RLE: A Developing Niche With Potential for More?
Refractive lens exchange (RLE) is gaining steam and, in some patient populations, taking on LASIK.
BY JOHN PARKINSON, ASSOCIATE EDITOR

The promise of RLE lies in the marriage of proven cataract surgical techniques with advanced phaco technology and new generation IOLs. Today, surgeons are removing the clearer, softer lenses of the typically younger patients who seek RLE procedures and replacing them with accommodating and multifocal IOLs that offer near, intermediate and distance vision. Contemporary phacoemulsification machines aid surgeons who are utilizing fluidics over ultrasound for these procedures.

While the procedure is still considered elective and involves off-label indications for IOLs, the thought of being spectacle-free is enticing to some patients and represents a good reason not to wait for significant cataract development to improve their vision. Although the procedure is being marketed to patients with presbyopia, one well-known surgeon is optimistic RLE may someday be a viable alternative to LASIK for patients in the 20 to 30 age group.

This article will discuss how surgeons screen potential candidates for RLE and perform their surgical techniques. Additionally, these surgeons will offer their insights and predictions into the RLE's role in the refractive surgery market.

Patient Expectations

I. Howard Fine, M.D., says an interesting trend is emerging. When discussing treatment options with patients who have cataracts but do not qualify for Medicare reimbursement at the time of the examination, many do not want to wait for surgery because they want to improve their quality of vision immediately.

"During the exam, we tell them within a year they probably would qualify for Medicare to do this [cataract surgery], but I have had very few patients want to wait because they are coming for refractive purposes."

While this signifies a possible change in patient expectations and may be promising for surgeons' practices, it can also put more pressure on surgeons. "These patients are paying out of pocket for these procedures, so it raises their expectations of what their results will be. Complications need to be minimal. The surgeon needs to be very adept with these procedures," says R. Bruce Wallace, M.D.

As such, Dr. Wallace's patients are given an intraoperative subtenon's Kenalog injection and put on topical steroids and NSAIDs for 3 days preoperatively and for approximately 1 month postoperatively to decrease the potential of inflammation and cystoid macular edema.

"The RLE patient is a tougher patient," says Richard J. Mackool, M.D. "They have higher expectations; they're more demanding than the cataract patients."

Although all RLE patients want better vision, Dr. Mackool says the key is listening to what individual patients expect going into the procedure and adjusting the discussions between doctor and patient accordingly. Dr. Mackool says patients with presbyopic hyperopia might be better candidates for RLE and need less explanation than those with presbyopia and myopia in terms of expectations. He says this because patients with presbyopic hyperopia are disabled for distance and near vision and they receive what he calls a "double payoff" with RLE. Dr. Mackool says patients with myopia might have certain issues after RLE leading to patient dissatisfaction. He points to some examples of preoperative patient feedback.

"The patient who says, 'I'll really be satisfied if I can just see in the distance and read without my glasses,' is a superb candidate. Those who would be happy without wearing glasses and ideally would like perfect vision, but understand that may not be in the cards are good candidates," explains Dr. Mackool.

Patients With High Myopia

One of the concerns for surgeons who perform RLE is performing the procedure on patients with high myopia because of their high risk of retinal detachment. Dr. Fine explains this fear stems from research performed several years ago by a French ophthalmologist, Joseph Colin, M.D. His research showed that patients undergoing RLE for high myopia had no increase of retinal detachment attributed to the procedure for the first 4 years. However, in the following 4 years of observing RLE patients postoperatively, Dr. Colin saw these complications quadruple.

Dr. Fine points out that Dr. Colin was using 7-mm PMMA lenses with large incisions. Additionally, Dr. Colin used round-edged IOLs and had as high as 60% incidences of YAG laser capsulotomies to address posterior capsule opacification (PCO).

Dr. Wallace says that a design change in the IOLs' edges from round to square-edged has decreased the need for posterior capsulotomies. "With the square edge, studies are showing that there is less chance for PCO and therefore less chance for YAG laser. YAG increases the risk of retinal detachment especially in patients with high myopia."

Dr. Wallace does caution that some patients will still need capsulotomies regardless of the change in optic design.

