BLOG: Mounting the IOL scaffold: How effective is it?
Read more blog posts from Priya Narang, MS
Encountering a posterior capsule rupture (PCR) and handling it effectively is quiet a challenging task for the surgeon, especially when the PCR occurs in the initial stages of cataract surgery where the nucleus is yet to be emulsified.
Mounting the IOL as a scaffold at this juncture offers a dual advantage of preventing the nuclear pieces from slipping in to the vitreous cavity while also facilitating the emulsification.
All said and done, it’s not easy to do this technique. The foremost mindset that a surgeon has to overcome is the thought of inserting an IOL in the presence of non-emulsified nuclear chunks lying in the anterior chamber as if saying “Hey, how are you gonna give me a smooth exit now?”
The second thought process a surgeon has to overcome is the fear of losing a nuclear chunk into the vitreous. Lastly, the thought of doing an effective vitrectomy and removal of the peripheral cortical matter is also a cause of concern.
To settle all these issues, it is imperative to understand the nuances of the surgery. Sharing some of the surgical tips for this technique, I would like to suggest the following:
- Immediately after a PCR; levitate all the nuclear fragments into the anterior chamber. Infusion should be introduced into the eye in the form of anterior chamber maintainer; care should be taken that the flow of fluid does not push the nuclear fragments into the vitreous cavity. A trocar infusion also can be introduced.
- Vitrectomy can be done in the pupillary area with the probe introduced from the limbal incision.
- Insert a three-piece foldable IOL beneath the nuclear fragments and position the leading haptic either above the iris or above the capsulorhexis margin.
- The trailing haptic has to be left extruded from the corneal incision. This prevents any accidental incidence of IOL drop on the operating table.The phacoemulsification procedure is then ensued and the nucleus is emulsified.
- An IOL dialler can be used to manipulate the position of the IOL by maneuvering at the optic-haptic junction. The IOL acts as a scaffold during the emulsification process and prevents the nuclear fragment drop.
- Thorough vitrectomy should be done. The cortical matter trapped behind the IOL can be removed by going behind the IOL and performing vitrectomy. A pars plana route also can be chosen.
- The IOL is then dialled in to the sulcus above the intact capsulorhexis margin.
Do not attempt to do IOL scaffold if the capsulorhexis margin is not intact and the surgeon is not accustomed to glued IOL surgery; as after nucleus emulsification, the IOL has to be repositioned either in to the sulcus or a glued IOL procedure has to be performed. Caution has to be exerted in:
- Hypermetropic eyes. These eyes have less anterior chamber depth, so performing an IOL-scaffold procedure in such cases is not recommended.
- Eyes with very dense cataract. Avoid eyes with grade 4 dense and brown cataracts. As the emulsification is done in anterior chamber, this procedure is not recommended in very hard cataracts due to the concern of traumatizing the corneal endothelium.
One-year postoperative outcome of IOL scaffold shows very promising results and the study is online in the “Ophthalmology” journal by AAO. It is titled as “Clinical outcomes of intraocular lens scaffold surgery: A one year study.” I hope some of the surgical tips which have been highlighted above are helpful to all the readers.