OPTIONS FOR CORNEAL CORRECTION OF PRESBYOPIA

Author: Roger F. Steinert, M.D.

Dr. Steinert is a paid Medical Monitor for ReVision Optics

Methods: Three Optical Approaches

Near Power in Pupil Center

Distance Power in Pupil Center

Pinhole Effect

LASIK

Excimer ablation implemented with either PRK or LASIK is used to alter the anterior corneal surface, creating either a “near center” or “distance center” ablation profiles.

Not FDA approved.

US Patent 6 280 435 B1

US Patent 6 969 386 B2

Femtosecond Laser Corneal Weakening

The INTRACOR® (Technolas Perfect Vision) procedure causes steepening of the central cornea by cutting a set of concentric cylinders. The width of the cylinders is very small, resulting in minimal loss of corneal tissue. The cuts begin below Bowman’s layer and extend through most of the stromal thickness (see cross-sectional sketch below). The cylindrical boundaries facilitate remodeling of the stroma, causing an increased central corneal curvature and a resulting near center zone.

Not FDA approved.

Pinhole Corneal Inlay The KAMRA™ (formerly AcuFocus) intracorneal inlay is an opaque,

polyvinylidene flouride, 3.8 mm diameter ring with a 1.6 mm diameter central opening. It is 5 microns thick and the body is fenestrated with 8400 randomly placed holes to facilitate nutritional flow.

Application of the pinhole effect to the human dioptric awaits the judgment of the ongoing US Clinical trial (KAMRA™ ).

KAMRA™ Corneal Inlay

Contact Lens

Refractive Corneal Inlays The PresbyLens® (ReVision Optics®) is a clear, 2 mm diameter,

sub 50 micron thick, hydrogel inlay placed under a LASIK-like flap, which steepens the central corneal curvature – creating a near center zone. The inlay has no intrinsic power ; its index of refraction is the same as the cornea’s.

In FDA clinical trial.

The Flexivue™ (Presbia™) intracorneal micro-lens is a 3 mm diameter, hydrophilic polymer disk with a 20 micron edge thickness. The center has no intrinsic power, creating a distance center zone for emmetropes, while the peripheral “donut” has additional intrinsic refractive power for near.

Not FDA approved.

PresbyLens

Inlay

Results: Uncorrected Near VA in Treated Eye

Near Center LASIK Profile: 6m Data; (1) J Ref Surg, 2009 25(1-suppl) : S148-S155

Near Center LASIK Profile: 6M Data; (2) J Cataract Ref Surg, 2008 34(2): 205-210

Near Center Stromal Relaxing Profile (Intracor): 3M Data; (3) J Ref Surg, 2009 25(10): 855-861

Pinhole Mechanism (AcuFocus): 24 M Data; (4) J Ref Surg, 2010 26(10): 707-715

Near Center Corneal Elevation Change (PresbyLens): 3M Data; (5) ReVision Optics, September 2010

J1 or Better J2 or Better J3 or Better J5 or Better0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Monocular Uncorrected Near VA

PresbyLens (5)KAMRA (4)PresbyLASIK-Nidek (1)PresbyLASIK-VISX (2)INTRACOR (3)

Results: Uncorrected Intermediate VA in Treated Eye

Pinhole Mechanism (AcuFocus): 24 M Data; (4) J Ref Surg, 2010 26(10): 707-715 Near Center Corneal Elevation Change (PresbyLens): 3M Data; (5) ReVision Optics,

September 2010

20/20 or Better 20/25 or Better 20/32 or Better 20/40 or Better0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Monocular Uncorrected Intermediate VA

PresbyLens (5)KAMRA (4)

Results: Uncorrected Distance VA in Treated Eye

Near Center LASIK Profile: 6m Data; (1) J Ref Surg, 2009 25(1-suppl) : S148-S155

Near Center Stromal Relaxing Profile (Intracor): 3M Data; (3) J Ref Surg, 2009 25(10): 855-861

Pinhole Mechanism (AcuFocus): 24 M Data; (4) J Ref Surg, 2010 26(10): 707-715

Near Center Corneal Elevation Change (PresbyLens): 3M Data; (5) ReVision Optics, September 2010

20/20 or Better 20/25 or Better 20/32 or Better 20/40 or Better0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Monocular Uncorrected Distance VA

PresbyLens (5)KAMRA (4)PresbyLASIK-Nidek (1)INTRACOR (3)

Results: Technique Comparison

Easily Reversible

Maximizes Available

Light

“Wow” Factor(Rapid Visual

Improvement)

Cosmetic Appeal

Refractive Inlays

Pinhole Inlays

___ ___ ___

PresbyLASIK / PRK

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Laser Remodeling of Stroma

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Conclusions: All procedures examined provide a clear improvement in

uncorrected near acuity, with only a minor loss in uncorrected distance acuity.

Of the solutions discussed, the PresbyLens® appears to give best correction of near and intermediate vision whereas PresbyLASIK from Nidek results in the least loss of distance vision.

Very good near and intermediate visions provided by hydrogel corneal inlays, as well as reversibility, are attractive though very long term biocompatibility is yet to be proved. “Wow factor” is a plus.

The reversibility of pinhole inlays is attractive though very long term biocompatibility is yet to be proved and reduced light may result in reduced vision in low light.

Use of a femtosecond laser system alone is attractive though long-term corneal stability is yet to be proved and reversibility may prove difficult. “Wow factor” is a plus. Not compatible with prior or simultaneous LASIK.

LASIK solutions are attractive though reversing the procedure may prove difficult and stability may be suboptimal.