This article is more than 5 years old. Information may no longer be current.
Glued IOL scaffold technique aids nuclear fragment removal amid insufficient iris, capsular support
An artificial posterior capsule is created by combining the glued IOL and scaffold techniques.
Click Here to Manage Email Alerts
Modern-day phacoemulsification is aimed at optimal postoperative vision, with the least amount of surgically induced astigmatism, quick postoperative visual recovery, the best quality of vision, and an early return to preoperative daily activities for patients such that the surgery may be an almost seamless event in their daily life.
For such surgical delivery, the cataract surgeon needs to be prepared for unwelcome intraoperative complications that may compromise the posterior capsule and/or the iris. When a breach in the posterior capsule occurs during nucleus removal, the paramount focus for every ophthalmic surgeon then shifts to proper surgical maneuvering to help prevent dropping any nuclear fragments into the posterior segment, into the vitreous cavity and ultimately onto the retina. This would potentially result in suboptimal postoperative vision associated with macular compromise, or even retinal detachment, and an unhappy patient.
Surgical techniques that can potentially reverse the downhill course in such situations and convert it to a relatively good postoperative outcome are always welcomed by ophthalmic surgeons. Jacob and Agarwal have introduced the concept of the glued IOL in posterior capsular defects and further expanded their techniques, including the IOL scaffold technique and glued IOL scaffolding.
In this column, Jacob and Agarwal describe their surgical technique of using a glued IOL scaffold to help complete phacoemulsification in the event of posterior capsular tear with nuclear material still present within the eye.
Thomas John, MD
OSN Surgical Maneuvers Editor
We described the IOL scaffold technique for posterior capsular rent. Here the IOL is pre-placed and acts as a scaffold to prevent nuclear fragments from falling down while being emulsified.
In patients with adequate capsular support, this can be done by placing the IOL in the sulcus. In patients with inadequate capsular support, the IOL can be placed as a scaffold over the iris either with one haptic trailing outside the wound to control the IOL or with both haptics over the iris. This can be done safely when the pupil is small, has a good tone and is not floppy. The IOL can then be converted into a glued IOL.
Soosan Jacob
Amar Agarwal
But in patients with inadequate iris and capsular support, these techniques can carry the risk of the IOL falling into the vitreous cavity. Alternatives to avoid this situation include the Sheets glide, the hydroxyethyl methacrylate contact lens lifeboat technique by Mehta, and emulsification after injecting perfluorocarbon liquid in collaboration with a vitreoretinal surgeon. The disadvantage in most of these techniques is the requirement of extending the corneal section, which can result in increased postoperative astigmatism. They also require temporary placement of a device or substance for nucleus support that later needs to be removed, causing additional trauma.
We have been using a new technique that we termed “glued IOL scaffolding” to provide support during nuclear fragment removal in eyes with insufficient iris support and absent or insufficient capsular support for sulcus placement of an IOL. We combine the glued IOL technique as well as the IOL scaffold technique for glued IOL scaffolding.
Surgical technique
Dispersive ophthalmic viscosurgical device (OVD) is injected through the side port, and the phaco probe is withdrawn. The remaining nuclear pieces are then brought into the anterior chamber (Figure 1) using a blunt rod introduced through the side port or by posterior assisted levitation.
The fragments are made to rest on the iris diaphragm, and dispersive OVD is again injected, both to protect the corneal endothelium and also to form a dispersive OVD trap for the fragments. An infusion cannula — or in cases with small nuclear fragments, an anterior chamber maintainer — is fixed directing away from the fragments, and the flow is kept just sufficient to keep the globe insufflated to avoid pushing the fragments down. Together, the direction of the anterior chamber maintainer, the low flow, and the OVD trap decrease the chances that the fragments resting on the iris will fall down.
Scleral flaps are then created exactly 180° apart in preparation for glued IOL surgery. A 20-gauge needle is used to create a sclerotomy 1 mm behind the limbus under the scleral flaps, and triamcinolone acetonide-assisted vitrectomy is performed with a 23-gauge vitrector passed through the sclerotomy to remove all vitreous traction. The vitrector is switched between cutting and aspiration modes to remove any residual trapped cortex, taking care to avoid any traction on the vitreous.
A three-piece foldable IOL is loaded into the injector in such a manner that the tip of the leading haptic just protrudes out of the cartridge tip. The cartridge tip is then introduced through the main port into the anterior chamber. At the same time, with the other hand, end-gripping glued IOL microforceps are passed through the sclerotomy (Figure 2). The haptic tip is grasped with the glued IOL forceps, and the IOL is gently injected into the anterior chamber.
Figure 1. Dilated pupil. Nucleus lying in the anterior chamber. Three-piece foldable IOL injected. Note the scleral flaps 180° apart and the glued IOL forceps on the left side ready to grab the haptic of the IOL.
Figure 2. Leading haptic externalized.
Images: Agarwal A, Jacob S
Figure 3. Handshake technique for trailing haptic.
Figure 4. Glued IOL forceps catch the trailing haptic tip to externalize.
Once the optic has unfolded, the haptic tip is exteriorized through the sclerotomy while simultaneously withdrawing the cartridge so that the second haptic trails out of the main port. Using the handshake technique, the trailing haptic is also externalized through the second sclerotomy (Figures 3 and 4).
These steps are relatively easy to perform once the nuclear pieces are displaced into the angle of the anterior chamber, and the cornea is coated liberally with dispersive viscoelastic, enhancing visualization. At all times, it should be verified that the nuclear fragments do not rub on the corneal endothelium.
Once both haptics are exteriorized, a 26-gauge needle is used to create intrascleral Scharioth tunnels at the edge of the scleral flaps, and both the haptics are tucked into the intrascleral tunnels (Figures 5 and 6). The glued IOL and the scaffold techniques are thus combined to create an artificial posterior capsule.
Figure 5. Both haptics externalized, and 26-gauge needle making the Scharioth pocket.
Figure 6. Haptic tucked in intrascleral pocket on the right. Left side haptic going to be tucked.
Figure 7. Phacoemulsification of the nuclear piece. The glued IOL now acts as a scaffold.
Figure 8. Glued IOL scaffold. Final nuclear piece emulsified, then fibrin glue will be applied to the scleral flaps.
Intracameral pilocarpine is administered to decrease the pupil size as much as possible. Phacoemulsification of the nuclear pieces is performed under low flow settings (Figures 7 and 8). The combination of the glued IOL scaffolding with low flow settings prevents the nuclear fragments from falling into the vitreous cavity while being emulsified.
Once the fragments are removed, any further vitrectomy is carried out if necessary. Once visualization is enhanced in this manner, centration of the IOL is adjusted by adjusting the degree of tuck of the individual haptics into the scleral tunnels, and air is injected into the anterior chamber. The anterior chamber maintainer or the infusion cannula is removed, and fibrin glue is used to seal the scleral flaps as well as the conjunctiva.
The IOP is checked digitally and if soft, balanced salt solution is gently infused into the anterior chamber until the eye becomes adequately firm again. A subconjunctival injection of antibiotic and steroid is given into the inferior fornix well away from the flaps and the sclerotomy at the end of surgery.
The biggest challenge is that if the nuclear pieces are too big, visualization of the haptic is difficult. Another problem to avoid is endothelial damage. One should use viscoelastics to prevent endothelial damage.
Combining the glued IOL and the IOL scaffold techniques, one can create an artificial posterior capsule in certain select cases of capsular deficiency in which the iris is deficient or the pupil too large to support an IOL.