Why LASIK not always the best option

Sep 15, 2013

Phakic IOL implantation is safe and efficacious for treating high myopia and other conditions not amenable to LASIK, with outcomes comparable to those of LASIK and PRK.

 

Take-Home:

Phakic IOL implantation is safe and efficacious for treating high myopia and other conditions not amenable to LASIK, with outcomes comparable to those of LASIK and PRK.

 

Dr. Vukich

By Lynda Charters; Reviewed by John Allan Vukich, MD

Madison, WI-LASIK has been a highly successful and popular procedure since its introduction. However, there are instances in which this refractive procedure is best substituted for implantation of a phakic IOL, said John Allan Vukich, MD.

More than 750,000 laser refractive procedures were estimated to have been performed in 2012-2% more than the previous year. That total included about 12,500 phakic IOL procedures performed during 2012, said Dr. Vukich, surgical director, Davis Duehr Dean Center for Refractive Surgery, Madison, WI.

In the United States, the phakic IOLs available are the Implantable Collamer Lens (Visian ICL) and the Artisan Verisys IOL (Abbott Medical Optics), the former of which currently commands 95% of the U.S. market.

The FDA is currently reviewing a toric ICL (Visian ICL) and an angle-supported IOL (Cachet, Alcon Laboratories).

“LASIK is not for everyone,” Dr. Vukich said. “There are some things that are limitations that preclude LASIK, such as high myopia, atypical topography, substantial dry eye disease, and keratoconus.”

Most patients who receive phakic IOLs in the United States receive the higher powers. The median power of the phakic IOLs implanted in the US is -10 D. The approved range of powers is up to -16 D, he said.

However, there are some patients who are candidates for LASIK and a phakic IOL.

The questions that arise in these cases, Dr. Vukich said, are:

·      Is there functional equivalency?

·      Are the safety profiles of the two procedures comparable?

Comparing efficacy

There is a great deal of data from comparisons of PRK and LASIK regarding the efficacy of LASIK.

However, there is also data that supports the efficacy of ICLs for treating myopia.

The ICL was evaluated in a multicenter clinical trial, and in April 2003, the FDA recommended approval of the phakic IOL in the United States. In the study, 59% of patients achieved 20/20 and 75% achieved 2025, Dr. Vukich said.

“The average myopia in that study was -10.1 D and the refractive result was very stable over the following 3 postoperative years,” he said.

Evaluation of a toric ICL in 2006 for myopic astigmatism found that 85% of patients achieved 20/20 or better and 92.8% achieved 20/25 or better. Most of these patients had -9 D of myopia and about 2 D of cylinder.

“In this trial, 77% of patients had better uncorrected visual acuity (UCVA) 1 year postoperatively than their preoperative best spectacle-corrected visual acuity (BSCVA) ,” Dr. Vukich said.

A prospective comparison of a toric ICL and PRK for moderate to high myopic astigmatism showed “remarkable” results.

“Seventy-nine percent of patients who received a phakic IOL had an UCVA of 20/16 or better 1 month postoperatively,” he said.

The results showed ICL were better than with PRK over the 1-year course of the study.

Implantation of the ICL also resulted in a dramatic improvement in the BCVA under mesopic conditions at 25% contrast. This found that the toric ICL had better postoperative outcomes than PRK in the BSCVA, UNVA, predictability, and photopic and mesopic contrast.

Safety

The safety profile of phakic IOL implantation is high. The first case of endophthalmitis was reported in 2009.

“Implantation of this IOL is an intraocular procedure and it must be performed with appropriate caution using a sterile technique,” he said.

A 2009 study found the incidence of endophthalmitis was 1 in 6,000 cases, which is one-third to one-tenth that of the incidence associate with cataract surgery, Dr. Vukich said.

The incidence of clinically relevant cataract development 5 years after implantation of a phakic IOL is 1.3%, and at 7 years the incidence was 1.7%.

“More than 10 years of data support the safety and efficacy of phakic IOL implantation . . . they are comparable to LASIK and PRK,” he said. “Phakic IOLs are a reasonable choice and if positioned as an option in the available power range, they will help surgeons make better treatment choices for their patients.”

 

 

John Allan Vukich, MD

E: javukich@gmail.com

Dr. Vukich is a consultant for Abbott Medical Optics and STAAR Surgical.

 

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