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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