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The growing popularity and long-term use of phakic IOLs inevitably will lead to more explantations, with cataract removal and with or without clear lens removal. An ophthalmologist outlines key steps to success.
Nantes, France-Explantation of phakic IOLs will become more common as these lenses are implanted more frequently and used for longer periods. When explantation is required, it is important to choose the appropriate surgical technique for each patient, said Danuta Horodynska, MD, of Clinique Sourdille, Nantes, France.
She described cases involving 13 eyes of eight patients with different types of phakic IOLs, including iris-claw, angle-supported anterior chamber, and posterior chamber designs. The patients were treated with phakic IOL removal, lens removal, and posterior chamber IOL implantation (surgeries were performed by co-author Jean-Michel Bosc, MD). The lenses were explanted as a result of cataract in seven eyes, phakic IOL subluxation in one eye, and endothelial cell loss in five eyes.
The technique used to remove anterior chamber rigid phakic IOLs (of either angle-supported or iris-claw design) involved performing phacoemulsification before explantation, which allowed use of a small-incision technique. All steps in phaco were performed under the phakic implant. In the case of an iris-claw phakic IOL, the surgeon had to desenclavate one claw to allow enough space for instruments. The other claw was desenclavated after phaco, just before the incision was enlarged for the explantation. In eyes with high myopia, capsular tension rings were implanted.
Lens type important
The type of lens to be implanted after the explantation is an important consideration, Dr. Horodynska said. Some of the choices made by the surgical team included "in-the-bag" implantation of a multifocal IOL or a "piggyback" technique in which a monofocal IOL was placed in the bag and a multifocal presbyopic IOL was placed in the sulcus (in cases of multifocal phakic IOLs explantation).
The primary issues pertaining to phakic IOL explantation include protection of the endothelium during the operation, whether to explant the lens before or after phaco, and whether to remove only the phakic IOL in eyes without cataract or also to remove the clear lens, Dr. Horodynska said.
"In our opinion, if you operate on just one eye of the patient with bilateral phakic IOLs, you have to do clear lens removal to be able to handle postoperative anisometropia. The same is true with one-eye multifocal phakic IOL explantation, to ensure bilateral multifocality," she said.
The power needed in the new implant can be calculated with optical biometry (IOL Master, Carl Zeiss Meditec) or, with somewhat more difficulty, using ultrasound biometry, she said.