Presbyopia – modern surgical treatments
Johan Lønsmann Poulsen, Euroeyes
Presbyopia – the earliest ”treatments”
Reading stones
Emperor Nero (37-68 AD)
Presbyopia – design trends
c. 1400s c. 1680 - 1750 c. 1800 – 1850
Presbyopia – surgical approaches
1979 1991 2007 2009
Presbyopic correction - the options • Intraocular approaches – Presbyopic IOLs
• Monovision (LASIK/PRK) – no binocularity! • Corneal reshaping for multifocality – PresbyLASIK / INTRACOR • Corneal approach: ”onlays” - experimental • Corneal approach: ”Inlays”
Multifocals – many attempts • First multifocal implants in 1970s
• Historically - not very successful! – Bad optics – Postoperative refractive error – Poor pre-op biometry / poor surgery
What is different now? •
Great advances in IOL design / optics – Refractive & diffractive techniques
•
Pre-operative and post-operative refractive error optimisation – Accurate biometry (eg. IOLmaster) – Accurate keratometry (eg. Orbscan, Pentacam) – Small incision cataract approach – LASIK !
IOL design & type
Review of Presbyopic IOLs: Multifocal and Accommodating IOLs Gooi, Patrick MD; Ahmed, Ike K. MD, FRCSC
Monofocal Distance focal point
Refractive Near focus
Distance focus
Diffractive
Near focus
Distance focus
Multifocal IOLs – Refractive v. Diffractive Refractive
Diffractive
Apodized or non-apodized
• Not much difference between refractive & diffractive IOLs – BUT better UCNVA with dif. IOL
Diffractive vs. Refractive – patient satisfaction 95 94 93 92 91 90 89 88 87 86 85
Distance Near Intermediate
Diffractive
Refractive
Aspheric Diffractive Versus Refractive Multifocal IOLs: Comparison of Visual Prognosis and Patient Satisfaction. Eltutar, Kadir; Akcetin, Tulay A.; Ozcelik, N. Demet
Multifocal IOLs – Bifocal or Trifocal
Multifocal IOLs – Bifocal or Trifocal
Accomodating IOLs • Single optic
• Double optic
Accomodating IOLs The Synchrony (Visiogen)
The Tetraflex (Lenstec)
The NuLens (NuLens Ltd.)
FluidVision accommodating IOL (PowerVision)
More than just the IOL • Optimal surgery – the challenges: – Multifocal IOLs are very unforgiving – Small amount of refractive error can be significant – IOL must be perfectly centered – High requirement on surgeon
The femtosecond laser • Long wavelength laser • Very short pulse • Vaporises tissue w. very little heat
Precise, quick & safe
Better surgery – the LensX
the LensX – the advantages • • • • • • •
Astigmatic control Predictable results Perfectly sized rhexis Perfectly centered rhexis Less phako energy needed Minimal trauma during surgery Improved safety
Good outcomes: Chose the right patient – not just the right lens Ideal patient: - Previous user of contact lenses / glasses - Self-motivated - Doesn’t mind sometimes having to wear glasses Caution: - Mild myopes who wear glasses for distance - Overly critical or analytical, unrealistic expectations - Night time driving occupations - Pilots - Amblyopia & pathology
Corneal reshaping - PresbyLASIK
• LASIK creates multifocal cornea •
Issues with quality of vision
• Upto 20% lose two lines of BCDA • Upto 50% lose two lines of BCNA • Less than half achieve 1.0 UCVA
PresbyLASIK
• Enhancements possible • Reversible if cornea permitting
Corneal reshaping - IntraCor • FemtoSecond laser creates multifocal cornea • For +0.5 to +1.5 • Newer procedure than PresbyLASIK • Upto 80% gain 4 lines of UCNA
IntraCor
• Upto 30% lose 2 lines of UCDA • Enhancements NOT possible • Irreversible
Corneal inlays – The KAMRA inlay
• • • •
Acufocus – a privately held company First launched 2002 CE certification in 2005 Currently an investigational device in the U.S. (IDE trial)
How the KAMRA Inlay Works • The small aperture: – Reduces blur when viewing near objects – Increases depth of focus – Minimally affects distance vision
Blocks unfocused light Allows focused light into the eye
The optical principle
Depth of field – an example SLR camera simulation of vision with a 4.0 mm pupil. Focus @ 7.69 feet, f-stop 5.6
Image courtesy of Jack Holladay, MD
SLR camera simulation of vision with a 1.6 mm pupil. Focus @ 7.69 feet, f-stop 22
Image courtesy of Jack Holladay, MD
KAMRA Inlay Design
3.8mm
1.6mm
5Îź
Total diameter
Aperture
Thick
The KAMRA inlay Made from Polyvinylidene Fluoride (PVDF) – Highly biocompatible – Good mechanical strength – Forms consistent thin films
8000 micro-fenestrations Oxygen
Glucose
Slide courtesy of Stephen D Klyce, PhD
8000 micro-fenestrations • Too many / too large holes: degrade vision – Light transmission of only 5% – Arranged in a pseudo-random pattern to minimise diffraction
Cosmesis
Cosmesis
Broad Application
Post-LASIK +0.25 to -0.50 D Cylinder ≤ 0.75 D
PEK Procedure
CLK Procedure
Surgical method
Surgical method
Uncorrected Near Visual Acuity (Implanted Eye)
Visual Acuity
Subjects gain on average 3.5 lines of near acuity in the inlay eye, which remains stable out to 24 months.
J2
Pre N = 508 1M N = 505 3M N = 500 6M N = 499 9M N = 485 12M N = 479 18M N = 423 24M N = 99 UCNVA
Post-Operative Period (Months)
Uncorrected Near Visual Acuity (Implanted Eye) – after 3 years Subjects gain on average 4 lines of near acuity in the inlay eye, which remains stable out to 36 months.
Uncorrected Intermediate Visual Acuity (Implanted Eye) Mean uncorrected intermediate visual acuity improved 1 line to 20/25 in the inlay implanted eye.
Visual Acuity
20/25
Pre N = 508 1M N = 505 3M N = 500 6M N = 499 9M N = 485 12M N = 479 18M N = 423 24M N = 99 UCIVA
Post-Operative Period (Months)
Uncorrected Distance Visual Acuity (Implanted Eye) In the inlay eye, mean uncorrected distance visual acuity remains stable at 20/20 out to 24 months.
Visual Acuity
20/20
Pre N = 508 1M N = 505 3M N = 500 6M N = 499 9M N = 485 12M N = 479 18M N = 423 24M N = 99 UCDVA
Post-Operative Period (Months)
Scores for visual tasks
Reading performance and patient satisfaction after corneal inlay implantation for presbyopia correction: Two-year follow-up Alois K. Dexl , Orang Seyeddain , Wolfgang Riha , Theresa Ruckl , Alexander Bachernegg , Martin Emesz , Josef Ruc... Journal of Cataract & Refractive Surgery Volume 38, Issue 10 2012 1808 - 1816
Summary of Global Results
• • • • •
Near vision of J2 achieved on average Distance vision is minimally affected Long-term data shows maintained visual gain High patient satisfaction Inlay may be implanted in: – Naturally occurring emmetropes – Simultaneous to a LASIK procedure
• Safe and reversible
Contrast sensitivity
The near future • Multifocal IOLs – Trifocals – Optics and design – Femtosecond assisted surgery • Inlays • Accomodating IOLs – Improvements
The future 10 to 20 years • Laser treatment of crystalline lens – Reversal of lens aging – Very experimental, but promising • Fluid/silicone filling of lens capsule – Technically challenging – Development will benefit from FS surgery
Thank you