When HIV Immunodeficiency and Heterochromia Confuse the Issue: Recurrent Zoster Uveitis Mistaken for Fuchs' Uveitis.

Purpose: We report a case with iris heterochromia misdiagnosed as Fuchs' uveitis which finally turned out to be a unilateral zoster uveitis in an HIV-positive patient.

Case Report: A 45-year old patient was seen for a recurrent right anterior uveitis treated with prednisolone 1% drops BID. The iris of the right eye was hypochromic and atrophic and several small granulomatous keratic precipitates (KPs) were present. After discontinuation of corticosteroid drops, severe uveitis developed with mutton-fat KPs, and laser flare photometry (LFP) increased from 20 to 50.3 ph/ms. He had presented with right zoster ophthalmicus two years earlier and HIV-serology revealed to be positive.

Conclusion: Iris heterochromia is not a good disease-defining criterion for Fuch's uveitis even when typical KPs are present and can lead to misdiagnosis. More reliable criteria including stellate KPs, low LFP values, absence of synechiae, vitreitis, and disc hyperfluorescence, all absent in this case, should be sought to confirm or exclude the diagnosis.