Anterior chamber maintainer (e.g., 25G infusion) in place, conjunctiva opened, ciliary sulcus sclerotomy at 6 o’clock position 1.5–2.0 mm postlimbal with a 23G sharp cannula
Second ciliary sulcus sclerotomy has to be placed exactly opposite; here, a cannula is used to estimate 180°
23G sharp cannula is used to create the second ciliary sulcus sclerotomy; note that it is directed toward the posterior pole to prevent damage to the iris base
Intrascleral tunnel is prepared starting from ciliary sulcus sclerotomy; a bent 23G sharp cannula is used
Sharp cannula is externalized after 2–3 mm; colibri is used to apply counterpressure during externalization. Note the limbus-parallel direction of intrascleral tunnel
Intrascleral tunnel is prepared from second ciliary sulcus sclerotomy. Note the counterclockwise direction
Three-piece intraocular lens is implanted with injector; leading haptic could be placed onto iris surface or into posterior chamber; continuous infusion is mandatory
IOL is implanted with trailing haptic fixated in the corneal incision
Two specially designed 25G forceps are used for intraocular manipulation (handshake technique
Curved forceps is introduced through side port incision and presenting the haptic; straight forceps is grasping the very tip of the haptic and then externalizing the haptic through ciliary sulcus sclerotomy
First IOL haptic is externalized
Second IOL haptic externalized through opposite sclerotomy
Curved Scharioth forceps is used to implant IOL haptic into limbus parallel intrascleral tunnel; it is very important to grasp the very tip of the IOL haptic
IOL haptic is pushed through intrascleral tunnel, and then forceps is opened; after releasing the haptic, the forceps is turned a little and retracted in closed position; care is taken not to withdraw the IOL haptic
Both haptics are positioned intrasclerally; note that the haptics are fully covered by sclera
26.2 Glued IOL and Other Modifications
Later, Agarwal presented a modification of this technique . Like for trans-scleral suture fixation technique, two half thickness scleral flaps are created 180° to each other. Initially, the haptics were just left under the flaps, and the flap and the conjunctiva were repositioned with fibrin glue. Recently, Agarwal is using an additional intrascleral fixation tunnel to increase stability (Scharioth tuck). A 27G cannula is used to create an intrascleral tunnel at the side of the scleral bed. Then, the IOL haptic is tucked into this tunnel, and the scleral flap and conjunctiva are repositioned with glue.
Totar and Kraadag present another modification of intrascleral haptic fixation . They place 23G or 25G vitrectomy trocars in the area of ciliary sulcus. The trocars are inserted oblique to create a short intrascleral tunnel. After IOL implantation, a forceps is introduced through the trocar, and the haptic is grasped. Now, the trocar is pulled over the forceps. While retracting the forceps, the IOL haptic is placed intrascleral. Reduced conjunctival trauma and surgical time seem to be favorable, but the shorter intrascleral fixation increases the risk for dislocation. An intraoperative “fine tuning” of the IOL position is also not possible. In a small study of 29 eyes, the authors did not find significant differences between the two techniques .
26.3 Intrascleral Haptic Fixation and Multifocal IOL
In young patients phakic in the other eye, the implantation of a multifocal IOL could be indicated. We consider this especially in patients with Marfan syndrome or after severe trauma with luxation of the crystalline lens. In 2011, we reported on our first experience with intrascleral fixation of multifocal IOL . The implantation technique is not different to standard IOL. Special care is taken for optimum centration of the IOL and to prevent IOL tilt. We have used three-piece multifocal IOL (ReZoom und Tecnis Multifocal, AMO, Santa Ana, USA). Three months after implantation, a laser refractive surgery (laser touch up) could be used to reduce residual refractive errors. We prefer LASEK or PRK to prevent any interaction of the suction ring with the area of the intrascleral haptic fixation. In some cases, we have used corneal wave front-guided ablation to reduce higher order aberrations.
26.4 Results and Complications
In a European multicenter study, intermediate results of intrascleral haptic fixation technique were presented . The median follow-up was 7 months. Sixty-three eyes of four European centers were analyzed. Dislocation of one haptic requiring refixation was found in two eyes. No severe complication such as endophthalmitis or retinal detachment occurred. The best uncorrected visual acuity improved in all patients.
Later, several other studies supported the excellent outcome and low complication rate of these techniques. Rare complications are cystoid edema, transient elevation of intraocular pressure, transient vitreous hemorrhage, or corneal edema.
In our patients, no severe late complication occurred. Almost all haptic dislocations occurred in the early postoperative period and affected only one haptic. Early postoperative hypotonia was the major reason for this complication. In all eyes, the dislocated haptic could be successfully refixated.