ABSTRACT
References 100
1. INTRODUCTION
Prior to 1968, glaucoma filtering operations were full-thickness procedures, that is, a
fistula was made at the limbus through the full thickness of the sclera and aqueous
drained freely into the subconjunctival space. In 1968, John Cairns (1) described trabecu-
lectomy. In the trabeculectomy procedure, an one-third thickness lamellar scleral flap is
fashioned to cover the scleral fistula. The scleral flap retards the aqueous outflow through
the fistula and significantly reduces the risk of postoperative complications, in particular,
over-filtration, flat anterior chamber (AC), hypotony, and suprachoroidal hemorrhage.