Tomey OA-2000 - Shammas-PL Formula

■ 4-8
4.1.6 Shammas-PL formula
1. Implanted IOL power (D) for emmentropization

1336
05.00125.1
1
)05.0(231.0
1336





C
K
c
CLL
P
emme
2. Implanted IOL power (D) for ametropia
 
1336
05.00125.1
1
05.0231.0
1336






C
REFcKc
CLL
P
amet
3. Predicted refractive power after surgery (D)






Kc
CLcCPLc
CLcP
REFc iol 





05.005.01336
05.0133613360125.1
L : Axial length (mm)
C ＝ pACD = (0.5835 × A) - 64.40
A : A-Constant
Kc = 1.14 × K - 6.8
K : Average corneal refractive power (D)
= (K1 + K2)/2
R : Radius of corneal curvature (mm)
= {(KI - 1) × 1000}/K
KI : Cornea equivalent refractive index
REFc : Refractive power at corneal refractive surface
VD
R
E
F


1000
1000
REF : Target Ref. after surgery (D)
P : Implanted IOL power (D)
Lc = L-0.1(L-23)
VD : Vertex distance (mm)
= 12
4. Personal A-Constant




























 4.6405.0
13361
1336
4
1336
2
1336
22
1336
5835.0
1
2
P
a
P
aLc
Lc
a
Lca
A
A
REFc
K
c
a


0125.1
AREFc: Eye refractive power at corneal refractive surface
VD
A
RE
F


1000
1000