Micro-instrumentation reduces trauma in IOL exchange

Take-home: Increased procedure volume and patient expectations have made IOL exchange procedures more common. Smaller incisions and the need to reduce trauma require new micro-instrumentation for best outcomes.

Intraocular lens (IOL) implantation is a well-established procedure with a success rate of 95% to 98%.¹

Improvements in design, materials, and techniques have helped to optimize outcomes.²

Over the past decade, patients’ expectations have risen along with procedure volumes. Even with precise lens calculations and thorough patient education, the best option for improved vision and patient satisfaction is an IOL exchange.³

While IOL exchange is not a common procedure, most ophthalmic surgeons will encounter the need to explant a lens. The use of micro-instrumentation specifically designed to cut and remove lenses through a small paracentesis can reduce trauma and improve outcomes.

New instrumentation needed

For many years, most IOL procedures have been performed using scissors and forceps designed for extracapsular cataract extraction (ECCE). Over the past decade, many surgeons have adopted manual small incision cataract surgery, which necessitates the use of instruments that enable access through small incisions.

However, where micro-instrumentation is important in IOL exchange is in the phase of lens division and removal. IOL exchange surgery requires the instruments that diminish the potential for ocular trauma and enable the surgeon to remove the lens out through a small incision - one as small as was used to introduce the new lens.

In the past, ECCE scissors and forceps were often modified. However, the length of the arm, and in the case of forceps, width, made it difficult to achieve the optimal angle and manoeuver through small incisions when working inside the eye.

For example, Vannas scissors were designed to work through a wide corneal incision. Yet, forceps designed for use inside the eye are too small and not robust enough for an IOL exchange.

IOL cutting system

IOL cutting system

The Packer/Chang IOL Cutting System (MicroSurgical Technology [MST]), developed by Mark Packer, MD, and David Chang MD, provides a set of instruments designed to meet the requirements for a safe IOL exchange. With the 1-mm diameter cannula (19-gauge) of the scissors and the 0.6-mm cannula of the micro-holding forceps (23-gauge), this system works through a 2-mm main incision and 1-mm paracentesis.

Once introduced, the wound does not gape, allowing the viscoelastic to remain in situ. This set of micro-instruments makes the surgeon’s job easier and improves safety by reducing surgical trauma.

The low profile of the Packer/Chang IOL cutters are small enough to be introduced entirely into the eye without distorting the cornea, thus enabling precise work without exerting trauma. Because of their innovative design, the scissors also can be used on thickest acrylic IOLs without bending the blades.

The scissors will cut through any foldable IOL. This system allows surgeons to cut the lens into two or three pieces intraocularly, and remove the fragments through a small wound.

The 23-gauge Micro-Holding Forceps in this set also are easy to use and can stabilize any IOL. By using the serrated micro-holding forceps through the paracentesis, surgeons can firmly grasp the lens while they cut it through the main incision. The forceps open wide enough to securely grasp any foldable lens material.

The stand-out aspects of this set of micro-instruments are the ability to cut any foldable IOL, diminish trauma in the anterior segment, and their use through the smallest incisions. They can easily stabilize any kind of IOL.

The modifications made in the design of this system are similar to vitreoretinal instruments, but they are strong enough to be used for precise maneuvers within the anterior segment.

Given the high-patient volume, I perform between 20 to 40 IOL exchange cases per year, and I appreciate the benefits offered in this system are important to patient outcomes.

References

1.    American Academy of Ophthalmology (2011). Cataract in the Adult Eye (Preferred Practice Pattern). San Francisco: American Academy of Ophthalmology, accessed April 14, 2016.

2.    George J.C. Jin, “Changing Indications For and Improving Outcomes of Intraocular Lens Exchange”, Am J of Opthalmol, 140(4), 688-694 (2005)

3.    Uday Devgan, “When All Else Fails: Pearls for IOL Exchange”, Review of Ophthalmology.

José Luis Güell, MD

E: guell@imo.es

Dr. Güell is an ophthalmologist and founding partner of the Institute of Ocular Microsurgery in Barcelona, Spain, where he is the coordinator of the Cornea, Cataract and Refractive Surgery Department. He also is the coordinator of Anterior Segment at the European School for Advanced in Ophthalmology (ESASO), president of the European Society of Cornea and Ocular Surface Disease Specialists (EUCORNEA), and a lecturer at the Institute of Ocular Microsurgery.

Dr. Güell has no financial disclosure with MST.