Accommodating the aging process

Hope for the presbyopes, even pre-cataract surgery.

By John A. Hovanesian, MD

For U.S. presbyopic patients, IOL implants have been the mainstay corrective procedure for about 10 years. However, many of these patients are well beyond the beginning stages of presbyopia, and it’s not just older patients with cataracts who have this condition. Patients first report symptoms of presbyopia at around age 40,¹ and much more profound loss of accommodation typically occurs between ages 50 and 55.²

So why aren’t we performing more presbyopia-correcting procedures, particularly for younger presbyopes? The nascent technology is out there. Specifically, two corneal inlays have recently received FDA approval along with IOLs specifically designed for presbyopia correction. Whether its due to lack of confidence in the technology or in their surgical skills, surgeons shouldn’t ignore these procedures.

Presbyopia-correcting options tend to have a direct correlation in terms of reversibility, invasiveness and level of surgeon trust. For example, surgeons have the greatest trust in IOL procedures because they are the most familiar, even though they are more invasive and not reversible, compared to corneal inlays.

Presbyopia correction should have more of a customized approach in terms of patient selection instead of a “one size fits all” approach. We need not wait until patients present with cataracts and late stages of presbyopia. We’ve all talked to presbyopic patients in their 40s who are motivated to find an alternative to readers but aren’t aware of promising available options beyond monovision or lens replacement surgery.

Here’s a look at the newest technology to correct presbyopia.

Corneal inlays

Until recently, the Kamra inlay (AcuFocus) was the only FDA-approved corneal inlay for presbyopes. However, in July, the Raindrop Near Vision microscopic hydrogel inlay (ReVision Optics) received FDA approval.

To implant the Raindrop, the surgeon makes a femtosecond laser-created flap (or, in the near future, a pocket) in the cornea of the patient’s non-dominant eye. Then, the device is inserted and the inlay implanted onto the stromal bed of the cornea (the device is preloaded into its inserter). The surgeon then centers the Raindrop over the light-constricted pupil, which creates a prolate-shaped cornea that increases power for focusing on near objects and improving near vision.

Alternatively, the Kamra inlay uses the small-aperture optics principle, also known as the pinhole effect, which improves vision by increasing depth of focus. It is indicated for presbyopic patients who have emmetropic refractions (+0.50 D to -0.75 D).

During my involvement with the Raindrop’s clinical trial, I became so impressed with the technology’s patient satisfaction that it bolstered my whole concept of corneal inlays, including the Kamra. Once surgeons and patients become more familiar with these devices, I am confident that we will see an uptick in the demand and the number of procedures, particularly involving emmetropic presbyopes.

Other in-the-pipeline corneal inlays for presbyopia include:

• The Presbia Flexivue Microlens technology. This refractive inlay does not require the removal of any eye tissue, which will potentially allow surgeons the opportunity to remove and replace it if the patient’s presbyopia advances, requiring a new prescription. Presbia is expected to submit its final PMA module to the FDA in Q4 2017.

• Neoptics’ Icolens. Similar to the Flexivue Microlens, Icolens is a refractive hydrophilic polymer lens with no power in the center but a peripheral zone possessing positive refractive power. Available in assorted powers, the inlay may be exchanged to accommodate for the progression of presbyopia. Icolens is in early-stage clinical development.

For surgeons who are comfortable with corneal flaps, corneal inlays require a steep learning curve. Also, the companies understand that the inlays’ success is strongly tied to the surgeon’s comfort level, so they have processes for properly training surgeons on the technique.

The inlays are highly effective, but it’s important to make sure patients understand that they also require more follow-up than LASIK to ensure long-term success. Postoperative visits ensure that dry eye is controlled and that other uncommon issues, like haze or late implant dislocation, do not occur. These patients must understand they are entering into a partnership with the surgeon. If the patients cannot commit to that and do not have a flexible schedule for follow-ups, they may be better suited for monovision LASIK.

