Bleb Morphology Assessment and Imaging

Abstract

Trabeculectomy has been widely applied as treatment for glaucoma since its introduction in 1968.1 The aim of trabeculectomy is to lower intraocular pressure (IOP) in order to slow the progression of glaucomatous optic neuropathy and visual loss.2,3 The outcome of this surgery depends upon the formation of a functioning shunt to enable egress of aqueous from the eye, leading to the development of a filtration bleb. The development of the bleb is crucial for long-term surgical success, and is affected by wound healing characteristics of the eye. Scarring of structures at the trabeculectomy site including conjunctiva, episclera, scleral flap and ostium may lead to poor formation of the bleb and hence poor shunt function resulting in suboptimal IOP control. Trabeculectomy blebs have been imaged using a range of imaging modalities in an effort to characterize bleb morphology in relation to function. Here we present a review of bleb imaging techniques and their potential uses in bleb morphology evaluation and classification.