A cheer to the new year with presbyopia correction

Advancements in corneal inlays and IOLs should benefit presbyopic patients and their premium surgeons.

Issue: January 10, 2016

ByMitchell A. Jackson, MD

It is that fun but reflective time of year again when all premium surgeons chanted the famous Scots poem “Auld Lang Syne,” written by Robert Burns in 1778, at the click of midnight on Dec. 31 to head into the 2016 new year. This poem is used traditionally to bid farewell to the old year at the stroke of midnight but by extension has also been used to bid farewell to or end other occasions. The good news is the advancement of presbyopia correction by corneal inlays and more advanced presbyopia-correcting IOLs during this past year will definitely bring cheer this new year to those of us and our patients suffering from the age-related “long-arm syndrome.”

Corneal inlays

The Kamra corneal inlay (AcuFocus) received FDA approval in April 2015, labeled for intrastromal corneal implantation to improve near vision by extending the depth of focus in the nondominant eye of phakic presbyopic patients between the ages of 45 and 60 years old who have cycloplegic refractive spherical equivalent of +0.5 D to –0.75 D with less than or equal to 0.75 D of refractive cylinder and who require near correction of +1 D to +2.5 D of reading add. I have been performing this inlay technology throughout the year and have found it works best in terms of uncorrected near vision gain in those patients who are –0.5 D to –0.75 D sphere preoperatively. The Kamra corneal inlay can be used in post-laser vision correction (LASIK, PRK) patients as an off-label use in my hands, but if patients had prior flap creation with a microkeratome blade, then OCT imaging of the cornea is critical to make sure you create the corneal pocket at least 100 µm below the old LASIK interface and still stay 250 µm from the corneal endothelium. The Kamra works on the pinhole principle, and use of the AcuTarget HD is critical to get proper alignment of the device based on the Purkinje image analysis of the optical and visual axes. Patients with larger angle kappa readings may not be the best candidates for this technology.

The Raindrop near vision inlay (ReVision Optics) is a microscopic hydrogel corneal inlay that is placed under a femtosecond laser flap and creates a prolate-shaped cornea and measures 2 mm in diameter and 32 µm in thickness. This technology is not yet FDA approved but will be best suited for patients who are in the low hyperopic range of +0.5 D to +0.75 D sphere preoperatively; it cannot be performed in patients who have undergone prior LASIK surgery. Many emmetropic presbyopes who come to our offices seeking presbyopic correction are typically low hyperopes functioning well in the distance without prescription glasses needs. Many of these patients do not want to undergo a two-step PRK/LASIK procedure and then the Kamra inlay, so this subset of patients might fare better with the Raindrop inlay option in the future.

Low-add multifocal IOLs

Many new low-add multifocal IOLs gained FDA approval, including the Tecnis low-add multifocals ZKB00 (+2.75 add) and ZLB00 (+3.25 add) (Abbott Medical Optics) and the Alcon low-add AcrySof IQ ReSTOR +2.5 D.

The Tecnis low-add multifocal IOLs are glistening free and pupil independent, with a full diffractive posterior surface and more than 90% of patients reporting no difficulty with night vision, similar to the Tecnis ZCB00 monofocal IOL. Spectacle-independence rates approached 75%, with patients stating they never need spectacles with these new low-add Tecnis multifocals.

The ReSTOR +2.5 D is pupil dependent and distributes more light for distance vision, with fewer diffractive zones and a larger central refractive zone than its +3.0 design. The focal point is also 0.5 D further out than the +3.0 design to improve intermediate vision.

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Angle kappa readings, if large, can have a significant impact on visual outcomes with any of the multifocal IOL designs. The new low-add IOLs are slightly more forgiving when it comes to angle kappa measurements, and utilizing the Marco OPD-Scan III and/or iTrace (Alphaeon) technologies can be helpful in determining the maximum angle kappa tolerated with multifocal IOLs. Traditionally, 0.4 mm was the tolerance in terms of angle kappa for multifocal IOLs, but now the new low-add Tecnis multifocal IOLs can tolerate up to 0.6 mm to 0.65 mm angle kappa deviation, and the new low-add ReSTOR multifocal IOL can tolerate up to 0.43 mm angle kappa deviation, both better than the 0.5 mm for ZMB00 (+4.0 add) and 0.37 mm for ReSTOR +3.0 add. Treating corneal astigmatism will also be critical in successful visual outcomes with any of the multifocal designs available today.

Trulign toric IOL

Although not FDA labeled as an accommodating IOL, the Trulign toric (Bausch + Lomb) belongs in the discussion for advanced presbyopic correction because it has the advantage of improving uncorrected near, intermediate and distance vision in patients who also have clinically significant corneal astigmatism. The zero aberration and aspheric optics of the Trulign toric IOL also provide an advantage in patients who have undergone previous refractive surgery (RK, PRK, LASIK) with known higher-order aberrations before cataract surgery. The Trulign toric IOL can simultaneously correct up to 2 D of corneal cylinder at the time of cataract surgery, reducing the need for further enhancements postoperatively.

Other extralenticular approaches for presbyopia correction, such as the VisAbility scleral implant (Refocus Group) and the LaserACE erbium scleral YAG laser procedure (ACE Vision Group), are future technologies not yet FDA approved but will provide a means to improve uncorrected intermediate and near vision without impacting the visual axis directly.

Trifocal and extended depth of focus IOLs are other technologies available in Europe that the U.S. contingent of premium surgeons hopes to see in OR suites soon as well.

I wish all a cheer to the new year and hope Auld Lang Syne brings us all closer to a cure for the “long-arm syndrome” we call presbyopia.

Reference:
Tyson FC, et al. US Ophthalmic Rev. 2013;doi:10.17925/USOR.2013.06.02.110.

For more information:
Mitchell A. Jackson, MD, can be reached at Jacksoneye, 300 N. Milwaukee Ave., Suite L, Lake Villa, IL 60046; email: mjlaserdoc@msn.com.

Disclosure: Jackson reports he is a consultant for Bausch + Lomb and Marco Ophthalmic.