SIGS or Stab Incision Glaucoma Surgery is a new technique that I have described as a new technique for guarded filtration surgery. It acts by making a single step entry into the anterior chamber via a sclero-corneal tunnel using a 2.8 mm keratome. The SIGS tunnel is then intentionally compromised by punching the posterior corneal lip with a 1mm Kelly's Descemet's punch. This punch extends backwards in the clear cornea upto the limbus as seen from the microscope. The punch need not be extended beyond the limbus which may cause excessive leakage. This surgery has advantages of only a single 2.8 mm cut in the conjunctiva, complete elimination of subconjunctival dissection and a greatly reduced risk of failure secondary to sub-conjunctival scarring which is so common in conventional trabeculectomy and all other related procedures which involve creating a limbal or fornix based conjunctival flap. Surgery is easier, faster.and less traumatic and flap related complications are minimized. The amount of virgin conjunctiva is maximized and the bleb is created not by scissor dissection but by the more physiological hydrostatic expansion of sub-conjunctival spaces and drainage channels. We have had excellent results with this procedure with a high safety profile. A PI is indicated only in cases with angle closure, PAS, shallow AC and intraoperative peaking of iris into the ostium. As it is not routinely required in open angle glaucoma, post-operative inflammation is greatly minimized.
For additional SIGS videos by Soosan Jacob, FRCS, watch:
Cataract Surgery • Glaucoma • Phacoemulsification