Combined Cataract Extraction and Glaucoma Drainage Implant Surgery

Introduction

The occurrence of concomitant cataract and glaucoma is frequent in the elderly population. When medical treatment is not enough to promote adequate intraocular pressure (IOP) control, a filtering procedure is usually required to avoid progression of optic nerve damage. Most surgeons elect trabeculectomy as the first-line glaucoma procedure to be performed in conjunction with phacoemulsification in this situation. However, in patients with refractory glaucomas, with previously failed trabeculectomies, extensive conjunctival scarring, and bleb-related complications, glaucoma drainage devices (GDD) are probably the best approach to reduce IOP.

Indications

There are several conditions where trabeculectomy (even with antimetabolites) is associated with a low success rate.

GDDs are generally reserved for complicated secondary glaucomas, such as uveitic glaucoma and neovascular glaucoma, young patients, eyes with previously failed filters, and in eyes with insufficient conjunctiva due to scarring from prior surgical procedures or injuries.

Table 106-1 displays a list of conditions where GDD may be employed in conjunction with phacoemulsification in patients with cataract and refractory glaucoma.

The two published series including patients undergoing combined phacoemulsification and glaucoma drainage implant surgery suggest that the most common indications for this procedure are failed trabeculectomy (47–58%) and neovascular glaucoma (3–22%).

Preoperative Considerations

Candidates for combined phacoemulsification and glaucoma drainage device implantation require a very careful biomicroscopic examination. Several aspects need to be taken into account.