Abstract
Abstract: :
Purpose: Formation of keratic precipitates (KP) is a characteristic finding in various forms of intraocular inflammation, including uveitis and corneal transplant rejection. Clinically KP may take a limited number of forms distinguished by size and distribution across the corneal endothelium. We evaluated the heterogeneity of KP in subtypes of uveitis by scanning confocal microscopy, a technique providing 500–fold magnification. Methods: Cornea and KP were viewed with an ASL–1000 Scanning Confocal Microscope (Advanced Scanning Ltd, New Orleans, LO) in patients (n=35) presenting to a tertiary referral uveitis service with immune–mediated and infectious forms of uveitis, including HLA B27–associated, sarcoidosis, Vogt–Koyanagi–Harada syndrome, juvenile idiopathic arthritis, Fuchs’ heterochromic iridocyclitis, CMV retinitis, herpetic anterior uveitis, ocular toxoplasmosis and idiopathic uveitis. Images were captured and digitalized in real time. Results: Keratic precipitates were successfully imaged by this non–invasive confocal microscopy system. Three–dimensional views were rendered from z–stacks of certain images. The KP could be classified into distinct morphological patterns including: smooth rounded, globular, dendritiform, cruciform and stellate. In general, in any given patient, the morphology of KP was consistent across the endothelium. Likewise, patients with a given disease tended to have KPs with similar morphologies. Patients with infections demonstrated KP architecture usually distinct from a non–infectious process. Conclusions: Scanning confocal microscopy has been used for the first time to describe the anatomy of KP in uveitis. Such observations reveal a heterogeneity that could not be appreciated by conventional slit lamp microscopy and may have diagnostic relevance.
Keywords: uveitis–clinical/animal model • imaging/image analysis: clinical