Abstract
Glaucoma drainage implants can effectively lower the intraocular pressure in eyes that have undergone prior vitrectomy or scleral buckling surgery. Acute angle closure without pupillary block may develop after scleral buckling surgery, particularly in eyes with pre-existent narrow chamber angles treated with anteriorly positioned, high-encircling elements, and extensive cryopexy. A drainage implant is indicated when conjunctival scarring and recession from a prior scleral buckling surgery reduce the likelihood of a successful trabeculectomy. Vitreoretinal surgeons often encounter patients with neovascular glaucoma associated with diabetic retinopathy, central retinal vein occlusion, prior complicated surgery, or trauma that requires a vitrectomy in conjunction with a Baerveldt Glaucoma Drainage Device (BGDD). Careful assessment of the conjunctiva, cornea, and lens is necessary to determine whether the BGDD tube should be implanted through the limbus or the pars plana. Pars plana tube insertion requires a complete vitrectomy, with special attention being paid to clearing the vitreous base in the quadrant of tube insertion.