Depth of focus - University of Houstonvoi.opt.uh.edu/VOI/WavefrontCongress/2005/presentations... ·...
Transcript of Depth of focus - University of Houstonvoi.opt.uh.edu/VOI/WavefrontCongress/2005/presentations... ·...
Depth of focusand critical pupil in anemmetropic population
H Ginis
A Pallikaris
S Plainis
University of Crete
Department of Medicine
Institute of Vision and Optics
83% circle
16.66mm
Critical pupil / 2
Sample:• 211 individuals; VA>0.8 (176 valid‡ 352 eyes)• Emmetropes• AR, Wavefront, VA • Wavelight ALLEGRO wavefront analyser.
Data analysis
• Aberration statistics
• Critical pupil
• Depth of Focus
Spherical Equivalent (D)
Nu
mb
er
of
eyes
Refractive error
Wavefront aberration
Wavefront error (m)ì
Nu
mb
er
of
eye
s
(
ì
m)Wavefront error (m)ì
Nu
mb
er
of
eye
s
(
ì
m)
PSF vs pupil diameter (5mm-1mm)
PSF vs wavelength (0.405 - 0.695 _m)
83%
Polychromatic PSF dimensions
83% circle
16.66mm
Critical pupil / 2
DOF calculation
Calculations
• WA, Polychromatic PSF as a function of pupil diameter
• 83% circle diameter
• MAR (as circle’s radius) as a function of pupil.
• Depth of Focus at this pupil size
MAR vs Pupil diameter (with 2nd order)(One subject : -0.7 spherical equivalent)
MAR vs Pupil diameter (HO only)
Results
Critical pupil VS HO RMS
0
1
2
3
4
5
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
HO RMS [?m]
Crit
ical
Pup
il [m
m]
. .
Depth of Focus VS HO RMS
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
HO RMS [?m]
Dep
th o
f Foc
us [D
]
.
Average = 2.34 mmSD = 0.4926N=352 eyes
Critical pupil (Sph-Cyl corrected for 550nm)
Polychromatic Monochromatic
Average = 3.37 mmSD = 0.9445
MAR at 3mm pupil diameter
Average = 1.5776’SD = 0.4462N=352 eyes
Average = 2.3601’SD = 0.5337
PolychromaticMonochromatic
Depth of Focus at critical pupil
Average = 0.1476 DSD = 0.0819N=352 eyes
Average = 0.2978 DSD = 0.1209
PolychromaticMonochromatic
Monochromatic VS polychromatic MAR
0
1
2
3
4
5
0 1 2 3 4 5
Polychromatic MAR
Mon
ochr
omat
ic M
AR
.
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Critical pupil (mm) a
Dep
th o
f F
ocu
s (D
)
aDOF at critical pupil vs Critical pupil
0
1
2
3
4
5
0 1 2 3 4 5
Critical Pupil (Right eye) [mm]
Crit
ical
Pup
il (L
eft e
ye) [
mm
]
.
Polychromatic critical pupil (left/right eye)
• Critical pupil is mostly governed by refractive errors• At the absence of refractive errors MAR vs pupil curve is not very steep near critical pupil. • Considering LCA results to a larger depth of focus associated to the increased PSF dimensions.• LCA is an aberration contributing significantly to the dimensions of the PSF in a common manner among individuals and therefore reducing the inter subject variability of parameters such as the critical pupil.
Discussion
Summer School20– 26 June (Part I)
27 June –1 July (Part II)
Summer School20– 26 June (Part I)
27 June –1 July (Part II)
Aegean Retina1 – 3 July 2005Aegean Retina1 – 3 July 2005
HE
RA
KLIO
N – C
RE
TE
2005H
ER
AK
LION
– CR
ET
E 2005
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