In vivo confocal microscopy of filtering blebs after trabeculectomy.

OBJECTIVES To analyze filtering blebs after trabeculectomy by means of in vivo confocal microscopy and to correlate the images with clinical bleb appearance and function. METHOD In vivo confocal microscopy using the Heidelberg Retina Tomograph/Rostock Cornea Module (Heidelberg Engineering, Heidelberg, Germany) was performed in 53 filtering blebs in 45 patients 6 days to 30 years postoperatively. RESULTS In vivo confocal microscopic findings significantly correlated with good bleb function included the number of epithelial microcysts (P = .03), a large total stromal cyst area (P = .009), the absence of encapsulated stromal cysts (P = .002), minimal vascularization (P = .05), and the absence of tortuous conjunctival vessels (P = .01). In contrast, a hyperreflective condensed bleb stroma was significantly associated with bleb failure (P<.001). Bleb stroma mainly consisting of a rarified collagenlike network was significantly linked to trabeculectomy performed with mitomycin C (P = .001). Epithelial and stromal inflammation were observed at a median of 1 and 4 months after surgery, respectively. CONCLUSIONS In vivo confocal microscopy using the Heidelberg Retina Tomograph/Rostock Cornea Module permits diagnostic imaging of filtering blebs and differentiation between good and insufficient bleb function. Moreover, the postoperative inflammatory reaction can be monitored directly for adapted postoperative anti-inflammatory treatment.