Looking Ahead to Phakic IOLs
A surgeon examines outcomes vs. LASIK with an eye toward patient satisfaction.
By Ophthalmology Management staff

As we move toward FDA approval of one or more phakic IOLs, refractive surgeons want to know how they perform compared with LASIK. Mohammed Alaa, M.D., of the El-Maghraby Eye Center in the United Arab Emirates, shed some light on that issue with his presentation during the annual meeting of the American Society of Cataract and Refractive Surgery in San Diego earlier this year.

Dr. Alaa highlighted some of the results from three series of procedures for the correction of myopia: In one, patients underwent LASIK; in another, they underwent phakic IOL (Artisan) implantation; and in another, patients had an Artisan lens implanted in one eye, and LASIK performed on the other eye. All patients were interviewed about their level of satisfaction with their procedures.

How many patients would undergo LASIK again?

The 323 patients who underwent LASIK were divided into three groups: low myopia (below 5D); moderate myopia; and high myopia (above 10D). As you would expect, at 1-year follow-up, the predictability for the low group was excellent. It was very good for the moderate group. For the high group, it was fairly good, but not as accurate. "This, however, isn't a major problem with LASIK as long as you can go back . . . and perform an enhancement," Dr. Alaa said.

He also looked at the post-op uncorrected visual acuity for each level of myopia. Eighty percent of the low myopes were 20/20 or better, compared with 90% pre-op with their correction. Post-op UCVA for the moderate myopes was also very good: 70% achieved 20/20 or better compared with 80% pre-op with correction. The percentages weren't as favorable for the high myopes, but they were acceptable.

So, Dr. Alaa explained, the LASIK results were good in terms of refraction and visual acuity. However, a somewhat different picture emerged when patients were asked whether they would undergo LASIK again:

• 98% of low myopes said yes
• 11% of moderate myopes said no
• 27% of high myopes said no.

"This means that when we do LASIK for our moderate and high myopes, we're giving a significant percentage of them results that they don't like," Dr. Alaa said. "Why is that?"

He explained that he and his colleagues studied the corneal wavefront aberrations of low myopes, between -2D and -5.5D, and found that after LASIK, a simulated pupillary dilatation from 3 to 7 mm increased the corneal aberration 28 to 46 fold. "So you might imagine what the quality of vision is that these patients are suffering from," he said. "You cannot fix this aberration . . ."

LASIK vs. phakic IOLs

In comparing the LASIK results to the phakic IOL results, (There was no significant difference between the baseline spherical equivalent refractions.), Dr. Alaa observed:

A Three months after the surgeries, the predictability was slightly better with the Artisan lens compared with LASIK. "But again, this isn't a problem in practical life because you can easily go and lift the flap and enhance your LASIK procedures," Dr. Alaa said. "So, at 1 year after the surgery, you've got very equal refractive outcomes.

• The stability for both procedures was good at 1 year.
• The spherical equivalent refraction in both groups was similar. There was no statistically significant difference. However, the patients with the phakic IOLs said they could see better. "You might say this isn't a true increase in vision because it is due to the magnification of the retinal image. Yes, but for the patient, this is a true improvement of his vision," Dr. Alaa noted.
• More than 40% of the 55 phakic IOL eyes gained two or more lines of spectacle-corrected vision after surgery.
• The phakic IOL patients had significantly better contrast sensitivity than the LASIK patients.
• At 12 months, endothelial cell loss in the IOL patients (0.7%) wasn't significant compared with the LASIK patients (0.3%), which is normal loss with aging.

Complications were reported in both series. Among the phakic IOL patients:

• one incorrect IOL calculation. "We had to go back and do LASIK," Dr. Alaa said.
• once case of severe night glare. Dr. Alaa explained, "This patient had a 5-mm pupil with a 5-mm Artisan lens. We removed the lens and implanted a 6-mm lens, although with a lower power. We did LASIK on the patient later on."

Among the LASIK patients:

• six patients with incapacitating night glare. "Unfortunately we couldn't do anything for these patients, and they are still suffering until now," Dr. Alaa said.
• one deep lamellar keratitis, which improved
• A one central island, which disappeared after 1 year.

Among the 18 patients who had the phakic IOL in one eye, and LASIK on the other:

• 72% preferred the Artisan eye
• 22% preferred the LASIK eye
• 5% said both were fine.

Patients were asked why they preferred one eye to the other. All those who preferred the Artisan eye said they preferred it because of the better quality of vision. Those who preferred the LASIK eye preferred it because the procedure was easier.

Several pros and cons to consider

With those particular clinical and patient-satisfaction highlights as his backdrop, Dr. Alla summarized the pros and cons of LASIK and phakic IOLs.

LASIK has some advantages over phakic IOLs, he said. It's an effective procedure that can correct a wide range of myopia efficaciously. Relatively speaking, it's not surgically demanding. It takes a short time, so surgeons like it. Recovery is fast and painless, so patients also like it. LASIK can correct astigmatism up to 5 or 6 diopters, he said, but work is being done on correcting astigmatism with toric phakic IOLs as well.

On the other hand, "LASIK is a high-tech procedure, dependent on the laser and the microkeratome," he said. "Even though we're surgeons, not engineers, every time we press the foot pedal, we're responsible for whatever this high technology might give us." He also noted some of the factors that limit LASIK, such as corneal thickness and pupil diameter, which when not taken into account properly put patients at great risk.

"But the big question is: Do phakic IOLs really solve these problems?" he said. "It's true that phakic IOLs maintain the prolate shape of the cornea. They provide better quality of vision. They're available in many styles to fit the preferences of all surgeons." He added: Predictability is high; they're more stable; they can be removed or exchanged when necessary. Patient satisfaction appears to be higher.

"But this is not all about phakic intraocular lenses," Dr. Alaa continued. With the Artisan, he said, good lens centration usually leads to a good outcome. But if the lens is slightly decentered, "You might imagine what kind of marred vision a patient will have when his pupil gets dilated to 6 or 7 mm in dim illumination."

Other complications can arise as well, including chronic uveitis, due to the lens rubbing against the iris. Also, Dr. Alaa said he had one case in which a patient had transient intraocular pressure after the surgery and the pupil became fixed and dilated and wasn't responsive to any medications. Also, lens dislocations were not uncommon during the early stages of Artisan development.

Complications are possible with every kind of phakic IOL, Dr. Alaa said, including cataract with the posterior chamber lenses and pupil ovalization for anterior chamber lenses.

The best of both worlds

According to Dr. Alaa, at this time, surgeons don't need to choose one option over the other. "It's not procedure one or procedure two, but I think today, in modern refractive surgery, we should have both procedures in our armamentarium so we can take the benefits and advantages of each," he said.

"My recommendations: For patients with myopia less than 9 diopters, LASIK is fine. Between 9 and 16 diopters, phakic IOLs are better, and above 16 diopters you might use both procedures combined to get the best of both worlds."

So, Dr. Alaa concluded, "If the question is Artisan lens or LASIK, my answer is both of them."