The surgical options for glaucoma are expanding with a growing body of evidence of the short- and longer-term results. This chapter will focus on description of newer surgical techniques that hold promise in the treatment of glaucoma. The ExPRESS Mini-shunt (Optonol Ltd., Neve Ilan, Israel/Alcon, Fort Worth, TX) has emerged as a device used to help standardize one part of the trabeculectomy filtering procedure. This biocompatible, stainless-steel device, which measure 400 microns wide by 3 mm long, contains a 50-micron non-valved opening to enable filtration for the treatment of glaucoma (Fig. 14.1) Currently recommended for use underneath a partial-thickness scleral flap • Using a standard fornix- or limbus-based conjunctival flap, and after application of antimetabolites, this device is placed underneath a partial-thickness scleral flap, fashioned identically to a trabeculectomy procedure. • A 26-gauge needle or commercially available Sapphire blade is used to enter the anterior chamber under the scleral flap at the color transition from clear cornea at an angle parallel to iris plane. • Using a preloaded injector, the device is placed into the anterior chamber through the previously fashioned tract so that the plate is flush with the bed of the sclera flap. • The desired position of the device under the sclera flap is into the anterior chamber with distance from the corneal endothelium. • The flap is then sutured as is typical for a trabeculectomy, titrating tightness of sutures to desired amounts of flow. These sutures can, as with a trabeculectomy, be released or lysed with laser subsequently depending on the suture technique. • An iridotomy is not performed with this procedure. Therefore, this procedure represents a modification of a guarded filtration procedure using a device with a standardized ostium size to replace the sclerostomy and iridotomy portions of the trabeculectomy procedure. • By eliminating the sclerostomy, the rate of aqueous egress from the 50-micron opening into the subconjunctival/sub-Tenon’s plane is reportedly more standardized in comparison to trabeculectomy. • Although there are reports suggesting a lower incidence of hypotony with the ExPRESS in the immediate postoperative period as compared to trabeculectomy, the rate of flow in both ExPRESS use and trabeculectomy is critically determined by the tension of the sutures at the scleral flap, which was not standardized among the two groups.
Perkembangan Sejarah dan Isu-Isu Terkini dalam Sastra Bandingan
