinguish between POHS and MFC without the need for ancillary testing. Angiography in addition to fundus photography does not appear to increase diagnostic ability. There appears to be a higher sensitivity for MFC than for POHS.