Conjunctival marking 3 mm from the limbus. For greater precision, the surgeon should use a dermographic pen to mark two points of the conjunctiva, 3 mm from the limbus, in the nasal-superior quadrant for example

Peripheral corneal incision. The surgeon must create a peripheral corneal incision, 1–1.2 mm long, in the sector that is diametrically opposite to the implantation site, for example, in the temporal-inferior quadrant. When a learning surgeon is performing his first procedures, we would recommend filling the AC with a cohesive VES to expand the spaces

Insertion of the injector into the AC towards the camerular angle. Through the AC, the tip of the injector is directed towards the camerular angle, preferably in a bevel-down position. The figures show a sagittal view (Fig. 12.5) of the procedure and a view from above (Fig. 12.6)

Insertion of the injector into the AC towards the camerular angle. Through the AC, the tip of the injector is directed towards the camerular angle, preferably in a bevel-down position. The figures show a sagittal view (Fig. 12.5) of the procedure and a view from above (Fig. 12.6)

Penetration of the sclera and the sub-conjunctival space. Compared to the other MIGS procedures, in this case the entrance zone to the angle is not well-defined: as maximum precision is not essential, the procedure can be performed without a gonioscopy lens. The needle can penetrate the camerular angle at any point, from the Schwalbe line to the scleral spur. The tip is guided through the sclera into the sub-conjunctival space, creating a slit. The tip’s bevel exits the sclera (the intrascleral tunnel measures 3 mm) and extends for approximately 3 mm posterior to the limbus: in this phase, the tip should emerge inside the sub-conjunctival space between the two marks (see the blue arrows in Fig. 12.8). Given that the bevel lies almost parallel to the conjunctiva in the sub-conjunctival space, conjunctiva perforation with the tip bevel exiting the sclera can be easily avoided. The surgeon can directly observe the entire bevel of the tip in the sub-conjunctival space. The figures show a sagittal view (Fig. 12.7) of the procedure and a view from above (Fig. 12.8)