Iris claw phakic IOL fills niche in refractive surgery

February 1, 2006

Charlotte, NC—The iris claw phakic IOL (Verisyse, AMO) is a welcome addition to the refractive surgeon's armamentarium for enabling treatment of patients who are not good candidates for custom wavefront-guided LASIK or IntraLASIK either because of level of myopia or corneal thickness, said Jonathan Christenbury, MD.

"My experience with this implant in the past year shows it has been a very safe and effective modality for myopic correction. Its advantages include rapid visual rehabilitation and good quality of vision. Certainly, it has been exciting to see a patient with –20 D myopia able to read 20/40 or better uncorrected on the first postoperative day, and patients who have had this surgery tell me their quality of vision during the day and at night is as good as or better than what it was preoperatively with glasses or contact lenses.

"So far, I have not implanted the lens in a single patient who hesitated to have the same surgery done for the second eye. Overall, I consider this phakic IOL a much better option than trying to push LASIK to its limits," said Dr. Christenbury, a private practitioner in Charlotte, NC.

"It is very helpful if the patient can wear a contact lens in the unoperated eye during the interim to avoid anisometropia-related symptoms," he said.

To date, Dr. Christenbury has used the implant to treat patients who need corrections between –6 and –20 D, generally aiming for a postoperative refractive target between plano and –0.50 D. Although he initially performed the surgery using peribulbar anesthesia and then a subtenon's local anesthetic, after just a few cases he began using topical 4% lidocaine and intracameral lidocaine 1% with good success and patient satisfaction.

After constricting the pupil with acetylcholine chloride (Miochol E) and filling the chamber with Healon GV, Dr. Christenbury inserts the IOL, places two sutures, and then rotates the lens into position to perform the enclavation. He places the remaining suture before removing the viscoelastic in order to maintain chamber depth and prevent the IOL from touching the endothelium.

"This approach seems very effective and helpful for achieving clearer corneas at the 1-day postop visit," Dr. Christenbury said.

For suturing, he uses either 10-0 Vicryl or 10-0 nylon, but tends to lean toward the absorbable material. So far, he has not encountered any problems with induced astigmatism. Refractive predictability has been excellent using the manufacturer-provided power calculation program, laser interferometry (IOLMaster, Carl Zeiss Meditec) for anterior chamber depth measurement, and a simple manifest refraction. About 15% of patients have had enhancement with conventional LASIK for residual astigmatism about 3 months after their phakic IOL surgery.

"These are patients who had higher astigmatism to begin with. I also had patients who had some residual astigmatism postop who were still very happy with their vision and did not wish to have any further surgery," Dr. Christenbury said.