Differentiation between presumed ocular histoplasmosis syndrome and multifocal choroiditis with panuveitis based on morphology of photographed funduslesions and fluorescein angiography

Objective: To evaluate whether inactive cases of presumed ocular histoplasm osis syndrome (POHS) and multifocal choroiditis with panuveitis (MFC) can b e 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 patie nts 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% confid ence 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 indeter minate 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 i ncreased to 0.825 (95% CI, 0.592-1). When pictures only were available, obs erver A and observer B kappa values against the gold standard were 0.625 (9 5% CI, 0.270-0.980) and 0.588 (95% CI, 0.235-0.940), respectively. The pict ures-only kappa values for observer A vs observer B were 0.582 (95% CI, 0.3 16-0.848) with indeterminate patients factored in and 1.0 (95% CI, 1.0-1.0) when indeterminate patients were excluded. Pictures and fluorescein angiog ram 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 observe r 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) excludins i ndeterminate 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 observ er can often accurately distinguish between POHS and MFC without the need f or ancillary testing. Angiography in addition to fundus photography does no t appear to increase diagnostic ability. There appears to be a higher sensi tivity for MFC than for POHS.