Tomey OA-2000 - Technical Information; IOL Calculation Formulas

4-1 ■
4. TECHNICAL INFORMATION
4.1 IOL power calculation formula
4.1.1 Haigis Standard / Haigis optimized
1. Implanted IOL power (D)
1000
1000
d
z
na
na
dL
na
P




Where:
1000
1
VREF
REF
DCZ



d = a0 + a1･ACD + a2･L (ACD ≠ 0)
d =(a0 – 0.241･a1) + (a2 + 0.139･a1)L (ACD = 0)
a0 = 0.62467A – 72.434….*


R
C
nc
DC
11000


2. Estimated refractive power after surgery (D)



XXDCYV
XDCY
REF
iol
10001000
10001000




Where:
X = d2･P + 1000L･na - d･L･P
Y = na (1000･na-L･P + d･P)
na : Aqueous humor and vitreous refractive index
= 1.336
nc : Corneal reflective index
= 1.3315
A : A-Constant
RC : Average radius of corneal curvature (mm)
= （r1 + r2）/2
R : Radius of corneal curvature (mm)
= {(KI - 1) × 1000}/K
K : Corneal refractive power (D)
KI : Cornea equivalent refractive index
DC : Average corneal refractive power (D)
L : Axial length
ACD : Anterior chamber depth (mm)
REF : Target Ref. after surgery (D)