Abstract
Purpose: :
Baerveldt glaucoma drainage implants (BGI) are one of the most common drainage implants used for the surgical treatment of glaucoma. Despite their popularity, published information describing the histopathologic characteristics of glaucoma implants in the human eye is limited. Few histopathologic reports of Molteno and Ahmed implants in the human eye have been published, but none for the BGI in humans. This study reports on the histopathologic features characteristics of BGIs in enucleated human eyes.
Methods: :
Enucleated human globes from years 2001 to 2005 that were submitted to the Bascom Palmer Eye Institute pathology lab with BGI were examined. Eleven BGI were received attached to the globe, and five BGI were received separate from the globe for histopathologic analysis. One eye had two BGIs. Histopathologic analysis included examination of gross specimens, as well as Haematoxylin and Eosin and Trichrome staining of histological sections. The capsule surrounding the BGI was assessed for cellularity, inflammation, vascularity, and capsular thickness.
Results: :
All enucleated specimens in this series were blind painful eyes or autopsy specimens associated with one of the following diagnoses: neovascular glaucoma, endophthalmitis, uveitic glaucoma, congenital glaucoma, or indeterminate. All capsules showed mild cellularity, inflammation, and vascularity using a mild, medium, or severe grading scale. The mean capsular thickness for all specimens was 400 ± 268 microns (n=11) for the inner capsule and 375 ± 170 microns (n=12) for the outer capsule.
Conclusions: :
To our knowledge, this is the first histopathologic description of Baerveldt glaucoma drainage implants in humans. In addition, this is the largest histopathologic series of any type of glaucoma drainage implants reported. BGI capsules were characterized by highly variable inner and outer capsule thickness and minimal cellularity, inflammation, and vascularity. Slightly thicker capsular thickness (500 microns) and similar levels of mild chronic inflammation were seen in one Ahmed valve case report (n=1). Histopathologic correlations with clinical information, such as intraocular pressure, will enable a better understanding of how capsular characteristics of glaucoma drainage implants affect intraocular pressure control.
Keywords: pathology: human • wound healing • inflammation