The View From Within: In Vivo Confocal Microscopy of Leukocyte-Endothelial Dynamics in Patients With Uveitis or Scleritis

Abstract

Abstract: : Purpose: In vivo confocal microscopy as described by Kirveskari, et al (Nature Med, 7:376, 2001) is a powerful tool to visualize leukocyte-endothelial rolling and sticking to vessel walls, two characteristics of the inflammatory response. We tested the hypothesis that leukocyte-endothelial dynamics are abnormal in superficial ocular vessels, even if they are clinically uninvolved. Methods: We studied 7 subjects with scleritis (5 men, 2 women, average age 54) and 10 subjects with uveitis (3 men, 7 women, average age 40). We included 23 control subjects (8 men,15 women, average age 37) who had no clinical eye disease. Intravital confocal biomicroscopy (Advanced Scanning, Ltd) of temporal superficial conjunctival vessels (4-5 mm temporal to limbus at 9 and 3 o'clock) was performed on each eye of each subject. Video images were captured and digitized using DPS Reality. Videos were analyzed in ten second segments for leukocyte rolling, sticking or free flowing using Adobe Premeire. These videos were graded based on density of cell adhesion to conjunctival vessel walls on a scale of 0-4 by two observers. Slit lamp exam was obtained in scleritis and uveitis subjects only. Anterior segment exam and information regarding demographics, medications, past medical history and eye history was obtained for all subjects. Results: Subjects with scleritis consistently demonstrated measurable rolling and sticking in clinically involved vessels. Less consistent but still frequent, increased rolling and sticking could be quantified in the clinically unaffected eye. Suprisingly, conjunctival vessels were more frequently and more severely inflamed as judged by rolling and sticking in either the affected or unaffected eye of patients with uveitis than control subjects. Conclusions: Slit lamp intravital confocal microscopy is a novel tool to quantitate an essential component of the inflammatory response. In uveitis and scleritis, clinically unaffected vessels may show substantial rolling and sticking. We speculate that this technique will help to define subsets of patients with uveitis or scleritis based on pathogenesis and response to therapy.

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