In addition to a different IOL design, Dr. Fine points out other new considerations when looking at the possibility of performing RLE on high myopes.

"Many of the new lenses that fill the bag, like the crystalens (eyeonics, Aliso Viejo, Calif.), which pushes back against the capsule, and the new Synchrony (Visiogen, Irvine, Calif.), stabilize the vitreous face and so they probably will add to the safety of refractive lens exchange in patients with high myopia," explains Dr. Fine. "In the technique we utilize — which is bimanual microincision refractive exchange — we never let the eye deflate, so during the lens removal itself and the implantation of the IOL, we keep the irrigating handpiece in the eye, so there is not a trampolining of the vitreous face during the surgery — putting traction on the vitreous face. We think all these considerations will make RLE in patients with high myopia safe."

Nonetheless, some surgeons do have some reservations about operating on patients with high myopia. Due to retrospective studies he has performed, Dr. Mackool says he will not perform RLE on men with an axial length of 25 mm or greater who are between 20 and 60 years of age because his data indicated a retinal detachment rate of 4.8% within 3 years after surgery. He will perform RLE on men older than 60 years of age, but warns them that the risk of detachment is approximately 1%. Conversely, Dr. Mackool will perform RLE on all women with high myopia.

"I think it is fine to perform RLE on women with high myopia because women have a retinal detachment risk of one in several hundred, regardless of how long their eye is," says Dr. Mackool.

Although patients' visual acuity (VA) results have been good in clinical studies, surgeons must still inform patients of potential complications and set realistic expectations. Part of Dr. Wallace's preoperative regimen for patients with high myopia includes a discussion about the risk for detachment and a referral to a posterior-segment surgeon. Nonetheless, he points to some of the disconnect in the medical community about who is at risk.

"We know there is some confusion about who is really at risk here," acknowledges Dr. Wallace. "Some retinal specialists will say that a patient who has a posterior vitreous detachment who is still a relative highly myope might not be as high risk as those that don't have a posterior vitreous detachment. We generally send these patients to a retinal specialist prior to their surgery to be certain there isn't an retinal pathology that may need treatment."

RLE Techniques and Results

Dr. Mackool employs a coaxial microincision technique for his RLE procedures. "The technique is identical to the one I use for phacoemulsification with the exception that the vast majority of these patients don't need any ultrasound energy at all; it's basically an aspiration procedure."

Dr. Mackool uses the Infiniti system (Alcon, Fort Worth, Texas), and uses an incision size that varies depending on the surgical goal. For example, if the patient has a spherical corneal curvature and he does not want to change this, he will create a 2.1-mm temporal incision with an Ultra sleeve and Infiniti flare tip (both the sleeve and the tip are from Alcon). If he wants to flatten the meridian slightly by 0.25 D to 0.50 D, Dr. Mackool will use a high infusion sleeve with the flare tip and a 2.75-mm incision. For 1.0 D or more of flattening, Dr. Mackool will create a second 2.75-mm incision on the opposite side of the primary incision.

The ReSTOR lens (Alcon) is the only multifocal IOL Dr. Mackool is presently implanting, and he reports that 95% of his patients are spectacle-free, assuming the refractive outcome is plano or near plano.

Dr. Wallace performs a clear corneal incision and carries out what he calls a bimanual, "quiet time" or QT phaco for the softer lenses that are associated with RLE. In most RLE patients, a hard cataract has not set in yet due to the patient populations' age; therefore, surgeons perform RLE differently than traditional phaco, according to Dr. Wallace. RLE involves the fluidics of the newer phaco systems and relies less on ultrasound energy.

"We have seen a steady progression away from the power and more of a dependence on the fluidics available," explains Dr. Wallace. He has been employing the Sovereign with WhiteStar phacoemulsification system (Advanced Medical Optics, AMO, Santa Ana, Calif.,) with version 6 software.

Dr. Wallace uses a diamond knife for both the side-port and the phaco incision. After he makes the side-port incision, he leaves the blunt side of the diamond knife inside the anterior chamber, instead of introducing viscoelastic. He injects viscoelastic after the phaco incision, and utilizes either a hemi-flip or full flip of the nucleus — depending on how soft the lens is —before removal.