Corneal inlays are great practice-builders. You may be surprised at how many current patients are candidates for corneal inlays. Generally, younger presbyopes around age 50 with healthy, relatively stable eyes and no progressive cataracts do best with these technologies. From my experience, patients who are more hyperopic do well with the Raindrop, while I may elect to use Kamra for patients more on the myopic side. Also, my patients tend to enthusiastically recommend them to friends and family. So, even if your practice does not initially perform a high volume of these procedures, they’re still worth adopting due to the chance of a significant number of referrals.

IOLs

Premium IOLs are permanent presbyopic correction options that offer plenty of benefits for cataract surgery patients. In my experience, premium IOLs don’t show refractive drift over time or require any additional surgery. Although this option requires some younger patients to have cataract surgery, it does not add to the patient’s total lifetime risk of surgery — these patients would have needed lens replacement during cataract surgery later in life. Also, these options should already be in general ophthalmologists’ armamentarium, so there’s no learning curve.

The recently approved Tecnis Symfony IOL is the first and only presbyopia-correcting extended range of vision IOL. The Symfony has already gained popularity internationally because the correction is very forgiving. Its approval was based on a U.S. pivotal study involving 298 patients that compared the Tecnis Symfony lens to a Tecnis aspheric monofocal lens. Those who received a Tecnis Symfony IOL achieved greater improvements in intermediate and near vision while maintaining similar distance vision. Symfony is available in toric and nontoric options.

Other previously available premium IOLs that correct presbyopia include Crystalens (Bausch + Lomb), Trulign (Bausch + Lomb) and AcrySof IQ ReSTOR Toric (Alcon). The FluidVision lens from PowerVision is currently not approved, but FDA studies are expected to start soon. As an experienced user, I’ve found that low-add multifocal lenses achieve low rates of glare and halos for a wide range of eyes. Although they sacrifice the nearest range of vision, these lenses make up for it with a high level of safety and confidence.

Reversible options

Although not yet FDA-approved, scleral expansion bands and eyedrops for presbyopia reversal are promising prospects. These options feature nearly invisible technology that restores a youthful range of vision and are reversible if not well tolerated, so the risk is low.

Currently, these options face credibility barriers. For instance, scleral expansion bands previously fell out of favor because the technology failed to achieve reproducible results. However, a retrospect analysis of the scleral expansion concept showed inconsistent band placement in terms of depth and position on the sclera. This occurred because the measurements were not obtained in a reproducible way. In an ongoing study, the Refocus Group attempted to standardize placement depth and orientation of the bands through some clever proprietary technology (VisAbility Implant System).³ Their clinical results with this system going out 30 months exceed the previous results, including distance-corrected near visual acuities that are comparable to other competing presbyopia technologies.⁴

Another option for patients who wish to avoid surgery altogether combines a parasympathomimetic drug (carbachol) with an alpha agonist (brimonidine), which creates optically-beneficial miosis to reduce the effect of presbyopia. This eyedrop treatment (Encore Vision) is not yet FDA-approved but has shown promise. One study of 48 naturally emmetropic and presbyopic subjects ages 43 to 56 showed statistically significant improvement in near visual acuity in all subjects who received carbachol plus brimonidine eyedrops.⁵ As with the corneal inlays, keep in mind the patients’ scheduling flexibility — they must be able to keep a daily drop schedule.

Overall, I’m optimistic about these technologies because they’re relatively safe and, even if they only work in a small percentage of patients, they are a good addition to the current options.

Conclusion

Although presbyopia is very much a first-world problem, it’s a very real one for our patients. We now have the variety of technology that can help a variety of patients — no more do we have to tell our patients, one size fits all. Also, these new treatment options will increase the breadth of surgeons’ presbyopia-correcting procedures, giving the refractively inclined general ophthalmologist a new set of skills.

Keep aware of what’s on the horizon, and cautiously employ new modalities as they become available. The demand is extremely high, and the patient satisfaction is akin to the contentment we witness with most other refractive procedures. OM

REFERENCES

About the Author
	Dr. Hovanesian practices at Harvard Eye Associates in San Clemente, Calif., and is a faculty member at the UCLA Jules Stein Eye Institute. He is an internationally recognized leader in corneal, cataract, refractive and laser surgery. Disclosures: Dr. Hovanesian is a consultant for ReVision Optics.