Tomey UD-600, Operator'S Manual, Page: 196 / 262

4-4
4. Personal A-Constant
A = P + AREF·RF + 2.5L + 0.9K - COR
where,
P:
Implanted IOL power (D)
AREF: Power of spherical lens equal to the post surgery
refractive power (D) = S+C/2
C: Cylinder lens power (D)
S: Spherical lens power (D)
RF: Refractive factor
P
>
16
→
RF = 1.25
P 16
→
RF = 1
L: Axial length (mm)
K: Average corneal refractive power
= (K1 + K2)/2
COR: Correction
L
<
20
→
COR = 3
20 L
<
21
→
COR = 2
21 L
<
22
→
COR = 1
22 L
<
24.5
→
COR = 0
24.5 L
→
COR = -0.5
4.3 IOL power calculation