Transcript MYOPIA, ASTIGMATISM, HYPEROPIA…

MYOPIA, ASTIGMATISM, HYPEROPIA…
PERSONALIZED
TREATMENT
Bernard Mathys, MD
Secretary-general of the Belgian Society of Cataract
& Refractive Surgery
Refractive surgery in 2004
Today we use mostly PRK (surface treatment) and
Lasik to perform surgery and our desire is to
improve our results
• How can we do this?
• Better instruments, new lasers, well-trained surgeons,
improvement of post-op treatments… and new algorithms?
Algorithm factor
• Improve the treatment itself: -3 of X is not
necessarily -3 of Y
• Personalize treatment =>Improve quality of
vision
• Possibility to help people with thin corneas, large
pupils, high ametropia
Different steps are needed:
Carefull preop examination
Technologically advanced Laser
Zyoptix: the name of the system
The laser custom treatment
Lasik
The intervention - making the flap
Lasik
Closing the flap
HOW DOES
«PERSONALIZED
TREATMENT»
WORK ?
The idea
The idea
Wavefront analyse
Reconstruction of wavefront by CCD-image
> Zernike coefficient
CCD-Image
Hartmann-Shack Wavefront Measurement
Lenslet
Array
CCD
Array
Spot Array
Wave Aberration
Perfect Eye
Aberrated Eye
Wave Aberration of a Surface
The shape of the wavefront is depicted in Zernike
coefficient, each shape describes a deformation
Zernike Modes
radial
order
2nd
Z02
Z-22
defocus
astigmatism
Conventional
Refraction
Z22
astigmatism
Higher Order
Aberrations
3rd
Z-3
3
coma
trefoil
4th
1
-1
Z3
coma
trefoil
Z04
Z-2
4
Z-44
Z3
astigmatism
secondary
spherical
astigmatism
secondary
Z-5
5
Z-3
5
Z5
-1
Z5
pentafoil
trefoil
secondary
coma
secondary
Z44
Z24
quadrafoil
5th
Z33
quadrafoil
coma
secondary
Z55
Z35
1
secondary
trefoil
pentafoil
Point Spread Function (PSF)
Point Spread Function: is the representation of an
optical system of a punctual and distant light
source ( star in the sky)
Airy Disc
Point Spread Function vs. Pupil Size
Perfect Eye
Point Spread Function vs. Pupil Size
Typical Eye
Each eye has different patterns
of High Order Aberrations.
Perfect eye
(diffraction limited)
MRB
GYY
MAK
Wave
Aberration
5.7 mm pupil
Pointspread
Function
Retinal
Image
Encouraging results
Encouraging resultsPreop –6.5 D
Zyoptix
Postop Plano 6M
VA 13/10
Zyoptix System – Clinical Outcomes
Quality of Vision after surgery
% (n)
No improvement
0,3% (1)
Slight improvement
1,2% (4)
Moderate improvement
1,8% (6)
Marked improvement
12,1% (41)
Extreme improvement
84,7% (288)
Night vision
Haloes
Custom treatment
NEW SCALE ?
• VA is a less sensitive measure of the correction of
high-order aberrations
• Increase the quality of the retinal image
• We need to assess quality of vision in true-life
conditions:
• Contrast & low-contrast sensitivity
•Different lightning conditions
•Color vision
•Glare & haloes
Custom treatment: the future ?
• Aberrometry
•Topography
•Linked to the laser, to achieve personal treatment
•Must improve our actual results in all cases
•Must be safe
•Not a higher complication rate
20/20/20/20
THANK YOU FOR
YOUR ATTENTION
Bernard Mathys, MD
Secretary-general of the Belgian Society of Cataract & Refractive Surgery