While the VAs of his patients vary, Dr. Wallace reports satisfactory results on all the IOLs he is implanting. Eighty percent of his patients who are fitted with the Array IOL (AMO) wear their glasses less than 20% of the time. For his patients who have the ReSTOR and ReZoom (AMO) IOLs implanted, he says approximately 80% of them are spectacle-free.

Dr. Fine's RLE surgical technique is a bimanual microincision with irrigation and aspiration for lens removal. Dr. Fine mentions the softer lenses of RLE patients perform differently than cataract lenses. Accordingly, he utilizes fluidics only and no ultrasound energy in completing RLE. He hydroexpresses the lens out of the capsular bag into the plane of the capsulorhexis and then carousels it in the plane of the capsulorhexis utilizing the vacuum only as an extraction technique. If the case is unusually firm, he will do cortical cleaving hydrodissection and hydrodelineation and remove it in the usual bimanual microincision manner.

The anterior chamber remains filled throughout the procedure because the irrigator is never removed from the eye giving the surgeon greater control and safety.

Dr. Fine has utilized multiple IOLs, and he also has been working with various vendors' phacoemulsification machines and utilizing different techniques. He has found that he achieves similar results even when utilizing different phaco machines and techniques. In one particular study, he found that with coaxial phaco, 97% of his patients had an UCVA of 20/40 or better on the first day postop for one machine and 100% had an UCVA of 20/40 or better with the other machine. When comparing results using the bimanual technique on the same machines, the percentage of patients seeing 20/40 or better on the first day postop were 96% for the first machine and 100% for the second.

The Middle-aged Procedure?

Patients with presbyopic hyperopia are actively being targeted as ideal candidates for RLE by surgeons. Some doctors have been saying RLE is ideally suited for patients who are older than 45 and younger than 60 years of age.

"Refractive lens exchange will gradually overtake LASIK as the procedure for patients over the age of 40 or 45; it already has in my practice, simply because patients get both good distance and near vision," explains Dr. Mackool.

Dr. Fine believes RLE could possibly serve a larger patient base. He says doctors currently use general treatment patterns for patients' refractive errors based on patients' age groups. As examples, he points to three types of adult age groups and how they have been treated. Dr. Fine says younger adults receive LASIK; middle-aged patients are prescribed bifocals; and senior citizens have cataract surgery. For the right candidates, he believes RLE could potentially do away with all three of these treatments.

"It can address younger adults by taking their lenses out and putting in an accommodating IOL. They will never have to get bifocals and they will never develop cataracts," explains Dr. Fine. "Increasingly, as new lenses come out and the technology for cataract surgery improves, [RLE] will become the dominant refractive surgery overwhelmingly because it addresses the full scope of refractive errors that a patient is confronted with, and it offers stability," says Dr. Fine. "The spherical aberration of the cornea doesn't change as we age; our crystalline lens does."

Dr. Fine notes that RLE comes naturally to surgeons who are already familiar with cataract procedures. Surgeons who will perform RLE as opposed to LASIK will not have to make equipment investments, such as buying keratomes.

Dr. Wallace, on the other hand, differs slightly in opinion from Dr. Fine in the possibility of offering RLE over LASIK to young patients. "When you are dealing with someone in their 20s, particularly a patient with myopia, it is a little bit more difficult to imagine those patients being ideal refractive lens patients compared to a LASIK procedure. Once a patient is past the age of 40, and presbyopia sets in, I think there is good reason to consider a lens procedure over a corneal procedure."

Dr. Wallace says there are two reasons for older patients to consider RLE as opposed to LASIK. First, in most older LASIK patients, their wavefront aberrations originate from the crystalline lenses and not the corneas. Second, patients who undergo RLE will never develop cataracts.

In just the last few years, the new generation of these IOLs has gone from promising clinical studies to a market reality. In addition, contemporary phaco machines' fluidics have made it safer to extract the softer lenses of younger patients who undergo RLE. The IOLs and relevant technology may someday advance to the point the procedure could be marketed to 20 or 30-something LASIK patients, but for now, all surgeons are in agreement about what RLE offers to presbyopic patients in practices today.