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Surgeon explains technique for placement of phakic IOL
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The Visian ICL, or implantable Collamer lens, from STAAR Surgical is a phakic IOL that introduces yet another surgical dimension in the arena of refractive surgery to correct very high myopia that cannot be corrected surgically with LASIK or PRK. This can be a boon for those individuals who need to wear very thick, cumbersome glasses that they depend upon to see the world around them on a daily basis. For those individuals with moderate myopia, the option for either an ICL or LASIK or PRK is available. In this group of individuals, the discussion should address the differences between a corneal or extraocular procedure vs. an intraocular procedure with the ICL, such that the individual can make an informed choice. While this technology to treat myopia is available in the U.S., currently there is no ICL approved by the U.S. Food and Drug Administration to correct astigmatism or hyperopia.
In 1953, Benedetto Strampelli was the first surgeon to successfully implant a phakic IOL in the anterior chamber for the correction of myopia. The first phakic IOL was made of PMMA and manufactured by Rayner in England. Six years later, Joaquin Barraquer reported on 239 phakic IOL implantations. However, several phakic IOLs had to be explanted due to secondary complications, including endothelial cell loss, pupil ovalization, peripheral anterior synechia and iris atrophy. In 1986, Svyatoslav Fyodorov designed the first posterior chamber phakic IOL with a collar-button or mushroom configuration that was made of silicone. The movement to the posterior chamber was based on greater distance from the endothelium and the idea that the iris would cover the optic border of the phakic IOL, reducing the risk of glare and halos.
The two phakic IOLs that are currently approved by the FDA for use in the U.S. are the Verisyse (Abbott Medical Optics) and the ICL.
In this column, Dr. Gimbel describes his surgical technique for the ICL phakic IOL insertion and offers some surgical pearls that can be useful when performing this procedure.
Thomas “TJ” John, MD
OSN Surgical Maneuvers Editor
Howard Gimbel
The corneal diameter is measured with the Orbscan (Bausch + Lomb) and confirmed with calipers. Topical anesthesia and intracameral anesthesia are used, with Marcaine 0.75% topically and non-preservative 1% lidocaine intracamerally. A corneal paracentesis is made at 6 and 12 o’clock, and lidocaine is instilled. If no backup ICL is available, the ICL is loaded into the cartridge before the main incision is made to be certain that the ICL is not contaminated or torn in the process. The cartridge is moistened with balanced salt solution, and the loading platform of the cartridge is filled with OcuCoat (2% hydroxypropyl methylcellulose, Bausch + Lomb). The ICL is placed onto the trough so that it can be grasped by Duet grasping forceps (Duckworth & Kent) and pulled into the cartridge. As it is pulled into the first part of the cartridge, it is gently moved back and forth to lubricate it with OcuCoat. If the resistance is too great before reaching the tip, it is pushed the rest of the way with a cartridge plunger. If the plunger is used to push the ICL, it is retracted to release the ICL every few millimeters, so that it does not bind the ICL against the side walls of the cartridge. If this occurs, it will not release in the eye and may tear the haptics.
Once the ICL is ready, the anterior chamber is filled with OcuCoat and the main incision is made. A 3-mm incision is made using a diamond knife. More OcuCoat is added to the anterior chamber to replace the aqueous, and the cartridge is placed within the incision. The OcuCoat cannula is placed into the paracentesis to add OcuCoat as needed to replace viscoelastic that escapes during cartridge insertion into the incision. The cannula is then removed, and the ICL injection into the anterior chamber starts.
The cartridge is tilted and rotated appropriately to have the ICL not touch the cornea or crystalline lens, ensuring that the unfolding haptics are parallel to the iris. The plunger is retracted a small amount and pressed forward again while the cartridge is still in the incision until the ICL is released from the plunger and the cartridge. The cartridge is then removed, and OcuCoat is used to push the ICL away from the incision and then farther away from the cornea to be able to safely get Pallikaris ICL manipulators (Duckworth & Kent) to the haptics for their placement under the iris.
OcuCoat before the incision.
Images: Gimbel H
OcuCoat after the incision.
Cartridge insertion.
ICL insertion while pressing the ICL away from the cornea.
Bimanual manipulation of ICL into the sulcus.
Flushing the OcuCoat out with Buratto cannula.
One manipulator is used in each hand so that the ICL can be stabilized, nudged, rotated and pulled away from the pupil to facilitate tucking of each corner of the ICL under the iris. If necessary, more OcuCoat is added before the other end of the ICL is tucked under the iris. The ICL is centered, and viscoelastic is flushed from the anterior chamber. No attempt is made to remove viscoelastic from under the ICL.
The inner lip of the main incision is uncurled, if necessary, and the wounds are confirmed to be watertight using above-normal IOP. A small amount of vancomycin in a concentration of 1 mg in 0.1 ml of balanced salt solution is added to the anterior chamber. The IOP is then brought to normal by bleeding aqueous. Miotics are not used unless the pupil stays so dilated that it is difficult to confirm that all of the haptics are actually under the iris.
For toric ICLs, reference marks at the limbus are used as with toric IOLs to place the ICL in the proper meridian. For ease of manipulation, the paracenteses are placed 90° to the meridian of toric ICL placement. The toric ICL is placed in the approximate axis before tucking the haptics.
Surgical pearls: Dos
- Gently pull on the ICL during loading when using Duet grasping forceps to not tear the ICL.
- Retract the plunger to release the ICL every few millimeters if pushing the ICL into the cartridge.
- Tilt and rotate the cartridge appropriately while injecting to prevent corneal and lens touch, and keep the ICL flat to the iris.
- Have the cartridge enter only far enough into the anterior chamber to guide the ICL as it is being ejected.
Surgical pearls: Don'ts
- Make the main incision or fill the anterior chamber with viscoelastic before loading the ICL if no backup lens is available.
- Insert an ICL with torn haptics.
- Attempt to remove viscoelastic from under the ICL.