Anterior Segment Considerations in Boston Type I Keratoprosthesis

Abstract

Prior to keratoprosthesis implantation, evaluation of anterior segment anatomy is of vital importance to ensure adequate space for the implant. In many cases, corneal opacity prevents direct examination of the anterior segment. In these cases, ancillary imaging studies such as anterior segment optical coherence tomography (OCT) or ultrasound biomicroscopy (UBM) are required for thorough evaluation. Important variables in anterior chamber anatomy include anterior chamber depth, phakic status, presence of synechial angle closure or iris-cornea touch, and location of any hardware such as a glaucoma drainage implant (GDI). These factors aid in the selection of a keratoprosthesis model and can indicate the necessity for additional procedures such as intraocular lens removal or GDI repositioning. Special considerations must be made in pediatric keratoprosthesis given the naturally shallow anterior chamber and in the presence of anterior segment malformations.